Evaluation on an ergonomic design of functional clothing for wheelchair users

Researchers have pointed out that people with physical disabilities find it difficult to obtain suitable clothing. In this study a set of wheelchair user oriented functional clothing was designed. Attention was paid to the wheelchair users' daily living activities related with clothing. An evaluating system combined with sports tournament and rehabilitation medicine was introduced to assess the new designed clothing. Six wheelchair users (3 males and 3 females) were invited to wear the clothing. A set of normal functional clothing was employed as a comparison (Control). The time required to complete three different daily living activities, i.e. dressing and undressing, going to toilet and bathing were recorded. Results showed that with the new clothing wheelchair users' competence of managing toilet was increased by 52.9%. The time needed for toilet was reduced by 45.7%. Their capability of managing dressing and undressing was improved by 24.6%. The study indicated that the newly designed clothing could facilitate wheelchair users' daily living activities related with clothing.     

Arm strength and impulse generation: Initiation of wheelchair movement by the physically disabled

The initiation of wheelchair movement is a function of starting technique, upper extremity strength and the stabilizing potential of the trunk musculature. This study examined the relation between arm strength, activity level, degree of disability and the maximum impulse generated from a resting position while seated in a wheelchair. Two starting techniques were examined using a force platform.

Sixteen male paraplegic adults (age 28·1 ±6·9 year, supine length l·62±0·16m, total body mass 61·2±16·2 kg) performed three grab starts and three strike starts on a Kistler force platform. For each technique, the processed data were averaged together and impulse in the forward/backward and vertical directions was determined. Isokinetic shoulder flexion and elbow extension moments of force were measured at an angular velocity of 60 degs^?1. Peak power and average power were calculated from digitized values of the moment of force-time curves.

Subjects were classified as highly active (HA, >2 exercise periods per week, N = 8) or less active (LA, N = 8). In addition, the site of spinal cord injury was quantified as a high level lesion (HL, above T10, N = 7) or low level lesion (LL, N = 9). There were no differences (p>0·05) between activity or lesion level groups with respect to age, height, total body mass or skinfold thicknesses. Nor were there significant differences between groups for shoulder and elbow power values. However, shoulder flexion scores for the combined groups were greater than those scores for elbow extension (peak power, 72·9 W versus 49·5 W; average power, 51·8 W versus 37·2 W). The grab start produced more forward impulse (the integral of forward force × time) (152·6 N s) than the strike start (119·5 N s, p < 0·05), but the magnitude of this difference was similar for the several groups. Wheelchair impulse scores were well correlated with strength values in both HA and LA subjects (r=0·74 to 0·89). However, the intercepts of the regression lines were dissimilar between activity groups, suggesting an interaction between activity pattern, muscle force and impulse.     

The Role of Peripheral Vision in Static Balancing

Abstract

A study was made to determine the role of peripheral vision in static balancing. Three groups of subjects were tested under sighted and blindfold conditions, and also under a minimal cues condition.

One of these groups was trained in the use of peripheral vision and after five days achieved sighted competence under the minimal cues condition. A second group had no training, but practised for a similar period and showed no such improvement. The third group was tested with progressively decreasing amounts of peripheral vision, and the stage at which deterioration in performance occurred was noted. The results are discussed in relation to the use of peripheral vision, and in the relevance of this work to the training of the blind.     

座面可调电动轮椅的机构运动仿真

通过运动仿真,对座面可调的多功能轮椅进行机构设计。基于人机工程学及位姿分析,设计各构件尺寸。在MATLAB中建立轮椅运动学模型,通过仿真分析得到了各刚体关键铰接点的位移、速度、加速度等参数。将得到的运动学参数与轮椅的功能要求进行比较,对轮椅整车机构进行修正。所设计的轮椅能辅助残障者实现坐立、站立、平躺等多种姿态间的转变,也便于轮椅与其它康复设备的安全对接。多刚体运动学仿真方法能更直观进行机构功能分析,从而缩短设计周期。     

Force sensorless control of power-assisted wheelchair based on motion coordinate transformation

Wheelchairs used by disabled people or caregivers are typical human-in-the-loop systems, of which the power-assisted control in accordance to a human’s perception is essential. This paper presents a force sensorless control based on a force/torque observer with a motion coordinate transformation for power-assisted wheelchairs. The output linear movement and angular velocity motions of a power wheelchair can be controlled independently by inherent coupling dual-driving-wheels with this transformation. A force observer design without numerical differentiation, which is utilized to indirectly measure the human’s pushing force, is proposed for realizing the force sensorless power-assisted control. An assistant performance index is adopted to evaluate the validity of the power-assisted control according to a specified power-assisted gain. Experimental results show that the proposed method can effectively estimate the human force exerted on the wheelchair for achieving power-assisted control.     

新型语音控制轮椅

语音控制具有方便、快捷的特点，在生活中的应用也越采越广泛。将其应用于轮椅具有更大现实意义。这里介绍了一种新型全方位运动语音控制轮椅的设计。对轮椅机械构造、运动功能做了简要的介绍，对其语音控制实现的主要方面进行了较为详细的说明，包括语音信号的预处理、动态时间规整及算法和模板匹配的训练方法。     

残疾人无缝对接系统的设计与仿真

针对残疾人远距离出行不便,设计了残疾人无缝对接系统。残疾人乘坐轮椅通过轮椅举升装置进入汽车驾驶室,由轮椅代替驾驶座椅,实现驾车远距离出行。为了验证系统工作的稳定性,建立基于ADAMS的虚拟样机模型,对轮椅举升装置工作过程进行动态仿真,结果表明此系统工作稳定可靠。基于Opti Struct对主要部件进行拓扑优化设计,得到了理想的轻量化结构。     

基于视觉导航的智能轮椅控制系统

为有效实现基于标识线的轮椅视觉导航功能,设计一种嵌入式智能轮椅控制系统。该系统采用图像数据压缩技术突破存储容量与运行速度的限制,提出标识线自适应阈值提取算法,用于实现不同光线环境下的阈值提取,引入模糊比例-积分-微分控制算法实现对轮椅路径跟踪的稳定控制,通过将超声波避障和手动干预等技术融合到视觉导航控制系统中,保障轮椅运行的安全性。实验结果表明,智能轮椅在各种环境下运行安全稳定。     

Efficient Body-Transfer Wheelchair for Assisting Functionally ImpairedPeople

Functionally impaired people always have difficulty accomplishing activities of daily living. In this regard, tasks including toileting and bathing have a higher prevalence rate of injuries and greater risk of falling. In this study, a body-transfer wheelchair was developed to assist people in transferring from bed to wheelchair for bathing, and toileting. The body-transfer wheelchair is a semi-automatic wheelchair that has features such as a controlled leg and backrest, linkage commode slot, and height adjustment. The wheelchair consists of a seat and a main frame that can be detached to enable bathtub transfer. This mechanism lets the user stay on the seat while being transferred into the bathtub without any risk of falling. A linkage mechanism was developed as a part of the seat for ease of toileting. Kinematic and force analysis was conducted to calculate the force required for each actuator. It has been proved by the experimental results that the wheelchair can securely and comfortably transfer a patient from the bed to the toilet or bathtub. A survey has been conducted to evaluate the wheelchair prototype design idea. Two focus groups were chosen: one comprised of functionally impaired people, and the other comprised of caregivers. The results of the survey show that 60% of both functionally impaired people and caregivers would like to use the body-transfer wheelchair for toileting and bathing purpose. Additionally, on average 65% of both focus groups find it convenient to operate the body-transfer wheelchair independently.     

Design based exploration of medical system adoption: Case of wheelchair ramps

This study focuses on the exploration of wheelchair users' expectations from portable ramps and their adoption factors, then correspondingly offers a smart mass customization design tool. Briefly, portable ramps are generally used by wheelchair users, and provide a temporary solution to increase accessibility in their daily lives. In this research, a rollable ramp was examined as this prototype was developed in a prior funded research and thesis study. Our aim in this study is to explore the critical factors of satisfaction of users' and potential users' of portable ramps. To maximize the usability of portable ramp in various outdoor/indoor spaces and physical structures, an efficient permutation of flexible/adjustable components is offered. The research includes flexibility and customization and many external factors effective for adoption of portable ramp. In this context, three research methods were applied; semi structured-face-to-face interviews, observation, and experimental study. The constructs of the survey were extracted from literature and patent reviews then refined during observation and interviews. Wheelchair users answered a web-based survey with multiple constructs. The survey uncovered that personalization, flexibility, extension capability, and cost is critical. As well, users prefer the chance to try the model before purchasing. The effort needed to carry and learn how to use the ramp seems to be one of the key factors. It is also found that the user's life style and product match has an effect on adoption. At the end of the study, a smart mass customization design tool will be developed, which potential users or sales representatives are able to easily interact with in order to customize the portable ramp.