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Objective To analyze the influence of different materials on thermal stress field of the bipolar high-frequency electric knife. Methods The electric-thermal coupling simulation analysis was performed for thermal stress field in working process of the bipolar high-frequency electric knife. The influence patterns for 4 kinds of insulating layer materials 304 stainless steel, 316 stainless steel, 317 stainless steel, Ti6Al4V and 4 kinds of electrode materials polypropylene (PP), polyamide-6 (PA6), polycarbonate (PC) and acrylonitrile butadiene styrene (ABS) on thermal stress field and thermal deformation field of insulating layer, electrode and coating of bipolar high-frequency electric knife and myocardial tissues were studied. Results The thermal deformation of myocardial tissues was much higher than that of the components of high-frequency electric knife in period of 2 s for continuous power. In terms of myocardial tissue protection, 304 stainless steel was the best electrode material for high-frequency electric knife. For choosing PP as the insulating layer material, thermal deformation of myocardial tissues caused by thermal stress was the smallest, which could better maintain the integrity of myocardial tissues. Conclusions The manufacturing materials of high-frequency electric knife have an important influence on thermal stress field in its working process. The regularity analysis results can provide guidance for the development of high-frequency electric knife.
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Objective To analyze the influence regularities of different sizes on thermal stress field of bipolar high-frequency electric knife. Methods Based on the ANSYS software, the electric-thermal coupling simulation analysis was performed for thermal stress field of bipolar high-frequency electric knife during working. The effects of 3 different insulation layer thicknesses (0-5, 1-0, 1-5 mm), electrode thicknesses (0-5, 1-0, 1-5 mm) and coating thicknesses (3, 6, 9 μm) on thermal stress field of bipolar high-frequency electric knife were studied. Results If thickness of the insulation layer was larger, deformation of the myocardial tissues would be smaller due to thermal stress, that is, the thickness of the insulation layer was inversely proportional to thermal deformation of the myocardial tissue during working process of the high-frequency electric knife. For the 3 electrode thicknesses, 1-0 mm was a better choice. And for the 3 coating thicknesses, 6 μm was a better choice. Conclusions The component sizes for the high-frequency electric knife have an important influence on thermal stress field, and the result can provide guidance for design of the high-frequency electric knife.
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Objective To evaluate the efficacy and safety of 1 940 nm thulium laser on peroral endoscopic myotomy (POEM) for treatment of patients with achalasia of cardia. Methods Fifteen patients undergoing POEM in Beijing Friendship Hospital from February 2016 to November 2016 were enrolled and divided into 1 940 nm thulium laser group ( n＝7) and high frequency electric knife group ( n＝8) using zelen′s design, with followed-up for three months. The operation time, success rate, efficacy, and complications were compared between the two groups. Results All the procedures were successfully completed. There was no significant difference on baseline between the two groups ( P＞0. 05). The time of total operation, creating submucosal tunnel, myotomy, and closing incision were not significantly different between the two groups (all P＞0. 05). The bleeding amount, creating tunnel bleeding amount, and myotomy bleeding amount were not significantly different between the two groups (all P＞0. 05). The complication rate during operation and one week after operation was not significantly different between the two groups ( P＝0. 76).The time of creating mucosal incision for the 1 940 nm thulium laser group was longer than that of the high frequency electric knife group ( 3. 7 ± 3. 0 min VS 2. 3 ± 1. 3 min, P＝ 0. 02). After one month of follow-up, the efficiency of the 1 940 nm thulium laser group and the high frequency electric knife group was 100. 0%(7/7) and 87. 5%(7/8), respectively (P＝0. 33), and the complication rate was 14. 3%(1/7) and 12. 5%(1/8), respectively (P＝0. 92). After three months of follow-up, the efficiency of the two groups was 100. 0%(7/7) and 75. 0%( 6/8), respectively ( P＝0. 16), and the complication rate was 28. 6%(2/7) and 12. 5%(1/8), respectively (P＝0. 60). Conclusion 1 940 nm thulium laser and high frequency electric knife both have good utility on POEM.1 940 nm thulium laser decreases the operating time and bleeding compared with high frequency electric knife.
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Objective To design a thermal alarm sensing controller to avoid burns by the high-frequency electric knife in the operating room. Methods The system development of the controller was executed under Visual DSP, and a thermal alarm sensing control method based on multi-thread temperature feedback regulation was proposed for eliminating the risk of the burns by the high-frequency electric knife in the operating room. The functional and technical indexes of the controller were analyzed to construct its overall framework model, the control law was designed for the temperature feedback control of the controller, and proportion-integral-derivative (PID) control algorithm was applied to the improvement of the controller. Modular design was involved in the controller hardware which was composed of the temperature sensing AD module, baseline drift suppression module, high voltage adjust module, interrupt module and alarm communication circuit. Software process was designed, and then simulation experiment was carried out to test the performances of the controller. Results The controller gained advantages in high loading performance and high-frequency baseline at zero level to realize compensation, and was gifted with high anti-interference ability and precision when fulfilling the safety control of the high-frequency electric knife by multi-thread temperature regulation and overheating interrupt. Conclusion The controller behaves well in the alarm against the burns by the high-frequency electric knife in the operating room.
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Objective To analyze the characteristic and distribution of colonic polyps and investigate the diagnosis of colorectal benign polyps for chromoendoscopy and curative effect of argon plasma coagulation, High frequency electric knife electric coagulation, EMR, Titanium clips treating Colorectal benign polyps.Methods 175 patients of benign colorectal polyps of endoscopic diagnosis combined with pathology and treated were collected from December 2015 to June 2016.Results by ordinary and staining endoscopy, solitary polyp quantity and multiple polyps types in many segments for colon were more. Which the polyps quantity of rectum and sigmoid colon were more and polyp diameter was smaller in the left colon, the polyps quantity of ascending colon were less and polyp diameter was larger in the right colon. Pigment endoscopy was conduce to diagnose the micro-polyp. Chromoscopy enhanced the detection of multiple polyps in the colon.Conclusions Staining endoscopy is improved the multiple polyps detection rate and reduce omission diagnose rate, to proift the differential diagnosis of benign polyps, according to the solitary polyp and multiple polyps combined with polyp size in colon, which select the one of APC, high-frequency electric coagulation electric cut and EMR or two kinds of therapeutic endoscopy, therapeutic endoscopy is efifcacy and safety technique and the most of APC.
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Objective To explore the means of haemostasis in gallbladder preserving cholecystolithotomy. Methods The clinical data of 31 cases were retrospectively analyzed, summarizes the successful experiences. Results There appeared 31 cases the gallbladder internal bleeding in 512 cases gallbladder preserving cholecystolithotomy. In all the cases, 31 operations were stopped bleeding satisfactorily and performed successfully without conversion to conventional laparoscopic surgery, without perforation of gallbladder. pressure and lavage hemostasis had common effect, the control coagulation hemostasis had satisfaction rate 96.6%. Except one patient used gallbladder whole layers suture method. Conclusion The control coagulation hemostasis with the high-frequency electric knife is the optimal way, pressure and lavage hemostasis is basal, and gallbladder whole layers suture method is supplement.
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Objective To discuss the feasibility and safety of total mesorectal excision under laparoscopy by ultrasonic scalpel for rectal carcinoma. Methods The data of 83 patients with rectal carcinoma who received gastrointestinal surgery under laparoscopy in our hospital from March 2011 to September 2013 were analyzed. According to the method of total mesorectal excision,they were divided into ultrasound knife group of 44 cases and a high-frequency electric knife group of 39 cases. The differences of the intraoperative and postoperative related index between two groups were compared and the postoperative complications were analyzed. Results All gastrointestinal operations under laparoscopy were completed successfully. The operation time(221. 6 ± 48. 7) min and the peri-operative bleeding (64. 2 ± 39. 5) mL of ultra-sound knife group were significantly lower than the operation time(284. 3 ± 52. 4) min and the peri-operative bleeding (98. 7 ± 49. 3) mL of high frequency electric knife group (P0. 05). The volume of harmful gas included CO and acryloni-trileis at the 15min,30min,45min during the operation of ultrasound knife group were significantly lower than that of high frequency electric knife group (P0. 05). Conclu-sion Treatment of laparoscopic surgery for rectal cancer by ultrasonic scalpel in total mesorectal excision has the advantages of less operation time,intraoperative blood loss and less harmful gases,which is effective and safe.