Basic Study on Cybernic Interface for Neuromuscular Intractable Rare Diseases Patients Operating an Electric Wheelchair

Patients suffering from neuromuscular intractable rare diseases gradually lose muscle strength; this muscle weakness can cause various motor dysfunctions, such as gait disturbance. In order to maintain their ability to move independently, these patients must use electric wheelchairs. Eventually, however, they will lose the muscle strength required to operate the joystick of their electric wheelchair as the disease progresses. In this study, we develop a cybernic interface that supports neuromuscular intractable rare disease patients in controlling their electric wheelchairs, and to establish the basic performance of this interface through experiments. The cybernic interface consists of a unit that can operate the joystick and an input interface that can detect small displacements. The joystick operation unit is equipped with two high-resolution linear stepping motors; it operates the electric wheelchair joystick with a high degree of sensitivity. Additionally, the small displacement of a fingertip, which is the input for the joystick operation unit, is measured by the input interface, which consists of a touch panel sensor. We conducted repetitive accuracy verification of the joystick operation unit and performed driving experiments using an electric wheelchair equipped with our system. Our results show that the system exhibited sufficient repeatability and controllability. In conclusion, we confirm that our developed system can aid neuromuscular intractable rare disease patients in controlling an electric wheelchair.