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.Implications for rehabilitationCerebral palsy is a major cause of motor dysfunction and spasticity and dyskinesia in the fingers and upper limbs may prevent children with cerebral palsy from using handheld input devices.Wearable devices may be useful for children with cerebral palsy who have limited access to handheld pointing devices.We developed a new wearable switch to control devices using a flexible stretchable sensor.The wearable switch contributed to the improvement of sitting posture and reduction of neck burden during the typing task at the speed equivalent to that using the previous method in a child with mixed type of cerebral palsy exhibiting choreoathetotic movements and bilateral spasticity.