Electric Wheelchair Navigation Simulators: why, when, how?

International audienc

Scapular kinematic variability during wheelchair propulsion is associated with shoulder pain in wheelchair users

The purpose of this study was to investigate whether wheelchair propulsion biomechanics differ between individuals with different magnitudes of shoulder pain. Forty (age 36 11 years) manual wheelchair users propelled their own daily living wheelchair at 1.11 m.s(-1) for three minutes on a dual-roller ergometer. Shoulder pain was evaluated using the Performance Corrected Wheelchair User's Shoulder Pain Index (PC-WUSPI). Correlation analyses between spatio-temporal, kinetic and upper limb kinematic variables during wheelchair propulsion and PC-WUSPI scores were assessed. Furthermore, kinematic differences between wheelchair users with no or mild shoulder pain (n = 33) and moderate pain (n = 7) were investigated using statistical parametric mapping. Participant mean PC-WUSPI scores were 20.3 +/- 26.3 points and varied from zero up to 104 points. No significant correlations were observed between kinetic or spatio-temporal parameters of wheelchair propulsion and shoulder pain. However, lower inter-cycle variability of scapular internal/external rotation was associated with greater levels of shoulder pain (r = 0.35, P = 0.03). Wheelchair users with moderate pain displayed significantly lower scapular kinematic variability compared to those with mild or no pain between 17 and 51% of the push phase for internal rotation, between 31-42% and 77-100% of the push phase for downward rotation and between 28-36% and 53-65% of the push phase for posterior tilt. Lower scapular variability displayed by wheelchair users with moderate shoulder pain may reflect a more uniform distribution of repeated subacromial tissue stress imposed by propulsion. This suggests that lower scapular kinematic variability during propulsion may contribute towards the development of chronic shoulder pain. (C) 2020 Elsevier Ltd. All rights reserved

Markerless Kinematics of Pediatric Manual Wheelchair Mobility

Pediatric manual wheelchair users face substantial risk of orthopaedic injury to the upper extremities, particularly the shoulders, during transition to wheelchair use and during growth and development. Propulsion strategy can influence mobility efficiency, activity participation, and quality of life. The current forefront of wheelchair biomechanics research includes translating findings from adult to pediatric populations, improving the quality and efficiency of care under constrained clinical funding, and understanding injury mechanisms and risk factors. Typically, clinicians evaluate wheelchair mobility using marker-based motion capture and instrumentation systems that are precise and accurate but also time-consuming, inconvenient, and expensive for repeated assessments. There is a substantial need for technology that evaluates and improves wheelchair mobility outside of the laboratory to provide better outcomes for wheelchair users, enhancing clinical data. Advancement in this area gives physical therapists better tools and the supporting research necessary to improve treatment efficacy, mobility, and quality of life in pediatric wheelchair users. This dissertation reports on research studies that evaluate the effect of physiotherapeutic training on manual wheelchair mobility. In particular, these studies (1) develop and characterize a novel markerless motion capture-musculoskeletal model systems interface for kinematic assessment of manual wheelchair propulsion biomechanics, (2) conduct a longitudinal investigation of pediatric manual wheelchair users undergoing intensive community-based therapy to determine predictors of kinematic response, and (3) evaluate propulsion pattern-dependent training efficacy and musculoskeletal behavior using visual biofeedback.Results of the research studies show that taking a systems approach to the kinematic interface produces an effective and reliable system for kinematic assessment and training of manual wheelchair propulsion. The studies also show that the therapeutic outcomes and orthopaedic injury risk of pediatric manual wheelchair users are significantly related to the propulsion pattern employed. Further, these subjects can change their propulsion pattern in response to therapy even in the absence of wheelchair-based training, and have pattern-dependent differences in joint kinematics, musculotendon excursion, and training response. Further clinical research in this area is suggested, with a focus on refining physiotherapeutic training strategies for pediatric manual wheelchair users to develop safer and more effective propulsion patterns

DEVELOPMENT AND EVALUATION OF AN ADVANCED REAL-TIME ELECTRICAL POWERED WHEELCHAIR CONTROLLER

Advances in Electric Powered Wheelchairs (EPW) have improved mobility for people with disabilities as well as older adults, and have enhanced their integration into society. Some of the issues still present in EPW lie in the difficulties when encountering different types of terrain, and access to higher or low surfaces. To this end, an advanced real-time electrical powered wheelchair controller was developed. The controller was comprised of a hardware platform with sensors measuring the speed of the driving, caster wheels and the acceleration, with a single board computer for implementing the control algorithms in real-time, a multi-layer software architecture, and modular design. A model based real-time speed and traction controller was developed and validated by simulation. The controller was then evaluated via driving over four different surfaces at three specified speeds. Experimental results showed that model based control performed best on all surfaces across the speeds compared to PID (proportional-integral-derivative) and Open Loop control. A real-time slip detection and traction control algorithm was further developed and evaluated by driving the EPW over five different surfaces at three speeds. Results showed that the performance of anti-slip control was consistent on the varying surfaces at different speeds. The controller was also tested on a front wheel drive EPW to evaluate a forwarding tipping detection and prevention algorithm. Experimental results showed that the tipping could be accurately detected as it was happening and the performance of the tipping prevention strategy was consistent on the slope across different speeds. A terrain-dependent EPW user assistance system was developed based on the controller. Driving rules for wet tile, gravel, slopes and grass were developed and validated by 10 people without physical disabilities. The controller was also adapted to the Personal Mobility and Manipulation Appliance (PerMMA) Generation II, which is an advanced power wheelchair with a flexible mobile base, allowing it to adjust the positions of each of the four casters and two driving wheels. Simulations of the PerMMA Gen II system showed that the mobile base controller was able to climb up to 8” curb and maintain passenger’s posture in a comfort position

Design and Validation of Control Interfaces for Anna

This project improves the control mechanisms for a semi-autonomous wheelchair with an assistive robotic arm system. The wheelchair is aimed at increasing the self-sufficiency of individuals with LIS. The objectives include the validation of the existing control interfaces, as well as the integration and design of new systems. The wireless brain-computer headset, used to implement the control system for navigation, is validated through several user studies. An EMG sensor system serves as an alternative control module. To increase physical interaction with the environment, a robotic arm system is integrated. The system includes a RGB-D camera for object detection, enabling autonomous object retrieval. The project outcomes include a demonstration performing navigation and manipulation tasks

A new approach for operating powered wheelchairs by people with severe impairments

This paper discusses the introduction of mechanisms to adapt commercial powered wheelchairs in order to facilitate its driving by people with severe impairments. Several models of operation are proposed and the most promising, at the moment, called legacy adapted mode, is detailed. A part of the formal operation model is presented. The model is then used in the STAGE simulator, not only for its valuation, but also to tune operational parameters that will be specific of each patient and to train the patients without a real wheelchair