In-situ measurement of electrodermal activity during occupational therapy

Abstract

Physiological arousal is an important part of occupational therapy for children with Sensory Processing Disorder (SPD) but therapists do not have a way to objectively measure how therapy affects arousal. We hypothesized that when children with SPD participate in guided activities within an occupational therapy setting, informative changes in electrodermal activity (EDA) can be detected using iCalm. iCalm is a small, wireless sensor developed at MIT that measures EDA and motion, worn on the wrist or above the ankle. Twenty-two children (ages 3-10) with a clinical diagnosis of SPD participated. EDA was measured from the backs of the children's ankles. Concurrent video recordings allowed for comparison of therapeutic activities and children's EDA. Overall, we measured 77 therapy sessions. All measurements were in-situ, during regularly scheduled therapy sessions. Statistical analysis describing how equipment affects EDA was inconclusive, suggesting that many factors play a role in how a child's EDA changes. Case studies provided examples of how occupational therapy affected children's EDA. This is the first study of the effects of occupational therapy's in-situ activities using continuous physiologic measures. The results suggest that careful case-study analyses of the relation between therapeutic activities and physiological arousal may inform clinical practice.