Technology and Health Care - Volume 22, issue 4

Authors: Bajelan, Soheil | Azghani, Mahmood Reza

Article Type: Research Article

Abstract: Background: The human chair-rise ability reduces according to various factors such as; Age, Incidents, diseases and etc. The Sit-to-Stand (STS) movement strategy modification is a way chosen to compensate the STS inabilities. Objective: Musculoskeletal evaluation of the effects of standing up strategy modification is beneficial for correct selection. The aim of this study is to compute, compare, and classify the biomechanical effects of each STS movement strategy. Methods: A full-body human who stands up from seat with three various strategies are modeled and simulated with commercial musculoskeletal simulation software, AnyBody (Anybody Technology, Aalborg, Denmark). A …specific algorithm is employed to compute time-histories of the reaction forces between body and seat. Results: Time-histories of joint moments, joint loads and muscles forces are computed and compared between strategies. Two statistical analyses (Pearson product-moment correlation and paired-samples t-test) are also employed to compare the effects of strategy modification in various aspects. The major finding is that the body joints and muscles reactions to strategy modification are different or even antithetical to each other. Conclusion: A table is derived which depicts the sequences of the body joints and muscles affected from strategy modification from the most to the least. This table could be practical for therapists, physicians, and rehabilitation devices experts. Show more

Keywords: Sit-to-Stand strategy, chair-rise pattern, biomechanics, musculoskeletal, modeling, simulation, AnyBody, rehabilitation

DOI: 10.3233/THC-140834

Citation: Technology and Health Care, vol. 22, no. 4, pp. 627-644, 2014

Authors: Correia, João | Kendoff, Daniel | Klatte, Till Orla | Gehrke, Thorsten | Citak, Mustafa

Article Type: Research Article

Abstract: Background: Total joint replacements provide many benefits to patients but expose them to a variety of possible complications. Revision surgery is demanding and associated to a greater number of risks and possible complications than primary joint replacement. Objective: We describe the unsuccessful technique of percutaneous cementing in a loosened revision total knee arthroplasty. Methods: We report on a 66-year old male patient, admitted to our clinic with a painful left knee, four months after percutaneous cementation without implant exchange of the loosened rotating hinge implant was performed. Results: Although less demanding, …for the surgeon and the patient, it resulted in a delayed revision surgery. This attempt at avoiding revision surgery could have led to even further complications. Conclusions: This case emphasizes the need to avoid novel techniques on patients, with no previous studies and to refer these patients to specialized joint replacement centers for revision surgery. Show more

Keywords: Percutaneous cementation, aseptic loosening, complication, total knee arthroplasty, revision surgery

DOI: 10.3233/THC-140810

Citation: Technology and Health Care, vol. 22, no. 4, pp. 645-650, 2014

Authors: Cuesta, Pedro | Lado, María J. | Vila, Xosé A. | Alonso, Raúl

Article Type: Research Article

Abstract: Background: Premature ventricular contractions (PVCs) are cardiac abnormalities that may occur in subjects with/without cardiovascular disorder. Detection is usually performed from electrocardiograms (ECGs); heart activity for a long period of time must be recorded at hospital or with ambulatory electrocardiography. An alternative with a common mobile device would be very interesting, because a simple heart rate sensor should be sufficient. Objective: To develop an algorithm to detect PVCs using the RR-interval (distance between consecutive beats) extracted from ECGs or from the heart rate signal captured by mobile devices. Methods: Feature extraction and classification techniques …were included: 1) two timing interval features (prematurity and compensatory pause) were extracted. 2) A linear classifier was applied. To validate the method, the MIT-BIH Arrhythmia Database was used. Considering the existence of unbalanced classes (normal beats and PVCs) at different decision costs, validation was performed with receiver operating characteristic (ROC) analysis. Results: A sensitivity of 90.13% and a specificity percentage of 82.52% were achieved. The area under the ROC curve (AUC) was 0.928. Conclusions: The method is advantageous since it only uses the RR-interval signal for PVC detection, and results compare well with more complex methods that use ECG recording. Show more

Keywords: Heart rate, premature ventricular contractions, pattern recognition, ECG, biomedical signal processing, linear classifiers

DOI: 10.3233/THC-140818

Citation: Technology and Health Care, vol. 22, no. 4, pp. 651-656, 2014

Authors: Le, Thai | Reeder, Blaine | Chung, Jane | Thompson, Hilaire | Demiris, George

Article Type: Research Article

Abstract: Background: Smart home sensor systems provide a valuable opportunity to continuously and unobtrusively monitor older adult wellness. However, the density of sensor data can be challenging to visualize, especially for an older adult consumer with distinct user needs. Objective: We describe the design of sensor visualizations informed by interviews with older adults. The goal of the visualizations is to present sensor activity data to an older adult consumer audience that supports both longitudinal detection of trends and on-demand display of activity details for any chosen day. Methods: The design process is grounded through participatory …design with older adult interviews during a six-month pilot sensor study. Through a secondary analysis of interviews, we identified the visualization needs of older adults. We incorporated these needs with cognitive perceptual visualization guidelines and the emotional design principles of Norman to develop sensor visualizations. Results: We present a design of sensor visualization that integrate both temporal and spatial components of information. The visualization supports longitudinal detection of trends while allowing the viewer to view activity within a specific date. Conclusions: Appropriately designed visualizations for older adults not only provide insight into health and wellness, but also are a valuable resource to promote engagement within care. Show more

Keywords: Information visualization, older adults, smart home, sensor

DOI: 10.3233/THC-140839

Citation: Technology and Health Care, vol. 22, no. 4, pp. 657-666, 2014