Most of the previous studies on the vibration ride comfort of the human-vehicle system were focused only on one or two aspects of the investigation. A hybrid approach which integrates all kinds of investigation method...Most of the previous studies on the vibration ride comfort of the human-vehicle system were focused only on one or two aspects of the investigation. A hybrid approach which integrates all kinds of investigation methods in real environment and virtual environment is described. The real experimental environment includes the WBV（whole body vibration） test, questionnaires for human subjective sensation and motion capture. The virtual experimental environment includes the theoretical calculation on simplified 5-DOF human body vibration model, the vibration simulation and analysis within ADAMS/VibrationTM module, and the digital human biomechanics and occupational health analysis in Jack software. While the real experimental environment provides realistic and accurate test results, it also serves as core and validation for the virtual experimental environment. The virtual experimental environment takes full advantages of current available vibration simulation and digital human modelling software, and makes it possible to evaluate the sitting posture comfort in a human-vehicle system with various human anthropometric parameters. How this digital evaluation system for car seat comfort design is fitted in the Industry 4.0 framework is also proposed.展开更多
Flexible pressure monitoring device can help correct the sitting posture and prevent health problems(e.g.,deformity of spinal column and musculoskeletal disease).Currently,most measurement systems hinder their wide ap...Flexible pressure monitoring device can help correct the sitting posture and prevent health problems(e.g.,deformity of spinal column and musculoskeletal disease).Currently,most measurement systems hinder their wide applications owing to the high cost or low accuracy.In this study,a flexible sitting pressure measurement system was proposed based on a textile-based capacitive pressure sensor array in order to measure sitting pressure distribution simply and conveniently.The capacitive pressure sensor array is sandwich structure composed of a high-density sponge layer and two electrode array fabrics,which possesses high resolution(2.26 sensors/cm2),high sensitivity(0.701 kPa-1)and fast response(≤35 ms).It is worth noting that the raw materials of the sensing fabric include commercialized copper sheets and polyester yarns.The as-prepared pressure measurement system can accurately measure the pressure distribution nephogram for sitting posture analysis.The sitting pressure of 10 volunteers was measured and six types of posture were distinguished clearly.展开更多
Pressure ulcers are a common complication among wheelchair-bound population. They are resulted from prolonged exposure to high pressure, which restricts blood flow and leads to tissue necrosis. In this work, a continu...Pressure ulcers are a common complication among wheelchair-bound population. They are resulted from prolonged exposure to high pressure, which restricts blood flow and leads to tissue necrosis. In this work, a continuous pressure monitoring system is developed for pressure ulcer prevention. The system consists of 64 pressure sensors on a 40×50 cm2 sheet. Real time pressure data and corresponding maps are displayed on a computer simultaneously. Furthermore, a posture detection procedure is proposed for sitting posture identification. Having information about the patient’s postural history, caregivers are capable of a better decision about repositioning and treating the patient.展开更多
The purpose of this study was to examine the hypothesis that the minimum angle-jerk with via-point model could account for the temporal consistency of kinematics in sit-to-stand (STS) and back-to-sit (BTS) movements. ...The purpose of this study was to examine the hypothesis that the minimum angle-jerk with via-point model could account for the temporal consistency of kinematics in sit-to-stand (STS) and back-to-sit (BTS) movements. The positions of bony landmarks on the subjects during the tasks were recorded using a Vicon motion analysis system to yield the angular displacement and position of the center of mass (COM) of a three-link rigid body model in the sagittal plane. Minimum angle-jerk and minimum jerk trajectories with a via-point were computed for joint angle and COM, respectively. Five to six candidate points were selected as the via-point from the measured trajectory based on the separate kinematic events. The results show the optimal angular trajectories using the via-points (via-angles) before the seat-off for STS, and at around the seat-contact for BTS resembles the measured angular trajectories well, indicating that the posture at the via-point was temporally optimal to produce the minimum angle-jerk trajectory for both movements. It is hypothesized that the multi-joint angular patterns during STS and BTS movements were organized to pass through the via-point, namely the via-posture along the minimum angle-jerk trajectory.展开更多
To reduce the vision problems caused by improper sitting posture,the research group used Raspberry Pi as the main controller for a multifunctional sitting posture detector with functions such as sitting posture detect...To reduce the vision problems caused by improper sitting posture,the research group used Raspberry Pi as the main controller for a multifunctional sitting posture detector with functions such as sitting posture detection,face positioning,cloud monitoring,etc.UUsing tech-nologies or algorithms such as machine vision and convolutional neural networks,our design can realize the user’s sitting posture error detec-tion,such as left,right,low head position,or forward body position with alarming,so that the user can maintain the appropriate sitting posture.展开更多
不正确的坐姿通常会导致青少年近视、脊柱侧弯和退行性疾病。研究能够快速、准确识别不规律坐姿的智能监测技术,有助于保持正确的姿势并预防健康问题。为了解决RGB图像易受光照强度以及遮挡因素的干扰并造成的识别率不高等问题,通过采...不正确的坐姿通常会导致青少年近视、脊柱侧弯和退行性疾病。研究能够快速、准确识别不规律坐姿的智能监测技术,有助于保持正确的姿势并预防健康问题。为了解决RGB图像易受光照强度以及遮挡因素的干扰并造成的识别率不高等问题,通过采用双流RGB-D图像作为双输入,利用ResNet网络中的残差结构改进EfficientNet基线网络结构,提出了一种基于改进R-EfficientNet的双流RGB-D多模态信息融合的坐姿识别方法。试验结果表明,提出的R-EfficientNet融合方法模型对8种坐姿的识别均值平均精度(mean average precision,mAP)达到了98.5%。与CNN、Vgg16、ResNet18、EfficientNet、RGB-D不同的输入方法相比,所提方法获得了最高的识别率。该方法不仅可以用于坐姿客观监测,具有医学和社会效益,此外还为人体工学研究者们提供改进办公家具的方案。展开更多
基金Supported by National Natural Science Foundation of China(Grant No.51465056)Xinjiang Provincial Natural Science Foundation of China(Grant No.2015211C265)Xinjiang University Ph D Start-up Funds,China
文摘Most of the previous studies on the vibration ride comfort of the human-vehicle system were focused only on one or two aspects of the investigation. A hybrid approach which integrates all kinds of investigation methods in real environment and virtual environment is described. The real experimental environment includes the WBV（whole body vibration） test, questionnaires for human subjective sensation and motion capture. The virtual experimental environment includes the theoretical calculation on simplified 5-DOF human body vibration model, the vibration simulation and analysis within ADAMS/VibrationTM module, and the digital human biomechanics and occupational health analysis in Jack software. While the real experimental environment provides realistic and accurate test results, it also serves as core and validation for the virtual experimental environment. The virtual experimental environment takes full advantages of current available vibration simulation and digital human modelling software, and makes it possible to evaluate the sitting posture comfort in a human-vehicle system with various human anthropometric parameters. How this digital evaluation system for car seat comfort design is fitted in the Industry 4.0 framework is also proposed.
基金Fundamental Research Fund for the Central Universities,China(Nos.2232020G-01 and 19D110106)Young Elite Scientists Sponsorship Program by China Association for Science and Technology,China(No.2017QNRC001)Graduate Student Innovation Fund of Donghua University,China(No.20D310111)。
文摘Flexible pressure monitoring device can help correct the sitting posture and prevent health problems(e.g.,deformity of spinal column and musculoskeletal disease).Currently,most measurement systems hinder their wide applications owing to the high cost or low accuracy.In this study,a flexible sitting pressure measurement system was proposed based on a textile-based capacitive pressure sensor array in order to measure sitting pressure distribution simply and conveniently.The capacitive pressure sensor array is sandwich structure composed of a high-density sponge layer and two electrode array fabrics,which possesses high resolution(2.26 sensors/cm2),high sensitivity(0.701 kPa-1)and fast response(≤35 ms).It is worth noting that the raw materials of the sensing fabric include commercialized copper sheets and polyester yarns.The as-prepared pressure measurement system can accurately measure the pressure distribution nephogram for sitting posture analysis.The sitting pressure of 10 volunteers was measured and six types of posture were distinguished clearly.
文摘Pressure ulcers are a common complication among wheelchair-bound population. They are resulted from prolonged exposure to high pressure, which restricts blood flow and leads to tissue necrosis. In this work, a continuous pressure monitoring system is developed for pressure ulcer prevention. The system consists of 64 pressure sensors on a 40×50 cm2 sheet. Real time pressure data and corresponding maps are displayed on a computer simultaneously. Furthermore, a posture detection procedure is proposed for sitting posture identification. Having information about the patient’s postural history, caregivers are capable of a better decision about repositioning and treating the patient.
文摘The purpose of this study was to examine the hypothesis that the minimum angle-jerk with via-point model could account for the temporal consistency of kinematics in sit-to-stand (STS) and back-to-sit (BTS) movements. The positions of bony landmarks on the subjects during the tasks were recorded using a Vicon motion analysis system to yield the angular displacement and position of the center of mass (COM) of a three-link rigid body model in the sagittal plane. Minimum angle-jerk and minimum jerk trajectories with a via-point were computed for joint angle and COM, respectively. Five to six candidate points were selected as the via-point from the measured trajectory based on the separate kinematic events. The results show the optimal angular trajectories using the via-points (via-angles) before the seat-off for STS, and at around the seat-contact for BTS resembles the measured angular trajectories well, indicating that the posture at the via-point was temporally optimal to produce the minimum angle-jerk trajectory for both movements. It is hypothesized that the multi-joint angular patterns during STS and BTS movements were organized to pass through the via-point, namely the via-posture along the minimum angle-jerk trajectory.
文摘To reduce the vision problems caused by improper sitting posture,the research group used Raspberry Pi as the main controller for a multifunctional sitting posture detector with functions such as sitting posture detection,face positioning,cloud monitoring,etc.UUsing tech-nologies or algorithms such as machine vision and convolutional neural networks,our design can realize the user’s sitting posture error detec-tion,such as left,right,low head position,or forward body position with alarming,so that the user can maintain the appropriate sitting posture.
文摘不正确的坐姿通常会导致青少年近视、脊柱侧弯和退行性疾病。研究能够快速、准确识别不规律坐姿的智能监测技术,有助于保持正确的姿势并预防健康问题。为了解决RGB图像易受光照强度以及遮挡因素的干扰并造成的识别率不高等问题,通过采用双流RGB-D图像作为双输入,利用ResNet网络中的残差结构改进EfficientNet基线网络结构,提出了一种基于改进R-EfficientNet的双流RGB-D多模态信息融合的坐姿识别方法。试验结果表明,提出的R-EfficientNet融合方法模型对8种坐姿的识别均值平均精度(mean average precision,mAP)达到了98.5%。与CNN、Vgg16、ResNet18、EfficientNet、RGB-D不同的输入方法相比,所提方法获得了最高的识别率。该方法不仅可以用于坐姿客观监测,具有医学和社会效益,此外还为人体工学研究者们提供改进办公家具的方案。
文摘目的研究不同刺激声在坐姿下诱发的前庭诱发肌源性电位(vestibular-evoked myogenic potentials,VEMPs)特征,提供各波潜伏期及振幅等参数的正常值参考范围。方法分别用500 Hz短纯音(tone-burst)及500 Hz线性调频脉冲音(CE-chirp)两种刺激声对21名(男11人,女10人)听力正常且无耳蜗及前庭系统疾病的青年人(年龄22~33岁,平均年龄23.95±3.29岁)进行VEMPs测试,测试起始强度为110 dB nHL,以5 dB为步阶测试至阈值,记录各强度参数,并进行分析。结果两种刺激声坐姿下诱发的cVEMP及oVEMP阈值分别为tone-burst cVEMP 85.00±6.10 dB nHL,CE-chirp cVEMP 84.63±4.99 dB nHL;tone-burst oVEMP 83.38±6.54 dB nHL,CE-chirp oVEMP 82.50±6.20 dB nHL。两种刺激声测得的各强度p1潜伏期、n1潜伏期有显著差异(P<0.05),p1-n1波间期、p1-n1振幅、双侧不对称性、双侧振幅比、双侧对称系数等均无显著差异(P>0.05)。结论坐姿下正常青年人两种刺激声给声强度100 dB nHL时VEMPs的引出率均为100%,500 Hz线性调频脉冲音可作为VEMPs测试的刺激声应用于临床,评估椭圆囊和球囊功能。
