RESUMEN
Objective:To design a novel electromagnetic ejection device for endoscopic suturing to achieve continuous deployment of suture nails.Methods:An electromagnetic ejection device and its accompanying suture nail structure were designed and a prototype was fabricated based on electromagnetic ejection principles. A finite element model of the electromagnetic ejection device was constructed to study the effects of armature-coil center distance and different driving voltages on suture nail ejection speed. An experimental platform for testing electromagnetic ejection velocity was constructed, and a high-speed camera was used to detect the ejection velocity. A platform for the suture embedding experiment was built to measure the effects of different voltages on the inserting speed of suture into the gastric wall tissue. A platform for a suture extraction force experiment was built to evaluate the extraction force of sutures embedded in tissues under different driving voltages.Results:A suture nail structure and electromagnetic ejection device were designed, and a prototype was fabricated. The ejection velocity increased and then decreased with the increase of the armature-coil center distance, and the maximum ejection velocity was 15.81 m/s at the center distance of 18 mm. At this distance, the voltage was linearly related to the ejection velocity, and the experimental values of the staple basically coincided with the simulated values. When the driving voltage was in the range of 150 to 180 V, the suture nails could successfully insert in the tissues, and the 180 V voltage group had a greater insertion depth. The extraction force of the suture nails at 120, 150, 180, and 210 V voltages were (0.49 ± 0.19), (1.14 ± 0.19), (1.23 ± 0.15), and (1.85 ± 0.31) N, respectively.Conclusions:A novel electromagnetic ejection device for endoscopic suturing is proposed that is capable of continuous firing of suture nails. This device provides a new long-distance driving method for intelligent, minimally invasive surgical instruments.
RESUMEN
Objective:The microstructure, tensile strength, and bursting strength of different brands of hernia meshes were compared and analyzed through experiments to evaluate the performance of different meshes.Methods:The balance and microscope were used to test the weight and microstructure of 15 common meshes and the tensile testing machine and burst testing machine were used to test the tensile and bursting properties of the mesh, and the mechanical properties of the mesh were analyzed.Results:The woven structures of the mesh are diamond, polygon and circle. The average weight of inguinal meshes is 0.08 mg/mm 2, and the average weight of abdominal wall hernia meshes is 0.18 mg/mm 2. The wire diameters of G3 - G6 meshes are larger, while the mesh opening ratio of G12 is lower. In the tensile performance test, it is known that G15 has the highest tensile strength, G12 and G14 have lower tensile strengths in lightweight meshes, and G1, G2, and G7 have lower tensile strengths in lightweight meshes. In the burst performance test, it is known that G3, G9, and G15 have the highest burst strength, while G12, G13, and G14 have the lowest burst strength in lightweight meshes. G1, G2, and G4 have the lowest burst strength in lightweight meshes. Conclusions:The mesh with a polygonal mesh and a large mesh opening ratio has better mechanical properties. The results of this study provide experimental evidence for optimizing hernia meshes, which is expected to provide better support for related research and applications.