Efficient Body-Transfer Wheelchair for Assisting Functionally Impaired People

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 bodytransfer 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.

Study on Characteristics of the Wheelchair-User Combination

To summarize the characteristics of wheelchair-user combination, this paper studied wheelchairs, wheelchair users, nursing staffs and interaction relationship between them. Firstly, the findings of some research on wheelchairs and wheelchair users were investigated, and the studies in four aspects of wheelchairs and their accessories, wheelchair users, wheelchairs and wheelchair users (man-machine system), and skills training for the performance of wheelchair were reviewed. Then “wheelchair-user combination” was put forward based on the relationship between wheelchairs and wheelchair users in real life, and the “wheelchair-user combination” was divided into “WUs-Ws system” and “WUs-Ws-NSs system” according to whether the nursing staffs were needed. Finally, this paper analytically studied the characteristics of wheelchair users, characteristics in use of wheelchair and characteristics of nursing staffs, as well as put forward the characteristics of the wheelchair-user combination.

Mechanics analysis of a wheelchair robot with wheel-track coupling mechanism

A barrier-free wheelchair robot with a mechanism coupled by wheel and track is presen- ted in this paper. Using the wheelchair, the lower limb disabled persons could be more relaxed to take part in outdoor activities whether on flat ground or stairs and obstacles in the city. The wheel- track coupling mechanism is designed and the stability of the bodywork of the wheelchair robot on the stairs is analyzed. In order to obtain the stability of wheelchair robot when it climbs obstacles, centroid projection method is applied to analyze the static stability, stability margin is proposed to provide the stability under some dynamic forces, and the push rod rotation angle in terms of the guaranteed stability margin is given. Finally, the dynamic model of the wheelchair robot based on Lagrange equation is established, which can be a theoretical foundation for the wheelchair control system design.

Implementation of a Biometric Interface in Voice Controlled Wheelchairs

In order to assist physically handicapped persons in their movements,we developed an embedded isolated word speech recognition system(ASR)applied to voice control of smart wheelchairs.However,in spite of the existence in the industrial market of several kinds of electric wheelchairs,the problem remains the need to manually control this device by hand via joystick;which limits their use especially by people with severe disabilities.Thus,a significant number of disabled people cannot use a standard electric wheelchair or drive it with difficulty.The proposed solution is to use the voice to control and drive the wheelchair instead of classical joysticks.The intelligent chair is equipped with an obstacle detection system consisting of ultrasonic sensors,a moving navigation algorithm and a speech acquisition and recognition module for voice control embedded in a DSP card.The ASR architecture consists of two main modules.The first one is the speech parameterization module(features extraction)and the second module is the classifier which identifies the speech and generates the control word to motors power unit.The training and recognition phases are based on Hidden Markov Models(HMM),K-means,Baum-Welch and Viterbi algorithms.The database consists of 39 isolated speaker words(13 words pronounced 3 times under different environments and conditions).The simulations are tested under Matlab environment and the real-time implementation is performed by C language with code composer studio embedded in a TMS 320 C6416 DSP kit.The results and experiments obtained gave promising recognition ratio and accuracy around 99%in clean environment.However,the system accuracy decreases considerably in noisy environments,especially for SNR values below 5 dB(in street:78%,in factory:52%).

The Design of Wheelchair Lifting Mechanism and Control System

In order to achieve a wheelchair lift function, this paper designs a tri-scissors mechanism. Through the so-called H-type transmission and L-type swing rod, the three scissors mechanisms lift in the same rate with only one liner motor while ensuring the stability of the lift. Finite element analysis in ANSYS is performed to verify the material strength. The control system with Sunplus SCM achieves the voice control of wheelchair walking and lifting.

Hand rim wheelchair training: Effects of intensity and duration on physical capacity

The purpose of this study was to compare the effects of intensity and duration of training on physical capacity in a 7 weeks hand rim wheelchair training in able-bodied men. Thirty-six able-bodied men participated in three groups: a 30% heart rate reserve (HRR) 70 min training group (N = 14), a 70% HRR 30 minutes training group (N = 13) and a 30% HRR 30 minutes training group (N = 9). All groups trained 3 times per week for 7 weeks on a treadmill. Pre and post tests on a wheelchair ergometer comprised a submaximal test at 20% and 40% of the estimated peak power output, in which submaximal heart rate, oxygen uptake and mechanical efficiency were determined. In maximal exercise tests, maximal isometric strength, sprint power, peak power output and peak oxygen uptake were measured. No significant differences were found between the training groups on submaximal and maximal parameters. It can be concluded that, in persons new to wheelchair use, seven weeks of wheelchair endurance training at an intensity of 30% HRR for 30 minutes is as effective as a training at a higher intensity (70% HRR) or with a longer duration (70 min).

Development of Voice Control Algorithm for Robotic Wheelchair Using MIN and LSTM Models

In this work,we developed and implemented a voice control algorithm to steer smart robotic wheelchairs(SRW)using the neural network technique.This technique used a network in network(NIN)and long shortterm memory(LSTM)structure integrated with a built-in voice recognition algorithm.An Android Smartphone application was designed and configured with the proposed method.A Wi-Fi hotspot was used to connect the software and hardware components of the system in an offline mode.To operate and guide SRW,the design technique proposed employing five voice commands(yes,no,left,right,no,and stop)via the Raspberry Pi and DC motors.Ten native Arabic speakers trained and validated an English speech corpus to determine the method’s overall effectiveness.The design method of SRW was evaluated in both indoor and outdoor environments in order to determine its time response and performance.The results showed that the accuracy rate for the system reached 98.2%for the five-voice commends in classifying voices accurately.Another interesting finding from the real-time test was that the root-mean-square deviation(RMSD)for indoor/outdoor maneuvering nodes was 2.2∗10–5(for latitude),while that for longitude coordinates was a whopping 2.4∗10–5(for latitude).

Wanting a Life in Decency!—A Qualitative Study from Experienced Electric Wheelchairs Users’ perspective

Background: The functionality and the safety of the electric wheelchairs were essential for users’ everyday life. Some evidence indicated that the wheelchair Per Se highly influenced users’ occupational life, their personal identity and social life;further, the wheelchair became an extension of the body and more than a technical device. Besides, there was still both environmental and self-efficacy or/and mental health factors obstacles for full social participation. Even so, there was to some extent stigma related to being a wheelchair user. There was a need to reflect users’ perspective on being depended on electric wheelchair. The aim, accordingly, was to describe and to get a deeper insight into electric wheelchairs users’ perspective and experiences of utilizing this device;a qualitative design with an inductive approach was used. Method: Qualitative latent and interpretative content analysis [1] [2] was used after repeated face-to-face semi-structured interviews with three experienced Swedish electric wheelchair users during the autumn 2017. Findings: The findings showed a high degree of dependability of the assistants that supported the users, and of the quality of that working relationship. The findings were formulated, abstracted and interpreted in several steps. It showed one theme of meaning: “Living in a space shifting between potential violation of or respect for human dignity”. Conclusion: The study showed that electric wheelchair users were relatively content with their lives as well as with their devices in turns of mobility and accessibility, but the meaning of their narrations showed a life at constant risk of having the respect of human rights and human respect violated. Besides, the importance of having access to good and high quality devices, good staffing, and environmental support, all in concordance with human rights, the clinical and practical implications of this study narrows down to a question of encountering the other person as a whole and worthy individual.

Influence of Wheelchair Cushions Fabricated by Therapists on Stability, Comfort, and Functionality

“Ease of comfort” and “functionality” are important factors that have been cited to improve wheelchair seating. The ability to maintain balance and posture while seated in a wheelchair improves stability, comfort, and functionality and is a prerequisite for daily activities. In this study, the authors used a sitting position measuring device to scientifically verify differences in sitting posture, comfort, and functionality depending on the presence or absence of cushions and the type of cushion in elderly individuals who used wheelchairs. Results suggested that a cushion fabricated by a therapist was more useful than a commercially available air cushion. While a commercially available air cushion was the most suitable, the therapist’s self-made cushion could be expected to demonstrate the same or better applicability than an air cushion.

Clothing Needs for Wheelchair Users: A Systematic Literature Review

The aim of this study was to identify the clothing needs of wheelchair users using relevant literatures in a global scale and to design a method to classify the clothing needs into a unified system, in order to generate a map of wheelchair users’ clothing needs with the information from multiple resources. The paper reviewed the previous studies about clothing needs and preference of wheelchair users. A three-tier screening was designed to extract main findings from the relevant literature. Content analysis and statistical analysis were used to integrate the information and identify implications. Information was categorized to represent the attributes of the clothing needs. The paper provides comprehensive insights about the specific barriers and abstract demands about the clothing needs of wheelchair users regarding their preference for apparel products. Eight essential attributes relating to the clothing needs of wheelchair users were identified: functional needs, fit attribute fabric and fiber, safety issue, aesthetic needs, expressive needs, quality of life, and extrinsic attributes. The attributes were classified into two general domains, reflecting the physical challenges and psychological desires of wheelchair users.

Measurement of the Wheelchair-Operating Time Spent by Stroke Patients Using a New Triaxial Accelerometer System

Purpose: We investigated the validity of a triaxial accelerometer system for measuring the time spent lying down, sitting, standing, walking, and operating a wheelchair by control subjects and stroke patients in a convalescence ward. Methods: Physical activities were measured using a new triaxial accelerometer system (A-MES;Activity Monitoring and Evaluation System) that consists of two sensors, a station, and analytical software used with a personal computer. In Experiment 1, the times that the healthy subjects (n = 12) spent operating a wheelchair, lying down, sitting, standing, and walking were measured both by the A-MES and by videotaping (video time). In Experiment 2, the amounts of time spent by the stroke patients not able to walk without support (n = 30) as they were lying down, sitting, standing, walking, and operating a wheelchair were measured by the A-MES. Results: The time spent operating a wheelchair measured with the A-MES was significantly correlated with the video time in the healthy subjects. The stroke patients’ average times (minutes) of total, operating a wheelchair, lying down, sitting, standing, and walking were 601.0 ± 18.1, 57.1 ± 28.8, 265.0 ± 86.3, 263.3 ± 60.6, 7.8 ± 7.0, and 7.7 ± 6.0, respectively. Conclusions: The A-MES accurately evaluated the stroke patients’ time spent operating a wheelchair. The stroke patients’ mean time spent operating a wheelchair over the course of one day was 57.1 ± 28.8 min in a Center for Rehabilitation.

Mean Threshold and ARNN Algorithms for Identification of Eye Commands in an EEG-Controlled Wheelchair

This paper represented Autoregressive Neural Network (ARNN) and meant threshold methods for recognizing eye movements for control of an electrical wheelchair using EEG technology. The eye movements such as eyes open, eyes blinks, glancing left and glancing right related to a few areas of human brain were investigated. A Hamming low pass filter was applied to remove noise and artifacts of the eye signals and to extract the frequency range of the measured signals. An autoregressive model was employed to produce coefficients containing features of the EEG eye signals. The coefficients obtained were inserted the input layer of a neural network model to classify the eye activities. In addition, a mean threshold algorithm was employed for classifying eye movements. Two methods were compared to find the better one for applying in the wheelchair control to follow users to reach the desired direction. Experimental results of controlling the wheelchair in the indoor environment illustrated the effectiveness of the proposed approaches.

Robust MPC Method for BMI Based Wheelchair

In this paper, robust MPC (Model Predictive Control) with adaptive DA converter method for the wheelchair using EEG (Electroencephalogram) based BMI (Brain Machine Interface) is discussed. The method is developed to apply to the obstacle avoidance system of wheelchair. This paper is the 1st stage for the development of the BMI based wheelchair in practical use. The robust MPC method is realized by using the minimax optimization with bounded constraint conditions. Some numerical examples are also included to demonstrate the effectiveness of the proposed methodas the former stage of the real experiments.

Improvement of a Joystick Controller for Electric Wheelchair User

The electric wheelchair is an effective machine for people with lower limb disability. The user controls the wheelchair by a joystick that helps the user to navigate the wheelchair along the desired path. Suppose the user on the wheelchair wants to operate the computer for his jobs or enjoyment, it is preferable for the user to be able to operate the computer without transferring from the wheelchair to a computer desk. Of course, some computer input devices are available for wheelchairs. One reasonable idea is to use the familiar joystick on the wheelchair as a computer input device. In this paper a joystick controller is proposed, which enables the user on the wheelchair to operate the computer settled on a nearby table. The proposed joystick controller can be achieved by mounting the sensor unit on the joystick without any modification of the conventional wheelchair controller. The principle of the sensing unit is to measure the inclination angle and the direction of the joystick with an acceleration and gyro sensor. Then the sensing unit sends the control data to the computer via an infrared or wireless signal. This proposal is based on a request done by the wheelchair users.

The Shift of the Ischial Region during Maneuvering the Standard Wheelchair and the Electric Wheelchair in Healthy Adults

Pressure injuries are frequent secondary complications that occur in patients with Spinal Cord Injury (SCI), and the recurrence rate of ischial pressure injury is highest in SCI patients. Most SCI patients use wheelchairs, and some studies have shown a relationship between buttock pressure and sitting posture. However, the pressure distribution during wheelchair maneuvering is unclear. We measured and compared the shift of the ischial region when maneuvering a standard wheelchair or electric wheelchair in healthy adults. The subjects drove wheelchairs on a flat ground of 10 m and the shift of ischial region was measured with a pressure distribution-measuring device. The ischial region shifted forward or backward while maneuvering both the standard wheelchair and the electric wheelchair, and the shift rate of the ischial region was not significantly different between the standard wheelchair and the electric wheelchair. The ischial region shift occurred when the forward head moved by the video while maneuvering both a standard wheelchair and an electric wheelchair. Therefore, the shift might occurred because the pelvis shifted forward in conjunction with head movement during maneuvering of both the standard wheelchair and the electric wheelchair. This result showed that it is important to reduce head and trunk movements when maneuvering a wheelchair to reduce the shear force on the buttocks and prevent pressure injuries.

Enhancing the Efficiency of Voice Controlled Wheelchairs Using NAM for Recognizing Partial Speech in Tamil

In this paper, we have presented an effective method for recognizing partial speech with the help of Non Audible Murmur (NAM) microphone which is robust against noise. NAM is a kind of soft murmur that is so weak that even people nearby the speaker cannot hear it. We can recognize this NAM from the mastoid of humans. It can be detected only with the help of a special type of microphone termed as NAM microphone. We can use this approach for impaired people who can hear sound but can speak only partial words (semi-mute) or incomplete words. We can record and recognize partial speech using NAM microphone. This approach can be used to solve problems for paralysed people who use voice controlled wheelchair which helps them to move around without the help of others. The present voice controlled wheelchair systems can recognize only fully spoken words and can’t recognise words spoken by semi-mute or partially speech impaired people. Further it uses normal microphone which hassevere degradation and external noise influence when used for recognizing partial speech inputs from impaired people. To overcome this problem, we can use NAM microphone along with Tamil Speech Recognition Engine (TSRE) to improve the accuracy of the results. The proposed method was designed and implemented in a wheelchair like model using Arduino microcontroller kit. Experimental results have shown that 80% accuracy can be obtained in this method and also proved that recognizing partially spoken words using NAM microphone was much efficient compared to the normal microphone.

A Star-Wheel Stair-Climbing Wheelchair

In order to achieve a wheelchair climb stairs function, this paper designs a star-wheel stair-climbing mechanism. Through the effect of the lock coupling, the star-wheel stair-climbing mechanism is formed to be fixed axis gear train or planetary gear train achieving flat-walking and stair-climbing functions. Crossing obstacle analysis obtains the maximum height and minimum width of obstacle which the wheelchair can cross. Stress-strain analysis in Solidworks simulation is performed to verify material strength.

Electric Wheelchair Control System Using Brain-Computer Interface Based on Alpha-Wave Blocking

A brain-computer interface(BCI)-based electric wheelchair control system was developed, which enables the users to move the wheelchair forward or backward, and turn left or right without any pre-learning. This control system makes use of the amplitude enhancement of alpha-wave blocking in electroencephalogram(EEG) when eyes close for more than 1 s to constitute a BCI for the switch control of wheelchair movements. The system was formed by BCI control panel, data acquisition, signal processing unit and interface control circuit. Eight volunteers participated in the wheelchair control experiments according to the preset routes. The experimental results show that the mean success control rate of all the subjects was 81.3%, with the highest reaching 93.7%. When one subject's triggering time was 2.8 s, i.e., the flashing time of each cycle light was 2.8 s, the average information transfer rate was 8.10 bit/min, with the highest reaching 12.54 bit/min.

Design of a New Multifunctional Wheelchair-bed

Currently, the aging of the population has become the world's social problem. With the increase of aging population and lots of disability, paralysis makes nursing care more difficult. Because of many elderly cannot get timely care, the phenomenon that the elderly have chronic diseases has become more and more serious. It is important to research and develop a new product which can help the elderly and the disabled for improving the quality of their life. This paper suggests a new type of multifunctional self-caring wheelchair-bed, which is combined with a wheelchair and a bed. The bed can realize the free conversion among user sitting, leg lifting and lying down, and also can implement the function of turning on sides. Particularly, the wheelchair can be easily separated from the bed and combined, so that patients and the elderly can move freely using it, and even it can be transformed into a standing type to satisfy the patient's standing demand, and to a certain extent, carry out the purpose of rehabilitation.

Navigation system for a smart wheelchair

Recent results on the development of a navigation system for a smart wheelchair are presented in this paper. In order to reduce the development cost, a modular solution is designed by using commercial and low cost devices. The functionalities of the tracking control system are described. Experimental results of the proposed assistive system are also presented and discussed.