Technology and Health Care - Volume 26, issue S1

Authors: Yarahmadian, Mehran | Zhong, Yongmin | Gu, Chengfan | Shin, Jaehyun

Article Type: Research Article

Abstract: BACKGROUND: Soft tissue modeling plays an important role in the development of surgical training simulators as well as in robot-assisted minimally invasive surgeries. It has been known that while the traditional Finite Element Method (FEM) promises the accurate modeling of soft tissue deformation, it still suffers from a slow computational process. OBJECTIVE: This paper presents a Kalman filter finite element method to model soft tissue deformation in real time without sacrificing the traditional FEM accuracy. METHODS: The proposed method employs the FEM equilibrium equation and formulates it as a filtering process to estimate …soft tissue behavior using real-time measurement data. The model is temporally discretized using the Newmark method and further formulated as the system state equation. RESULTS: Simulation results demonstrate that the computational time of KF-FEM is approximately 10 times shorter than the traditional FEM and it is still as accurate as the traditional FEM. The normalized root-mean-square error of the proposed KF-FEM in reference to the traditional FEM is computed as 0.0116. CONCLUSIONS: It is concluded that the proposed method significantly improves the computational performance of the traditional FEM without sacrificing FEM accuracy. The proposed method also filters noises involved in system state and measurement data. Show more

Keywords: Soft tissue deformation, finite element, real-time estimation, Kalman filter

DOI: 10.3233/THC-174640

Citation: Technology and Health Care, vol. 26, no. S1, pp. 317-325, 2018

Authors: Chai, Xin | Wang, Qisong | Zhao, Yongping | Liu, Xin | Liu, Dan | Bai, Ou

Article Type: Research Article

Abstract: Emotion recognition based on EEG signals is a critical component in Human-Machine collaborative environments and psychiatric health diagnoses. However, EEG patterns have been found to vary across subjects due to user fatigue, different electrode placements, and varying impedances, etc. This problem renders the performance of EEG-based emotion recognition highly specific to subjects, requiring time-consuming individual calibration sessions to adapt an emotion recognition system to new subjects. Recently, domain adaptation (DA) strategies have achieved a great deal success in dealing with inter-subject adaptation. However, most of them can only adapt one subject to another subject, which limits their applicability in real-world …scenarios. To alleviate this issue, a novel unsupervised DA strategy called Multi-Subject Subspace Alignment (MSSA) is proposed in this paper, which takes advantage of subspace alignment solution and multi-subject information in a unified framework to build personalized models without user-specific labeled data. Experiments on a public EEG dataset known as SEED verify the effectiveness and superiority of MSSA over other state of the art methods for dealing with multi-subject scenarios. Show more

Keywords: EEG, emotion recognition, domain adaptation, multi-subject learning, logistic regression

DOI: 10.3233/THC-174739

Citation: Technology and Health Care, vol. 26, no. S1, pp. 327-335, 2018

Authors: Lu, Yanan | Ma, Yu | Chen, Chen | Wang, Yuanyuan

Article Type: Research Article

Abstract: BACKGROUND: Epilepsy is a common chronic neurological disorder of the brain. Clinically, epileptic seizures are usually detected via the continuous monitoring of electroencephalogram (EEG) signals by experienced neurophysiologists. OBJECTIVE: In order to detect epileptic seizures automatically with a satisfactory precision, a new method is proposed which defines hybrid features that could characterize the epileptiform waves and classify single-channel EEG signals. METHODS: The hybrid features consist of both the ones usually used in EEG signal analysis and the Kraskov entropy based on Hilbert-Huang Transform which is proposed for the first time. With the hybrid …features, EEG signals are classified and the epileptic seizures are detected. RESULTS: Three datasets are used for test on three binary-classification problems defined by clinical requirements for epileptic seizures detection. Experimental results show that the accuracy, sensitivity and specificity of the proposed methods outperform two state-of-the-art methods, especially on the databases containing signals from different sources. CONCLUSIONS: The proposed method provides a new avenue to assist neurophysiologists in diagnosing epileptic seizures automatically and accurately. Show more

Keywords: Epilepsy, epileptic seizures detection, electroencephalogram (EEG), hybrid features, Kraskov entropy, Hilbert-Huang transform

DOI: 10.3233/THC-174679

Citation: Technology and Health Care, vol. 26, no. S1, pp. 337-346, 2018

Authors: Wu, Jianlei | Liu, Yunfeng | Zhang, Jianxing | Peng, Wei | Jiang, Xianfeng

Article Type: Research Article

Abstract: BACKGROUND: Orthodontic treatment planning (OTP) is primarily depended on clinical experiences of orthodontists at present, while equivocal OTP would increase the possibility of treatment failure. OBJECTIVE: The objective was to investigate a methodology for quantitatively evaluating OTP, using theoretical analyses, orthodontic forces measurement (OFM) and finite element method (FEM). METHODS: An OTP was theoretically designed based on a clinical case and forces on incisors in OTP were measured on a specialized platform. Further, FEM simulations were performed on the designed OTP and control group. At last, an 18-month tracking was carried out to …observe treatment effects of the designed OTP. RESULTS: The moving tendencies of incisors were in keeping with ideal treatment from the designed OTP through FEM; the maximal hydrostatic stress and logarithmic strain in periodontal ligament (PDL) decreased by 26.81% and 32.60% compared to the control group. Clinical feedback indicated that a controllable correction of incisors was realized after 18 months, which was in accord with the FEM result and root/bone resorption by reason of stress/strain reduction on PDL did not occur. CONCLUSIONS: Biomechanical responses of periodontium can be quantitatively estimated using OTM and FEM. This study provided an alternative technological mean for the predictability and optimization of clinical OTP. Show more

Keywords: Biomechanics, orthodontic treatment planning (OTP), orthodontic forces measurement (OFM), finite element method (FEM)

DOI: 10.3233/THC-174689

Citation: Technology and Health Care, vol. 26, no. S1, pp. 347-359, 2018

Authors: Xu, Wenbin | Xia, Hong | Liu, Wei | Zheng, Weiying | Hua, Lin

Article Type: Research Article

Abstract: BACKGROUND AND OBJECTIVE: Muscle-invasive bladder cancers (MIBCs) are heterogeneous cancers and can be grouped into basal-like and luminal subtypes that are highly reminiscent of those found in breast cancer. Like basal-like breast cancers, basal-like MIBCs are associated with advanced stage and metastatic disease. However, the biological and clinical significance of molecular subtypes of MIBCs remain unclear. Therefore, we implemented a serious of bioinformatics methods to explore genetic similarities between bladder and breast cancers. METHODS AND RESULTS: In the current study, by the application of multiple levels data analysis including random forest analysis, PPI and transcription factor …regulation network construction, Gene Ontology (GO) and KEGG pathway enrichment analysis, we explored the genetics commonness between MIBC and breast cancers from the molecular heterogeneity based on the disease subtypes. CONCLUSIONS: Our study identified some basal-related and luminal-related genes shared by two cancers. These studies can help shed light on the potential relationships between MIBC and breast cancer as a whole. Show more

Keywords: Bladder cancer, breast cancer, genetic commonness, regulation network

DOI: 10.3233/THC-174699

Citation: Technology and Health Care, vol. 26, no. S1, pp. 361-377, 2018

Authors: Zhang, Yiyan | Li, Qin | Xin, Yi | Lv, Weiqi | Ge, Chuanbin

Article Type: Research Article

Abstract: BACKGROUND: Magnesium ion, as important cation in the human body, involved in various enzymatic reactions, glucose transport and insulin release. Now diabetes mellitus and diabetic complications have become important public health problems around the world. OBJECTIVE: This paper explores the association between concentration levels of serum magnesium and common complications and comorbidities of diabetes mellitus and other biochemical indexes. METHODS: There are 1217 eligible patients selected from 14,317 cases of diabetic hospitalization patients from January 2010 to December 2011. Random forest algorithm was applied to assess the importance of various biochemical indexes and …to perform diabetic complications prediction. RESULTS: The research results showed that low concentration of serum magnesium and four common diabetic complications – diabetic retinopathy, diabetic nephropathy, diabetic neuropathy and diabetic macroangiopathy – exists association, but no obvious correlation with other comorbidities like hypertension. CONCLUSIONS: The specific factors of four common diabetic complications were selected from the biochemical indexes to provide a reference direction for further research. Show more

Keywords: Serum magnesium, diabetic complications, biochemical index, random forest, associated factor

DOI: 10.3233/THC-174702

Citation: Technology and Health Care, vol. 26, no. S1, pp. 379-387, 2018

Authors: Ren, Fulong | Cao, Peng | Zhao, Dazhe | Wan, Chao

Article Type: Research Article

Abstract: BACKGROUND: Diabetic macular edema (DME) is one of the severe complication of diabetic retinopathy causing severe vision loss and leads to blindness in severe cases if left untreated. OBJECTIVE: To grade the severity of DME in retinal images. METHODS: Firstly, the macular is localized using its anatomical features and the information of the macula location with respect to the optic disc. Secondly, a novel method for the exudates detection is proposed. The possible exudate regions are segmented using vector quantization technique and formulated using a set of feature vectors. A semi-supervised learning with graph based …classifier is employed to identify the true exudates. Thirdly, the disease severity is graded into different stages based on the location of exudates and the macula coordinates. RESULTS: The results are obtained with the mean value of 0.975 and 0.942 for accuracy and F1-scrore, respectively. CONCLUSION: The present work contributes to macula localization, exudate candidate identification with vector quantization and exudate candidate classification with semi-supervised learning. The proposed method and the state-of-the-art approaches are compared in terms of performance, and experimental results show the proposed system overcomes the challenge of the DME grading and demonstrate a promising effectiveness. Show more

Keywords: Retinal images, diabetic macular edema, exudate detection, classification

DOI: 10.3233/THC-174704

Citation: Technology and Health Care, vol. 26, no. S1, pp. 389-397, 2018

Authors: Zou, Yupeng | Ma, Huizi | Han, Zhiyuan | Song, Yang | Liu, Kai

Article Type: Research Article

Abstract: BACKGROUND: To solve the technical problems associated with the research on lower limb rehabilitation robot in terms of configuration design, human-machine compatibility, lightweight, and multimodel rehabilitation. OBJECTIVE: This study introduced a parallel wire driving lower limb rehabilitation robot. The robot featured modular design, reconfiguration, multimodel, and good human-machine compatibility. METHODS: The dynamics model of the wire driving module (WDM) was built based on which a multiple feedback loop controller (including a forward controller and a surplus force compensator) was designed. RESULTS: The experimental results showed that the WDM could load force …accurately and reliably during the loading procedure. CONCLUSIONS: The machinery and control system of the WDM met the design request. Show more

Keywords: Parallel wire driving robot, dynamics modeling, force control, lower limb rehabilitation

DOI: 10.3233/THC-174714

Citation: Technology and Health Care, vol. 26, no. S1, pp. 399-408, 2018

Authors: Kwon, Yuri | Kim, Ji-Won | Heo, Jae-Hoon | Jeon, Hyeong-Min | Choi, Eui-Bum | Eom, Gwang-Moon

Article Type: Research Article

Abstract: BACKGROUND: The sitting in an awkward posture for a prolonged time may lead to spinal or musculoskeletal disease. It is important to investigate the joint loads at spine while sitting. OBJECTIVE: The purpose of this study was to investigate the joint moment and antero-posterior (AP) reaction force at cervico-thoracic and lumbosacral joint for various sitting postures. METHODS: Twenty healthy males participated in this study. Six sitting postures were defined from three spinal curvatures (slump, flat, and lordosis) and two arm postures (arms-on-chest and arms-forward). Kinematic and kinetic data were measured in six sitting …postures from which joint moment and AP reaction force were calculated by inverse dynamics. RESULTS: In the cervico-thoracic joint, joint moment and AP reaction force were greater in slump than the flat and lordosis postures (p < 0.001) and also in arms-forward posture compared to arms-on-chest posture. In the lumbosacral joint, joint moment and AP reaction force were greater in slump than flat and lordotic posture (p < 0.001) but there was no difference between different arm postures. The joint loads (moment and AP reaction force) at the cervico-thoriacic joint were closely related to the head flexion angle (r > 0.86) while those at the lumbosacral joint were correlated to the trunk flexion angle (r > 0.77). In slump posture, the joint moments were close to or over the extreme of the daily life such as sit-to-stand and walking. Consequently, if the slump is continued for a long time, it may cause pain and diseases at the cervico-thoracic and lumbosacral joints. CONCLUSIONS: The results of the study indicated that the lordosis or flat would be better spinal postures. Also, keeping arms close to body would be desirable to reduce joint loads. Show more

Keywords: Sitting posture, cervico-thoracic joint, lumbosacral joint, joint moment, joint reaction force

DOI: 10.3233/THC-174717

Citation: Technology and Health Care, vol. 26, no. S1, pp. 409-418, 2018

Authors: Kim, Ji-Sun | Baek, Jin-Young | Oh, Han-Byeol | Lee, Seong-Su | Jun, Jae-Hoon

Article Type: Research Article

Abstract: BACKGROUND: The laser is able to irradiate the exact amount of stimulation to an area by a non contact method, and has the advantage of being able to stimulate the local target area. OBJECTIVE: This study examined an efficient method of laser tactile stimulation using laser parameter combinations. METHODS: The laser parameters that could cause an increase in the cognitive response rate of human subjects were examined without increasing the amount of total laser energy. RESULTS: As a result, the appropriate matching parameters such as duty ratio, pulse frequency, and …exposure time of laser pulses showed a dominant influence in effectively increasing the tactile response rate of subjects with limited amount of total laser energy. CONCLUSIONS: This study can be applied to neurophysiology, cognitive research, and clinical laser application. Show more

Keywords: Laser tactile stimulation, laser parameter, diode pulse laser, tactile response rate

DOI: 10.3233/THC-174718

Citation: Technology and Health Care, vol. 26, no. S1, pp. 419-425, 2018