Knetex – Development of a textile-integrated sensor system for feedback-supported rehabilitation after surgery of the anterior cruciate ligament

Abstract

Patients often report an effect after surgery of the anterior cruciate ligament which is called "giving way". This manifest itself by a drop of the knee or a felt instability. This phenomenon is difficult to measure and validate because it usually does not occur regularly and is not reproducible under laboratory conditions. The Knetex project takes up this point by trying to actively support the rehabilitation process with a bandage that can be worn in everyday life and is constructed as a smart textile using sensors and actuators. For this purpose, on the one hand it is attempted to actively record the phenomenon of the "giving way" by measuring knee angles etc. and by active user feedback. At the same time, the patient is specifically advised by means of actuators to correct incorrect posture or movement in order to make the rehabilitation process more effective and prevent further damage. Two 9-axis IMUs (inertial measurement units) form the basis of the system. These are used together with a textile strain sensor to calculate the knee angles. This paper gives an overview of the planned system, the initial experiments to measure the knee angles and the first results of the actuator study.

Keywords

• cruciate ligament rupture
• imus
• smart textiles
• motion detection
• giving way
• knetex