Children with multiple disabilities and minimal motor behavior using chin movements to operate microswitches to obtain environmental stimulation

Contrasting approaches to the response-contingent learning of young children with significant delays and their social-emotional consequences

AIMS

The purpose of the analyses described in this paper was to evaluate the direct and indirect effects of two different approaches to child response-contingent learning on rates of child learning and both concomitant and collateral child social-emotional behaviour.

METHOD

The participants were 71 children with significant developmental delays or multiple disabilities randomly assigned to either of the two contrasting approaches to interventions.

RESULTS

Findings showed that an intervention which employed practices that built on existing child behaviour (asset-based practices) was more effective than an intervention focusing on teaching children missing skills (needs-based practices) for influencing changes in the rates of child learning as well as rates of child social-emotional behaviour mediated by differences in rates of child learning.

IMPLICATIONS

Both the theoretical and practical importance of the results are described in terms of the extended social-emotional benefits of asset-based response-contingent learning games.

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.

Challenges of developing communicative interaction in individuals with congenital profound intellectual and multiple disabilities

BACKGROUND

Physiological responses have been used in individuals with acquired disability to enable communicative interaction without motor movement. This study explored four autonomic nervous system (ANS) signals-electrodermal activity, skin temperature, cardiac patterns and respiratory patterns-to enable interaction with individuals born with profound intellectual and multiple disabilities (PIMD).

METHOD

A series of case studies were conducted to teach a 15-year-old individual with PIMD to voluntarily control his ANS signals for the purposes of communicative interaction. Training was carried out according to an alternating treatment single-subject research design.

RESULTS

Training was unsuccessful; however, ANS signal patterns revealed issues unique to people with PIMD: profound intrasubject variability, discrepancy between physiological responses and caregiver perspectives, and the participant's lack of contingency awareness.

CONCLUSIONS

These three priority areas unique to people with congenital PIMD must be addressed before ANS signals can be used to enable communicative interaction with this population.

Validating an infrared thermal switch as a novel access technology

Background

Recently, a novel single-switch access technology based on infrared thermography was proposed. The technology exploits the temperature differences between the inside and surrounding areas of the mouth as a switch trigger, thereby allowing voluntary switch activation upon mouth opening. However, for this technology to be clinically viable, it must be validated against a gold standard switch, such as a chin switch, that taps into the same voluntary motion.

Methods

In this study, we report an experiment designed to gauge the concurrent validity of the infrared thermal switch. Ten able-bodied adults participated in a series of 3 test sessions where they simultaneously used both an infrared thermal and conventional chin switch to perform multiple trials of a number identification task with visual, auditory and audiovisual stimuli. Participants also provided qualitative feedback about switch use. User performance with the two switches was quantified using an efficiency measure based on mutual information.

Results

User performance (p = 0.16) and response time (p = 0.25) with the infrared thermal switch were comparable to those of the gold standard. Users reported preference for the infrared thermal switch given its non-contact nature and robustness to changes in user posture.

Conclusions

Thermal infrared access technology appears to be a valid single switch alternative for individuals with disabilities who retain voluntary mouth opening and closing.

Client-centred development of an infrared thermal access switch for a young adult with severe spastic quadriplegic cerebral palsy

PURPOSE

This study reports a client-centred development of a non-contact access switch based on an infrared thermal imaging of mouth opening-closing activity of an individual with severe spastic quadriplegic cerebral palsy.

METHOD

Over a 6-month period, the client participated in five test sessions to inform the development of an infrared thermal switch. The client completed eight stimulus-response trials (switch test) and eight word-matching trials (scan test) using the infrared thermal switch and provided subjective feedback throughout.

RESULTS

For the switch test, the client achieved an average correct activation rate of 90% and average response time of 2.4 s. His mean correct activation rate on the scan test improved from 65 to 80% over the course of system development, with an average response time of 11.7 s.

CONCLUSIONS

An infrared thermography switch tuned to a client's extant orofacial gestures is a practical non-invasive access solution and warrants further research in clients with severe physical disability.

Upgraded technology for contingent stimulation of mouth wiping by two persons with drooling and profound developmental disabilities

Many persons with developmental and physical disabilities experience drooling (i.e., loss of saliva from the mouth). Technology was recently developed to help two of these persons reduce the negative effects of drooling by increasing mouth-wiping responses. This study upgraded our initial approach and tested it with the two persons who we previously treated. Upgrading ensured that all technology components, including the stimulation sources, were on the participant's body and that stimulation for mouth wiping caused no (or limited) environmental disturbance. We also conducted a social validation assessment of the new technology and its effects, employing university students as social raters. Evidence showed that the participants used the upgraded technology successfully in settings attended by varieties of other persons. The university students involved in the social validation viewed the use of the technology as enjoyable, beneficial, and environmentally acceptable, and they largely supported it.

Microswitch-Based Programs for Persons with Multiple Disabilities: An Overview of Some Recent Developments

Persons with multiple disabilities are often unable to interact with their environment due to their limited response repertoire. Microswitch programs are designed to help them control environmental events, generally preferred stimulation, through simple (feasible) responses. To make microswitch programs a more widely usable and relevant resource for intervention with these persons, a number of new developments were pursued in recent years. This paper examines three of those developments as specifically addressed in our research activity, namely, (a) assessment of new, nontypical responses and matching microswitches, (b) fostering of multiple responses and exercise of choice, and (c) targeting of habilitative and clinical (therapeutic) objectives. The encouraging outcomes of these developments are reviewed in relation to their potentially wide implications for daily practice and the need of additional developments in the area.

Enabling a young man with minimal motor behavior to manage independently his leisure television engagement

Persons with severe spastic tetraparesis and minimal motor behavior may be confined to a wheelchair or bed and have virtually no chances of constructive engagement with their immediate environment. A possible way to modify this situation may involve the use of technology. The present study (a) assessed specific technology to enable a young adult to manage his leisure television engagement independently and (b) carried out a social validation assessment of the technology-supported performance involving 90 teacher trainees as raters. The intervention period with the new technology included 67 sessions, during which the participant performed independently 392 of the 408 television-management responses, i.e., turning on the television, finding a channel with a preferred program, setting the volume, and turning off the television. He also indicated preference for using the technology as opposed to not using it. The raters provided relatively high (positive) scores for the technology-supported performance compared to the baseline performance. Implications of the findings are discussed.

Persons with multiple disabilities and minimal motor behavior using small forehead movements and new microswitch technology to control environmental stimuli

Persons with multiple disabilities and minimal motor behavior may be unable to use available microswitch technology to control environmental stimuli. For these persons, one may need to rely on small motor expressions (as responses) and new, matching microswitch technology to ensure a successful outcome. In the present study, a small movement of the forehead skin was selected as the response for two participants (ages 6.5 and 14.2 years) with profound multiple disabilities. The microswitch technology included (a) an optic sensor, i.e., barcode reader, (b) a small tag with horizontal bars attached to the participants' forehead, and (c) an electronic control system which activated stimuli in relation to response occurrence. Movement of the forehead skin shifted up or down the tag with bars and this shifting, if greater than a preset limit and therefore recorded as a response, led to the activation of the control system. Each participant received an ABAB sequence, in which A represented baseline and B intervention phases, and a 6-wk. 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 were discussed.

Extending the Evaluation of Novel Microswitch Technology for Small Responses in Children With Profound Multiple Disabilities

This study extended the evaluation of microswitch technology (i.e., a position sensor and an optic device), recently introduced for chin and eyelid responses, with two new participants with profound multiple disabilities. The participants were girls of 12.5 and 4.0 years of age who did not possess any specific response that they could profitably use in their environment. The study was conducted according to an ABAB design with a 3-week postintervention check. The results showed that both participants increased their level of responding during the intervention phases and postintervention check compared to the baseline phases. This positive outcome was discussed in terms of (a) the apparent suitability of the technology and responses used in the study, (b) the beneficial implications for the participants, and (c) new developments in the area.