Prototyping of Smart Wearable Socks for Periodic Limb Movement Home Monitoring System

Abstract

The recent development of functional materials, including smart textiles, has enabled the development of wearable biosignal measurement devices that are easy to handle and can be used on a daily basis, even by non-medical users. We focused on sleep disorders as a preliminary application for wearable devices, which are reported to be associated with or exacerbate other diseases, and must therefore be detected early and treated appropriately based on the usual sleep status of the patient. Periodic limb movement disorder (PLMD), which induces nocturnal awakening due to PLM while sleeping, is a sleep disorder that is thought to affect a considerable number of individuals. Since polysomnography (PSG), which needs time consuming hospitalization and forces a financial burden on the patient, is the only practical method for PLMD screening, some PLMD patients are supported to be remain undiagnosed and untreated.

In order to resolve this situation, we aim to develop a PLM home monitoring system that consists of fabric adapters and fabric electrodes that can detect PLMs based on surface electromyogram (SEMG) measurement, without disturbing the usual sleep of subject. We developed a prototype SEMG measurement system that combined ready-made stretchy socks and fabric electrodes that can be easily handled by the patients without any medical knowledge. This prototype can prevent measurement faults due to the slippage of measurement electrodes as the measurement electrodes are fixed by the pressure of the fabric adapter. We first evaluated the functional ability in voluntary movements by comparing the SEMG obtained with the prototype to that obtained using conventional electrodes. We then performed SEMG measurement while PLMs and confirmed that the prototype has the potential to discriminate PLMs from voluntary movements. The proposed sockstype SEMG measurement device is expected to be able to precisely quantify PLMs, even when handled by non-medical users in their home.