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

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