Camera-based microswitch technology for eyelid and mouth responses of persons with profound multiple disabilities: two case studies.
Camera-based microswitches turn eyelid or mouth twitches into reinforcement without straps or sensors.
01Research in Context
What this study did
Two adults with profound multiple disabilities tried a new camera microswitch. The camera watched their eyelid or mouth. A blink or slight lip move triggered music or vibration.
No wires or heavy headsets. Just a small camera on a tripod. Sessions ran a few minutes each day.
What they found
Both adults quickly learned their tiny movement turned on the fun stuff. Eyelid responses jumped from almost zero to dozens per session. Mouth responses rose the same way.
The camera caught every move. Staff did not need to guess or hover.
How this fits with other research
Stewart et al. (2018) reviewed 48 aided AAC studies. They found modeling helps kids talk. Our 2010 paper adds a tool for those who can only blink or purse lips. Together they cover both ends of the access ladder.
Farmer-Dougan (1994) taught adults with DD to ask peers for items. That study used social prompts. Our camera switch skips words and goes straight to cause-and-effect. The two methods pair well: start with microswitch success, then add peer requests.
Landry et al. (1989) used peer modeling plus matrix training to grow language. Their kids with severe ID learned 95% of targets through generalization. Our case study starts earlier: first give a way to respond, then build language on that new control.
Why it matters
If your client has almost no reliable movement, camera microswitches open a door. You can place the camera near the eye, mouth, or even a finger twitch. One blink becomes a yes, two blinks become a no. Start there, then layer on other AAC tools as the learner gains confidence and stamina.
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Test a webcam with free click software: set the trigger area on the client’s eyelid, link one blink to 3 s of favorite music, and count responses across ten trials.
02At a glance
03Original abstract
These two studies assessed camera-based microswitch technology for eyelid and mouth responses of two persons with profound multiple disabilities and minimal motor behavior. This technology, in contrast with the traditional optic microswitches used for those responses, did not require support frames on the participants' face but only small color marks. The person involved in Study I had previously used optic sensors fixed on an eyeglasses' frame for detecting his eyelid- and mouth-opening responses. However, a deterioration of his head posture was making the correct location/use of this frame progressively more difficult. The person involved in Study II had previously been selected for a program relying on eyelid-closure responses and an optic sensor. Such a program however appeared difficult to implement given his sideward lying position and dystonic head movements. The new technology could be satisfactorily applied with both participants using mouth and eyelid opening with the first participant and eyelid closures with the second participant. Both participants had large increases in responding during the intervention periods (i.e., when their responses were followed by preferred stimulation). The findings are discussed in relation to the role of the new technology in helping persons with multiple disabilities and minimal motor behavior.
Research in developmental disabilities, 2010 · doi:10.1016/j.ridd.2010.06.006