Development of a novel 3D printed sensor for measuring joints flexion and extension

Knee range of motion (ROM) is one of the most important outcome in understanding the effective progression in rehabilitation process after anterior cruciate ligament (ACL) reconstruction. Early recovery of ROM not only has not negative effects as increasing effusion, emarthrosis, periarticular soft tissue edema and swelling but also can decrease morbidity of major intraarticular ligamentous procedures1 and allow the patient to a faster return to daily life activities. During the rehabilitation process patients are asked to achieve precise degrees of flexion and extension depending on the rehabilitation phase, moreover certain degrees of ROM are also required to progress in rehabilitation exercises. ROM is also very important in athletes rehabilitation, indeed obtaining full ROM is considered a fundamental condition for return to sport. Nowadays the normal procedure for physiotherapist is to use a standard goniometer for measuring knee flexion and extension on patient in supine position. There is an increasing interest in measuring joint motion with wearable devices, these devices are light and low energy consuming sensor that can be inserted into garment in order to analyze patient’s motion also when they are not at the clinic. These sensors can be either flexible and stretchable and in general are resistive or capacitive sensors. The sensors work changing his resistance/capacitance when is bended or stretched. There are few devices on the market and some of them are 3D printed offering the possibility to make a custom made sensor. The aim of this thesis is to design a novel smart garment to detect motion activity in patient after surgery. Different stretchable and flexible sensors will be tested in order to choose which one is the best for measuring knee ROM.