Development of Alert System Using Visual and Auditory Stimuli to Assist Patients with Cognitive Impairment During Wheelchair Operation

Abstract

This study develops an alert system to provide support for daily activities to patients with unilateral spatial neglect and cognitive impairment during wheelchair operation. Eight consenting individuals participated in this experiment. All participants were inpatients at a neurosurgery hospital. The proposed system has two specific functions: (a) calling the attention of the user to the proper use of the wheelchair, and (b) warning the user of erroneous use or possible danger. Mechanical sensors are mounted on a conventional manual wheelchair to detect the application of brakes, flipping up of footrests, and getting up from the seat. The signals from the sensors are sent to a microprocessor to assess the state of the brakes, footrests, and whether the user is sitting or standing. Light-emitting diodes (LEDs) on the brakes and footrests and a speaker tell the user what to do next. If an erroneous operation is detected, the LEDs blink and a warning audio message is given. Multiple voice messages are used to lead the user to the proper procedure for operating a wheelchair. A head-mounted display was designed for patients with unilateral spatial neglect cognitive impairment and to provide additional visual information. Experiments were performed with a standard wheelchair and one equipped with the proposed alert system, and the results were compared. A video motion analysis system was used to analyze neck, trunk, and limb joint movements. The time required to complete the trial operations was measured and operational errors were analyzed. The results show that the number of incorrect operations of the brakes and footrests was decreased by the proposed alarm system. The alarm system may be able to assist correcting wheelchair operation for patients with cognitive impairment.