Application Of A Wearable Switch To Perform A Mouse Left Click For A Child With Mix Type Of Cerebral Palsy: A Single Case Study

Purpose: Children with cerebral palsy may face difficulties using handheld pointing devices, due to involuntary muscle movements. This study aimed at describing the idea of the new wearable sensor switch and assessing its feasibility as an access solution in a case of mixed-type cerebral palsy. Methods: The study participant was a 17-year-old male with mixed-type cerebral palsy characterized by chorea-athetotic movements and bilateral spasticity with gross motor function classification system level V. He exhibited sudden and irregular involuntary upper limb movements when sitting. Because spastic finger movements limited his ability to use a handheld mouse, he used a trackball near his neck as a pointing device (previous input method). The wearable switch system using a stretchable strain sensor was introduced; the sensor was attached to a groove worn on the dorsal regions of the right hand crossing the proximal interphalangeal and metacarpophalangeal joints of the middle finger (new input method). The switch turned on when the subject flexed his middle finger. Results: The user successfully turned the switch on and typed almost the same numbers of characters per trial compared with the previous input method. The speed of his head movements during typing reduced (p < .01), and his sitting posture was nearly upright during computer operation (p < .01). No involuntary movement, requiring physical assistance, was observed when using the wearable switch. Conclusion: The new switch system can be a new option for people with difficulty using standard handheld input devices due to paralysis and involuntary muscle movements.