Development of an Ergonomic Handle for Laparoscopic Surgery

The objective of this project was to develop an ergonomic laparoscopic instrument handle based on the dimensions of human hand in gripping position for reducing discomfort and muscle fatigue. Eight human subjects (4 male and 4 female; height: 172.5±10.5 cm; weight: 58.4±12.6 kg) were recruited. The statues of their right hands in gripping position were made by using Alginoplast powder and plaster. A 3D scanning machine was used to obtain digital images of the 8 hand statues for measurements. The following dimensions were recorded from the digital images: distance between the tip of thumb and the tip of last finger (81.2±10.2 mm), distance between the tip of thumb and the tip of ring finger (71.0±7.3 mm), distance between the tip of thumb and the tip of middle finger (63.2±9.5 mm), distance between the tip of thumb and the tip of index finger (50.8±10.2 mm), distance between “Hu Kou arc” and the bottom of middle phalanx in index finger (47.9±6.4 mm), angle between the thumb-middle finger line and the thumb-last finger line (36.1±7.6 degree), angle between the thumb-middle finger line and the thumb-ring finger line (19.3±3.8 degree), angle between the thumb-middle finger line and the thumb-index finger line (20.4±2.7 degree), and the distances from thumb to phalanx joint arc at -20° (61.2±10.4 mm), -10° (73.0±9.3 mm), 0° (assigned as the line between thumb and middle finger, 84.9±9.1 mm), 10° (91.5±7.4 mm), 20° (95.6±7.1 mm), 30° (98.8±8.8 mm), and 40° (101.6±11.3 mm). The mean dimensions were used to make a laparoscopic handle prototype, with special consideration on the thumb ring and the finger contact surface curvature based on the measurement. In conclusion, we demonstrated a new approach to develop an ergonomic laparoscopic instrument handle based on the dimensions of human hand in gripping position.