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.

Objective:To design a single-line low-temperature plasma ablation electrode, aiming to solve the problem of uniform, continuous and stable microbubbles generated by conventional electrodes, and improve the ablation and cutting effect of low-temperature plasma.Methods:The structures of low temperature plasma three-wire electrode and single-line electrode were modeled in SolidWorks 2021 3D modeling software, and the prototype was made by 3D printing. The finite element analysis of electric field and temperature field of the two kinds of electrode ablation process was carried out by COMSOL Multiphysics 6.1 software, and the validity and correctness of the finite element simulation model were verified by temperature test experiment, and the ablation effect and plasma excitation process of the two kinds of electrode were compared by tissue ablation experiment and low temperature plasma excitation experiment.Results:The results of finite element analysis showed that the maximum surface temperature of three-wire electrode and single-wire electrode were 70.2 and 63.3 ℃, respectively, and the surface temperature of single-wire electrode was more ideal, and the maximum electric field intensity of the two electrodes was more than 1.0 × 10 7 V/m, which met the electric field condition of microbubble breakdown. The electric field intensity of the two ends of the three-wire electrode was much higher than that of the other regions, while the electric field intensity of the single-wire electrode had no obvious sudden change and fluctuation. The experimental values of the temperature at the electrode surface and a distance of 1 cm on the electrode surface were basically consistent with the simulation values, the degree of fit was good, and the relative error was 3.2%. The highest ablation temperature of single linear electrode on pig fat was 46.8 ℃. After ablation, there was no coking area in morphology, and the tissue cutting depth of 0.5 mm could be reached in 1 s. When connected to the energy platform, microbubbles would occur on the working electrode surface of the single-wire electrode; when 6 ms was electrified, the working electrode surface was completely covered by microbubbles; when 9 ms was energized, the low-temperature plasma was excited and the blue-purple plasma could be seen; when 25 ms was energized, the microbubbles were still regular and stable. Conclusions:A kind of single-line low-temperature plasma ablation electrode is designed, which can produce uniform, continuous and stable microbubbles and achieve better ablation and cutting effect than the traditional electrode.

Objective:To study the effects of various parameters in the structural design and usage methods of insulin pen needles on their performance.Methods:Twenty-one conventional needles and five self-destructive needles were selected. A testing machine was used to clamp the needle and make it vertically puncture the test material with a constant speed of 50, 100, 150, 200, and 250 mm/min, respectively. The influence of the needle insertion speed on the puncture force was analyzed. The deformation of the needle on the small contact surface and the large contact surface at 4 N was recorded by a Photron high-speed digital camera. The penetration depth at 1 N and 3 N was measured by an indirect measurement and a direct measurement method, respectively, and the maximum damage width of the damage area was recorded. The tilt resistance of the needle at 6°, 9° and 12° under 2 N pressure was obtained by the testing machine. SPSS 27.0 software was used for statistical analysis of the experimental data, and the LSD multiple comparison method was used for one-way analysis of variance.Results:The difference in puncture force between the needle insertion speed of 50 mm/min and the other four needle insertion speeds was statistically significant (all P < 0.05), while the differences between the other groups were not statistically significant (all P > 0.05). The small contact surface needle was significantly deformed, with a large penetration depth, a large maximum damage width, and low anti-tilting resistance. The large contact surface needle was deformed slightly, with a smaller penetration depth, a smaller maximum damage width, and greater resistance to tilting. Conclusions:The influence of the usage method on the large contact surface of the needle is relatively small. The hexagonal and cross-shaped needle seats have stronger anti-tilt ability than the circular needle seat. The hexagonal needle seat is not easy to change with the rotation axis, and the performance is optimal. In the structural design, the size of the connection part should be reduced, and the appropriate shape of the needle base should be selected.

Objective:To establish and validate a gallstones classification method based on deep learning.Methods:A total of 618 gallstones samples were collected from East Hospital Affiliated to Tongji University, and 1 023 high-definition cross-sectional gallstones profile images were captured to construct a cross-sectional gallstones profile image dataset. Based on the traditional eight-category gallstones classification method, a lightweight network model, MobileNet V3, was trained using deep learning and transfer learning methods. The classification performance of MobileNet was evaluated using a confusion matrix with metrics such as accuracy rate, precision rate, F1 score, and recall rate. The MobileNet V3 was improved and further validated using accuracy and loss values.Results:The accuracy rate (94.17%), precision rate (94.03%), F1 score (92.96%) and recall rate (92.99%) of the improved MobileNet V3 model were better than other networks. The improved MobileNet V3 model achieved the highest accuracy rate (94.17%) in gallstones profile classification and was validated by the test set. The confusion matrix showed a weighted average of accuracy rate (92.0%), precision rate (92.6%), and F1 score (92.2%) for each category of gallstones.Conclusions:Based on deep learning, a high-accuracy gallstones classification method is proposed, which provides a new idea for the intelligent identification of gallstones.

Objective To evaluate the accuracy of three-dimensional(3D)reconstruction of the gallbladder volume based on computed tomography(CT)images and study the biomechanical changes in gallbladder motility to explore the relationship between gallbladder dynamics and gallstone formation.Methods A method for calculating gallbladder volume based on CT 3D reconstruction of The gallbladder model was proposed and compared with the ellipsoid method.A finite element model of the gallbladder was constructed for fluid dynamics analysis to simulate changes in gallbladder motor function under different angles of convergence between the cystic and common bile ducts and in the presence of gallstones.Results The mean errors of the specific gallbladder model volume and ellipsoid volume of the 50 patients were 7.26％and 25.35％,respectively.During the refilling period,the maximum pressure,deformation,and flow velocity of the pear-shaped gallbladder were significantly higher than those of the gourd-shaped gallbladder.The angle between the gallbladder and common bile duct had little effect on the bile flow pattern,and the maximum bile flow rate was reached at an angle of 120°.The bile flow velocity of the gallbladder with calculus was lower than that of the gallbladder without calculus,and there was a vortex near the calculus.Conclusions Calculating gallbladder volume based on CT 3D reconstruction is more accurate than the ellipsoid method.Compared with a pear-shaped gallbladder,a gourd-shaped gallbladder has lower gallbladder wall contraction,bile flow rate,and poor motor function.The bile flow rate in the gallbladder is slow,which is more likely to lead to the enlargement of gallstones or the formation of new gallstones.

Objective To improve the efficiency and quality of end-to-end anastomosis,a novel degradable vascular anastomotic device was designed,and the relationship between pressure distances and biomechanical properties of the anastomotic stoma was explored.Methods The three-dimensional(3D)structure of the vascular anastomotic device was designed and the prototype was fabricated with extruded high-purity magnesium.The finite element model of the end-to-end vascular anastomosis was established to study the stress distributions of the anastomotic end face under different pressure distances(0.4,0.5,0.6,0.7,and 0.8 mm)and their change rules.In vitro experiments were conducted to verify the rationality of the finite element results as well as the feasibility and effectiveness of the vascular anastomotic device.Results When the pressure distance was 0.6 mm,the anastomotic tensile force,and burst pressure could reach(11.79±0.64)N and(39.32±2.99)kPa,respectively,meeting the clinical requirement for the strength of vascular anastomosis,and with the minimal mechanical damages to tissues.Conclusions The device designed in this study can be used for vascular anastomosis by adjusting the pressure distance,and it can improve operation efficiency,reduce mechanical damage to tissues,and further improve the quality of anastomosis.These results provide an essential reference for the design of degradable vascular anastomotic devices.

Magnetic resonance (MR) imaging is an important tool for prostate cancer diagnosis, and accurate segmentation of MR prostate regions by computer-aided diagnostic techniques is important for the diagnosis of prostate cancer. In this paper, we propose an improved end-to-end three-dimensional image segmentation network using a deep learning approach to the traditional V-Net network (V-Net) network in order to provide more accurate image segmentation results. Firstly, we fused the soft attention mechanism into the traditional V-Net's jump connection, and combined short jump connection and small convolutional kernel to further improve the network segmentation accuracy. Then the prostate region was segmented using the Prostate MR Image Segmentation 2012 (PROMISE 12) challenge dataset, and the model was evaluated using the dice similarity coefficient (DSC) and Hausdorff distance (HD). The DSC and HD values of the segmented model could reach 0.903 and 3.912 mm, respectively. The experimental results show that the algorithm in this paper can provide more accurate three-dimensional segmentation results, which can accurately and efficiently segment prostate MR images and provide a reliable basis for clinical diagnosis and treatment.
Male ; Humans ; Prostate/diagnostic imaging* ; Image Processing, Computer-Assisted/methods* ; Magnetic Resonance Imaging/methods* ; Imaging, Three-Dimensional/methods* ; Prostatic Neoplasms/diagnostic imaging*

Objective Aiming at improving biomechanical strength of the anastomotic stoma as well as reducing tissue thermal damage, a novel radiofrequency (RF) tissue welding electrode was developed. Methods A novel electrode with a hollow structure on the surface ( the plum electrode) was designed and the ring electrode was used as control group to conduct the welding of intestinal tissues based on RF energy. Biomechanical properties of anastomotic stoma were studied by shear test and burst pressure test. The tissue thermal damage during welding was investigated by finite element electro-thermal-mechanical multi-field coupling simulation analysis and thermocouple probe, and the tissue microstructures were also studied. Results Under 120 W RF energy, 8 s welding duration and 20 kPa compression pressure, the anastomotic stoma had the optimal biomechanical properties. Compared with the ring electrode group, biomechanical strength of the anastomotic stoma in plum electrode group was higher, with the shear strength and burst pressure increasing from (9. 7±1. 47) N, (84. 0±5. 99) mmHg to (11. 1±1. 71) N, (89. 4±6. 60) mmHg, respectively. There was a significant reduction in tissue thermal damage, and intact and fully fused stomas could be formed in anastomotic area. Conclusions The proposed novel electrode could improve biomechanical strength of the anastomosis as well as reduce tissue hermal damage, thus achieve better fusion. The research result provide references for realizing the seamless connection of human lumen tissues

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.

Objective:To analyze the microstructure of commonly used surgical hemostatic powders and investigate their hemostatic properties.Methods:The microstructures of seven commonly used surgical hemostatic powders were observed by scanning electron microscopy and analyzed by particle size testing, and then the hemostatic properties of the seven commonly used surgical hemostatic powders were evaluated by an in vitro coagulation promotion test and a rabbit liver bleeding model.Results:The average particle size of Aristide hemostatic powder was 45.143 μm, and there were many grooves on the surface of the particles with increased specific surface area. The results of in vitro coagulation promotion tests showed that the absorbance and coagulation index of Aviagen were the lowest, which were 0.039 30±0.006 03 and 3.42, respectively. The rabbit liver bleeding experiment showed that the hemostatic effect of hemostatic powder materials in the experimental group was better than that in the control group (all P<0.001), among which Aviagen and Aristide were more effective. The hemostatic time and the effective bleeding volume of the experimental group and the control group were (44±17) s and (48±9) s, and (63±19) mg and (73±18) mg, respectively, and the differences were statistically significant (all P<0.05). Conclusions:There are many grooves on the surface of Arista granules, which gives them a better performance in homeostasis in surgical applications. Avitene has lower absorbance and coagulation index, and better hemostatic properties.