The effects of Twiddle muff vs. physical restraints on facial emotions of hospitalized cognitively impaired persons

Abstract

Several studies have reported adverse effects of physical restraints use. In the United Kingdom, the Twiddle muff has attracted attention as an alternative intervention, with similar reports in Japan. This study evaluated the effects of Twiddle muffs using artificial intelligence (AI)-based facial emotion analysis and the Faces Rating Scale. Fourteen patients who had undergone physical restraints and dementia care rounds at our hospital were enrolled between February and July 2025. The participants were classified into Delirium and Non-Delirium Group using the Delirium Rating Scale-Revised-98 (cutoff score: 14.5). Facial expressions were recorded for one minute during both physical restraints and Twiddle muff use. Emotions were categorised as Neutral, Happy, Sad, Angry, and Surprised. AI-based facial emotion analysis showed a decrease in Neutral scores in all patients during Twiddle muff use. In the Delirium Group, Neutral scores decreased, whereas Sad scores increased. In contrast, in the Non-Delirium Group, Neutral scores decreased and Happy scores increased. The Faces Rating Scale indicated reduced distress with Twiddle muff use. These findings suggest that Twiddle muffs may elicit different emotional responses depending on clinical status and could promote favourable emotional changes, particularly in patients without delirium.