Measurement of 3D Wrist Angles by Combining Textile Stretch Sensors and AI Algorithm

Sensors (Basel). 2024 Mar 5;24(5):1685. doi: 10.3390/s24051685.

Abstract

The wrist is one of the most complex joints in our body, composed of eight bones. Therefore, measuring the angles of this intricate wrist movement can prove valuable in various fields such as sports analysis and rehabilitation. Textile stretch sensors can be easily produced by immersing an E-band in a SWCNT solution. The lightweight, cost-effective, and reproducible nature of textile stretch sensors makes them well suited for practical applications in clothing. In this paper, wrist angles were measured by attaching textile stretch sensors to an arm sleeve. Three sensors were utilized to measure all three axes of the wrist. Additionally, sensor precision was heightened through the utilization of the Multi-Layer Perceptron (MLP) technique, a subtype of deep learning. Rather than fixing the measurement values of each sensor to specific axes, we created an algorithm utilizing the coupling between sensors, allowing the measurement of wrist angles in three dimensions. Using this algorithm, the error angle of wrist angles measured with textile stretch sensors could be measured at less than 4.5°. This demonstrated higher accuracy compared to other soft sensors available for measuring wrist angles.

Keywords: AI algorithms; multi-layer perceptron; smart wearable sensors; textile stretch sensors; wrist angle.

Grants and funding

This research was financially supported by Soongsil University, Seoul 156-743, Korea. This research was partly supported by the Technology Innovation Program (or Industrial Strategic Technology Development Program-Materials/Parts Package Type) (20016038, Development of the textile-IT converged digital sensor modules for smart wear to monitor bio and activity signal in exercise, and KS standard) funded by the Ministry of Trade, Industry and Energy (MOTIE, Republic of Korea), and Korea Institute for Advancement of Technology(KIAT) grant funded by the Korea Government (MOTIE) (P0012770).