1：Experimental Design and Method Selection:

The study involved designing a glove with FBG sensors to measure PIP joint angles, using an interrogation system based on tunable diode laser spectroscopy for FBG signal processing, and comparing results with IMU sensors as a reference.

2：Sample Selection and Data Sources:

Four human subjects were selected, and data were collected from the PIP joints of the index, middle, and ring fingers.

3：List of Experimental Equipment and Materials:

Equipment included FBG sensors with specified wavelengths and reflectivities, a DFB laser (Toptica Photonics, LD-1550-0040-DFB-1), laser controllers (ThorLabs TED 200C and LDC 220C), photo-detectors (ThorLabs PDA10D-EC), optical switches (Lightwave Link 1-2-L-9-L-3 and 2-2-L-9-L-3), a data acquisition system (Measurement Corp USA USB-1608G), IMU sensors (InvenSense MPU6050), and an Arduino Mega

4：Materials included a spring with stiffness constant 100 Nm?1, wire diameter 2 mm, outer diameter 9 mm, length 10 mm, and acrylate SMF-28 fiber. Experimental Procedures and Operational Workflow:

25 Subjects wore the glove and bent fingers slowly; FBG and IMU data were recorded at 2° intervals using a LabVIEW application. Calibration involved fitting a linear model to IMU readings and wavelength shifts. Repeatability was tested with five runs per subject.

5：Data Analysis Methods:

Data were analyzed using statistical measures (R-Squared, mean error, standard deviation) and compared with existing sensors. Wavelength shifts were calculated using MZI peaks and acetylene gas-line referencing.