Objective To investigate the clinical value of transumbilical single-port laparoscopic colorectal operation.Methods The clinical data of 25 patients with benign or malignant carcinoma at the upper part of the colon or rectum who were admitted to the No.4 People's Hospital of Zigong from January 2010 to December 2012 were retrospectively analyzed,and the clinical experience of transumbilical single-port laparoscopic colorectal operation was summarized.Surgical procedure was selected according to the position and nature of the lesion.Patients were followed up via out-patient examination and phone call till March 2013.Results Partial colorectal resection was done on 14 patients,radical resection of right colon on 1 patient,radical resection of transverse colon on 1 patient,radical resection of left colon on 1 patient,radical resection of sigmoid colon on 2 patients and radical rectectomy on 6 patients.The operation was successfully carried out on 22 patients,2 patients received four-port laparoscopic colorectal operation,and 1 patient was converted to open surgery.The median length of the incision of single-port laparoscopic colorectal operation was 3.8 cm (range,3.5-4.5 cm),and the operation time was (192 ± 32) minutes.The intraoperative blood loss was (61 ± 21)mL,and the median diameter of the tumor was 2.7 cm (range,1.0-5.0 cm).The median number of lymph nodes dissected was 7 (range,3-22),the mean time of postoperative anal exhaust time was 2 days (range,1-5 days),and the mean time of postoperative hospital stay was 8 days (range,6-20 days).The incidence of postoperative complications was 8.0％ (2/25),including 1 patient with wound infection and 1 patient with anastomotic leakage.The circumferential resection margins of radically resected specimens were negative in 11 patients.Twenty-two patients who received transumbilical single-port laparoscopic colorectal resection were followed up,and the median time of follow-up was 12 months.Colorectal liver metastasis was detected on 1 patient at postoperative month 10,and the other patients survived without tumor recurrence or metastases.Conclusions Transumbilical singleport laparoscopic colorectal operation is safe,micro-traumatic and feasible,and it also has less complication and good cosmetic effect.

Objective To develop a digital signal processing method for magnetic positioning of electronic capsules according to the theory of multiple alternating magnetic field source electromagnetic positioning, so as to reduce the volume and power consumption of electronic capsules. Method Based on STM32 MCU, software algorithms such as fast digital filtering, peak detection and frequency detection were designed to replace the corresponding analog hardware circuits such as analog filtering, peak detection and comparison circuits. Results The experimental results showed that the average relative error of the peak detection and frequency detection of the digital signal processing system were 1.51％ and 0.28％ , respectively. The linear relationships of theoretical amplification factor and actual amplification factor of the programmable amplifier were basically consistent, and the average ratio difference was 4.51 dB. Conclusions The proposed digital signal processing system can replace some analog hardware circuits, providing a basis for reducing the size and power consumption of electronic capsules.

Objective     To investigate the effects of different types of tricuspid regurgitation, implantation positions, and device models on the treatment outcomes of K-Clip for tricuspid regurgitation using numerical simulations. Methods     Three-dimensional reconstruction of the heart model was performed based on CT images. Two different regurgitation orifices were obtained by modifying the standard parameterized tricuspid valve leaflets and chordae tendineae. The effects of different K-Clip models at different implantation positions (posterior leaflet midpoint, anterior-posterior commissure, anterior leaflet midpoint, posterior septal commissure) were simulated using commercial explicit dynamics software Ls-Dyna. Conclusion     For the two types of regurgitation in this study, clipping at the posterior leaflet midpoint resulted in a better reduction of the regurgitation orifice (up to 75% reduction in area). Higher clamping forces were required for implantation at the anterior leaflet midpoint and posterior septal commissure, which was unfavorable for the smooth closure of the clipping components. There was no statistical difference in the treatment outcomes between the 18T and 16T K-Clip components, and the 16T component required less clamping force. Therefore, the use of the 16T K-Clip component is recommended.