Technology and Health Care - Volume 29, issue 3

Authors: Tian, Qiuhong | Bao, Jiaxin | Yang, Huimin | Chen, Yingrou | Zhuang, Qiaoli

Article Type: Research Article

Abstract: BACKGROUND: For a traditional vision-based static sign language recognition (SLR) system, arm segmentation is a major factor restricting the accuracy of SLR. OBJECTIVE: To achieve accurate arm segmentation for different bent arm shapes, we designed a segmentation method for a static SLR system based on image processing and combined it with morphological reconstruction. METHODS: First, skin segmentation was performed using YCbCr color space to extract the skin-like region from a complex background. Then, the area operator and the location of the mass center were used to remove skin-like regions and obtain the valid …hand-arm region. Subsequently, the transverse distance was calculated to distinguish different bent arm shapes. The proposed segmentation method then extracted the hand region from different types of hand-arm images. Finally, the geometric features of the spatial domain were extracted and the sign language image was identified using a support vector machine (SVM) model. Experiments were conducted to determine the feasibility of the method and compare its performance with that of neural network and Euclidean distance matching methods. RESULTS: The results demonstrate that the proposed method can effectively segment skin-like regions from complex backgrounds as well as different bent arm shapes, thereby improving the recognition rate of the SLR system. Show more

Keywords: Static sign language recognition, image segmentation, bent arm shape, transverse distance, geometric feature

DOI: 10.3233/THC-192000

Citation: Technology and Health Care, vol. 29, no. 3, pp. 527-540, 2021

Authors: Zhang, Yuxin | Gao, Qiang | Song, Yu | Wang, Zhe

Article Type: Research Article

Abstract: BACKGROUND: People with severe neuromuscular disorders caused by an accident or congenital disease cannot normally interact with the physical environment. The intelligent robot technology offers the possibility to solve this problem. However, the robot can hardly carry out the task without understanding the subject’s intention as it relays on speech or gestures. Brain-computer interface (BCI), a communication system that operates external devices by directly converting brain activity into digital signals, provides a solution for this. OBJECTIVE: In this study, a noninvasive BCI-based humanoid robotic system was designed and implemented for home service. METHODS: …A humanoid robot that is equipped with multi-sensors navigates to the object placement area under the guidance of a specific symbol “Naomark”, which has a unique ID, and then sends the information of the scanned object back to the user interface. Based on this information, the subject gives commands to the robot to grab the wanted object and give it to the subject. To identify the subject’s intention, the channel projection-based canonical correlation analysis (CP-CCA) method was utilized for the steady state visual evoked potential-based BCI system. RESULTS: The offline results showed that the average classification accuracy of all subjects reached 90%, and the online task completion rate was over 95%. CONCLUSION: Users can complete the grab task with minimum commands, avoiding the control burden caused by complex commands. This would provide a useful assistance means for people with severe motor impairment in their daily life. Show more

Keywords: Brain-computer interface, Steady-state visual evoked potential, Humanoid robot, Home service, Channel projection-based canonical correlation analysis (CP-CCA)

DOI: 10.3233/THC-202442

Citation: Technology and Health Care, vol. 29, no. 3, pp. 541-556, 2021

Authors: Zhang, Li | Li, Xian | Rüwald, Julian M. | Welle, Kristian | Schildberg, Frank A. | Kabir, Koroush

Article Type: Review Article

Abstract: BACKGROUND: Minimally invasive total knee arthroplasty (TKA) has been actively advertised by the orthopedic industry. The purpose of this network meta-analysis was to comprehensively compare the effectiveness of four minimally invasive surgery (MIS) approaches and the medial parapatellar (MPP) approach to improve the American Knee Society Score (KSS) in primary TKA. MATERIALS AND METHODS: Studies were comprehensively searched on PubMed, Embase, Cochrane Library (CENTRAL), Web of Science and Science Direct up to June 2018 with a major focus on the outcome of KSS. Risk of bias was assessed using the Cochrane risk of bias tool. Quality …assessment was performed using the GRADE system. Both pair-wise and network meta-analyses are calculated to comprehensively compare the effectiveness of four MIS and TKA approaches. RESULTS: Eleven trials with 1025 knees undergoing TKA were included. Our analysis showed that both MPP and MIS approaches provided improvement in terms of short-term (four-eight weeks) total, objective and functional KSS. The network-meta analysis revealed that MIS approaches showed a trend towards superior KSS improvement over standard MPP approaches. However, statistical advantages were only observed in the mini-MPP group for functional KSS compared to the conventional MPP and quadriceps-sparing (QS) groups. CONCLUSIONS: Evidence shows that MIS TKA approaches are effective alternatives to MPP approaches. However, orthopedic surgeons should be cautiously optimistic about minimally invasive TKA in terms of KSS improvement. Show more

Keywords: Minimally invasive surgery, total knee arthroplasty, total knee replacement, network meta-analysis, bayesian model

DOI: 10.3233/THC-192078

Citation: Technology and Health Care, vol. 29, no. 3, pp. 557-574, 2021

Authors: Weißenberger, Manuel | Klug, Alexander | Heinz, Tizian | Rueckl, Kilian | Kollenda, Hans | Rudert, Maximilian | Hoffmann, Reinhard | Schmidt-Horlohé, Kay

Article Type: Research Article

Abstract: BACKGROUND: The distal biceps brachii tendon rupture is a rare injury of the musculoskeletal system. Multiple surgical techniques have been described for distal biceps brachii tendon repairs including suture anchors. OBJECTIVE: The aim of this study was to evaluate the outcome of anatomical distal biceps tendon refixation using either one or two suture anchors for reattachment and to determine whether there are significant clinically important differences on the number of anchors used for refixation. METHODS: A monocentric, randomized controlled trial was conducted, including 16 male patients with a mean age of 47.4 years (range, …31.0 to 58.0) in Group 1 (two suture anchors for refixation) and 15 male patients with a mean age of 47.4 (range, 35.0 to 59.0) in Group 2 (one suture anchor for refixation). All surgeries were performed through an anterior approach. The outcome was assessed using the Oxford Elbow Score (OES), the Mayo Elbow Performance Score (MEPS), the Disabilities of the Arm, Shoulder and Hand (DASH) score, the Andrews Carson Score (ACS) and by isokinetic strength measurement for the elbow flexion after six, twelve, 24 and 48 weeks. Radiographic controls were performed after 24 and 48 weeks. RESULTS: No significant differences between both groups were evident at any point during the follow-up period. A continuous improvement in outcome for both groups could be detected, reaching an OES: 46.3 (39.0 to 48.0) vs. 45.5 (30.0 to 48.0), MEPS: 98.0 (85.0 to 100.0) vs. 99.0 (85.0 to 100.0), DASH: 3.1 (0.0 to 16.7) vs. 2.9 (0.0 to 26.7), ACS: 197.0 (175.0 to 200.0) vs. 197.7 Show more

DOI: 10.3233/THC-202476

Citation: Technology and Health Care, vol. 29, no. 3, pp. 575-588, 2021

Authors: Kraxenberger, Michael | Dreu, Manuel | Sadoghi, Patrick | Birkenmaier, Christof | Teske, Wolfram | von Schulze Pellengahr, Christoph | Büttner, Andreas | Wegener, Bernd

Article Type: Research Article

Abstract: BACKGROUND: The use of fresh-frozen (FF) specimens represents the gold standard for biomechanical investigations. Since FF specimens are often difficult to obtain, chemical-fixed specimens (formalin (FA), Thiel (TH)) are also used. OBJECTIVE: Since fixation methods can alter the mechanical properties of bone tissue, the purpose of this study was to examine their influence on the fracture force of lumbar vertebral bodies (VB). METHODS: First the VB were subdivided into three focus groups: FF, TH, and FA. After removing the soft tissue and the processus transverses of all VB, the endplates were planned with …a thin layer of epoxy resin, in order to apply a constant strain to the surface and sub-surface. The VB were subjected to axial compression tests in order to determine fracture force. Lastly a standardized compression fracture was generated. RESULTS: The mean values of the fracture force of the focus groups were 4529.5 N (FF), 3211.3N (TH) and 2947.9N (FA). Consequently a significant difference between the FF and the other two groups could be demonstrated (p < 0.05). CONCLUSION: The preliminary tests showed that the fraction force of fresh-frozen VB were significantly higher than TH/FA-fixed VB. Therefore, these fixation methods could potentially have an influence on the biomechanical properties of VB. This leads to the assumption that if load-to-failure tests are performed, it is probably recommended to use fresh-frozen specimens. Show more

Keywords: Vertebral body, spine, chemical fixation, compression, fracture force

DOI: 10.3233/THC-202354

Citation: Technology and Health Care, vol. 29, no. 3, pp. 589-594, 2021

Authors: Fang, Juan | Schuwey, Andres | Stocker, Niklaus | Pedrini, Brian | Sampaio, Antonio | Hunt, Kenneth J.

Article Type: Research Article

Abstract: BACKGROUND: To provide effective rehabilitation in the early post-injury stage, a novel robotic rehabilitation platform is proposed, which provides full-body arm-leg rehabilitation via belt actuation to severely disabled patients who are restricted to bed rest. OBJECTIVE: To design and technically evaluate the preliminary development of the rehabilitation platform, with focus on the generation of various leg movements. METHODS: Two computer models were developed by importing the components from SolidWorks into Simscape Multibody in MATLAB. This allowed simulation of various stepping movements in supine-lying and side-lying positions. Two belt-actuated test rigs were manufactured and …automatic control programs were developed in TIA Portal. Finally, the functionality of the test rigs was technically evaluated. RESULTS: Computer simulation yielded target positions for the generation of various stepping movements in the experimental platforms. The control system enabled the two-drive test rig to provide three modes of stepping in a supine position. In addition, the four-drive test rig produced walking-like stepping in a side-lying position. CONCLUSIONS: This work confirmed the feasibility of the mechanical development and control system of the test rigs, which are deemed applicable for further development of the overall novel robotic rehabilitation platform. Show more

Keywords: Belt actuation, arm-leg movement, supine-lying stepping, side-lying stepping, whole body rehabilitation

DOI: 10.3233/THC-202392

Citation: Technology and Health Care, vol. 29, no. 3, pp. 595-607, 2021

Authors: Cao, Wujing | Yu, Hongliu | Wu, Xinyu | Li, Sujiao | Meng, Qiaoling | Chen, Chunjie

Article Type: Research Article

Abstract: BACKGROUND: Stroke and other neurological disorders have an effect on mobility, which has a significant impact on independence and quality of life. The core rehabilitation requirements for patients with lower limb motor dysfunction are gait training, re-stand and mobility. OBJECTIVE: A wheelchair called ReChair was invented that seamlessly integrated mobility, gait training and multi-posture transformation with voice control. METHODS: The mechanical structure and control system of ReChair were designed. The overall evaluation included voice recognition and balance training test to quantitatively verify the performance of ReChair. RESULTS: The average success …recognition rate of posture transformation by voice control can reach 91% to 96% in a quiet environment (20–30 DB). The balance training game is easy to operate and the score can be used as a quantified guideline for rehabilitation. CONCLUSION: The proposed rehabilitation wheelchair can realize multi-posture transformation and balance training by the voice control system. Show more

Keywords: Wheelchair, voice control, posture transformation, lower limb rehabilitation training

DOI: 10.3233/THC-202386

Citation: Technology and Health Care, vol. 29, no. 3, pp. 609-614, 2021

Authors: Lee, Jeong-Hyun | Kim, Yeona | So, Wi-Young

Article Type: Other

DOI: 10.3233/THC-202509

Citation: Technology and Health Care, vol. 29, no. 3, pp. 615-617, 2021