A Fiber Bragg Grating Strain Sensor-Based Glove to Accurately Measure the Bend Angle of the Finger Flexed at the Proximal Interphalangeal Joints

Accurate measurement of finger joint angles is very important in the fields such as rehabilitation, bionics, etc. In this paper, we present a fiber Bragg grating (FBG) sensor-based flexure sensing glove to measure the finger joint angles with high accuracy. We evaluate its accuracy and repeatability on four human subjects by measuring their proximal interphalangeal (PIP) joint angles of the index, middle and the ring fingers. Our glove showed excellent agreement (R-Squared: 0.9985) with the inertial measurement unit (IMU) sensor readings. The glove outperforms several existing sensors exhibiting a maximum error (1.42 degrees), mean error (0.45 degrees) and maximum standard deviation (0.56 degrees). In the future, the study will be extended to all the joints.