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.
ABSTRACT
Objective To develop a novel electric stapler, so as to improve the automation, convenience and precision of minimally invasive surgery. Methods The clamping, firing and turning mechanism of the new electric stapler was innovatively designed to realize the electric drive of minimally invasive surgical anastomosis on the basis of traditional mechanical stapler. The motion process of electric clamping, firing and double-screw turning mechanism was analyzed in detail, and the equations for motion function of three mechanisms were solved, providing a theoretical basis for the intelligent control algorithm of electric stapler. Results The electric clamping and firing process was simulated using ADAMS software to verify the equation of motion. The prototype of the new electric stapler was made, and the anastomosis experiment and blasting pressure experiment of the in vitro small intestine tissues were carried out. The range of anastomotic blasting pressure was between 3.7 kPa and 11.67 kPa, meeting the basic requirements in clinic. Conclusions The structure of the new electric stapler can meet the requirements of electric pressing and firing in minimally invasive surgery, contributing to achieve tissue anastomosis more conveniently, quickly and effectively.