Objective: To develop a virtual reality (VR)-based simulator that can assist clinicians in performing standardized wheelchair driving assessments. Design: A completely within-subjects repeated measures design. Methods: Participants drove their wheelchairs along a virtual driving circuit modeled after the Power Mobility Road Test (PMRT) and in a hallway with decreasing width. The virtual simulator was displayed on computer screen and VR screens and participants interacted with it using a set of instrumented rollers and a wheelchair joystick. Driving performances of participants were estimated and compared using quantitative metrics from the simulator. Qualitative ratings from two experienced clinicians were used to estimate intraand inter-rater reliability. Results: Ten regular wheelchair users (seven men, three women; mean age ± SD, 39.5 ± 15.39 years) participated. The virtual PMRT scores from the two clinicians show high inter-rater reliability (78-90%) and high intra-rater reliability (71-90%) for all test conditions. More research is required to explore user preferences and effectiveness of the two control methods (rollers and mathematical model) and the display screens. Conclusions: The virtual driving simulator seems to be a promising tool for wheelchair driving assessment that clinicians can use to supplement their real-world evaluations.

Eating is an essential activity of daily living (ADL) for staying healthy and living at home independently. Although numerous assistive devices have been introduced, many people with disabilities are still restricted from independent eating due to the devices' physical or perceptual limitations. In this work, we present a new meal-assistance system and evaluations of this system with people with motor impairments. We also discuss learned lessons and design insights based on the evaluations. The meal-assistance system uses a general-purpose mobile manipulator, a Willow Garage PR2, which has the potential to serve as a versatile form of assistive technology. Our active feeding framework enables the robot to autonomously deliver food to the user's mouth, reducing the need for head movement by the user. The user interface, visually-guided behaviors, and safety tools allow people with severe motor impairments to successfully use the system. We evaluated our system with a total of 10 able-bodied participants and 9 participants with motor impairments. Both groups of participants successfully ate various foods using the system and reported high rates of success for the system's autonomous behaviors. In general, participants who operated the system reported that it was comfortable, safe, and easy-to-use.

Objective To compare wheelchair driving performance in a driving simulator using a conventional joystick and an isometric joystick. Design Study participants with a Traumatic Brain Injury (TBI) drove a simulated wheelchair within four tasks, in two driving orientations (forward and reverse) and with five repetitions each. A total of forty driving trials were completed for each of the two joysticks. Setting A research facility based in a hospital or in an independent living center. Participants Twenty participants (age: 30.62±10.91; 12 male, 8 female) who were at least one year post a traumatic brain injury. Intervention Driving performance using an Isometric joystick compared to a conventional movement joystick. Main Outcome Measures Average trial completion time, and trajectory specific measures measured orthogonal to the center of driving tasks: Root mean squared error, movement offset, movement error, number of significant changes in heading. Results After statistically controlling for driving speed, participants were able to complete the driving tasks faster with an Isometric Joystick than while using a conventional movement joystick. Compared to the conventional joystick, an isometric joystick used for driving forward demonstrated fewer driving errors. During reverse driving the conventional joystick performed better. Conclusions The customizable Isometric Joystick seems to be a promising interface for driving a powered wheelchair for individuals with TBI.

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Abstract-Upper-limb fatigue is a common problem that may restrict people with multiple sclerosis (MS) from using their electric powered wheelchair effectively and for a long period of time. The objective of this research is to evaluate whether participants with MS can drive better with a variable compliance joystick (VCJ) and customizable algorithms than with a conventional wheelchair joystick. Eleven participants were randomly assigned to one of two groups. The groups used the VCJ in either compliant or noncompliant isometric mode and a standard algorithm, personally fitted algorithm, or personally fitted algorithm with fatigue adaptation running in the background in order to complete virtual wheelchair driving tasks. Participants with MS showed better driving performance metrics while using the customized algorithms than while using the standard algorithm with the VCJ. Fatigue adaptation algorithms are especially beneficial in improving overall task performance while using the VCJ in isometric mode. The VCJ, along with the personally fitted algorithms and fatigue adaptation algorithms, has the potential to be an effective input interface for wheelchairs.

The PMRT has high interrater reliability in conditions 1 and 4 and could be used to assess EPW driving performance virtually in VRSIM-2. However, further psychometric assessment is necessary to assess the feasibility of administering the PMRT using the different interfaces of VRSIM-2.

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Objective Approximately 40% of Americans with disabilities cannot operate wheeled mobility devices and computers adequately due to diminished upper-limb motor control, sensory limitations, and cognitive impairments. We developed tuning software that can customize control interfaces for individuals with upper limb impairments. This study compared differences in each parameter among different diagnostic groups. Design Subjects ranged from 18 to 80 years. Athetoid Cerebral Palsy (ACP), Spastic Cerebral Palsy (SCP), Multiple Sclerosis (MS), Upper Limb Spasticity (ULS) and Control groups were used. We used a validated tuning software protocol to customize an isometric joystick prior to a virtual tracing or driving task. Tuning parameters were then compared across groups. Results Seventy-five subjects were included. Gain, the parameter responsible for force to output ratios, in each directional axis (leftward gain: p=0.018, rightward gain: p=0.003, reverse gain: p=0.007, forward gain: p=0.014) was significant across diagnostic groups. Post-hoc analyses showed that the control group required smaller leftward gain than SCP, MS and ULS groups and smaller gain in all other directions compared to SCP. Conclusions Gain may be a useful parameter for tuning by clinicians and efforts aimed at gain customization may aid the development of commercially available tuning software packages.