Evaluating treatment efficacy in attention-deficit/hyperactivity disorder by analyzing the movement-induced deformation of load cells under a chair in a simulated classroom: A pilot study.

Background: Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in children. Several tools are available for evaluating the efficacy of ADHD treatment, such as, for example, the Swanson, Nolan, and Pelham (SNAP-IV) questionnaire; and the Vanderbilt ADHD Diagnostic Rating Scale. However, these scales are subjective. In this study, we developed an objective method by using load cells for evaluating the efficacy of ADHD treatment.

Methods: A situational classroom was prepared to simulate a real classroom. The setup included a desk, a chair, and a large screen. The four legs of the chair were equipped with load cells-materials that deform under force. These cells are used to detect the activity of patients with ADHD. This study included 13 patients with ADHD (12 boys and 1 girl). Before and after 1-month treatment with methylphenidate 10 mg p.o. QD, the patients were instructed to watch an age-appropriate educational video on Mathematics while sitting. Their movements were indicated by data gathered from the load cells under the chair. The average trajectory length (ATL) was measured to analyze the signal from the load cells. SNAP-IV questionnaires were completed by parents and teachers before and after treatment.

Results: The ATL values before and after treatment were 0.0316 ± 0.0139 and 0.0208 ± 0.0127 (p = 0.0055), respectively. The patients' SNAP-IV scores assigned by parents before and after treatment were 38.89 ± 8.07 and 23.67 ± 16.87 (p = 0.0167) and those provided by teachers were 44.11 ± 11.47 and 22.22 ± 13.50 (p = 0.0048), respectively. The coefficients of the correlations between ATL values and SNAP-IV hyperactivity-impulsivity scores from parents and from teachers were 0.109 and 0.200, respectively.

Conclusion: In conclusion, the smart chair equipped with load cells is an effective tool for objectively evaluating the efficacy of ADHD treatment on hyperactivity of children with ADHD.