Bio-Medical Materials and Engineering - Volume 24, issue 6

Authors: Chung, Soon-Cheol | Choi, Mi-Hyun | Kim, Hyung-Sik | You, Na-Rae | Hong, Sang-Pyo | Lee, Jung-Chul | Park, Sung-Jun | Baek, Ji-Hye | Jeong, Ul-Ho | You, Ji-Hye | Lim, Dae-Woon | Kim, Hyun-Jun

Article Type: Research Article

Abstract: This study investigated neuronal activation differences under two conditions: driving only and distracted driving. Driving and distraction tasks were performed using a Magnetic Resonance (MR)-compatible driving simulator with a driving wheel and pedal. The experiment consisted of three blocks, and each block had both a Rest phase (1 min) and a Driving phase (2 min). During the Rest phase, drivers were instructed to simply look at the stop screen without performing any driving tasks. During the Driving phase, each driver was required to drive at 110 km/h under two conditions: driving only and driving while performing additional distraction tasks. The …results show that the precuneus, inferior parietal lobule, supramarginal gyrus, middle frontal gyrus, cuneus, and declive are less activated in distracted driving than in driving only. These regions are responsible for spatial perception, spatial attention, visual processing and motor control. However, the cingulate gyrus and sub-lobar regions (lentiform nucleus and caudate), which are responsible for error monitoring and control of unnecessary movement, show increased activation during distracted driving compared with driving only. Show more

Keywords: Distraction, driving, fMRI, MR-compatible driving simulator

DOI: 10.3233/BME-141117

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 2971-2977, 2014

Authors: Jorge-Hernandez, Fernando | Garcia Chimeno, Yolanda | Garcia-Zapirain, Begonya | Cabrera Zubizarreta, Alberto | Gomez Beldarrain, Maria Angeles | Fernandez-Ruanova, Begonya

Article Type: Research Article

Abstract: Graph theory is also widely used as a representational form and characterization of brain connectivity network, as is machine learning for classifying groups depending on the features extracted from images. Many of these studies use different techniques, such as preprocessing, correlations, features or algorithms. This paper proposes an automatic tool to perform a standard process using images of the Magnetic Resonance Imaging (MRI) machine. The process includes pre-processing, building the graph per subject with different correlations, atlas, relevant feature extraction according to the literature, and finally providing a set of machine learning algorithms which can produce analyzable results for physicians …or specialists. In order to verify the process, a set of images from prescription drug abusers and patients with migraine have been used. In this way, the proper functioning of the tool has been proved, providing results of 87% and 92% of success depending on the classifier used. Show more

Keywords: Functional MRI (fMRI), graph theory, migraine, machine learning, synchronization likelihood

DOI: 10.3233/BME-141118

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 2979-2986, 2014

Authors: Wang, Liye | Tang, Xiaoying | Liu, Weifeng | Peng, Yuhua | Gao, Tianxin | Xu, Yong

Article Type: Research Article

Abstract: In the neural science society, multi-subject brain decoding is of great interest. However, due to the variability of activation patterns across brains, it is difficult to build an effective decoder using fMRI samples pooled from different subjects. In this paper, a hierarchical model is proposed to extract robust features for decoding. With feature selection for each subject treated as a separate task, a novel multi-task feature selection method is introduced. This method utilizes both complementary information among subjects and local correlation between brain areas within a subject. Finally, using fMRI samples pooled from all subjects, a linear support vector machine …(SVM) classifier is trained to predict 2-D stimuli-related images or 3-D stimuli-related images. The experimental results demonstrated the effectiveness of the proposed method. Show more

Keywords: Multi-subject brain decoding, fMRI, hierarchical model, multi-task feature selection, classification

DOI: 10.3233/BME-141119

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 2987-2994, 2014

Authors: García Chimeno, Yolanda | García Zapirain, Begonya | Saralegui Prieto, Ibone | Fernandez-Ruanova, Begonya

Article Type: Research Article

Abstract: Functional Magnetic Resonance Imaging (fMRI) and Diffusion Tensor Imaging (DTI) are a source of information to study different pathologies. This tool allows to classify subjects under study, analysing in this case, the functions related to language in young patients with dyslexia. Images are obtained using a scanner and different tests are performed on subjects. After processing the images, the areas that are activated by patients when performing the paradigms or anatomy of the tracts were obtained. The main objective is to ultimately introduce a group of monocular vision subjects, whose brain activation model is unknown. This classification helps to assess …whether these subjects are more akin to dyslexic or control subjects. Machine learning techniques study systems that learn how to perform non-linear classifications through supervised or unsupervised training, or a combination of both. Once the machine has been set up, it is validated with the subjects who have not been entered in the training stage. The results are obtained using a user-friendly chart. Finally, a new tool for the classification of subjects with dyslexia and monocular vision was obtained (achieving a success rate of 94.8718% on the Neuronal Network classifier), which can be extended to other further classifications. Show more

Keywords: Classifier, dyslexic, fMRI, PCA, monocular vision

DOI: 10.3233/BME-141120

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 2995-3002, 2014

Authors: Bertora, Franco | Borceto, Alice | Viale, Andrea | Sandini, Giulio

Article Type: Research Article

Abstract: A study of the motor cortex during the programming, execution and mental representation of voluntary movement is of great relevance; its evaluation in conditions close to reality is necessary, given the close integration of the visuomotor, sensory feedback and proprioceptive systems, as of yet, a functional Magnetic Resonance Imaging (fMRI) scanner allowing a human subject to maintain erect stance, observe the surroundings and conserve limb freedom is still a dream. The need for high field suggests a solenoid magnet geometry that forces an unnatural posture that affects the results, particularly when the motor cortex is investigated. In contrast in a …motor functional study, the scanner should allow the subject to sit or stand, with unobstructed sight and unimpeded movement. Two approaches are presented here to solve this problem. In the first approach, an increased field intensity in an open magnet is obtained lining the “back wall” of the cavity with a sheet of current: this boosts the field intensity at the cost of the introduction of a gradient, which has to be canceled by the introduction of an opposite gradient; The second approach is an adaptation of the “double doughnut” architecture, in which the cavity widens at the center to provide additional room for the subject. The detailed design of this kind of structure has proven the feasibility of the solution. Show more

Keywords: Functional magnetic resonance, cerebral activation, motor cortex, driving simulator, magnet design, MRI scanner

DOI: 10.3233/BME-141121

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3003-3015, 2014

Authors: Cheng, Sainan | Liu, Qiang | Lv, Yubo | Han, Wenwen | Yu, Ke | Li, Yuchao | Gong, Tao | Zhang, Yi

Article Type: Research Article

Abstract: Fractional anisotropy (FA) is currently an ideal index capable of reflecting the white matter structure. 1 H magnetic resonance spectroscopy (1 H-MRS) is often used as a noninvasive concentration measurement of important neurochemicals in vivo. This study was conducted to investigate the relationship between FA and metabolite concentrations by comparing 1 H-MRS of bilateral medium corona radiata in healthy adults. The data of diffusion tensor imaging (DTI) and 1 H-MRS were acquired from 31 healthy adults using a 3.0 T MR system. All subjects were divided into three groups: the total group (mean age=42 years), the junior group (mean age=29 …years) and the senior group (mean age=56 years). There was a negative correlation between FA and age in three groups (r=-0.146, r=-0.204, r=-0.162, p<0.05). The positive correlation of FA with corresponding concentrations of N-acetylaspartate (NAA) was significant in three groups (r=0.339, r=0.213, r=0.430, respectively, p<0.05). The positive correlation of FA with the corresponding NAA/Cr was only significant difference between the total 353 samples and the junior group (r=0.166, r=0.305, respectively, p<0.05). Combining 1 H-MRS with DTI reveals the relationship between structure and metabolic characteristics of white matter. Show more

Keywords: Diffusion tensor imaging (DTI), magnetic resonance spectroscopy (MRS), white matter

DOI: 10.3233/BME-141122

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3017-3024, 2014

Authors: Yang, Fei | Zhang, Lei | Lu, Weigang | Zuo, Wangmeng | Wang, Kuanquan | Zhang, Henggui | Li, Yeming

Article Type: Research Article

Abstract: A crucial role during the implementation of volume visualization is to identify the optimal transfer function, since the vital information and structure can be highlighted and revealed. The boundary of the volume is shared by respective portion of the two materials formed out of it, which causes undesirable thickening and ambiguity of the boundary explored via traditional LH (Low and High) histogram. To address this issue, initially a modified LH histogram construction method is introduced to intuitively and conveniently visualize cardiac volume for user interaction. Subsequently, the f-LH histogram is presented to further identify and visualize each portion of the …boundary accurately. An appropriate multidimensional transfer function generation is proposed by using variables in f-LH space and spatial information, for visualizing the multi-boundary cardiac volume data. Show more

Keywords: Interactive visualization, partial effect, multidimensional transfer function, multi-boundary data

DOI: 10.3233/BME-141123

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3025-3032, 2014

Authors: Eum, Nyeon Sik | Han, Jung Hyun | Seong, Ki Woong | Lee, Jong Ha | Park, Hee Joon

Article Type: Research Article

Abstract: The portable visible and near-infrared (NIR) imaging equipment for a pre-clinical test with small animals was designed and developed in this paper. The developed equipment is composed of a CCD camera, a focusing lens, an objective lens, a NIR band pass filter and a NIR filter driving motor. An NIR ray is mainly used for imaging equipment because it has high light penetration depth in biological tissue. Therefore, NIR fluorescent agents are available for chemical conjugation to targeting molecules in vivo. This equipment can provide a visible image, NIR image and merged image simultaneously. A communication system was specifically established …to check obtained images through a smart pad in real time. It is less dependent on space and time than the conventional system. Show more

Keywords: Visible/NIR image, animal imaging, fluorescence, mobile-based, merged image

DOI: 10.3233/BME-141124

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3033-3041, 2014

Authors: Xu, Yuanyuan | Wang, Yawei | Ji, Ying | Jin, Weifeng | Bu, Min | Shang, Xuefu

Article Type: Research Article

Abstract: A phase retrieval method is introduced in quantitative phase imaging (QPI) based on two-step phase-shifting technique. By acquiring two measured interferograms and calculating the addition and subtraction between them, the quantitative phase information can be directly retrieved. This method is illustrated by both theory and simulation experiments of a ball. The results of the simulation and the experiment of the red blood cell show a good agreement, demonstrating its application for studying cells.

Keywords: Biotechnology, quantitative phase imaging, phase retrieval, two-step phase shifting, addition and subtraction

DOI: 10.3233/BME-141125

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3043-3048, 2014

Authors: Ding, Yong | Dai, Hang | Zhang, Hang

Article Type: Research Article

Abstract: For improving the detection of micro-calcifications (MCs), this paper proposes an automatic detection of MC system making use of multi-fractal spectrum in digitized mammograms. The approach of automatic detection system is based on the principle that normal tissues possess certain fractal properties which change along with the presence of MCs. In this system, multi-fractal spectrum is applied to reveal such fractal properties. By quantifying the deviations of multi-fractal spectrums between normal tissues and MCs, the system can identify MCs altering the fractal properties and finally locate the position of MCs. The performance of the proposed system is compared with the …leading automatic detection systems in a mammographic image database. Experimental results demonstrate that the proposed system is statistically superior to most of the compared systems and delivers a superior performance. Show more

Keywords: Automatic detection, mammographic calcifications, multi-fractal spectrum

DOI: 10.3233/BME-141126

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3049-3054, 2014

Authors: Ergen, Burhan | Baykara, Muhammet

Article Type: Research Article

Abstract: The developments of content based image retrieval (CBIR) systems used for image archiving are continued and one of the important research topics. Although some studies have been presented general image achieving, proposed CBIR systems for archiving of medical images are not very efficient. In presented study, it is examined the retrieval efficiency rate of spatial methods used for feature extraction for medical image retrieval systems. The investigated algorithms in this study depend on gray level co-occurrence matrix (GLCM), gray level run length matrix (GLRLM), and Gabor wavelet accepted as spatial methods. In the experiments, the database is built including hundreds …of medical images such as brain, lung, sinus, and bone. The results obtained in this study shows that queries based on statistics obtained from GLCM are satisfied. However, it is observed that Gabor Wavelet has been the most effective and accurate method. Show more

Keywords: Content-based image retrieval, GLCM, GLRLM, Gabor wavelet

DOI: 10.3233/BME-141127

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3055-3062, 2014

Authors: Yuan, Zhen | Ieong, Fong H. | Jiang, Huabei | Sobel, Eric S.

Article Type: Research Article

Abstract: The goal of this study is to capture the quantitative optical features of degenerative finger joints based on x-ray aided three-dimensional (3D) diffuse optical tomography (DOT). It is anticipated that the fused imaging technique can be applied to identifying the significant differences between osteoarthritis (OA) and psoriatic arthritis (PA). For a case study, total 6 subjects were selected to study the distal interphalangeal (DIP) finger joints. 2 OA patients, 2 PA patients and 2 healthy subjects were examined clinically first. Their DIP finger joints were then scanned by the multimodality imaging method. Our findings suggested that the developed multimodality imaging …approach may aid to contradistinguish OA patients from PA patients with the healthy control, which is essential for a better diagnosis and treatment of inflammatory arthritis in humans. Show more

Keywords: diffuse optical tomography, osteoarthritis, psoriatic arthritis, x-ray

DOI: 10.3233/BME-141128

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3063-3071, 2014

Authors: Zhai, Yi | Wang, Yan | Wang, Zhaoqi | Liu, Yongji | Zhang, Lin | He, Yuanqing | Chang, Shengjiang

Article Type: Research Article

Abstract: An achromatic element eliminating only longitudinal chromatic aberration (LCA) while maintaining transverse chromatic aberration (TCA) is established for the eye model, which involves the angle formed by the visual and optical axis. To investigate the impacts of higher-order aberrations on vision, the actual data of higher-order aberrations of human eyes with three typical levels are introduced into the eye model along visual axis. Moreover, three kinds of individual eye models are established to investigate the impacts of higher-order aberrations, chromatic aberration (LCA+TCA), LCA and TCA on vision under the photopic condition, respectively. Results show that for most human eyes, the …impact of chromatic aberration on vision is much stronger than that of higher-order aberrations, and the impact of LCA in chromatic aberration dominates. The impact of TCA is approximately equal to that of normal level higher-order aberrations and it can be ignored when LCA exists. Show more

Keywords: Visual optics, eye model, optical design, optical effects on vision, aberrations

DOI: 10.3233/BME-141129

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3073-3081, 2014

Authors: Chan, Yu-Chen

Article Type: Research Article

Abstract: Although considerable attention has been paid to the cognitive structure of humor, its emotional structure tends to be overlooked. Humor is often associated with the single emotion of mirth or amusement, while other aspects of its rich emotional structure are ignored. The purpose of the present study was to explore this structure by analyzing the content of a Taiwanese corpus of 204 ‘negative’ jokes to identify the basic emotion was induced and the emotional shift pattern of the joke. Additionally, the corpus might be used to compare emotional reversal jokes (negative to positive emotion) and regular jokes (neutral to positive …emotion) as an aid when preparing materials for use in functional Magnetic Resonance Imaging (fMRI) investigations on the neural substrates of humor. In terms of basic emotions, 82 fear jokes, 61 disgust jokes, 42 sadness jokes and 19 anger jokes were found. The most common type of emotional shift was from negative to positive, with the punch lines of 114 jokes providing relief from the negative emotion by either diverting attention away from it or dissolving it entirely. Show more

Keywords: Joke corpus, emotional reversal, emotional shift pattern, negative joke, humor

DOI: 10.3233/BME-141130

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3083-3090, 2014

Authors: Yoo, Ie Ryung | Chung, Soo Kyo | Park, Hye Lim | Choi, Woo Hee | Kim, Young Kyoon | Lee, Kyo Young | Wang, Young-Pil

Article Type: Research Article

Abstract: This paper aimed to evaluate the prognostic value of maximum standardized uptake value (SUVmax) and metabolic tumor volume (MTV) of the primary tumor on 18 F-FDG PET/CT scan in early stage non-small cell cancer (NSCLC) patients without lymph node (LN) metastasis. In the experiment, eighty NSCLC patients pathologically staged as T1N0 or T2N0 were included (M:F=50:30; mean age, 64.8 years). All patients had preoperative 18 F-FDG PET/CT scan and curative surgery. FDG uptake in the primary tumor was measured by SUVmax and MTV with various SUV threshold values. SUVmax, MTV of the primary tumor, age, tumor size, histology and differentiation …grade were analyzed for association with disease-free survival (DFS). The experimental results showed that the histology types included adenocarcinoma (n=58), squamous cell carcinoma (n=20), and others (n=2); Twenty-two (27.5%) of the 80 patients had a recurrence during follow-up at a median time of 29.1 months; The median SUVmax was 5.26, and the median MTV2.5 was 2.2 cm3 . Univariate analysis showed higher SUVmax (>4), greater MTV (MTV2.5 >4 cm3 ), and non-squamous histology were significantly associated with shorter period DFS (p=0.001, p=0.030 and p<0.001). In multivariate analysis, higher SUVmax (p=0.004) and adenocarcinoma histology (p=0.005) were associated with shorter DFS. Therefore, high SUVmax (>4) of the primary tumor on preoperative 18 F-FDG PET/CT scan is an independent prognostic factor of shorter DFS in early stage of NSCLC. Show more

Keywords: Non-small-cell lung cancer, PET/CT, standardized uptake value, metabolic tumor volume, early stage

DOI: 10.3233/BME-141131

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3091-3103, 2014

Authors: Fu, Jian | Yu, Guangyuan | Fan, Dekai

Article Type: Research Article

Abstract: X-ray phase contrast computed tomography (CT) uses the phase shift that x-rays undergo when passing through matter, rather than their attenuation, as the imaging signal and may provide better image quality in soft-tissue and biomedical materials with low atomic number. Here a geometry-constraint-scan imaging technique for in-line phase contrast micro-CT is reported. It consists of two circular-trajectory scans with x-ray detector at different positions, the phase projection extraction method with the Fresnel free-propagation theory and the filter back-projection reconstruction algorithm. This method removes the contact-detector scan and the pure phase object assumption in classical in-line phase contrast Micro-CT. Consequently it …relaxes the experimental conditions and improves the image contrast. This work comprises a numerical study of this technique and its experimental verification using a biomedical composite dataset measured at an x-ray tube source Micro-CT setup. The numerical and experimental results demonstrate the validity of the presented method. It will be of interest for a wide range of in-line phase contrast Micro-CT applications in biology and medicine. Show more

Keywords: X-ray in-line phase contrast imaging, micro computed tomography, geometry-constraint scanning mode, reconstruction algorithm

DOI: 10.3233/BME-141132

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3105-3111, 2014

Authors: Cui, Xueli | Gao, Xin | Xia, Wei | Liu, Yangchuan | Liang, Zhiyuan

Article Type: Research Article

Abstract: To build a patient specific respiratory motion model with a low dose, a novel method was proposed that uses a limited number of 3D lung CT volumes with an external respiratory signal. 4D lung CT volumes were acquired for patients with in vitro labeling on the upper abdominal surface. Meanwhile, 3D coordinates of in vitro labeling were measured as external respiratory signals. A sequential correspondence between the 4D lung CT and the external respiratory signal was built using the distance correlation method, and a 3D displacement for every registration control point in the CT volumes with respect to time can …be obtained by the 4D lung CT deformable registration. A temporal fitting was performed for every registration control point displacements and an external respiratory signal in the anterior-posterior direction respectively to draw their fitting curves. Finally, a linear regression was used to fit the corresponding samples of the control point displacement fitting curves and the external respiratory signal fitting curve to finish the pulmonary respiration modeling. Compared to a B-spline-based method using the respiratory signal phase, the proposed method is highly advantageous as it offers comparable modeling accuracy and target modeling error (TME); while at the same time, the proposed method requires 70% less 3D lung CTs. When using a similar amount of 3D lung CT data, the mean of the proposed method's TME is smaller than the mean of the PCA (principle component analysis)-based methods' TMEs. The results indicate that the proposed method is successful in striking a balance between modeling accuracy and number of 3D lung CT volumes. Show more

Keywords: Motion model, 4D lung CT, external respiratory signal, deformable registration, temporal fitting

DOI: 10.3233/BME-141133

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3113-3120, 2014

Authors: Shi, Han | Du, Dong | Su, Zhihong | Peng, Qiyu

Article Type: Research Article

Abstract: Positron Emission Tomography (PET) systems using detectors with Depth of Interaction (DOI) capabilities could achieve higher spatial resolution and better image quality than those without DOI. Up till now, most DOI methods developed are not cost-efficient for a whole body PET system. In this paper, we present a DOI decoding method based on flood map for low-cost conventional block detector with four-PMT readout. Using this method, the DOI information can be directly extracted from the DOI-related crystal spot deformation in the flood map. GATE simulations are then carried out to validate the method, confirming a DOI sorting accuracy of 85.27%. …Therefore, we conclude that this method has the potential to be applied in conventional detectors to achieve a reasonable DOI measurement without dramatically increasing their complexity and cost of an entire PET system. Show more

Keywords: Positron emission tomography, depth of interaction, GATE simulation

DOI: 10.3233/BME-141134

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3121-3127, 2014

Authors: Qiao, Huiting | Wang, Libin | Li, Deyu | Wang, Daifa | Wang, Yu

Article Type: Research Article

Abstract: Positron emission tomography (PET) has been widely used in early diagnosis of tumors. Though standardized uptake value (SUV) is a common diagnosis index for PET, it will be affected by the size of the tumor. To explore how the tumor size affects imaging diagnosis index, dynamic PET images were simulated to study the relationship between tumor size and the imaging diagnosis index. It was found that the SUV of the region of the tumor varied with scan time, and the SUV was always lower than the true value of tumor. Even more deviations were found in SUV with a reduced …tumor size. The diagnosis index SUVmax was more reliable than SUV, for it declined only when the volume of tumor was less than 3 mm3 . Therefore, the effect of tumor size on the SUV and SUVmax that are used as diagnosis indices in the early diagnosis of tumors should not be neglected. Show more

Keywords: Standardized uptake value, maximum standardized uptake value, positron emission tomography, tumor size, diagnosis

DOI: 10.3233/BME-141135

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3129-3136, 2014

Authors: Yong, Jin Rim | Qi, Shouliang | van Triest, Han J.W. | Kang, Yan | Qian, Wei

Article Type: Research Article

Abstract: Extraction of lung tumors is a fundamental step for further quantitative analysis of the tumor, but is challenging for juxta-pleural tumors due to the adhesion to the pleurae. An automatic algorithm for segmentation of juxta-pleural tumors based on the analysis of the geometric and morphological features was proposed. Initially, the lung is extracted by means of thresholding using 2D Otsu's method. Next a center point is suggested to find a starting point and endpoint of outward facing pleura. A model based on the variation of incline angle was adopted to identify potentially affected regions, and to full segment juxta-pleural tumors. …The results were compared with the manual segmentation by two radiologists. Averaged for ten experimental datasets, the accuracy calculated by Dice index between the results of the algorithm and by the two radiologists is 91.2%. It indicates the proposed method has comparable accuracy with the experts (the inter-observer variability is 92.4%), but requests much less manual interactions. The proposed algorithm can be used for segmenting juxta-pleural tumors from CT images, and help improve the diagnosis, pre-operative planning and therapy response evaluation. Show more

Keywords: Juxta-pleural tumor segmentation, morphological analysis, incline angle

DOI: 10.3233/BME-141136

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3137-3144, 2014

Authors: Gan, Hong-Seng | Tan, Tian-Swee | Wong, Liang-Xuan | Tham, Weng-Kit | Sayuti, Khairil Amir | Abdul Karim, Ahmad Helmy | bin Abdul Kadir, Mohammed Rafiq

Article Type: Research Article

Abstract: In medical image segmentation, manual segmentation is considered both labor- and time-intensive while automated segmentation often fails to segment anatomically intricate structure accordingly. Interactive segmentation can tackle shortcomings reported by previous segmentation approaches through user intervention. To better reflect user intention, development of suitable editing functions is critical. In this paper, we propose an interactive knee cartilage extraction software that covers three important features: intuitiveness, speed, and convenience. The segmentation is performed using multi-label random walks algorithm. Our segmentation software is simple to use, intuitive to normal and osteoarthritic image segmentation and efficient using only two third of manual segmentation's …time. Future works will extend this software to three dimensional segmentation and quantitative analysis. Show more

Keywords: Interactive segmentation, Knee cartilage, Magnetic resonance image, Random walks, User interface

DOI: 10.3233/BME-141137

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3145-3157, 2014

Authors: Liu, Hao | Zhao, Jianning | Dai, Ning | Qian, Hongbo | Tang, Yuehong

Article Type: Research Article

Abstract: Separation of the femur head and acetabulum is one of main difficulties in the diseased hip joint due to deformed shapes and extreme narrowness of the joint space. To improve the segmentation accuracy is the key point of existing automatic or semi-automatic segmentation methods. In this paper, we propose a new method to improve the accuracy of the segmented acetabulum using surface fitting techniques, which essentially consists of three parts: (1) design a surface iterative process to obtain an optimization surface; (2) change the ellipsoid fitting to two-phase quadric surface fitting; (3) bring in a normal matching method and an …optimization region method to capture edge points for the fitting quadric surface. Furthermore, this paper cited vivo CT data sets of 40 actual patients (with 79 hip joints). Test results for these clinical cases show that: (1) the average error of the quadric surface fitting method is 2.3 (mm); (2) the accuracy ratio of automatically recognized contours is larger than 89.4%; (3) the error ratio of section contours is less than 10% for acetabulums without severe malformation and less than 30% for acetabulums with severe malformation. Compared with similar methods, the accuracy of our method, which is applied in a software system, is significantly enhanced. Show more

Keywords: Acetabulum, segmentation, ellipsoid fitting, edge points, computer tomography

DOI: 10.3233/BME-141138

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3159-3177, 2014

Authors: Jia, Tong | Zhang, Hao | Meng, Haixiu

Article Type: Research Article

Abstract: Lung vessels often interfere with the detection of lung nodules. In this paper, a novel computer-aided lung nodule detection scheme on vessel segmentation is proposed. This paper describes an active contour model which can combine image region mean gray value and image edge energy. It is used to segment and remove lung vessels. A selective shape filter based on Hessian Matrix is used to detect suspicious nodules and remove omitted lung vessels. This paper extracts density, shape and position features of suspicious nodules, and uses a Rule-Based Classification (RBC) method to identify true positive nodules. In the experiment results, the …detection sensitivity is about 90% and FP is 1/scan. Show more

Keywords: Lung vessel segmentation, lung nodule detection, active contour model, CT image

DOI: 10.3233/BME-141139

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3179-3186, 2014

Authors: Mao, Yihao | Liu, Hong | Ye, Rong | Shi, Yonghong | Song, Zhijian

Article Type: Research Article

Abstract: Plaque assaying, measurement of the number, diameter, and area of plaques in a Petri dish image, is a standard procedure gauging the concentration of phage in biology. This paper presented a novel and effective method for implementing automatic plaque assaying. The method was mainly comprised of the following steps: In the training stage, after pre-processing the images for noise suppression, an initial training set was readied by sampling positive (with a plaque at the center) and negative (plaque-free) patches from the training images, and extracting the HOG features from each patch. The linear SVM classifier was trained in a self-learnt …supervised learning strategy to avoid possible missing detection. Specifically, the training set which contained positive and negative patches sampled manually from training images was used to train the preliminary classifier which exhaustively searched the training images to predict the label for the unlabeled patches. The mislabeled patches were evaluated by experts and relabeled. And all the newly labeled patches and their corresponding HOG features were added to the initial training set to train the final classifier. In the testing stage, a sliding-window technique was first applied to the unseen image for obtaining HOG features, which were inputted into the classifier to predict whether the patch was positive. Second, a locally adaptive Otsu method was performed on the positive patches to segment the plaques. Finally, after removing the outliers, the parameters of the plaques were measured in the segmented plaques. The experimental results demonstrated that the accuracy of the proposed method was similar to the one measured manually by experts, but it took less than 30 seconds. Show more

Keywords: Plaque assay, HOG, SVM, local adaptive image segmentation

DOI: 10.3233/BME-141140

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3187-3198, 2014

Authors: Wu, Huiqun | Geng, Xingyun | Zhang, Xiaofeng | Qiu, Mingyan | Jiang, Kui | Tang, Lemin | Dong, Jiancheng

Article Type: Research Article

Abstract: The optic disc (OD) is one of the important anatomic structures on the retina, the changes of which shape and area may indicate disease processes, thus needs computerized quantification assistance. In this study, we proposed a self-adaptive distance regularized level set evolution method for OD segmentation without the periodically re-initializing steps in the level set function execution to a signed distance function during the evolution. In that framework, preprocessing of an image was performed using Fourier correlation coefficient filtering to obtain initial boundary as the beginning contour, then, an accurate boundary of the optic disc was obtained using the self-adaptive …distance regularized level set evolution method. One hundred eye fundus color numerical images from public database were selected to validate our algorithm. Therefore, we believe that such automatic OD segmentation method could assist the ophthalmologist to segment OD more efficiently, which is of significance for future computer-aided early detection of glaucoma and retinopathy diseases. Show more

Keywords: Optic disk, retinal imaging, level set evolution, imaging informatics

DOI: 10.3233/BME-141141

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3199-3206, 2014

Authors: Li, Fang | Song, Zhijian

Article Type: Research Article

Abstract: Surface registration is widely used in image-guided neurosurgery to achieve spatial registration between the patient space and the image space. Coarse registration, followed by fine registration, is an important premise to ensure the robustness and efficiency of surface registration. In this paper, a coarse registration algorithm based on the principal axes is proposed to achieve this goal. The extraction of the principal axes relies on the approximated surface with an adaptive Gaussian kernel, the width of which is consistent with neighborhood relation so that it is applicable for various scanning data. Determining the corresponding centers of translation is another problem …for aligning different scanning data, which is solved through heuristics. Six pairs of points on two surfaces with the farthest projections on the principal axes were regarded as the candidates of translation centers, and then through tentative alignments of local regions around them, a pair of candidates with the minimum registration error was selected as the optimal translation centers. Automatic registration of two scans of a head phantom is presented in this paper. Experimental results confirmed the robustness of the algorithm and its feasibility in clinical applications. Show more

Keywords: Image-guided neurosurgery, coarse registration, principal axes, adaptive Gaussian kernel, heuristics

DOI: 10.3233/BME-141142

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3207-3214, 2014

Authors: Guo, Song | Luan, Fangjun | Song, Xiaoyu | Li, Changyou

Article Type: Research Article

Abstract: To better analyze images with the Gaussian white noise, it is necessary to remove the noise before image processing. In this paper, we propose a self-adaptive image denoising method based on bidimensional empirical mode decomposition (BEMD). Firstly, normal probability plot confirms that 2D-IMF of Gaussian white noise images decomposed by BEMD follow the normal distribution. Secondly, energy estimation equation of the ith 2D-IMF (i=2,3,4,......) is proposed referencing that of ith IMF (i=2,3,4,......) obtained by empirical mode decomposition (EMD). Thirdly, the self-adaptive threshold of each 2D-IMF is calculated. Eventually, the algorithm of the self-adaptive image denoising method based on BEMD is …described. From the practical perspective, this is applied for denoising of the magnetic resonance images (MRI) of the brain. And the results show it has a better denoising performance compared with other methods. Show more

Keywords: Image denoising, BEMD, self-adaption, Gaussian white noise, energy

DOI: 10.3233/BME-141143

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3215-3222, 2014

Authors: Geng, Lei | Shao, Yi-Ting | Xiao, Zhi-Tao | Zhang, Fang | Wu, Jun | Li, Min | Shan, Chun-Yan

Article Type: Research Article

Abstract: It has been demonstrated that shape, area and depth of the optic disc are relevant indices of diabetic retinopathy. In this paper, we present a new fundus optic disc localization and segmentation method based on phase congruency (PC). Firstly, in order to highlight the optic disc, channel images with the highest contrast between optic disc and background are selected in LAB, YUV, YIQ and HSV spaces respectively. Secondly, with the use of PC, features of four selected channel images can be extracted. Multiplication operation is then used to enhance PC detection results. Thirdly, window scanning and gray accumulating are utilized …to locate the optic disc. Finally, iterative OTSU automatic threshold segmentation and Hough transform are performed on location images, before the final optic disc segmentation result can be obtained. The experimental results showed that the proposed method can effectively and accurately perform optic disc location and segmentation. Show more

Keywords: Fundus image, phase congruency, optic disc localization, optic disc segmentation, diabetic retinopathy

DOI: 10.3233/BME-141144

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3223-3229, 2014

Authors: Cong, Jinyu | Wei, Benzheng | Yin, Yilong | Xi, Xiaoming | Zheng, Yuanjie

Article Type: Research Article

Abstract: Simple Linear Iterative Clustering (SLIC) algorithm is increasingly applied to different kinds of image processing because of its excellent perceptually meaningful characteristics. In order to better meet the needs of medical image processing and provide technical reference for SLIC on the application of medical image segmentation, two indicators of boundary accuracy and superpixel uniformity are introduced with other indicators to systematically analyze the performance of SLIC algorithm, compared with Normalized cuts and Turbopixels algorithm. The extensive experimental results show that SLIC is faster and less sensitive to the image type and the setting superpixel number than other similar algorithms such …as Turbopixels and Normalized cuts algorithms. And it also has a great benefit to the boundary recall, the robustness of fuzzy boundary, the setting superpixel size and the segmentation performance on medical image segmentation. Show more

Keywords: Medical image, superpixels, SLIC, image segmentation, performance evaluation

DOI: 10.3233/BME-141145

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3231-3238, 2014

Authors: Bian, Zijian | Tan, Wenjun | Yang, Jinzhu | Liu, Jiren | Zhao, Dazhe

Article Type: Research Article

Abstract: The quantitative analysis of the airway tree is of critical importance in the CT-based diagnosis and treatment of popular pulmonary diseases. The extraction of airway centerline is a precursor to identify airway hierarchical structure, measure geometrical parameters, and guide visualized detection. Traditional methods suffer from extra branches and circles due to incomplete segmentation results, which induce false analysis in applications. This paper proposed an automatic and robust centerline extraction method for airway tree. First, the centerline is located based on the topological thinning method; border voxels are deleted symmetrically to preserve topological and geometrical properties iteratively. Second, the structural information …is generated using graph-theoretic analysis. Then inaccurate circles are removed with a distance weighting strategy, and extra branches are pruned according to clinical anatomic knowledge. The centerline region without false appendices is eventually determined after the described phases. Experimental results show that the proposed method identifies more than 96% branches and keep consistency across different cases and achieves superior circle-free structure and centrality. Show more

Keywords: Airway tree, centerline extraction, topological thinning, graph-theoretic analysis

DOI: 10.3233/BME-141146

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3239-3249, 2014

Authors: Geng, Chen | Yang, Jian | Dai, Yakang | Liu, Zhaobang | Dong, Yuefang

Article Type: Research Article

Abstract: Computed tomography angiography (CTA) is a major noninvasive technology for imaging coronary artery disease, and effective and accurate vessel tracking method can help radiologists diagnose the disease more accurately. In this paper, a novel 3D vessel tracking method based on CTA data is presented. The method is comprised of preprocessing, a novel spherical operator, and hierarchical clustering, where the spherical operator consists of rays that are casted different directions in a spherical coordinate system. The vascular boundary is extracted by the spherical operator, and the tracking direction is also obtained by the hierarchical clustering. The method is evaluated with the …Rotterdam Coronary Artery Algorithm Evaluation Framework. Results indicate that our method outperforms current state-of-the-art methods in terms of the overlap ratio on the vessel tracking of coronary arteries in CTA data. Show more

Keywords: 3D vessel tracking, spherical operator, hierarchical clustering

DOI: 10.3233/BME-141147

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3251-3258, 2014

Authors: Zhang, Zulin | Yi, Xinzhong | Peng, Hong

Article Type: Research Article

Abstract: This paper proposes a tissue membrane system-based framework to deal with the optimal image fusion problem. A spatial domain fusion algorithm is given, and a tissue membrane system of multiple cells is used as its computing framework. Based on the multicellular structure and inherent communication mechanism of the tissue membrane system, an improved velocity-position model is developed. The performance of the fusion framework is studied with comparison of several traditional fusion methods as well as genetic algorithm (GA)-based and differential evolution (DE)-based spatial domain fusion methods. Experimental results show that the proposed fusion framework is superior or comparable to the …other methods and can be efficiently used for image fusion. Show more

Keywords: Membrane computing, membrane systems, tissue membrane systems, image fusion

DOI: 10.3233/BME-141148

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3259-3266, 2014

Authors: Yang, Jinzhu | Ma, Shuang | Sun, Qi | Tan, Wenjun | Xu, Mengjia | Chen, Nan | Zhao, Dazhe

Article Type: Research Article

Abstract: Traditional Hessian multiscale filter consider only the local geometric feature but not the global grayscale information. In medical image analysis, Hessian filter is usually used to enhance the blood vessels. However, it also produces some pseudo vascular structures or some isolate noise points, such as the nasal soft tissues that have the similar shape with the vessels in MRA data, which will increase the difficulty of cerebrovascular segmentation. To resolve this issue, an improved Hessian multiscale filter is proposed in this paper. An image grayscale factor is added to the vascular similarity function computed by Hessian matrix eigenvalue. This method …is experimented on brain MRA data and lung CTA data. Experimental results show that this method can enhance vascular structures, and simultaneously reduce the appearance of the pseudo vascular structures and the isolated noise points. Show more

Keywords: Hessian filter, multiscale enhancement, grayscale, CT image, MRA image

DOI: 10.3233/BME-141149

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3267-3275, 2014

Authors: Li, Hong | Liu, Kaihua | Sun, Hang | Bao, Nan | Wang, Xu | Tian, Shi | Qi, Shouliang | Kang, Yan

Article Type: Research Article

Abstract: Computed tomography (CT) radiation dose can be reduced significantly by region of interest (ROI) CT scan. Automatically positioning the heart in CT scout images is an essential step to realize the ROI CT scan of the heart. This paper proposed a fully automatic heart positioning method in CT scout image, including the anteroposterior (A-P) scout image and lateral scout image. The key steps were to determine the feature points of the heart and obtaining part of the heart boundary on the A-P scout image, and then transform the part of the boundary into polar coordinate system and obtain the whole …boundary of the heart using slant elliptic equation curve fitting. For heart positioning on the lateral image, the top and bottom boundary obtained from A-P image can be inherited. The proposed method was tested on a clinical routine dataset of 30 cases (30 A-P scout images and 30 lateral scout images). Experimental results show that 26 cases of the dataset have achieved a very good positioning result of the heart both in the A-P scout image and the lateral scout image. The method may be helpful for ROI CT scan of the heart. Show more

Keywords: CT scout, heart positioning, ROI scan, automatic positioning method

DOI: 10.3233/BME-141150

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3277-3286, 2014

Authors: Nawaz, Shoukat | Fu, Jian | Fan, Dekai

Article Type: Research Article

Abstract: X-ray computed tomography (CT) is a powerful clinical diagnosis tool and has been used widely in many clinical and biological settings. Metal artifacts, caused by high density implants, are commonly encountered in clinical CT applications, thereby affecting the detection of abnormal structures and undermining CT's diagnostic value. In this paper, we developed a metal artifact reduction approach based on image segmentation and forward-projection. We further demonstrate the usefulness of our approach by using a biomedical specimen consisting of muscles, bones and metals. Our aim is to remove the inaccurate metal artifact pixels in the original CT slices and exactly reconstruct …the soft-tissue using the forward projections with no metal information. During the reconstruction, artifacts are reduced by replacing the metal projection using the forward projection. The presented work is of interest for CT biomedical applications. Show more

Keywords: Computed tomography, metal artifacts, image segmentation, forward-projection

DOI: 10.3233/BME-141151

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3287-3293, 2014

Authors: Lee, Gihyoun | Na, Sung Dae | Cho, Jin-Ho | Kim, Myoung Nam

Article Type: Research Article

Abstract: This paper presents a voice activity detection (VAD) approach using a perceptual wavelet entropy neighbor slope (PWENS) in a low signal-to-noise (SNR) environment and with a variety of noise types. The basis for our study is to use acoustic features that have large entropy variance for each wavelet critical band. The speech signal is decomposed by the proposed perceptual wavelet packet decomposition (PWPD), and the VAD function is extracted by PWENS. Finally, VAD is decided by the proposed VAD decision rule using two memory buffers. In order to evaluate the performance of the VAD decision, many speech samples and a …variety of SNR conditions were used in the experiment. The performance of the VAD decision is confirmed using objective indexes such as a graph of the VAD decision and the relative error rate. Show more

Keywords: Voice activity detection, wavelet transform, wavelet decomposition, neighbor slope, entropy

DOI: 10.3233/BME-141152

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3295-3301, 2014

Authors: Na, Sung Dae | Lee, Gihyoun | Lee, Jyung Hyun | Kim, Myoung Nam

Article Type: Research Article

Abstract: In this paper, a new method for individual tooth segmentation was proposed. The proposed method is composed of enhancement and extraction of boundary and seed of watershed algorithm using trisection areas by morphological characteristic of teeth. The watershed algorithm is one of the conventional methods for tooth segmentation; however, the method has some problems. First, molar region detection ratio is reduced because of oral structure features that is low intensities in molar region. Second, inaccurate segmentation occurs in incisor region owing to specular reflection. To solve the problems, the trisection method using morphological characteristic was proposed, where three tooth areas …are made using ratio of entire tooth to each tooth. Moreover, the enhancement is to improve the intensity of molar using the proposed method. In addition, boundary and seed of watershed are extracted using trisection areas applied other parameters each area. Finally, individual tooth segmentation was performed using extracted boundary and seed. Furthermore, the proposed method was compared with conventional methods to confirm its efficiency. As a result, the proposed method was demonstrated to have higher detection ratio, better over segmentation, and overlap segmentation than conventional methods. Show more

Keywords: Segmentation, tooth, watershed, oral scanner

DOI: 10.3233/BME-141153

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3303-3309, 2014

Authors: Birtane, Sibel | Korkmaz, Hayriye

Article Type: Research Article

Abstract: In this paper, 2-steps software using image processing and enhancement technologies is developed to obtain a scoliosis patient's spine pattern from 2D coronal X-Ray images without manual land marking. Then, a Rule-based Fuzzy classifier is implemented on those images to classify the spine patterns using the King-Moe classification approach.

Keywords: Image processing, scoliosis, king-moe type classification, fuzzy logic, computer aided classification, rule-based classification

DOI: 10.3233/BME-141154

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3311-3319, 2014

Authors: Liu, Xi | Liu, Lixiong

Article Type: Research Article

Abstract: We analyzed the principle of the traditional local binary fitting operation, Gaussian kernel function weighted summation (GKFWS), to develop a novel level set model in this paper. In this model, the traditional GKFWS operation is replaced with the median filter operation in the second procedure of local fitting of the energy domain. Furthermore, we incorporated the edge stopping function of GAC model into it to introduce the edge information for segmentation. Experiments on synthetic and real images demonstrate that this model has promising performance in terms of computational cost, robustness to noises and segmentation of images with intensity inhomogeneity.

Keywords: Active contour, median filter, image segmentation, level set, edge information

DOI: 10.3233/BME-141155

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3321-3332, 2014

Authors: Yin, Lim Khai | Rajeswari, Mandava

Article Type: Research Article

Abstract: To segment an image using the random walks algorithm; users are often required to initialize the approximate locations of the objects and background in the image. Due to its segmenting model that is mainly reflected by the relationship among the neighborhood pixels and its boundary conditions, random walks algorithm has made itself sensitive to the inputs of the seeds. Instead of considering the relationship between the neighborhood pixels solely, an attempt has been made to modify the weighting function that accounts for the intensity changes between the neighborhood nodes. Local affiliation within the defined neighborhood region of the two nodes …is taken into consideration by incorporating an extra penalty term into the weighting function. Besides that, to better segment images, particularly medical images with texture features, GLCM variance is incorporated into the weighting function through kernel density estimation (KDE). The probability density of each pixel belonging to the initialized seeds is estimated and integrated into the weighting function. To test the performance of the proposed weighting model, several medical images that mainly made up of 174-brain tumor images are experimented. These experiments establish that the proposed method produces better segmentation results than the original random walks. Show more

Keywords: Random walks, weighting function, gray-level co-occurrence, kernel density estimation

DOI: 10.3233/BME-141156

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3333-3341, 2014

Authors: Zhang, Ziqun | Zhang, Ran | Song, Zhijian

Article Type: Research Article

Abstract: Skull defect reconstruction is an important aspect of surgical repair. Historically, a skull defect prosthesis was created by the mirroring technique, surface fitting, or formed templates. These methods are not based on the anatomy of the individual patient's skull, and therefore, the prosthesis cannot precisely correct the defect. This study presented a new hybrid level set model, taking into account both the global optimization region information and the local accuracy edge information, while avoiding re-initialization during the evolution of the level set function. Based on the new method, a skull defect was reconstructed, and the skull prosthesis was produced by …rapid prototyping technology. This resulted in a skull defect prosthesis that well matched the skull defect with excellent individual adaptation. Show more

Keywords: Skull defect, image segmentation, level set method, rapid prototyping

DOI: 10.3233/BME-141157

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3343-3351, 2014

Authors: Xia, Yong | Liu, Yixuan | Wang, Kuanquan

Article Type: Research Article

Abstract: Having the ability to visualize the heart clearly and precisely would be beneficial for pathology research, presurgical planning, and clinical approaches. Multi-dimensional transfer functions were employed to improve the overall performance of images. To provide a satisfactory visualization quality on the shape and boundaries of the heart, a new hybrid transfer function combining structure size with gradient was designed to highlight the area of the heart. Initially, a histogram of gradient and histogram of size was computed and then classification was performed for providing the spatial information. Finally, several hybrid strategies were presented for the design of the transfer function, …including opacity and color. By experimental evaluation, the proposed hybrid transfer function visualized the cardiac outline and internal structure more clearly and easily. Show more

Keywords: visualization of heart, multi-dimensional transfer function, histogram of structure size, histogram of gradient

DOI: 10.3233/BME-141158

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3353-3359, 2014

Authors: Bao, Nan | Chen, Yu | Yue, Yong | Li, Hong | Cui, Zhiming | Zhuang, Jinfeng | Tian, Shi | Kang, Yan

Article Type: Research Article

Abstract: The rigid registration is a key step of Image Guided Surgery (IGS), and the point-pair method is the main way used for registration. However the configuration of fiducial points has a great influence on the registration accuracy at the target point. Now almost all the optimization method of fiducial points configuration relies on the empirical simulation-based Fitzpatrick's target registration error (TRE). In this paper, a phantom and some markers were designed and some experiments were conducted to measure and compare the affecting factors on the registration. By the markers repeated selections, the fiducial location error (FLE) has a small deviation …of maximum 0.4 mm, and the average of the Fitzpatrick's TRE (F-TRE) has almost 86% proportion to the average of the actual TRE (A-TRE), but the standard deviation (STD) just has 7% proportion. Also, the experiment result showed that six fiducial markers already had the 86% accuracy, and spreading the fiducial markers led to 30% reduction in mean of A-TRE and 40% reduction in STD of A-TRE comparing with the centralized. Overall, to find a strategy of optimization, reducing the TRE has the great meaning to support safer and more accurate minimally IGS procedures. Show more

Keywords: Image guided surgery, target registration error, registration, fiducial markers, number and distribution

DOI: 10.3233/BME-141159

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3361-3371, 2014

Authors: Ji, Bing | Yang, Qing | Genever, Paul G. | Fagan, Michael J.

Article Type: Research Article

Abstract: Multiple myeloma (MM)-induced bone disease is mortal for most MM patients. Bisphosphonates are first-line treatment for MM-induced bone disease, since it can inhibit osteoclast activity and the resultant bone resorption by suppressing the differentiation of osteoclast precursors into mature osteoclasts, promoting osteoclast apoptosis and disrupting osteoclast function. However, it is still unclear whether bisphosphonates have an anti-tumour effect. In our previous work, a computational model was built to simulate the pathology of MM-induced bone disease. This paper extends this proposed computational model to investigate the efficacy of bisphosphonates treatment and then clear the controversy of this therapy. The extended model …is validated through the good agreement between simulation results and experimental data. The simulation results suggest that bisphosphonates indeed have an anti-tumour effect. Show more

Keywords: Multiple myeloma, MM-induced bone disease, bisphosphonates, anti-tumour, computational model

DOI: 10.3233/BME-141160

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3373-3378, 2014

Authors: Wu, Yixiao | Yang, Ran | Jia, Sen | Li, Zhanjun | Zhou, Zhiyang | Lou, Ting

Article Type: Research Article

Abstract: This work was aimed at studying the method of computer-aided diagnosis of early knee OA (OA: osteoarthritis). Based on the technique of MRI (MRI: Magnetic Resonance Imaging) T2 Mapping, through computer image processing, feature extraction, calculation and analysis via constructing a classifier, an effective computer-aided diagnosis method for knee OA was created to assist doctors in their accurate, timely and convenient detection of potential risk of OA. In order to evaluate this method, a total of 1380 data from the MRI images of 46 samples of knee joints were collected. These data were then modeled through linear regression on an …offline general platform by the use of the ImageJ software, and a map of the physical parameter T2 was reconstructed. After the image processing, the T2 values of ten regions in the WORMS (WORMS: Whole-organ Magnetic Resonance Imaging Score) areas of the articular cartilage were extracted to be used as the eigenvalues in data mining. Then,a RBF (RBF: Radical Basis Function) network classifier was built to classify and identify the collected data. The classifier exhibited a final identification accuracy of 75%, indicating a good result of assisting diagnosis. Since the knee OA classifier constituted by a weights-directly-determined RBF neural network didn't require any iteration, our results demonstrated that the optimal weights, appropriate center and variance could be yielded through simple procedures. Furthermore, the accuracy for both the training samples and the testing samples from the normal group could reach 100%. Finally, the classifier was superior both in time efficiency and classification performance to the frequently used classifiers based on iterative learning. Thus it was suitable to be used as an aid to computer-aided diagnosis of early knee OA. Show more

Keywords: Knee OA, MR T2 mapping, RBF neural network, computer-aided diagnosis

DOI: 10.3233/BME-141161

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3379-3388, 2014

Authors: Zhu, Lei | Zheng, Ran | Jin, Hai | Zhang, Qin | Zhang, Wei

Article Type: Research Article

Abstract: Silicosis remains one of the most harmful occupational respiratory diseases. It threatens the workers exposed to dust environment. Chest radiograph is the main available image source for silicosis diagnosis according to the diagnostic criteria of pneumoconiosis (DCP). Automatic detection and recognition of silicosis in chest radiograph has great importance on aiding the process of silicosis diagnosis. This paper proposes a multi-scale opacity detection approach to detect all suspected opacities from the chest radiograph. A support vector machine (SVM) based computer-aided silicosis diagnosis is proposed to recognize silicosis opacity from a large amount of candidate regions, and gives processing result for …radiologist reference. Comprehensive experiments conducted on real world chest radiographs demonstrate that the proposed approach can reveal changes of silicosis pathology well, and it can be adopted as an effective tool for automatic silicosis diagnosis. Show more

Keywords: Silicosis, diagnostic criteria of pneumoconiosis, chest radiograph, support vector machine, silicosis pathology

DOI: 10.3233/BME-141162

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3389-3395, 2014

Authors: Li, Peng | Bi, Tingting | Huang, Jiuling | Li, Siben

Article Type: Research Article

Abstract: The frequent occurrence of breast cancer and its serious consequences have attracted worldwide attention in recent years. Problems such as low rate of accuracy and poor self-adaptability still exist in traditional diagnosis. In order to solve these problems, an AdaBoost-SVM classification algorithm, combined with the cluster boundary sampling preprocessing techniques (CBS-AdaBoost-SVM), is proposed in this paper for the early diagnosis of breast cancer. The algorithm uses machine learning method to diagnose the unknown image data. Moreover, not all of the characteristics play positive roles for classification. To address this issue the paper delete redundant features by using Rough set attribute …reduction algorithm based on the genetic algorithm (GA). The effectiveness of the proposed methods are examined on DDSM by calculating its accuracy, confusion matrix, and receiver operating characteristic curves, which give important clues to the physicians for early diagnosis of breast cancer. Show more

Keywords: Computer-aided diagnosis, image data mining, support vector machine, clustering sampling

DOI: 10.3233/BME-141163

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3397-3404, 2014

Authors: Song, In-Uk | Kim, Joong-Seok | Chung, Sung-Woo | Lee, Kwang-Soo | Oh, Jin-Kyoung | Chung, Yong-An

Article Type: Research Article

Abstract: Cognitive dysfunction is a common feature of Parkinson's disease (PD). Recent research has focused on the detection and management of subjective memory impairment (SMI) as the stage that precedes mild cognitive impairment (MCI). Nevertheless, few clinical studies have biomarkers of SMI in PD. Therefore, this study was designed to investigate differences in perfusion brain SPECT between PD with SMI (PD+SMI) and PD without SMI (PD-SMI) to identify a potential prodromal biomarker of progression to dementia in patients with PD. In this study, 30 PD patients with SMI and 24 PD patients without SMI have been recruited. All subjects underwent perfusion …brain SPECT and neuropsychological testing. Brain SPECT images were analyzed by using the SPM program and comparing between patients with PD+SMI and PD-SMI. The PD+SMI and PD-SMI groups did not differ in any neuropsychological tests, except for MMSE. Despite a significant difference in MMSE scores, all scores of both groups were in the normal range. Brain SPECT analysis of PD+SMI patients showed hypoperfusion in the frontal and inferior temporal regions, anterior cingulate and thalamus compared with PD-SMI patients. This pilot study investigated the role of decreased brain perfusion SPECT findings in PD+SMI patients compared with PD-SMI patients as a predictive biomarker of pre-dementia as the stage that precedes MCI in PD. Larger, prospective studies are warranted for further investigation of the pathophysiology of neuronal systems during cognitive decline. Show more

Keywords: Parkinson's disease, subjective memory impairment, perfusion SPECT

DOI: 10.3233/BME-141164

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3405-3410, 2014

Authors: Liu, Yubin | Li, Zhifang | Li, Hui | Yuan, Zhen

Article Type: Research Article

Abstract: In this study, the change of tumors' chemical composition in the temperature range of 20~70°C is quantified for photothermal tumor therapy by photoacoustic spectroscopy (PAS) with the wavelengths of 700~1000 nm. Based on the measured photoacoustic signals, two absorption peaks at the wavelengths of 750nm and 950nm are identified. It is also observed that high temperature (>55°C) is able to induce the physical and chemical degeneration of tumors. According to the in vitro tests, a new chemical species, met-hemoglobin, which is absent in normal blood, is generated at high temperature with enhanced near-infrared absorption.

Keywords: PAS, photothermal therapy, photoacoustic signals, hemoglobin

DOI: 10.3233/BME-141165

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3411-3418, 2014

Authors: Bianchi, Mariana | Adur, Javier | Ruff, Silvana Y. | Izaguirre, María F. | Carvalho, Hernandes F. | Cesar, Carlos L. | Casco, Víctor H.

Article Type: Research Article

Abstract: Murine induced colon cancer has been used to demonstrate that Second Harmonic Generation (SHG) microscopy images, combined with Two-Photon Excitation Fluorescence (TPEF) and specific quantization scoring methods allow distinguishing early alterations in colon mucosa. TPEF was used only to identified crypts and submucosa regions, whereas the image analysis was used to get quantitative data (Integrated Intensity and Aspect Ratio scoring) of different cancer stages. The submucosa amount of collagen fibers was significant and their orientation suffering proportional changes with the development of the pathological processes. Both after the fourth and eighth weeks after colon cancer induction, integrated intensity and aspect …ratio values have shown significant statistical differences compared with control samples. Thus, SHG microscopy has proved to be a useful quantitative tool to highlight early changes of submucosa and the progression of these through the cancer development. Show more

Keywords: Colon cancer, early detection, second harmonic generation, two-photon excitation fluorescence

DOI: 10.3233/BME-141166

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3419-3426, 2014

Authors: Li, Sujiao | Zhang, Zhengxiang | Wang, Jue

Article Type: Research Article

Abstract: Prevention of pressure sores remains a significant problem confronting spinal cord injury patients and the elderly with limited mobility. One vital aspect of this subject concerns the development of cushions to decrease pressure ulcers for seated patients, particularly those bound by wheelchairs. Here, we present a novel cushion system that employs interface pressure distribution between the cushion and the buttocks to design custom contoured foam cushion. An optimized normalization algorithm was proposed, with which interface pressure distribution was transformed into the carving depth of foam cushions according to the biomechanical characteristics of the foam. The shape and pressure-relief performance of …the custom contoured foam cushions was investigated. The outcomes showed that the contoured shape of personalized cushion matched the buttock contour very well. Moreover, the custom contoured cushion could alleviate pressure under buttocks and increase subjective comfort and stability significantly. Furthermore, the fabricating method not only decreased the unit production cost but also simplified the procedure for manufacturing. All in all, this prototype seat cushion would be an effective and economical way to prevent pressure ulcers. Show more

Keywords: Prototype, manufacture system, custom-contoured cushion (CCC), pressure sores, optimized normalization algorithm

DOI: 10.3233/BME-141167

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3427-3438, 2014

Authors: Huan, Cheng | Qu, Yuanming | Ren, Zongming

Article Type: Research Article

Abstract: The purpose of this study was to assess gender-related distinction in the performance of Cushing's disease (CD) regarding clinical features, radiological findings, neurological and endocrine status, surgical outcome, and quality of life in Han Chinese. A retrospective study was conducted on 87 patients treated by trans-sphenoidal surgery, between 2006 and 2011, at a single treatment center in Shandong Provincial Hospital, China. Features of CD were compared and quality of life was analyzed between genders. The female-to-male ratio was 2.78: 1. Results showed that men have a younger age of diagnosis (P<0.001), a larger adenoma diameter (P<0.001), and a higher invasion …rate (P=0.032) and apoplexy rate (P=0.04) than women. To be specific, compared with women, men are more prone to suffering from osteoporosis, hypokalemia, sexual dysfunction, and hypertension (P<0.05), have significantly higher preoperative and postoperative (six months after surgery) cortisol levels (P<0.001, P=0.003) and a higher recurrence rate (30.43% vs. 7.81%; P=0.028). No significant differences were seen in the CushingQoL scores between genders. Therefore, male patients with CD need more careful and long-term follow-up than female patients. Show more

Keywords: Cushing's disease, gender differences, transsphenoidal surgery, CushingQoL scores

DOI: 10.3233/BME-141168

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3439-3446, 2014

Authors: Zhang, Bowen | Chai, Hua | Yang, Ziyi | Liang, Yong | Chu, Gejin | Liu, Xiaoying

Article Type: Research Article

Abstract: Heart disease has become the number one killer of human health, and its diagnosis depends on many features, such as age, blood pressure, heart rate and other dozens of physiological indicators. Although there are so many risk factors, doctors usually diagnose the disease depending on their intuition and experience, which requires a lot of knowledge and experience for correct determination. To find the hidden medical information in the existing clinical data is a noticeable and powerful approach in the study of heart disease diagnosis. In this paper, sparse logistic regression method is introduced to detect the key risk factors using …L1/2 regularization on the real heart disease data. Experimental results show that the sparse logistic L1/2 regularization method achieves fewer but informative key features than Lasso, SCAD, MCP and Elastic net regularization approaches. Simultaneously, the proposed method can cut down the computational complexity, save cost and time to undergo medical tests and checkups, reduce the number of attributes needed to be taken from patients. Show more

Keywords: Heart disease, feature selection, sparse logistic regression, L1/2 regularization

DOI: 10.3233/BME-141169

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3447-3454, 2014

Authors: Zhang, Liang | Liu, Peiguo | Dong, Xiuzhen | Zhou, Dongming | Shi, Xuetao

Article Type: Research Article

Abstract: In this paper, a convenient and noninvasive scanning imaging method using microwave frequency band for abnormal subepidermal tissues detection is proposed in the aim to improve diagnosis and prognosis in clinical environments. This method is based on the reflective detection technology with coaxial probe that is used to measure the dielectric properties of tissues. An improved equivalent circuit and simulated annealing algorithm (SA) were used in this work to analyze the dielectric properties of tissues. Computational simulations incorporating a simplified model of subcutaneous hemorrhage described in this work were used to evaluate this method. The dielectric properties data of tissues …in the model of simulation is derived from the literature. The simulation results demonstrated the potential of this method to detect abnormal subepidermal tissues conveniently and expose them in the image accurately. Show more

Keywords: Coaxial probe, dielectric properties, scanning imaging, simulated annealing, subepidermal tissues

DOI: 10.3233/BME-141170

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3455-3462, 2014

Authors: He, Ying | Jiang, Pengjun | Han, Shanshan | Wang, Rong | Li, Yue | Teng, Yichao | Gao, Tianxin

Article Type: Research Article

Abstract: Near-infrared spectroscopy (NIRS) was used to investigate the cerebral oxygenation of Moyamoya and healthy subjects. Continuous recordings of NIRS signals for 20 min (20 min signals) were obtained from 17 healthy subjects (age: 37.4±11.3) and 17 Moyamoya subjects (age: 40.1±11.2). Spectral analysis based on wavelet transformation identified five frequency intervals (I, 0.0095 Hz to 0.02 Hz; II, 0.02 Hz to 0.06 Hz; III, 0.06 Hz to 0.15 Hz; IV, 0.15 Hz to 0.40 Hz; and V, 0.40 Hz to 2.00 Hz) in the 20 min signals and three frequency intervals (III, 0.06 Hz to 0.15 Hz; IV, 0.15 Hz to …0.40 Hz; and V, 0.40 Hz to 2.00 Hz) in the 3 min signals (the first 3 min signals were continuously extracted from the 20 min signals). Significant differences (p < 0.05) were found in frequency intervals III and V. The former exhibited the myogenic activity of smooth muscle inside the blood vessels in both 20 min and 3 min signal analyses; the latter showed hemodynamic oscillation caused by heart pumping. This finding agrees with the vascular pathological changes in Moyamoya disease. As a potential screening method for Moyamoya disease, the simple threshold method exhibited 73.5% accuracy. Show more

Keywords: Moyamoya disease, near-infrared spectroscopy, cerebral oxygenation, wavelet transformation, screening

DOI: 10.3233/BME-141171

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3463-3469, 2014

Authors: Yang, Jian | Fu, Tianyu | Ai, Danni | Xing, Huijun | Li, Qin | Wang, Yongtian

Article Type: Research Article

Abstract: Shoulder instability is a major threat to people's daily life. Many patients suffer from shoulder instability such as the loss of the glenoid and humeral head. In clinical practice, an accurate 3D structure estimation of damaged joints is necessary to diagnose and treat bone defects. This study quantifies osteoarticular defects through the modeling and visualization of osteoarticular structures. An improved algorithm to extract the 3D structure of the bones is proposed. The bone contour is then automatically extracted using prior shape and gray scale intensity distribution of joint CT images. Joint structures with mirror symmetry are matched using the Iterative …Closest Point registration algorithm. Osteoarticular defects can be quantified on the basis of the symmetric information of the bones. Experimental results demonstrate that the proposed method can effectively segment the joint structures from the CT image. In addition, the proposed mirror symmetrical method can effectively estimate osteoarticular defects. Show more

Keywords: Joint bone, segmentation, modeling, quantitative analysis

DOI: 10.3233/BME-141172

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3471-3478, 2014

Authors: Zhou, Zhengdong | Chen, Yuanhua | Yu, Zili | Wang, Dongdong | Zhao, Chunsheng | Xu, Jun | Song, Wei | Li, Bing | Shen, Junshu | Zhu, Xixu

Article Type: Research Article

Abstract: Intensity-Modulated Radiation Therapy (IMRT) mathematically forms a large-scale optimization problem. The development of an IMRT plan is computationally expensive resulting in time-consuming, inefficient, and difficult to develop high-quality IMRT plans. By combining prior knowledge with proposed novel measures derived from both Overlap Volume Histogram (OVH) descriptors and Dose Volume Histograms (DVHs), a novel quality control method for IMRT planning is proposed to assure the high quality of IMRT plan. Clinical approved nasopharyngeal IMRT plans were employed for the experiments, where the reference plan is firstly retrieved from IMRT plan database for each query case by using measures derived from both …OVH descriptors and DVHs. Then the DVHs of the reference plan are served as additional goals for the IMRT plan re-optimization. The experimental results show that the proposed method can effectively pick out those IMRT plans, whose quality could be improved substantially (i.e. the doses of their Clinical Targets Volume (CTV) could be effectively increased) and the dose of their Organs at Risk (OARs) could be reduced after the IMRT plan has being re-optimized. In conclusion, the proposed methods can effectively guarantee the high quality of the IMRT planning. Show more

Keywords: Intensity-modulated radiation therapy (IMRT), quality control, overlap volume histogram (OVH), prior knowledge

DOI: 10.3233/BME-141173

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3479-3485, 2014

Authors: Wang, Chunxi | Cai, Xiangjun | Liang, Faqi | Chu, Futao | Chen, Gang | Duan, Zhiquan

Article Type: Research Article

Abstract: The celiomesenteric trunk is a rare anomaly characterized by a common origin of the celiac axis and superior mesenteric artery from the aorta, which accounts for less than 1% of all celiac artery anomalies, so the aneurysm occurred in such trunk is even rarer. There have been few reports on how to diagnose and deal with such malformed celiomesenteric trunk aneurysms till now. This paper tries to summarize the experience of how to expose and excise such kind of aneurysm according to the seven cases' data. The clinic data were collected retrospectively. There were seven cases with celiomesenteric trunk aneurysm …from February 2000 to February 2013, including 5 males and 2 females aged 35~62. The operations were done including aneurysm resection and vascular reconstruction under general anesthesia. The operated patients were followed-up at the sixth month and each year post operation. The vascular stomas were detected or examined by Color Doppler Sonography, spiral Computed Tomography angiography (SCTA). The seven operated patients were cured and discharged from hospital, and they were followed up for 3~10 years (mean time 5 years), with four patients being followed up longer than 5 years. No sign of intestinal ischemia or hepatic ischemia or splenic ischemia was found, and no image of anastomosis stricture or stenosis was found during the follow-up. Five patients are alive now while two patients were dead, with one dying of large area myocardial infarction unexpectedly at 6 years post operation and the other dying of cerebral infarction abruptly at 4 years post operation. It is an effective and safe method to treat the celiomesenteric trunk aneurysm by using by-pass operation with artificial blood vessels, originating from inferior kidney aorta to visceral arteries including hepatic artery, splenic artery and superior mesenteric artery. Its short-term and middle-term effects are relatively better. Show more

Keywords: Celiomesenteric trunk, superior mesenteric artery, celiac trunk, aneurysm, operation

DOI: 10.3233/BME-141174

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3487-3492, 2014

Authors: Eguiluz-Perez, Gonzalo | Garcia-Zapirain, Begonya

Article Type: Research Article

Abstract: People with Multiple Sclerosis (MS) need regular physical activities along with medical treatment despite their ability or disability level. However, poorly performed exercises could aggravate muscle imbalances and worsen their health. The goal of our work is to create a comprehensive system, encompassing a face-to-face sessions performed by MS patients one day a week at the medical center with exercises at home the rest of the week through a web platform in combination with a tracking tool to analyze the position of patients during exercise and correct them in real-time. The whole system is currently testing during six months with …ten participants, five persons with MS and 5 professionals related with MS. Two tests, the Functional Independence Measure and the Berg Balance Scale will be act as a barometer for measuring the degree of independence obtained by the people with MS and also the validity of the whole system as a rehabilitation tool. Preliminary results about the usability of the system using SUS scale, 72 and 76 points over 100 (patients and professionals respectively), demonstrate that our system is usable for both patients and professionals. Show more

Keywords: Multiple Sclerosis, telerehabilitation, web application, verticality analysis

DOI: 10.3233/BME-141175

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3493-3502, 2014

Authors: Tran, Thang Viet | Chung, Wan-Young

Article Type: Research Article

Abstract: This paper proposes the design and implementation of a low-voltage and low-power body sensor node based on the IEEE 802.15.4 standard to collect electrocardiography (ECG) and photoplethysmography (PPG) signals. To achieve compact size, low supply voltage, and low power consumption, the proposed platform is integrated into a ZigBee mote, which contains a DC-DC booster, a PPG sensor interface module, and an ECG front-end circuit that has ultra-low current consumption. The input voltage of the proposed node is very low and has a wide range, from 0.65 V to 3.3 V. An RF energy harvester is also designed to charge the …battery during the working mode or standby mode of the node. The power consumption of the proposed node reaches 14 mW in working mode to prolong the battery lifetime. The software is supported by the nesC language under the TinyOS environment, which enables the proposed node to be easily configured to function as an individual health monitoring node or a node in a wireless body sensor network (BSN). The proposed node is used to set up a wireless BSN that can simultaneously collect ECG and PPG signals and monitor the results on the personal computer. Show more

Keywords: Body sensor network, electrocardiography, photoplethysmography, low-power node, radio frequency energy harvester

DOI: 10.3233/BME-141176

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3503-3510, 2014

Authors: Viqueira Villarejo, María | Maeso García, Jose | García Zapirain, Begoña | Méndez Zorrilla, Amaia

Article Type: Research Article

Abstract: This paper describes a study dealing with a technological solution to measure gait quality in people suffering from multiple sclerosis (MS) by selecting objective parameters that focus on their step. Android mobile technology, online services and four wireless pressure sensors are used in concert for this purpose. The objective of this work is the early detection of deterioration of the patient so that a physician can quickly intervene. Tests were carried out on a group of 8 persons with MS, and these results were compared with a control a group of 6 healthy participants. The results indicated a statistical difference …in 7 of 40 general step features, with a minimum σ=0.013 and a maximum σ=0.029. These characteristics showed differences between first and fifth metatarsals for each group. It was concluded that these parameters can be used to evaluate gait degeneration in people with MS and that further information could be obtained from measurements with sensors to monitor activities such as bending and inertial sensors. Show more

Keywords: Gait analysis, objective parameterization, sensors

DOI: 10.3233/BME-141177

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3511-3522, 2014

Authors: Viqueira Villarejo, María | García Zapirain, Begoña | Méndez Zorrilla, Amaia

Article Type: Research Article

Abstract: This paper presents a shoe-integrated sensor device which collects objective information concerning the gait quality in patients' physical rehabilitation. It involves four pressure sensors, two bending sensors, an ultrasonic sensor and a 9dof IMU, an Inertial Measurement Unit with three accelerometers, three gyroscopes and three magnetometers. The device includes a SDRAMPS with the aim of storing the information for long periods of time. The collected data can be sent to the server for later visualization by the specialist and the patient on a web platform. An interface shows the data in real time, allowing it to verify the connections and …to check different movements. Show more

Keywords: Gait, sensor, wireless

DOI: 10.3233/BME-141178

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3523-3528, 2014

Authors: Tan, Yee-Yong | Chung, Wan-Young

Article Type: Research Article

Abstract: Promising development in the light emitting diode (LED) technology has spurred the interest to adapt LED for both illumination and data transmission. This has fostered the growth of interest in visible light communication (VLC), with on–going research to utilize VLC in various applications. This paper presents a mobile–health monitoring system, where healthcare information such as biomedical signals and patient information are transmitted via the LED lighting. A small and portable receiver module is designed and developed to be attached to the mobile device, providing a seamless monitoring environment. Three different healthcare information including ECG, PPG signals and HL7 text information …is transmitted simultaneously, using a single channel VLC. This allows for a more precise and accurate monitoring and diagnosis. The data packet size is carefully designed, to transmit information in a minimal packet error rate. A comprehensive monitoring application is designed and developed through the use of a tablet computer in our study. Monitoring and evaluation such as heart rate and arterial blood pressure measurement can be performed concurrently. Real–time monitoring is demonstrated through experiment, where non–hazardous transmission method can be implemented alongside a portable device for better and safer healthcare service. Show more

Keywords: Visible light communication, light emitting diode, mobile–health monitoring system, healthcare

DOI: 10.3233/BME-141179

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3529-3538, 2014

Authors: Moon, Yeon-Kwan | Lee, Jyung Hyun | Park, Hee-Joon | Cho, Jin-Ho | Choi, Hyun-Chul

Article Type: Research Article

Abstract: Recently, several medical devices that use wireless communication are under development. In this paper, the small size frequency shift keying (FSK) transmitter and a monofilar antenna for the capsule endoscope, enabling the medical device to transmit VGA-size images of the intestine. To verify the functionality of the proposed wireless communication system, computer simulations and animal experiments were performed with the implemented capsule endoscope that includes the proposed wireless communication system. Several fundamental experiments are carried out using the implemented transmitter and antenna, and animal in-vivo experiments were performed to verify VGA image transmission.

Keywords: Capsule endoscope, wireless communication, antenna

DOI: 10.3233/BME-141180

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3539-3547, 2014

Authors: Lopez-Samaniego, Leire | Garcia-Zapirain, Begonya | Mendez-Zorrilla, Amaia

Article Type: Research Article

Abstract: This paper presents the results of research that applies cognitive therapies associated with memory and mathematical problem-solving in elderly people. The exercises are programmed in an iPad and can be performed both from the Tablet and in an interactive format with a LEGO robot. The system has been tested with 2 men and 7 women over the age of 65 who have slight physical and cognitive impairment. Evaluation with the SUS resulted in a mean of 48.45 with a standard deviation of 5.82. The score of overall satisfaction was 84.37 with a standard deviation of 18.6. Interaction with the touch …screen caused some usability problems due to the elderly people's visual difficulties and clicking accuracy. Future versions will include visualization with more color contrast and less use of the keyboard. Show more

Keywords: iPad, cognitive rehabilitation, objective-C, system usability scale (SUS)

DOI: 10.3233/BME-141181

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3549-3556, 2014

Authors: Chang, Yen-Ching

Article Type: Research Article

Abstract: The discrete-time fractional Gaussian noise (DFGN) has been proven to be a regular process. Therefore, an autoregressive (AR) model of an infinite order can describe DFGN based on Wold and Kolmogorov theorems. A fast estimation algorithm on the Hurst exponent of DFGN or discrete-time fractional Brownian motion (DFBM) has been proposed, but the algorithm did not consider the order selection of AR model. Recently, a Hurst exponent estimator based on an AR model with six existing methods of order selection has been proposed to raise the accuracy of estimating the Hurst exponent. Although the estimation accuracy has been confirmed to …be better than the one without order selection, the estimator still requires computing all parameter sets through the Levinson algorithm. In order to lower computational cost, this paper proposes an efficient method of order selection, simply called data induction, which uses simulation data to induce an appropriate threshold of terminating the Levinson algorithm before computing all parameter sets. Experimental results show that the proposed data-induction method has a competitive advantage over six existing methods of order selection in terms of lowering computational cost and raising the accuracy. Show more

Keywords: Fractional Brownian motion, fractional Gaussian noise, Hurst exponent, autoregressive, order selection

DOI: 10.3233/BME-141182

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3557-3568, 2014

Authors: Ishaq, Rizwan | García Zapirain, Begoña

Article Type: Research Article

Abstract: This paper presents the single channel speech enhancement system using subband Kalman filtering by estimating optimal Autoregressive (AR) coefficients and variance for speech and noise, using Weighted Linear Prediction (WLP) and Noise Weighting Function (NWF). The system is applied for normal and Oesophageal speech signals. The method is evaluated by Perceptual Evaluation of Speech Quality (PESQ) score and Signal to Noise Ratio (SNR) improvement for normal speech and Harmonic to Noise Ratio (HNR) for Oesophageal Speech (OES). Compared with previous systems, the normal speech indicates 30% increase in PESQ score, 4 dB SNR improvement and OES shows 3 dB HNR …improvement. Show more

Keywords: Kalman filter, autoregressive, speech enhancement, weighted linear prediction

DOI: 10.3233/BME-141183

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3569-3578, 2014

Authors: Zhang, Ziyi | Liu, Peiguo | Zhou, Dongming | Zhang, Liang | Lei, Hengdong

Article Type: Research Article

Abstract: Biomedical magnetic induction measurement is a promising method for the detection of intracerebral hemorrhage (ICH), especially in China. Aiming at overcoming the problem of low sensitivity, a magnetic induction sensor is chosen to replace the conventional sensors. It uses a two-arm Archimedean spiral coil as the exciter and a circular coil as the receiver. In order to carry out high-fidelity simulations, the Chinese head model with real anatomical structure is introduced into this novel sensor for the first time. Simulations have been carried out upon early stage ICH measurements. By calculating the state sensitivity and time sensitivity of the perturbation …phase of two types of sensors using the electromagnetic software, we conclude that the primary signal received can be largely reduced using the novel sensor, which could effectively increase the time and state sensitivity simultaneously. Show more

Keywords: Intracerebral hemorrhage (ICH), magnetic induction measurement, sensor sensitivity, two-arm archimedean spiral coil (TAASC), Chinese head model

DOI: 10.3233/BME-141184

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3579-3587, 2014

Authors: Lin, Jium-Ming | Lu, Hung-Han | Lin, Cheng-Hung

Article Type: Research Article

Abstract: This paper proposes a bio-potential measurement apparatus including a wireless device for transmitting acupuncture bio-potential information to a remote control station for health conditions analysis and monitor. The key technology of this system is to make replaceable foam-rubber cushions, double-side conducting tapes, chip and antenna on the radio frequency identification (RFID) tag. The foam-rubber cushions can be wetted with salt-water and contact with the acupuncture points to reduce contact resistance. Besides, the double-side conducting tapes are applied to fix foam-rubber cushions. Thus, one can peel the used cushions or tapes away and supply new ones quickly. Since the tag is …a flexible plastic substrate, it is easy to deploy on the skin. Besides, the amplifier made by CMOS technology on RFID chip could amplify the signals to improve S/N ratio and impedance matching. Thus, cloud server can wirelessly monitor the health conditions. An example shows that the proposed system can be used as a wireless health condition monitor, the numerical method and the criteria are given to analyze eleven bio-potentials for the important acupunctures of eleven meridians on a person's hands and legs. Then a professional doctor can know the performance of an individual and the cross-linking effects of the organs. Show more

Keywords: RFID tag, bio-potential, flexible substrate, wireless health monitor, wetted replaceable foam-rubber cushion

DOI: 10.3233/BME-141185

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3589-3596, 2014

Authors: Tsai, Jang-Zern | Chen, Ching-Jung | Shie, Dung-Ting | Liu, Jen-Tsai

Article Type: Research Article

Abstract: The piezoelectric biosensor have been widely used in ultra-small mass detection of biomolecular, based on PZT piezoelectric material can create a variety of compositions geometrically; it could widely develop a high-frequency resonator and measure the change of the slightest mass while improve the limited detection simultaneously. Therefore, the piezoelectric biosensor of this study was fabricated by a spin-coating method and backside etching process for improving the characteristic of piezoelectric biosensor. The result exhibited that the 250 μm × 250 μm working size has the most favorable piezoelectric characteristic. The tunability was approximately 38.56 % and it showed that reducing the …substrate thickness could obtain a clear resonance signal in a range of 60 to 380 MHz. In theory calculated for gravimetric sensing, it could achieve 0.1 ng sensing sensitivity. In gravimetric sensing, the sensing range was between 50,000~100,000 CFU/ml. Sensing range was lower in clinical urinary tract infection (100,000 CFU/ml), thus demonstrating its usefulness for preventive medicine. It can understand the piezoelectric sensor of this study has potential application in the future for biomedical gravimetric sensing. Show more

Keywords: Lead zirconate titanate (PZT), piezoelectric, biosensor, resonance-frequency, escherichia coli (E. coli)

DOI: 10.3233/BME-141186

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3597-3604, 2014

Authors: Xu, Lisheng | Yao, Yang | Wang, Hao | He, Dianning | Wang, Lu | Jiang, Yongsheng

Article Type: Research Article

Abstract: Pulse wave contains much information on a cardiovascular system. Pulse wave variability during exercise is of great significance as it reflects more information combining with pulse wave under stationary state. This paper studied the morphology variability of radial pulse wave during exercise. Radial pulse waves were collected from 30 subjects with two pressure pulse sensors worn at the wrists of the right and left hands, respectively. Electrocardiography (ECG) was also detected synchronously. After data preprocessing and feature point extraction, the variability of several parameters of pulse wave and ECG were analyzed. It is notable that pulse rate (PR) and heart …rate (HR) change synchronously. During the exercise period, both systolic phase and diastolic phase of a radial pulse shorten but the latter is more obvious. The amplitude of the dicrotic notch decreases and even turns negative. Aligning the radial pulse waveforms together, the radial pulse waveforms prior to, during and after exercise coincide with each other except for some details like the tidal wave which fades away during exercise. Show more

Keywords: Pulse morphology, exercise, radial pulse wave

DOI: 10.3233/BME-141187

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3605-3611, 2014

Authors: Yoo, Ji Won | Lee, Dong Ryul | Sim, Yon Ju | You, Joshua H. | Kim, Cheol J.

Article Type: Research Article

Abstract: Sensorimotor control dysfunction or dyskinesia is a hallmark of neuromuscular impairment in children with cerebral palsy (CP), and is often implicated in reaching and grasping deficiencies due to a neuromuscular imbalance between the triceps and biceps. To mitigate such muscle imbalances, an innovative electromyography (EMG)-virtual reality (VR) biofeedback system were designed to provide accurate information about muscle activation and motivation. However, the clinical efficacy of this approach has not yet been determined in children with CP. The purpose of this study was to investigate the effectiveness of a combined EMG biofeedback and VR (EMG-VR biofeedback) intervention system to improve muscle …imbalance between triceps and biceps during reaching movements in children with spastic CP. Raw EMG signals were recorded at a sampling rate of 1,000 Hz, band-pass filtered between 20–450 Hz, and notch-filtered at 60 Hz during elbow flexion and extension movements. EMG data were then processed using MyoResearch Master Edition 1.08 XP software. All participants underwent both interventions consisting of the EMG-VR biofeedback combination and EMG biofeedback alone. EMG analysis resulted in improved muscle activation in the underactive triceps while decreasing overactive or hypertonic biceps in the EMG-VR biofeedback compared with EMG biofeedback. The muscle imbalance ratio between the triceps and biceps was consistently improved. The present study is the first clinical trial to provide evidence for the additive benefits of VR intervention for enhancing the upper limb function of children with spastic CP. Show more

Keywords: Virtual reality, EMG visual feedback, neuromotor control, muscle imbalance, cerebral palsy

DOI: 10.3233/BME-141188

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3613-3618, 2014

Authors: Chung, Soon-Cheol | Choi, Mi-Hyun | Park, Sung-Jun | Lee, Jung-Chul | Jeong, Ul-Ho | Baek, Ji-Hye | You, Ji-Hye | Choi, Young Chil | Lim, Dae-Woon | Yi, Jeong-Han | Kim, Hyung-Sik

Article Type: Research Article

Abstract: In this study, a tactile stimulator that could separately or simultaneously display the vibrotactile and pressure sense was developed. The developed system consisted of a control unit, a drive unit, and an actuator, and can be operated with PC or manually. This system quantitatively controls the stimulation parameters such as the stimulation intensity, duration, frequency, and stimulation type. A preliminary electroencephalogram (EEG) experiment for three types of stimulation (vibrotactile, pressure sense, vibrotactile + pressure sense) highlights that the system could be used in complex tactile cognitive studies. An event-related desynchronization (ERD) and synchronization (ERS) were measured at the area of …C3 and C4 for all three types of stimulation, and a clear response was identified in the contralateral somatosensory area from the brain topology. Therefore, it is expected that this system could be widely used in single and complex human tactile cognition and perception studies for vibrotactile and pressure sensation. Show more

Keywords: Tactile stimulator, vibration, pressure, simultaneous stimulation, electroencephalogram

DOI: 10.3233/BME-141189

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3619-3627, 2014

Authors: Zhang, Cheng | Zhang, Guanghao | Rong, Wei | Wang, Aihua | Wu, Changzhe | Huo, Xiaolin

Article Type: Research Article

Abstract: Demyelination is part of the cascading secondary injury after the primary insult and contributes to the loss of function after spinal cord injury (SCI). Oligodendrocyte precursor cells (OPCs) are the main remyelinating cells in the central nervous system (CNS). We explored whether oscillating field stimulation (OFS) could efficiently promote OPC differentiation and improve remyelination after SCI. SD rats with SCI induced by the Allen method were randomly divided into two groups, the SCI+OFS group and SCI group. The former group received active stimulator units and the latter group received sham (inoperative) stimulator units. Additionally, rats that only received laminectomy were …referred as the sham group. The electric field intensity was 600μV/mm, and the polarity was alternated every 15 minutes. The results showed that the SCI+OFS rats had significantly less demyelination and better locomotor function recovery after 12-weeks treatment. The OFS treatment significantly increased the number of Gal C-positive OPCs after 2-weeks treatment. Furthermore, these rats had higher protein expression of oligodendroglial transcription factors Olig2 and NKx2.2. These findings suggest OFS can promote locomotor recovery and remyelination in SCI rats and this effect may be related to the improved differentiation of OPCs in the spinal cord. Show more

Keywords: Oligodendrocyte precursor cells, remyelination, oscillating field stimulation, spinal cord injury, rat

DOI: 10.3233/BME-141190

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3629-3636, 2014

Authors: Xiong, Shi | Cheng, Chen | Wu, Xia | Guo, Xiaojuan | Yao, Li | Zhang, Jiacai

Article Type: Research Article

Abstract: Recent studies have shown that working memory (WM) performance can be improved by intensive and adaptive computerized training. Here, we explored the WM training effect using Electroencephalography (EEG) neurofeedback (NF) in normal young adults. In the first study, we identified the EEG features related to WM in normal young adults. The receiver operating characteristic (ROC) curve showed that the power ratio of the theta-to-alpha rhythms in the anterior-parietal region, accurately classified a high percentage of the EEG trials recorded during WM and fixation control (FC) tasks. Based on these results, a second study aimed to assess the training effects of …the theta-to-alpha ratio and tested the hypothesis that up-regulating the power ratio can improve working memory behavior. Our results demonstrated that these normal young adults succeeded in improving their WM performance with EEG NF, and the pre- and post-test evaluations also indicated that WM performance increase in experimental group was significantly greater than control groups. In summary, our findings provided preliminarily evidence that WM performance can be improved through learned regulation of the EEG power ratio using EEG NF. Show more

Keywords: Electroencephalography, neurofeedback, working memory, power spectrum, self-regulation

DOI: 10.3233/BME-141191

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3637-3644, 2014

Authors: Su, Jing | Zhu, Wenting | Liu, Jing | Yin, Jian | Qin, Wei | Jiang, Changbin

Article Type: Research Article

Abstract: The aim of the present study was to research the role of nitric oxide (NO) as a mediator of alpha (α)-asarone effect at the pentylenetetrazol (PTZ)-induced epileptiform discharge in rat. α-Asarone that was injected intraperitoneally twenty minutes before PTZ injection suppressed the clonic discharge effectively and the significant actions lasted for 30 min with no change of clonic amplitude. Administration of α-asarone did not influence interictal discharge. Four kinds of NO regulators were administered, including non-selective NG-nitro-L-arginine methyl ester (L-NAME), selective neuronal nitric oxide synthase (nNOS) inhibitor, 7-nitroindazole (7-NI), inducible nitric oxide synthase (iNOS) inhibitor, aminoguanidine (AG) and NO substrate, …L-arginine (ARG) and their influence on the actions of α-asarone were studied, and all of the regulators were administered fifteen minutes before α-asarone injection. L-NAME and 7-NI reversed the anticlonic activity of α-asarone, and a significant increase of clonic activity was induced by L-NAME later in L-NAME + .α-asarone + PTZ group. There were no significant differences between AG + α-asarone + PTZ and α-asarone + PTZ group. L-ARG played a dual role in this study. It aggravated clonic discharge in the early stage but relieved interictal discharge in the late stage compared with PTZ group alone, and the beneficial effect of α-asarone was also reversed. All the above results suggest that nNOS/NO pathway mediates the anticonvulsant effect of α-asarone, and NO played a biphasic role in PTZ modeling process, while iNOS was unrelated to the inhibition effect of α-asarone on PTZ induced epileptiform activity. Show more

Keywords: Alpha-asarone, epileptiform activity, nitric oxide synthase, pentylenetetrazol

DOI: 10.3233/BME-141192

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3645-3655, 2014

Authors: Zhang, Guanghao | Huo, Xiaolin | Wu, Changzhe | Zhang, Cheng | Duan, Zhongping

Article Type: Research Article

Abstract: Bioelectrical impedance phase angle has been recommended as a tool to assess nutrition state, but there are no measuring devices have been specially designed for hospital residents. In this study, a system was established for the measurement of bioelectrical impedance phase angle. The electrical composition, calculation method and measuring method of this system are presented in this paper. Experiments showed excellent performance of this system in measuring impedance made of resistors and capacitors. The designed system was also used to measure the bioelectrical impedance phase angle of both healthy subjects and patients with malnutrition, and the results demonstrated that the …phase angle of patients with malnutrition is lower than that of healthy subjects (P < 0.01 for male and P < 0.05 for female). These results suggest that phase angle has the potential to be a useful tool for the quantitative assessment of nutritional status. Show more

Keywords: Phase angle, bioelectrical impedance, nutritional status

DOI: 10.3233/BME-141193

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3657-3664, 2014

Authors: Yang, Banghua | Han, Zhijun | Zan, Peng | Wang, Qian

Article Type: Research Article

Abstract: Classification methods are a crucial direction in the current study of brain-computer interfaces (BCIs). To improve the classification accuracy for electroencephalogram (EEG) signals, a novel KF-PP-SVM (kernel fisher, posterior probability, and support vector machine) classification method is developed. Its detailed process entails the use of common spatial patterns to obtain features, based on which the within-class scatter is calculated. Then the scatter is added into the kernel function of a radial basis function to construct a new kernel function. This new kernel is integrated into the SVM to obtain a new classification model. Finally, the output of SVM is calculated …based on posterior probability and the final recognition result is obtained. To evaluate the effectiveness of the proposed KF-PP-SVM method, EEG data collected from laboratory are processed with four different classification schemes (KF-PP-SVM, KF-SVM, PP-SVM, and SVM). The results showed that the overall average improvements arising from the use of the KF-PP-SVM scheme as opposed to KF-SVM, PP-SVM and SVM schemes are 2.49%, 5.83 % and 6.49 % respectively. Show more

Keywords: Kernel fisher, posterior probability, support vector machine, brain computer interface, common spatial pattern

DOI: 10.3233/BME-141194

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3665-3673, 2014

Authors: Chen, Xiaoyan | Lv, Xinqiang | Du, Meng

Article Type: Research Article

Abstract: The electrode polarization effects on bioelectrical impedance measurement at low-frequency cannot be ignored. In this paper, the bioelectrical data of mice livers are measured to specify the polarization effects on the bio-impedance measurement data. We firstly introduce the measurement system and methodology. Using the depolarization method, the corrected results are obtained. Besides, the specific effects of electrode polarization on bio-impedance measurement results are investigated using comparative analysis of the previous and posterior correction results from dielectric spectroscopy, Cole-Cole plot, conductivity and spectroscopy of dissipation tangent. Experimental results show that electrode polarization has a significant influence on the characteristic parameters of …mouse liver tissues. To be specific, we see a low-frequency limit resistance R0 increase by 19.29%, a reactance peak XP increase by 8.50%, a low-frequency limit conductivity Kl decrease by 17.65% and a dissipation peak tangent decrease by 160%. Show more

Keywords: Electrode polarization, depolarization correction, impedance measurement, low-frequency

DOI: 10.3233/BME-141195

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3675-3683, 2014

Authors: Woo, Seong Tak | Lee, Gihyoun | Jung, Eui Sung | Lim, Hyung-Gyu | Seong, Ki Woong | Lee, Jyung Hyun | Kim, Myoung Nam | Cho, Jin-Ho

Article Type: Research Article

Abstract: The microphone in a fully implantable hearing device (FIHD) is generally implanted under the skin covering the temporal bone. However, the implanted microphone can be affected by the skin, which causes both sound attenuation and distortion, particularly at high frequencies. As the degree of attenuation and distortion through the skin is severe, speech quality evaluation parameters are needed for the received signal when designing an implantable microphone. However, the performance of most implantable microphones is only assessed based on the sensitivity and frequency response. Thus, practical indicators based on human auditory characteristics are needed for an objective evaluation of the …performance of implantable microphones. In this study, a subcutaneously implantable microphone was designed, and its frequency response investigated using an in vivo experiment. Plus, to evaluate the objective indicators, the speech quality of the signals measured by the implanted microphone was calculated using a MATLAB program, and the indicators compared before and after implantation. Show more

Keywords: Implantable microphone, in vivo experiment, speech quality score, fully implantable hearing devices

DOI: 10.3233/BME-141196

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3685-3691, 2014

Authors: Wang, Aihua | Zhang, Guanghao | Zhang, Cheng | Wu, Changzhe | Song, Tao | Huo, Xiaolin

Article Type: Research Article

Abstract: Injury potential, a significant index of spinal cord injury (SCI), is generated by the movement of extracellular ions. It can be compensated through applied direct current (DC) stimulation, which prevents the influx of the free calcium, and eventually reduces the development of secondary injury. Therefore, the compensation of injury potential is beneficial to the repairing of the function of spinal cord. The compensation effect can be evaluated by whether the magnitudes of longitudinal electric fields (EFs) are compensated to zero. However, there have been no established criteria to determine the distribution and shape of stimulating electrodes. In this study, in …order to optimize the stimulating electrodes, a finite element model (FEM) of rat spinal cord was developed, and the EFs changes induced by electrodes of different sizes, shapes and locations after SCI were calculated. All the designed configurations of electrodes were able to compensate injury potential, but the resultant compensation effects vary. Pin and disc electrodes produced uneven EFs, while ring electrodes produced uniformly distributed EFs. Moreover, large ring electrodes can compensate the longitudinal EFs almost to zero with relatively low current density (0.55 μA/mm2 ) applied. These results provide a basis for the determination of electrical stimulation parameters in the compensation of injury potential. Show more

Keywords: Direct current stimulation, finite element model, spinal cord injury, electric fields

DOI: 10.3233/BME-141197

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3693-3700, 2014

Authors: Kim, Jungyoon | Son, Jongsang | Kim, Youngho

Article Type: Research Article

Abstract: In this study, the bandwidth of the filter-based fatigue index was determined by the comparison of optimized cut-off frequencies in different inter-electrode distances. Sixty-one subjects participated in isometric knee extension, isotonic ankle dorsiflexion, and isotonic elbow extension exercises. Electromyography (EMG) signals were obtained from right rectus femoris, triceps brachii, and tibialis anterior muscles during exercises. The filter-based fatigue index was compared with mean root-mean-square values, median frequency, Dimitrov spectral index, and Gonzalez-Izal wavelet index. Optimized cut-off frequencies of the high-pass filter for three different exercises and three different inter-electrode distances were about 350 Hz. Results from this study support that …around 350 Hz high-pass filter could be useful to determine cut-off frequency for fatigue prediction in general purposes. Show more

Keywords: Electromyography, fatigue, filter, bandwidth optimization, inter-electrode distance

DOI: 10.3233/BME-141198

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3701-3708, 2014

Authors: Yi, Hui | Bo, Cuimei | Song, Xiaofeng | Yuan, Yuhao

Article Type: Research Article

Abstract: Clustering is considered one of the most powerful tools for analyzing gene expression data. Although clustering has been extensively studied, a problem remains significant: iterative techniques like k-means clustering are especially sensitive to initial starting conditions. An unreasonable selection of initial points leads to problems including local minima and massive computation. In this paper, a spatial contiguity analysis-based approach is proposed, aiming to solve this problem. It employs principal component analysis (PCA) to identify data points that are likely extracted from different clusters as initial points. This helps to avoid local minima, and accelerates the computation. The effectiveness of the …proposed approach was validated on several benchmark datasets. Show more

Keywords: Gene expression data, k-means, initial points, spatial contiguity analysis

DOI: 10.3233/BME-141199

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3709-3717, 2014

Authors: Zou, Qingyu | Liu, Fu | Hou, Tao | Jiang, Yihan | Mo, Reifeng

Article Type: Research Article

Abstract: The transcriptional regulation of cellular functions is carried out by the overlapping functional modules of a complex network. In this paper, a statistical approach for detecting functional modules in the transcriptional regulatory networks (TRNs) is studied. The proposed method defines modules as groups of links rather than nodes since nodes naturally belong to more than one module. Furthermore, the proposed algorithm is evaluated on the Escherichia coli TRN. The experimental results demonstrate that it detected a suitable number of overlapping modules that were biologically meaningful without any prior knowledge about the modules.

Keywords: Transcriptional regulation, network, functional module

DOI: 10.3233/BME-141200

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3719-3727, 2014

Authors: Cui, Haibo | Wei, Xiaomei | Huang, Yu | Hu, Bin | Fang, Yaping | Wang, Jia

Article Type: Research Article

Abstract: Among human influenza viruses, strain A/H3N2 accounts for over a quarter of a million deaths annually. Antigenic variants of these viruses often render current vaccinations ineffective and lead to repeated infections. In this study, a computational model was developed to predict antigenic variants of the A/H3N2 strain. First, 18 critical antigenic amino acids in the hemagglutinin (HA) protein were recognized using a scoring method combining phi (ϕ) coefficient and information entropy. Next, a prediction model was developed by integrating multiple linear regression method with eight types of physicochemical changes in critical amino acid positions. When compared to other three known …models, our prediction model achieved the best performance not only on the training dataset but also on the commonly-used testing dataset composed of 31878 antigenic relationships of the H3N2 influenza virus. Show more

Keywords: Influenza A virus, H3N2, antigenic variant, multiple linear regression, physicochemical properties

DOI: 10.3233/BME-141201

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3729-3735, 2014

Authors: Lee, Min Su | Oh, Sangyoon | Tang, Haixu

Article Type: Research Article

Abstract: Microorganisms interact with each other within a community. Within the same community, some microorganisms tend to co-exist, whereas some others tend to avoid each other. The association among microorganisms can be revealed by computing the correlation between their abundance patterns that are measured through metagenomic sequencing across multiple communities. In this paper, we built an association network among microorganisms from the human oral microbiome. To improve its accuracy, we adopted a network deconvolution algorithm to filter out indirect associations, and we used an ensemble of three correlation measures to filter out the false-positive associations. When applying on the metagenomic data …from human oral samples, experimental results showed that phylogenetically close microorganisms formed highly correlated network clusters. Additionally, most of the identified mutually exclusive associations were related to the order Lactobacillales. Show more

Keywords: Association network, correlation, microbiome, network deconvolution

DOI: 10.3233/BME-141202

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3737-3744, 2014

Authors: Zhang, Wen | Wang, Chenyin | Tam, Kin Y.

Article Type: Research Article

Abstract: The objective of this study is to evaluate whether the accumulation model developed by Zarfl et al. (2008) could be used to predict the minimal inhibitory concentration (MIC) of a group of antibacterial fluoroquinolones (FQs) for Escherichia coli (E. coli). Our model, which is based on the “Fick-Nernst-Planck” equation and the permeability of the neutral and charged species as well as the physicochemical parameters of the FQs, could predict 1/MIC9 0 using a linear function. It is envisaged that in the drug development projects of new FQs, the accumulation model described in this study could be utilized as an effective …tool to enable early assessment of MIC value using physiochemical parameters. Show more

Keywords: Fluoroquinolones, minimal inhibitory concentration, Escherichia coli, physicochemical parameters

DOI: 10.3233/BME-141203

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3745-3751, 2014

Authors: Wu, Jingli | Chen, Xixi | Li, Xianchen

Article Type: Research Article

Abstract: The minimum error correction model is an important combinatorial model for haplotyping a single individual. In this article, triploid individual haplotype reconstruction problem is studied by using the model. A genetic algorithm based method GTIHR is presented for reconstructing the triploid individual haplotype. A novel coding method and an effectual hill-climbing operator are introduced for the GTIHR algorithm. This relatively short chromosome code can lead to a smaller solution space, which plays a positive role in speeding up the convergence process. The hill-climbing operator ensures algorithm GTIHR converge at a good solution quickly, and prevents premature convergence simultaneously. The experimental …results prove that algorithm GTIHR can be implemented efficiently, and can get higher reconstruction rate than previous algorithms. Show more

Keywords: Triploid, haplotype, Single nucleotide polymorphism (SNP), the minimum error correction, genetic algorithm

DOI: 10.3233/BME-141204

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3753-3762, 2014

Authors: Lu, Yaosheng | Li, Xiaodong | Wei, Shouyi | Liu, Xiaolei

Article Type: Research Article

Abstract: In order to assign appropriate baseline estimation algorithms to different fetal heart rate tracing, a method to evaluate the fetal heart rate (FHR) baseline combining with the fetal movement information was proposed. Fetal actography and tocography were used to extract the fetal movement information. The results showed that the combined method, where the fetal movement detection result was the union of results of actography and tocography, achieved a better performance with the highest sensitivity and an acceptable positive predictive value (PPV). Furthermore, the mean absolute errors (MAEs) of basal FHR values between the two algorithms and the expert were calculated …with respect to the duration coefficient of fetal movement. The results showed that the algorithm using empirical mode decomposition (EMD) and Kohonen neural network (KNN) had lower MAEs than a traditional linear baseline estimation algorithm as the duration coefficient increased. However, if the duration coefficient is below 0.2, the errors may be tolerant for the FHR baseline estimation by a linear baseline estimation algorithm, which indicates that different algorithms may be selected for FHR baseline estimation based on different duration coefficients of fetal movement. Show more

Keywords: Fetal heart rate, baseline estimation, fetal movement, Ostu method

DOI: 10.3233/BME-141205

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3763-3769, 2014

Authors: Sun, Xin | Dong, Junyu | Xu, Mantao | Wang, Shengke | Xie, Cui

Article Type: Research Article

Abstract: Microarray technologies offer practical diagnostic tools for cancer detection. One great challenge is to identify salient genes from the high dimensionality of microarray data that can directly contribute to the symptom of cancer. Interactions among genes have been recognized to be fundamentally important for understanding biological function. This paper proposes an interacting gene selection method for cancer classification by identifying useful interacting genes. The method firstly evaluates the interactivity degree of each gene according to the intricate interrelation among genes by cooperative game analysis. Then genes are selected in a forward way by considering both interactivity and relevance characters. Experimental …comparisons are carried out on four publicly available microarray data sets with three outstanding gene selection methods. Moreover a gene set enrichment analysis is also performed on the selected gene subset. The results show that the proposed method achieves better classification performance and enrichment score than other gene selection methods. Show more

Keywords: Medical diagnosis, cancer classification, gene selection, information theory, cooperative game analysis

DOI: 10.3233/BME-141206

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3771-3778, 2014

Authors: Wu, Xiaohui | Zhao, Chuang | Su, Yaru

Article Type: Research Article

Abstract: Polyadenylation [poly(A)] of mRNA is a critical step during gene expression, which plays an important role in the termination of transcription. Prediction of poly(A) sites can help identify 3' ends of genes and improve genome annotation. Due to the limited knowledge of poly(A) signals in plants, predictive modeling of poly(A) sites in agricultural crops remains challenging. Recent studies have uncovered widespread occurrences of alternative poly(A) (APA) sites in intron and coding sequence (CDS), whereas the study on the prediction of these APA sites is scarce. In this study, four feature representation methods, involving a position weight matrix, the k-gram frequency, …core hexamers, and a transition matrix, were adopted to characterize poly(A) signals surrounding APA sites. The classification model was built to predict each group of APA sites. Experimental results showed that this model was effective in the identification of APA sites located in different genomic regions, with a compromise between sensitivity and specificity higher than 87%. Compared with previous model PASS rice, accuracies for the prediction of APA sites in 3'-UTR, intron and CDS were enhanced by 5%, 7%, and 27%, respectively. This model will contribute to genetic engineering by enabling researchers to control poly(A) site selection. Show more

Keywords: Rice, polyadenylation, alternative polyadenylation, prediction, classification model

DOI: 10.3233/BME-141207

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3779-3785, 2014

Authors: Wang, Gongming | Xu, Fan

Article Type: Research Article

Abstract: The output of icosahedral symmetry-adapted functions (ISAF) reconstruction algorithm is a virus capsid, where the density function of every outside point is theoretically zero. However, original ISAF algorithm takes reconstructed map as a solid sphere and density function of every point in the whole sphere is calculated. The density functions outside virus capsid may not be always zero, which may sometimes produce noise. In this study, Fourier shell correlation (FSC) is used for proving that density function calculation of original ISAF algorithm can reduce reconstruction precision. Subsequently, the range of virus capsid is determined with radial density function curve and …the original ISAF algorithm is improved by calculating density function inside virus capsid. The experimental results on Cryo-electron microscopy (Cryo-EM) data of cytoplasmic polyhedrosis virus (CPV) indicate that the improved ISAF algorithm can generate more details of virus capsid and achieve a higher resolution. Show more

Keywords: Single-particle reconstruction, icosahedral symmetry-adapted functions, virus capsid, density function, Fourier shell correlation

DOI: 10.3233/BME-141208

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3787-3795, 2014

Authors: Bao, Wenzheng | Chen, Yuehui | Wang, Dong

Article Type: Research Article

Abstract: Prediction of protein structural classes is of great significance to better understand protein folding patterns. An array of methods has been proposed to predict these structures based on sequences. However, the accuracy is strongly affected by the homology of sequences. In the present study, the features based on correlation coefficient of sequence and amino acid composition are extracted. Flexible neutral tree is employed as the classification model. To examine the performance of this method, four benchmark datasets are selected. Altogether, the results show that a higher prediction accuracy of alpha/beta can be achieved by the method compared to others.

Keywords: Protein structural classification, flexible neural tree, correlation coefficient

DOI: 10.3233/BME-141209

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3797-3806, 2014

Authors: Lee, Nung Kion | Fong, Pui Kwan | Abdullah, Mohd Tajuddin

Article Type: Research Article

Abstract: Using Genetic Algorithm, this paper presents a modelling method to generate novel logical-based features from DNA sequences enriched with H3K4mel histone signatures. Current histone signature is mostly represented using k-mers content features incapable of representing all the possible complex interactions of various DNA segments. The main contributions are, among others: (a) demonstrating that there are complex interactions among sequence segments in the histone regions; (b) developing a parse tree representation of the logical complex features. The proposed novel feature is compared to the k-mers content features using datasets from the mouse (mm9) genome. Evaluation results show that the new feature …improves the prediction performance as shown by f-measure for all datasets tested. Also, it is discovered that tree-based features generated from a single chromosome can be generalized to predict histone marks in other chromosomes not used in the training. These findings have a great impact on feature design considerations for histone signatures as well as other classifier design features. Show more

Keywords: Genetic algorithm, tree-based feature, histone feature

DOI: 10.3233/BME-141210

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3807-3814, 2014

Authors: Zheng, Shichao | Ren, Zhenzhen | Zhang, Yanling | Qiao, Yanjiang

Article Type: Research Article

Abstract: Tanshinone IIA (Tan IIA) is one of the major fat-soluble ingredients in Salvia miltiorrhiza which has been widely used for various inflammatory conditions associated with cardiovascular and cerebrovascular disorders. However, the underlying anti-inflammatory mechanisms of Tan IIA are incompletely understood. The purpose of this study was to illuminate the anti-inflammatory mechanism of Tan IIA based on the protein interaction network (PIN) analysis. A PIN of Tan IIA was constructed with 281 nodes and 814 interactions and analyzed by gene ontology (GO) enrichment analysis based on Markov Cluster algorithm (MCL). Three modules were associated with anti-inflammatory actions. The most interesting finding …of this study was that the anti-inflammatory effect of Tan IIA may be partly attributable to the mediate activation of TRAF2, TRAF3 and TRAF6, to inhibit the toll-like receptor signaling pathway and combine with AGER. Therefore, the module-based network analysis approach will be a new method for better understanding the anti-inflammatory mechanism of Tan IIA. Show more

Keywords: Protein interaction network, module, anti-inflammatory actions, Tanshinone IIA, GO enrichment analysis

DOI: 10.3233/BME-141211

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3815-3824, 2014

Authors: Fernández-Granero, M.A. | Sánchez-Morillo, D. | León-Jiménez, A. | Crespo, L.F.

Article Type: Research Article

Abstract: Chronic Obstructive Pulmonary Disease (COPD) is a progressive disease of the lung with a great prevalence and a remarkable socio-economic impact on patients and health systems. Early detection of exacerbations could diminish the adverse effects on patients' health and cut down costs burdened on patients with COPD. A group of 16 patients were telemonitored at home using a novel electronic daily symptoms questionnaire during a 6-months field trial. Recorded data were used to train and validate a Probabilistic Neural Network (PNN) classifier in order to enable the automatic prediction of exacerbations. The proposed system was able to predict COPD exacerbations …early with a margin of 4.8±1.8 days (average ± SD). Detection accuracy was 80.5% (33 out of 41 exacerbations were early detected); 78.8% (26 out of 33) of theses detected events were reported exacerbation and 87.5% (7 out of 8) were unreported episodes. The proposed questionnaire and the designed automatic classifier could support the early detection of COPD exacerbations of benefit to both physicians and patients. Show more

Keywords: Chronic Obstructive Pulmonary Disease, exacerbation, telehealth, symptoms, questionnaire, early detection, Probabilistic Neural Network, telemonitoring

DOI: 10.3233/BME-141212

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3825-3832, 2014

Authors: Wang, Yong-Tang | Lu, Xiu-Min | Shu, Ya-Hai | Xiao, Lan | Chen, Kai-Ting

Article Type: Research Article

Abstract: To select tag single nucleotide polymorphisms (SNPs) within and around human p75 neurotrophin receptor (p75NTR) gene in Chinese Han population, the sequence involving p75NTR gene as well as the upstream and downstream of the gene was identified according to the data from National Center for Biotechnology Information (NCBI) GenBank database, and the SNP genotype data involving 63 SNPs in the regions were obtained from Chinese Han Beijing (CHB) population of HapMap database. Then, Haploview (version 4.2) was used to calculate linkage disequilibrium (LD) statistics for the selected 32 common SNPs with a minor allele frequence (MAF) more than 0.05. Haplotype …blocks were constructed throughout the p75NTR gene according to the upper and the lower 95% confidence bound of D' value, and the tag SNPs were selected based on the r2 and LOD values between SNPs as well as the results of bioinformatics analysis. The results indicated that five haplotype blocks were constructed within and around p75NTR gene and 12 tag SNPs including rs2537710, rs603769, rs614455, rs2537706, rs534561, rs2072445, rs2072446, rs7219709, rs734194, rs741071, rs741073 and rs2671641 were selected to represent the other 51 SNPs in p75NTR gene. Therefore, the 12 selected SNPs may act as tag SNPs for the entire p75NTR gene in Chinese Han population, which will provide an effective way to select tag SNPs in a whole gene, and its biological significance is to further guide the clinical association studies between the candidate gene and disease susceptibility. Show more

Keywords: p75NTR, haplotype block, tag SNP, haplotype, bioinformatics analysis

DOI: 10.3233/BME-141213

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3833-3839, 2014

Authors: Zhang, Jinping | Zhang, Leijia | Liu, Xuehong | Zhou, Fuqun

Article Type: Research Article

Abstract: To study the expression and roles of Connexin43 (Cx43) and Paired-box3 (Pax3) proteins in the human Chorionic villi and decidua during early pregnancy, Cx43 and Pax3 protein expression in the human placental villi and decidua at 5–7 weeks of early pregnancy was studied by immunohistochemistry (SABC). Integrated optical density (IOD) of Cx43 and Pax3 protein expression was obtained by using special image analysis software. Cx43 and Pax3 proteins were expressed in all trophoblastic cells, cells of villi central axis and decidual cells. IOD of Cx43 and Pax3 proteins expressed in the syncytiotrophoblast decreased from 5 to 7 weeks, while Cx43 …and Pax3 expressed in cytotrophoblast cells and decidual cells showed increased IOD during the same period. The differences between any two groups were statistically significant (P<0.05). Cx43 and Pax3 proteins were expressed during differentiation and development of placental villous cells in early phases of pregnancy. We propose that Cx43 and Pax3 may participate in endometrial decidualization and the regulation of trophoblastic invasion and differentiation. It is likely that Cx43 and Pax3 play critical roles in cell proliferation and differentiation during the processes of chorionic villi initiation/development and placental morphogenesis. Show more

Keywords: Connexin43, pax3, Chorionic villi, decidua, Immunohistochemistry

DOI: 10.3233/BME-141214

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3841-3847, 2014

Authors: Wang, Chenyin | Avdeef, Alex | Zhang, Wen | Tam, Kin Y.

Article Type: Research Article

Abstract: The purpose of this study is to predict human jejunal permeability (Peff ) and fraction absorbed in human (%Fa) for a group of antibacterial fluoroquinolones (FQs), by using a biophysical model based on measured Caco-2 permeability. The predicted Peff (in 10−4 cm·s−1 units) ranged from 0.7 (norfloxacin) to 4.5 (pefloxacin). The calculated %Fa for norfloxacin = 51% (lit. 35%) and for ciprofloxacin = 76% (lit. 81%). Most of the FQs showed calculated %Fa >90%, and are expected to be well-absorbed. Estimates of Peff can be predicted by the biophysical model. From these values, the human absorption may …be calculated. Where absorption comparisons were possible, the agreement was acceptably good. Show more

Keywords: permeability, fraction absorbed, fluoroquinolones, human intestine, Caco-2

DOI: 10.3233/BME-141215

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3849-3854, 2014

Authors: Xue, Dan | Na, Ri | Guo, Jiu Feng | Liu, Teng

Article Type: Research Article

Abstract: With a goal of obtaining the engineering probiotics that can produce both lactic acid and laccase, Pleurotus eryngii was selected as the test material. First, the laccase gene (Lacc1) was cloned by using RT-PCR (the length of which is 1596bp), and then, the gene was ligated to the food-grade vector pMG36e from Lactobacillus buchneri. The recombinant expression vector pMG36e-Lacc1 was constructed by transforming it into Lactobacillus buchneri via an electroporation method. The recombinant plasmid was constructed successfully as confirmed by gel electrophoresis. Then, the optimum conditions for electroporation were determined. The research revealed that when the electric field intensity is …1.75 kV with an SMRS medium recovery for 1.5 h, the electroporation translation efficiency reaches its maximum level. Show more

Keywords: Laccase, Lactobacillus buchneri, expression vector system

DOI: 10.3233/BME-141216

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3855-3861, 2014