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The purpose of this study is to compare the differences among neck muscle fatigue evaluation algorithms and to find a more effective algorithm which can provide a human factor quantitative evaluation method for neck muscle fatigue during bending over the desk. We collected surface electromyography signal of sternocleidomastoid muscle of 15 subjects using wireless physiotherapy Bio-Radio when they bent over the desk using memory pillows for 12 minutes. Five algorithms including mean power frequency, spectral moments ratio, discrete wavelet transform, fuzzy approximation entropy and the complexity algorithms were used to calculate the corresponding muscle fatigue index. The least squares method was used to calculate the corresponding coefficient of determination and slope of the linear regression of the muscle fatigue metric. The coefficient of determination evaluates anti-interference ability of algorithms. The maximum vertical distance which is obtained by the Kolmogorov-Smirnov test for the slopes evaluates the ability to distinguish fatigue of algorithms. The results indicate that in the aspect of anti-interference ability, the fuzzy approximation entropy has the largest when using memory pillows with different heights. When the fuzzy approximate entropy is compared with average power frequency or the discrete wavelet transform, the differences are significant ( < 0.05). In terms of distinguishing the degree of fatigue, the approximate entropy is still the largest, with a maximum of 0.496 7. Fuzzy approximation entropy is superior to other algorithms in ability of anti-interference and distinguishing fatigue. Therefore, fuzzy approximation entropy can be used as a better evaluation algorithm in the evaluation of cervical muscle fatigue.
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The OPT101 photoelectric sensor has the characteristics of good photoelectric response,buih-in transimpedance amplifier and small size,which meet the needs of accurately near-infrared spectral measurement in medical near-infrared spectroscopy (NIRS) range.Our research team has developed a series of portable NIRS instruments for NIRS measuring in intensive care units (ICU).The characteristics and advantages of OPT101 in the development of clinical ICU-specific NIRS instruments were introduced.The research progress of our team on the development of ICU-NIRS instruments using OPT101 was reviewed.The prospect of OPT101 in clinical noninvasive detection was discussed.
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Objective To study the influences of 8 important factors on fatigue evaluation as performing typical upper extremity operation. Methods Thirty-two subjects were divided into young male (G1),mid-age male (G2) and female (G3) groups. They were required to perform right arm flex/extend operation under different situations for 16 runs. L16 (44?23) orthogonal array was used to combine different situations (factors). Brief fatigue inventry(BFI) were recorded and simultaneous manual works (energy) were calculated. Both of them were used to evaluate the operation strategies. Results Difference between G1 and G2 was not significant,whereas it was as large as 39%,between G1+G2 and G3 (P
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The human workload is of great importance to ergonomic evaluation of man-machine system.The local muscle fatigue is considered to be one of the main indexes.In this paper,the cause of local muscle fatigue,its assessment methods and development trends were described in detail.Some related technological problems about its mechanism,measurement and assessment methods were analyzed and induced.Finally,some views were put forward for discussion.
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Vehicle driver fatigue is an important factor in traffic accidents.This paper introduced three kinds of detecting techniques,namely driver's physical signals and individual characteristics,vehicle parameters,and five detecting devices.But there still are limitations of the mentioned detecting techniques and devices in the paper.The problems and developing trend are briefly analyzed.