Small Hand-Closure Movements Used as a Response through Microswitch Technology by Persons with Multiple Disabilities and Minimal Motor Behavior

This study assessed small hand-closure movements as a potential response for microswitch activation with two participants with profound multiple disabilities of 5.2 and 20.6 yr. of age. The microswitch consisted of a two-membrane thin pad fixed to the palm of the hand and a control system. The outer membrane (the one facing the fingers) was a touch-sensitive layer; the inner membrane was activated if the participant applied a pressure of over 20 gm. The activation of either membrane triggered an electronic control system, which in turn activated one or more preferred stimuli for 6 sec. except in baseline phases. Each participant received an ABAB sequence, in which A represented baseline and B intervention phases, and a 1-mo. postintervention check. Analysis showed both participants increased their responding during the intervention phases and maintained that responding at the postintervention check. Implications of the findings are discussed.

Assessing a New Response-Microswitch Combination with a Boy with Minimal Motor Behavior

This study assessed whether a boy with profound multiple disabilities and minimal motor behavior could learn to use a new response-microswitch combination to control environmental stimulation. The response selected was a chin movement; a mechanical microswitch was set up for this response. The boy learned to use the microswitch, increasing the frequency of the chin response and the level of pleasant stimulation following such response. The performance was retained at a 2-mo. postintervention check.

Evaluating a computer system used as a microswitch for word utterances of persons with multiple disabilities

PURPOSE

To assess the effectiveness of a computer system used as a microswitch for word utterances of two adults with multiple disabilities. The system combined a new control software programme with a commercially available speech recognition programme.

METHOD

Nine word utterances were targeted for each participant. The participant's emission of those utterances triggered the occurrence of related (favourite) stimuli during the intervention and the post-intervention check.

RESULTS

Intervention data showed that (1) the participants increased the frequencies of the target utterances and (2) the computer system recognized about 80% of those utterances correctly, providing the participants with high levels of favourite stimulation. The post-intervention check showed comparable data with both participants.

CONCLUSIONS

The computer system proved an adequate microswitch for word utterances. Based on this evidence, microswitch programmes could be extended beyond the use of conventional motor responses.

Extending the evaluation of a computer system used as a microswitch for word utterances of persons with multiple disabilities

BACKGROUND

Micro-switches can be vital tools to help individuals with extensive multiple disabilities acquire control of environmental stimulation. This study was aimed at extending the evaluation of a computer system used as a microswitch for word utterances with three participants with multiple disabilities.

METHOD

Sets of 7 or 12 word utterances were used for the participants. The utterances were divided into three groups, which were exposed to intervention successively. During the intervention and a 2-month post-intervention check, the participants' emission of the target utterances led the system to present favourite, matching stimuli (i.e. provided that it recognized the utterances).

RESULTS

Intervention data showed that (1) the participants increased the frequencies of the target utterances and (2) the computer system recognized approximately 80% of those utterances. These findings were maintained at the post-intervention check. An analysis of the levels of occurrence of individual utterances showed statistically significant differences among them, in line with the notions of preference and choice.

CONCLUSIONS

The computer system was useful as a microswitch to enable access to favourite stimuli. There is a need to improve the accuracy of the system with respect to its recognition of the participants' utterances.