Development of a Hybrid Measurement System for Surgical Instrument Motion of Laparoscopic Surgery

Laparoscopic surgery has become a common surgical technique owing to its minimal invasiveness. However, surgeons require advanced techniques, and several studies have evaluated surgical skills through motion measurements to improve skill proficiency. However, existing measurement systems have a low tolerance for occlusion and are difficult to use in operating rooms with many obstacles. Therefore, a hybrid measurement system was developed for laparoscopic surgery. This system consists of an inertial measurement unit (IMU), a distance sensor, and an optical motion capture (MoCap). When MoCap data are unavailable, surgical instrument motion is calculated using the IMU and distance sensor data, and when it is available, the IMU drift is corrected using MoCap data. The MoCap markers were arranged individually, thus facilitating the measurement of multiple instruments simultaneously. The validation experiment in the wet-lab training confirmed that the error was smaller than that measured using MoCap alone, and the subjects expressed that the subjective disturbance caused by the sensors was very small during the procedure. The measurement experiment was conducted in cadaver surgical training, and 15 cases of nephrectomy were successfully recorded. This system facilitated highly accurate measurements during practical surgical training and surgical skills analysis.