Design Optimization, Function Analysis and in vitro Experiments of an Electric Stapler for Minimally Invasive Surgery / 医用生物力学

ABSTRACT

Objective To develop a new type of electric stapler, so as to solve the problems of insufficient rotation angle, inconvenient operation and difficulty in controlling the pressing strength of existing products. Methods An electric stapler was designed and manufactured. The motion trajectory curve of the prototype was measured by using the three-coordinate imaging instrument to build functional test platform of the prototype, and the goodness of fit was used to evaluate consistency between the theoretical curve and the measured curve. The small intestine tissues of fresh pig were anastomosed at different bending angles of the front end, and the forming rate of the anastomotic stoma was measured. Results The goodness of fit between the test curve and the theoretical curve for both turning motion and shooting motion was ideal, while the goodness of fit between the test curve and the theoretical curve for pressing motion was not ideal when the turning joint was bent at 0°-30°, and was ideal when it was bent at 45°-60°. In performance test, the deformity rate of the nail was smaller than 1.14%, indicating that the bending angle had no significant impacts on the anastomotic effect. Conclusions The kinematics curves of shooting motion and turning motion are consistent with the theoretical curves. The pressing motion curves fluctuate at different bending angles, which will not affect the anastomotic effect, and the effect of the electric stapler meets the clinical requirements.