A Tailored Textile Sensor-based Wrap for Shoulder Complex Angles Monitoring

The shoulder joint plays a crucial role in the recovery of upper limb function. However, conventional wearable technologies employed for monitoring shoulder joint movements predominantly rely on inertial sensing units (IMUs), which may suffer alignment errors and compromise the freedom and wearability experienced by patients during their daily activities. This paper contributes in two facets, first, it presents the design, implementation, and technical evaluation of a new wearable system, a customized unilateral shoulder wrap that utilizes flexible and breathable textile sensors. Diverging from earlier studies, our system not only facilitates the monitoring of glenohumeral joint angles but also concurrently tracks the movement angles of the scapula. Secondly, to estimate joint angles, we propose a specific model called the Channel-Temporal Encoding Network (CTEN), which leverages Transformer and Long Short-Term Memory (LSTM) architectures. In a preliminary technical evaluation, the results demonstrate root mean square errors (RMSEs) of 2.24°and 1.13°for the glenohumeral joint and scapula, respectively. This study is intended to contribute to the development of more advanced wearables tailored for shoulder joint rehabilitation training.