Wyniki wyszukiwania - BazTech

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Development and testing of a wearable passive lower-limb support exoskeleton to support industrial workers

Yan Zefeng, Han Bin, Du Zihao, Huang Tiantian, Bai Ou, Peng Ansi

Biocybernetics and Biomedical Engineering

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2021

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Vol. 41, no. 1

221--238

EN

A custom-designed, wearable, lightweight, and passive exoskeleton was proposed to provide gravity support for industrial workers to reduce prevalence of musculoskeletal disorders, joint injures, and arthritis caused by repeatedly or persistently squatting task. The designed exoskeleton can act as a wearable chair to allow workers to squat for an extended period when performing prolonged tasks. The exoskeleton employs torsion springs to store energy harvested from the squatting motion, and the stored energy is released to help the workers stand up. Dimensions optimization designs based on the finite element analysis program were implemented for a lightweight of the device. Besides, the exoskeleton effectiveness was investigated by performing an ergonomic assessmenton muscular activity, plantar pressure, endurance time, and comfort. The plantar pressure and electromyography of rectus femoris, biceps femoris, vastus medialis, and vastus laterals were measured in a simulated assembly task with the knee bend for three different angles (60°, 90°, 120°) under two conditions of with and without the exoskeleton. The endurance time was recorded in three different static squatting tasks. The comfort with the exoskeleton was recorded. Under the condition of wearing the exoskeleton, the average reduction of muscle activity was 44.8–71.5%, and the plantar pressure was 58.5–64.2%. The exoskeleton contributed to an increase in endurance time from 2.76 to 13.58 min. Moreover, 70% of the subjects exhibited a comprehensive exoskeleton comfort score of higher than 70. The experimental results demonstrated that this exoskeleton has good potential to reduce physical workload and increase endurance time during industrial assembly tasks.

2

Three-dimensional analysis of gait in children and adolescents with juvenile idiopathic arthritis

Bazarnik-Mucha Katarzyna, Snela Sławomir, Szczepanik Magdalena, Jarmuziewicz Agnieszka, Guzik Agnieszka, Wolińska Olga, Drużbicki Mariusz

Acta of Bioengineering and Biomechanics

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2020

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Vol. 22, no. 2

35--45

EN

The paper aimed to assess the gait pattern in children and adolescents with juvenile idiopathic arthritis (JIA) treated at the rehabilitation center and to assess changes in this pattern after the end of treatment and 9 months later. Methods: 50 children with JIA were enrolled into the study. 35 healthy volunteers were enrolled into the study for a comparison. Spatiotemporal and kinematic gait parameters were obtained using a movement analysis system. The Gait Deviation Index (GDI) was calculated. The assessment was performed three times: on the day of admission to the rehabilitation center, after the end of a 4-week treatment period and 9 months later. Results: With regard to the majority of spatiotemporal and kinematic parameters, differences in their distribution were highly statistically significant between the study group and the control group ( p < 0.001). In two subsequent tests, differences were less significant when compared to the control group ( p < 0.01). In the study group, ranges of motion in the sagittal plane in the hip ( p < 0.01), knee ( p < 0.001) and ankle joints ( p < 0.01) increased significantly between tests 1 and 2, and 1 and 3. A significantly lower value of GDI was observed in the study group (right limb; p = 0.036). Conclusions: The gait pattern of children with JIA is significantly different from the one observed in healthy children. A rehabilitation program significantly improved gait in children with JIA, but differences compared to healthy children were still observed, and it indicates that the abnormal gait pattern became permanent in this group of subjects.

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RASIT: Region shrinking based Accurate Segmentation of Inflammatory areas from Thermograms

Bardhan S., Bhowmik M. K., Debnath T., Bhattacharjee D.

Biocybernetics and Biomedical Engineering

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2018

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Vol. 38, no. 4

903--917

EN

Effective segmentation of thermal images reflecting the inflamed region in human body to assist medical diagnosis is a challenging task. In this paper we propose a method for thermal image segmentation, named as ‘‘Region shrinking based Accurate Segmentation of Inflammatory areas from Thermograms’’, in short RASIT. The method comprising of four steps encompassing thermal image contextual electrostatic force extraction, intensity adjustment as applicable, automated generation of the weighted threshold, and segmentation of thermograms based on the computed threshold. The proposed method is operative devoid of the subjective and possibly questionable task of parameter selection clearly offering an edge over the state-of-the-art methods in terms of usage. The efficacy of our proposed technique is shown by experimenting on abnormal thermograms taken from two datasets: one is newly created knee arthritis thermogram dataset and another is online available Database of Mastology Research (DMR) of breast thermograms. The averages on correct detection rates obtained by the proposed method for both the knee and breast thermograms are 98.2% and 96.98% respectively with favorable inference on basis of Wilcoxon's test. Application of the proposed method minimizes the complexity of parameter selection, time complexity of execution and amount of under segmentation compared to existing state-of-the-art methods of thermogram segmentation.

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Biomechanical analysis of a new type of compressive splint used in carpal arthrodesis

Jiroušek O., Máca J., Jira J.

Acta of Bioengineering and Biomechanics

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2001

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Vol. 3, nr 1

59-73

EN

This paper presents a numerical analysis of the state of stress in a new type of splint used for carpal arthrodesis. Using the finite element method we evaluated the state of stress of the splint and the respective bones in two important load cases. Results of the numerical analysis were confirmed by photoelasticity test applied to the splint model. A qualitative comparison of different approaches to modelling short bones used in the finite element method is also made.