Bio-Medical Materials and Engineering - Volume 24, issue 1

Authors: Chiang, Chih-Yen | Hsu, Steen J. | Chan, Chia-Tai

Article Type: Research Article

Abstract: The design of elaborate healthcare services is becoming increasingly difficult in today's nursing home. In this work, we develop a model that simulates the nursing home residents' behavior to assist the facility planners in making fair and feasible management. Since a series of activities constituted one behavior, every activity is performed in a time interval and then starts next activity consequently. Whether the resident's activity posed at any particular state, its future behavior is always having the same occurrence probability regardless of how it positioned in that state. This simulation model used exponential distribution to produce the stochastic activity interval …for each activity. The activity transitions can be formalized through a randomized probability with respect to each activity frequency (AF). In the simulation model, the characteristics of nursing home residents' activities can be generated to simulate a large scaled resident's behavior and aid the facility managers in providing higher quality of healthcare services. Show more

Keywords: Simulation Model, Nursing Home, Residents' Behavior, Healthcare Services

DOI: 10.3233/BME-130785

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 69-75, 2014

Authors: Yang, Zhaochu | Dong, Tao | Halvorsen, Einar

Article Type: Research Article

Abstract: This work describes a capacitive sensor for identification of microfluidic two-phase flow in lab-on-chip devices. With interdigital electrodes and thin insulation layer utilized, this sensor is capable of being integrated with the microsystems easily. Transducing principle and design considerations are presented with respect to the microfluidic gas/liquid flow patterns. Numerical simulation results verify the operational principle. And the factors affecting the performance of the sensor are discussed. Besides, a feasible process flow for the fabrication is also proposed.

Keywords: microfluidic, flow patterns, two-phase flow, lab on a chip, interdigital electrode, microchannel

DOI: 10.3233/BME-130786

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 77-83, 2014

Authors: Zhang, Shu-xu | Zhou, Ling-hong | Lin, Sheng-qu | Yu, Hui | Zhang, Guo-quan | Wang, Rui-hao | Qi, Bing

Article Type: Research Article

Abstract: To date, commercial 4D-CT systems typically depend on an external respiratory monitoring device. Immobilizing patients in a thermoplastic mask while receiving radiotherapy may result in a failure of 4D-CT reconstruction. The aim of this study is to investigate the feasibility of 4D-CT reconstruction based on a method using pulmonary average CT values (ACV) without an external respiratory monitoring device. The ACV of the whole lung assumes cyclical variation during respiration. Phases of CT images were identified by calculating the ACV over time. Subsequently, five sets of 4D-CT images based on a Real-time Position Management (RPM) system were selected to verify …the ACV method. The entire lung CT datasets of another sixteen free-breathing patients were acquired in Cine scan mode for multiple couch positions. The phase of every CT image was identified and re-sorted into different phase 4D-CT volumes by analyzing the time dependence of the corresponding ACVs. This paper demonstrates the ACV method using the 4D-CT data sets based on the RPM system. Convenient and reliable 4D-CT reconstruction can be accomplished without any external respiratory monitoring device using ACVs. Show more

Keywords: 4D-CT, image reconstruction, average CT value, respiration phase

DOI: 10.3233/BME-130787

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 85-94, 2014

Authors: Kan, Yao-Chiang | Hsu, Cheng-Chih | Ho, Wen-Kai | Wu, Tsai-Chen | Ho, Yao-Yaun | Yang, Chia Yu

Article Type: Research Article

Abstract: In this paper, the poly-Si nanowire sensor was fabricated by top-down technique for sodium chloride concentration measurement. The results showed that the smallest threshold voltage and the best resolution were 1.65 V and 0.41 μM, respectively. Furthermore, the sensor can be reused more than 50 times which maintained acceptable performance and showed good linearity of the calibration within wide range of the concentration. Based on these results, it can be concluded that the proposed sensor has great potential to be used for measuring complicated sample with suitable modification on the surface of nanowires.

Keywords: NaCl concentration, poly-silicon nanowire, ion sensitive field-effect transistor

DOI: 10.3233/BME-130788

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 95-99, 2014

Authors: Gao, Hongzhi | Lu, Qipeng | Ding, Haiquan

Article Type: Research Article

Abstract: Subtracted blood volume spectrometry (SBVS) can eliminate the background information in near infrared spectroscopy (NIRS) noninvasive biochemical sensing. However, the spectrum obtained by this method is accompanied by serious noises which are to the disadvantage of the calibration models. Empirical mode decomposition (EMD) was applied to restrict the noises in order to improve the performance of subtracted blood volume spectrometry. Certain criteria were used to evaluate the performance of the method, such as the average correlation coefficient, and the average and standard deviation of the Euclidean distance. EMD was applied to three subtracted spectra with different ΔL, and the criteria …were calculated accordingly. All of the criteria were improvement. Especially for the subtracted spectra with ΔL=0.5mm, the correlation coefficient increased from 0.9970 to 0.9999, the average Euclidean distance decreased from 0.0265 to 0.0118, and the standard deviation of the Euclidean distance decreased from 0.0148 to 0.0033 after EMD filtering. The PLS models of the processed spectra were promoted as well. These preliminary results suggest that EMD is a promising means of improving the performance of subtracted blood volume spectrometry. Show more

Keywords: Near-infrared spectroscopy, noninvasive biochemical sensing, subtracted blood volume spectrometry, empirical mode decomposition

DOI: 10.3233/BME-130789

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 101-107, 2014

Authors: Wang, Fang | Ji, Zhong

Article Type: Research Article

Abstract: In biomedical signal processing, Gibbs oscillation and severe frequency aliasing may occur when using the traditional discrete wavelet transform (DWT). Herein, a new denoising algorithm based on the dual-tree complex wavelet transform (DTCWT) is presented. Electrocardiogram (ECG) signals and heart sound signals are denoised based on the DTCWT. The results prove that the DTCWT is efficient. The signal-to-noise ratio (SNR) and the mean square error (MSE) are used to compare the denoising effect. Results of the paired samples t-test show that the new method can remove noise more thoroughly and better retain the boundary and texture of the signal.

Keywords: discrete wavelet transform, dual-tree complex wavelet transform, signal-to-noise ratio, mean square error, paired samples t-test

DOI: 10.3233/BME-130790

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 109-115, 2014

Authors: Liu, Guangmao | Zhang, Yan | Chen, Haibo | Sun, Hansong | Zhou, Jianye | Hu, Shengshou

Article Type: Research Article

Abstract: The properties of blood flow in the outflow cannula of an axial blood pump play a critical role in potential thrombus formation and vascular injury. In this study, an in vitro flow visualization technique using particle image velocimetry (PIV) was applied to investigate the flow characteristics in the outflow cannula of a FW-2 model axial pump. The two-dimensional (2-D) flow field in the axial central section and the three-dimensional (3-D) flow field in the whole outflow cannula were examined with the PIV system. Tests were carried out with a blood-mimic working fluid in the axial pump at a rotational speed …of 8500±20 rpm with a flow rate of 5 L/min. The velocity distribution in the outflow cannula was analyzed to evaluate the flow characteristics. There was no backflow or stagnant flow in the tested area, while the flow velocity rapidly increased outside the boundary layer. A spiral flow was observed near the boundary layer, but this was worn off within the tested area. Based on the results, hemolysis and thrombus formation in the cannula, and injury to aortic endothelium are unlikely to occur due to spiral flow. Show more

Keywords: particle image velocimetry, axial blood pump, outflow cannula, thrombus formation

DOI: 10.3233/BME-130791

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 117-122, 2014

Authors: Yamamoto, Ikuo | Inagawa, Naohiro | Matsui, Miki | Hachisuka, Kenji | Wada, Futoshi | Hachisuka, Akiko

Article Type: Research Article

Abstract: Compact rehabilitation robot system which can support movement of the wrist of patients has been developed. The robot system can detect and analyze the patient's intention to move the wrist by such a biological signal as muscle potential, then, assist the wrist exercise of patients. Also, both-wrist rehabilitation robot system by mirror effect has been successfully developed for practical use in the hospital and at home.

Keywords: Compact rehabilitation robot, biological signal, mirror effect

DOI: 10.3233/BME-130792

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 123-128, 2014

Authors: Hu, Shan | Xu, Chao | Guan, WeiQiao | Tang, Yong | Liu, Yana

Article Type: Research Article

Abstract: Osteosarcoma is the most common malignant bone tumor among children and adolescents. In this study, image texture analysis was made to extract texture features from bone CR images to evaluate the recognition rate of osteosarcoma. To obtain the optimal set of features, Sym4 and Db4 wavelet transforms and gray-level co-occurrence matrices were applied to the image, with statistical methods being used to maximize the feature selection. To evaluate the performance of these methods, a support vector machine algorithm was used. The experimental results demonstrated that the Sym4 wavelet had a higher classification accuracy (93.44%) than the Db4 wavelet with respect …to osteosarcoma occurrence in the epiphysis, whereas the Db4 wavelet had a higher classification accuracy (96.25%) for osteosarcoma occurrence in the diaphysis. Results including accuracy, sensitivity, specificity and ROC curves obtained using the wavelets were all higher than those obtained using the features derived from the GLCM method. It is concluded that, a set of texture features can be extracted from the wavelets and used in computer-aided osteosarcoma diagnosis systems. In addition, this study also confirms that multi-resolution analysis is a useful tool for texture feature extraction during bone CR image processing. Show more

Keywords: Feature selection, gray-level co-occurrence matrix, osteosarcoma diagnosis, texture feature, wavelet transform

DOI: 10.3233/BME-130793

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 129-143, 2014

Authors: Yu, Hui | Zhang, Shu-xu | Wang, Rui-hao | Zhang, Guo-qian | Tan, Jian-ming

Article Type: Research Article

Abstract: Calculating an accurate cumulative dose through individual phases for four-dimensional computed tomography (4DCT) images from the lung is time-consuming. Although the dose distribution of different phases is similar, copying the dose distribution of one phase directly to another phase would yield a dosimetric error of approximately 4% without further optimization. To reduce the dosimetric error, three-dimensional B-spline elastic deformable image registration (DIR) was used to quickly obtain a relatively accurate cumulative dose of 4DCT images acquired from ten lung cancer patients. The dose distribution of the end-expiration phase was mapped to the end-inspiration phase using DIR. The mapped dose in …the end-inspiration phase was then compared with the directly copied dose by analysis (3cm/3%) and the t-test. The results showed that optimization using DIR was significantly better in the average pass rate (by 0.6–4.7%). Our results indicate it is feasible to map the dose distribution of 4DCT images in lung with DIR, and that the motion amplitude of individual respiratory and different DIR algorithms affect the differences between the mapped and actual dose. Show more

Keywords: 4DCT, deformable image registration, dose distribution, γ analysis

DOI: 10.3233/BME-130794

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 1, pp. 145-153, 2014