Objective:To investigate an accurate and quantitative method to measure the eyeball morphological parameters of guinea pigs through a method that combines programmed digital techniques and mathematical geometric principles.Methods:Twenty-two three-week-old clean-grade male tricolor guinea pigs were selected and sacrificed by anesthesia overdose.Eyeballs were enucleated.The horizontal and sagittal images of the eyeball were taken with the high-speed photographic model of 13 million pixels macro meter, and the pictures were imported into pycharm programming software.Using the pre-written analysis program of Python 3.9, the conversion coefficient between the photo pixel and the actual length was obtained by a scale, and then the corneal surface was fitted by arc fitting and conic curve fitting.The results of arc fitting were converted to calculate the corneal radius of curvature.The corneal eccentricity was calculated according to the general conic equation (Ax 2+ Bxy+ Cy 2+ Dx+ Ey+ F=0). The corneal asphericity was evaluated by curve fitting between the central 3-mm and the whole cornea.The use and care of the animals complied with Regulations for the Administration of Affairs Concerning Experimental Animals by State Science and Technology Commission.The study protocol was approved by the Ethics Committee of Shanghai Public Health Clinical Center (No.2022-A009-01). Results:The digital method of Python programming can show the corneal contour of guinea pigs completely and clearly.In the transverse plane, there was no significant difference in the corneal curvature measurements among the digital fitting in central 3-mm cornea, digital fitting in whole cornea and curvature meter ( F=1.693, P=0.190). In the sagittal plane, there was a significant difference in the corneal curvature measurements among the three methods ( F=3.500, P=0.030), and the corneal curvature measurements of the whole cornea measured by the curvature meter were significantly greater than those measured by the digital fitting ( P<0.05). There was no statistical significance in the measurements of corneal curvature radius among the three methods in the transverse plane and the sagittal plane ( F=1.817, P=0.170; F=2.050, P=0.133). The horizontal and sagittal corneal eccentricity measured by digital fitting in central 3-mm cornea were 0.55±0.15 and 0.53±0.17, which were lower than 0.66±0.10 and 0.64±0.14 measured by digital fitting in whole cornea, and the differences were statistically significant ( t=-4.860, -5.210; both at P<0.01). Conclusions:It is feasible to use Python programming digital method to measure the corneal curvature and eccentricity of guinea pigs.

Objective: To investigate the anatomical features of the safe zone for sacral lateral mass screw placement and find the safe trajectory, so as to provide reference for clinical application. Methods: The three-dimensional computed tomography scan materials of sacrococcygeal vertebrae in 60 patients admitted to the Liaocheng People's Hospital of Shandong Province were analyzed by Mimics software to establish three-dimensional models. There were 33 males and 27 females, aged 25-78 years, with an average age of 45.7 years. After the safe zone was separated from sacral lateral mass model, a maximum cylinder was placed into the safe zone according to its anatomical feature. The cylinder was established as safe trajectory. Anatomical data were measured, including the length and diameter of screw trajectory, the distance between the entry point and the middle jaw, and adjacent upper and lower foramen, as well as the intersection angle between the screw direction and sagittal plane, between the screw direction and the adjacent upper end plate. Results: The restriction factor of screw size on S₁, S₂ lateral mass was transverse diameter, while the restriction factor on S₃, S₄ was the distance between adjacent intervertebral foramen. The maximal length of screw from S₁ to S₄ was 30 mm, 35 mm, 30 mm, 14 mm respectively, while the maximal diameter was 12 mm, 9 mm, 5 mm, 5 mm respectively. The best entry point of S₁ mass screw was lateral to the zygopophysis. The best entry point of S₂-S₄ mass screw was located at the midpoint of a line connecting the lateral edge of adjacent posterior sacral foramen approximately about 2 cm from median sacral crest. The leaning angles of screw was increased successively, and the sagittal plane was slightly inclined. There were significant differences between male and female groups in the leaning angle in S₂ [male: (35.8±1.2)°, female: (37.9±3.7)°] and the distance between entry point and median sacral crest [male: (20.5±1.0)mm, female: (19.1±1.4)mm](P<0.05), while there was no significant difference in other parameters (P>0.05). Conclusions Cylindrical bony channel which is feasible for screw placement can be found in the lateral mass of sacrum. Individualized measurement can provide reference for application of lateral mass screw.

At present, there still exist some limitations in the laparoscopic surgery robot represented by da Vinci surgical robot, such as the lack of force feedback function. Doctor can not feel the force feedback while operating. In this paper, a new minimally invasive laparoscopic surgery robot system is designed. Based on the master side surgeon's console, stereo vision subsystem and the slave side surgical cart, the multi-dimensional instrument force feedback technology and force feedback based safety protection strategy are introduced. The design realizes the force sensing function of full state operation. Besides, a number of different live pig experiments are carried out. The amount of bleeding in these experiments is relatively small compared with the data of the same kind of surgical robots, which effectively validates the force feedback and surgical safety protection strategies of the new robot system.
Animals ; Equipment Design ; Laparoscopy ; instrumentation ; Minimally Invasive Surgical Procedures ; Robotic Surgical Procedures ; instrumentation ; Robotics ; Swine