Technology and Health Care - Volume 25, issue S1

Authors: Yang, Hua | Cao, Tingting | Gao, Li | Wang, Lili | Zhu, Chengying | Xu, Yuanyuan | Jing, Yu | Zhu, Haiyan | lv, Na | Yu, Li

Article Type: Other

DOI: 10.3233/THC-171329

Citation: Technology and Health Care, vol. 25, no. S1, pp. 259-, 2017

Authors: Zhang, Guoan | Liu, Gangfeng | Ma, Sun | Wang, Tianshuo | Zhao, Jie | Zhu, Yanhe

Article Type: Research Article

Abstract: In this paper, an obstacle-surmounting-enabled lower limb exoskeleton with novel linkage joints that perfectly mimicked human motions was proposed. Currently, most lower exoskeletons that use linear actuators have a direct connection between the wearer and the controlled part. Compared to the existing joints, the novel linkage joint not only fitted better into compact chasis, but also provided greater torque when the joint was at a large bend angle. As a result, it extended the angle range of joint peak torque output. With any given power, torque was prioritized over rotational speed, because instead of rotational speed, sufficiency of torque is …the premise for most joint actions. With insufficient torque, the exoskeleton will be a burden instead of enhancement to its wearer. With optimized distribution of torque among the joints, the novel linkage method may contribute to easier exoskeleton movements. Show more

Keywords: Lower limb, novel linkage joints, exoskeleton, escalading

DOI: 10.3233/THC-171330

Citation: Technology and Health Care, vol. 25, no. S1, pp. 267-273, 2017

Authors: Wang, Wendong | Zhang, Lei | Li, Jinzhe | Yuan, Xiaoqing | Shi, Yikai | Jiang, Qinqin | He, Lijing

Article Type: Research Article

Abstract: BACKGROUND: Massage robot is considered as an effective physiological treatment to relieve fatigue, improve blood circulation, relax muscle tone, etc. The simple massage equipment quickly spread into market due to low cost, but they are not widely accepted due to restricted massage function. Complicated structure and high cost caused difficulties for developing multi-function massage equipment. OBJECTIVE: This paper presents a novel massage robot which can achieve tapping, rolling, kneading and other massage operations, and proposes an improved reciprocating path planning algorithm to improve massage effect. METHODS: The number of coil turns, the coil …current and the distance between massage head and yoke were chosen to investigate the influence on massage force by finite element method. The control system model of the wheeled massage robot was established, including control subsystem of the motor, path algorithm control subsystem, parameter module of the massage robot and virtual reality interface module. The improved reciprocating path planning algorithm was proposed to improve regional coverage rate and massage effect. RESULTS: The influence caused by coil current, the number of coil turns and the distance between massage head and yoke were simulated in Maxwell. It indicated that coil current has more important influence compared to the other two factors. The path planning simulation of the massage robot was completed in Matlab, and the results show that the improved reciprocating path planning algorithm achieved higher coverage rate than the traditional algorithm. CONCLUSIONS: With the analysis of simulation results, it can be concluded that the number of coil turns and the distance between the moving iron core and the yoke could be determined prior to coil current, and the force can be controllable by optimizing structure parameters of massage head and adjusting coil current. Meanwhile, it demonstrates that the proposed algorithm could effectively improve path coverage rate during massage operations, therefore the massage effect can be improved. Show more

Keywords: Massage robot, electromagnetic induction, massage force, path planning, coverage rate

DOI: 10.3233/THC-171331

Citation: Technology and Health Care, vol. 25, no. S1, pp. 275-285, 2017

Authors: Zhang, Zuo | Jiang, Youhao | Sun, Yaoru | Zhang, Hong

Article Type: Research Article

Abstract: BACKGROUND: Multi-voxel pattern analysis (MVPA) provides a powerful tool to investigate neural mechanisms for various cognitive processes under functional brain imaging. However, the high sensitivity of the MVPA method could bring about false positive results, which has been overlooked by previous research. OBJECTIVE: We investigated the potential for obtaining false positives from the MVPA method. METHODS: We conducted MVPA on a public functional MRI dataset on the neural encoding of various object categories. Different scenarios for pattern classification were involved by varying the number of voxels for each region of interest (ROI) and …the number of object categories. RESULTS: The classification accuracy became higher with more voxels involved, and false positive results emerged for the primary auditory cortex and even a white matter ROI, where object-related neural processing was not supposed to occur. CONCLUSIONS: Our results imply that the classification accuracy obtained from MVPA may be inflated due to the high sensitivity of the method. Therefore, we suggest involving control ROIs in future MVPA studies and comparing the classification accuracy for a target ROI with that for a control ROI, instead of comparing the obtained accuracy with the chance-level accuracy. Show more

Keywords: Multi-voxel pattern analysis, brain imaging, functional MRI, false positive

DOI: 10.3233/THC-171332

Citation: Technology and Health Care, vol. 25, no. S1, pp. 287-294, 2017

Authors: Wang, Hua | Wen, Yingyou | Zhao, Dazhe

Article Type: Research Article

Abstract: BACKGROUND: Medical applications have begun to benefit from Internet of Things (IoT) technology through the introduction of wearable devices. Several medical applications require accurate patient location as various changes affect pressure parameters inside the body. OBJECTIVE: This study aims to develop a system to measure indoor altitude for IoT medical applications. METHODS: We propose a differential barometric-based positioning system to estimate the altitude between a reference sensor and a localizing sensor connected to the human body. The differential barometric altimetry model is introduced to estimate indoor elevations and eliminate environmental artifacts. In addition, …a Gaussian filter processing is adopted to remove noise from the elevation measurements. The proposed system is then investigated through extensive experiments, using various evaluation criteria. RESULTS: The results indicate that the proposed system yielded good accuracy with reduced implementation complexity and fewer costs. CONCLUSIONS: The proposed system is resilient compared to other indoor localization approaches, even when numerous environmental artifacts in indoor environments are present. Show more

Keywords: Internet of Things, wearable wireless sensors, barometric altimetry, medical monitoring, health monitoring system

DOI: 10.3233/THC-171333

Citation: Technology and Health Care, vol. 25, no. S1, pp. 295-304, 2017

Authors: Peng, Ran | Luo, Yang | Li, Zhangyong | Wang, Wei | Pang, Yu

Article Type: Research Article

Abstract: BACKGROUND: Due to different physical and biological mechanisms behind ultrasound hyperthermia and phonophoresis, the requirement for ultrasound power, frequency and control modes varies. OBJECTIVE: This paper introduces an adaptive ultrasonic physiotherapy system based on real-time surveillance over physiological characteristics of the patients, which in turn assists the individual treatment and dose limitation in auxiliary rehabilitation. METHODS: The method essentially takes advantage of distinctive characteristics of two different phases (systole and diastole) of the human cardiac cycle as a medium for modulation. The abundance of blood flow during systole enables energy exchange for hyperthermia …while blood flow insufficiency caused by diastole assists in drug penetration. Said method could improve the adjuvant therapy as it provides partial drug penetration and therapeutic dosage control. RESULTS: By adjusting time window and intensity of multi-frequency ultrasound, it is possible to reduce the irradiation dosage to around 22% of that during continuous irradiation at 1 MHz. The method shows high potential in clinical practice. CONCLUSION: Frequency-tuning ultrasound therapy would be more efficient regarding drug penetration and improve the therapeutic efficacy of hyperthermia. Show more

Keywords: Ultrasonic physiotherapy, ultrasound hyperthermia, drug penetration, physiological parameter feedback, real-time control

DOI: 10.3233/THC-171334

Citation: Technology and Health Care, vol. 25, no. S1, pp. 305-315, 2017

Authors: Zhu, Liangfan | Yang, Xi | Wu, Yue | Wang, Minghui | Luo, Yun

Article Type: Research Article

Abstract: BACKGROUND: A rotary blood pump with a passively levitated impeller and a large bearing gap between housing and impeller in the range of 0.6 mm has been developed for Left ventricular assist device (LVAD). OBJECTIVE: The purpose of the present study is to determine the optimal injection angle of the impeller to improve its radial stability by increasing the radial suspension force. MTEHODS: Since the radial and axial suspension forces generated by an injection channel were equal, the axial suspension force obtained from numerical simulation was chosen as the evaluation parameter. First, the …impellers with different injection angles were calculated with numerical simulation to obtain the maximum axial suspension force. Second, the radial motion of the impeller was experimentally measured for the evaluation of the radial stability. RESULTS: The numerical analysis revealed that the axial suspension force acting on the impeller reached the maximum value at the injection angle of 60 degrees. In the measurement test, the impeller with injection angle of 60 degrees achieved the most stable radial movement. Therefore, the effectiveness of the numerical analysis was validated. CONCLUSIONS: The injection angle of impeller could be optimized to improve its radial stability, and the optimal injection angle was 60 degrees. Show more

Keywords: Left ventricular assist device, numerical simulation, injection angle, suspension force, radial motion

DOI: 10.3233/THC-171335

Citation: Technology and Health Care, vol. 25, no. S1, pp. 317-324, 2017

Authors: Wang, Huiya | Feng, Jun | Wang, Hongyu

Article Type: Research Article

Abstract: BACKGROUND: Detection of clustered microcalcification (MC) from mammograms plays essential roles in computer-aided diagnosis for early stage breast cancer. OBJECTIVE: To tackle problems associated with the diversity of data structures of MC lesions and the variability of normal breast tissues, multi-pattern sample space learning is required. METHODS: In this paper, a novel grouped fuzzy Support Vector Machine (SVM) algorithm with sample space partition based on Expectation-Maximization (EM) (called G-FSVM) is proposed for clustered MC detection. The diversified pattern of training data is partitioned into several groups based on EM algorithm. Then a series …of fuzzy SVM are integrated for classification with each group of samples from the MC lesions and normal breast tissues. RESULTS: From DDSM database, a total of 1,064 suspicious regions are selected from 239 mammography, and the measurement of Accuracy, True Positive Rate (TPR), False Positive Rate (FPR) and EVL = TPR* 1 - FPR are 0.82, 0.78, 0.14 and 0.72, respectively. CONCLUSION: The proposed method incorporates the merits of fuzzy SVM and multi-pattern sample space learning, decomposing the MC detection problem into serial simple two-class classification. Experimental results from synthetic data and DDSM database demonstrate that our integrated classification framework reduces the false positive rate significantly while maintaining the true positive rate. Show more

Keywords: Pattern classification, EM algorithm, partition of sample space, grouped fuzzy SVM, computer aided detection

DOI: 10.3233/THC-171336

Citation: Technology and Health Care, vol. 25, no. S1, pp. 325-336, 2017

Authors: Zhang, Jinao | Zhong, Yongmin | Smith, Julian | Gu, Chengfan

Article Type: Research Article

Abstract: BACKGROUND: Currently, the mechanical dynamics of soft tissue deformation is achieved by numerical time integrations such as the explicit or implicit integration; however, the explicit integration is stable only under a small time step, whereas the implicit integration is computationally expensive in spite of the accommodation of a large time step. OBJECTIVE: This paper presents a cellular neural network method for stable simulation of soft tissue deformation dynamics. METHOD: The non-rigid motion equation is formulated as a cellular neural network with local connectivity of cells, and thus the dynamics of soft tissue deformation …is transformed into the neural dynamics of the cellular neural network. RESULTS: Results show that the proposed method can achieve good accuracy at a small time step. It still remains stable at a large time step, while maintaining the computational efficiency of the explicit integration. CONCLUSION: The proposed method can achieve stable soft tissue deformation with efficiency of explicit integration for surgical simulation. Show more

Keywords: Soft tissue deformation, cellular neural network, dynamic systems, numerical time integration

DOI: 10.3233/THC-171337

Citation: Technology and Health Care, vol. 25, no. S1, pp. 337-344, 2017

Authors: Zhu, Hongbo | Pak, Chun-Hyok | Song, Chunhe | Dou, Shengchang | Zhao, Hai | Cao, Peng | Ye, Xiangyun

Article Type: Research Article

Abstract: The fuzzy degree of lung nodule boundary is the most important cue to judge the lung cancer in CT images. Based on this feature, the paper proposes a novel lung cancer detection method for CT images based on the super-pixels and the level set segmentation methods. In the proposed methods, the super-pixels method is used to segment the lung region and the suspected lung cancer lesion region in the CT image. The super-pixels method and a level set method are used to segment the suspected lung cancer lesion region simultaneously. Finally, the cancer is determined by the difference between results …of the two segmentation methods. Experimental results show that the proposed algorithm has a high accuracy for lung cancer detection in CT images. For gross glass nodule, pleural nodule, the vascular nodules and solitary nodules, the sensitivity of the detection algorithm are respectively 91.3%, 96.3%, 80.9% and 82.3%. Show more

Keywords: Image segmentation, malignant nodule detection, super-pixels, level-set

DOI: 10.3233/THC-171338

Citation: Technology and Health Care, vol. 25, no. S1, pp. 345-355, 2017