Improving the suction performance of centrifugal pumps by using jetting device is presented. The theoretical analysis, experimental study and engineering implementation show that suction performance of centrifugal pum...Improving the suction performance of centrifugal pumps by using jetting device is presented. The theoretical analysis, experimental study and engineering implementation show that suction performance of centrifugal pump can be improved with jetting device and be used for delivering the liquid media requiring high suction performance, whereas the efficiency and head of the pump will decrease a little. The effect of feed-back jetting on suction performance is the most obvious at design point. The suitable rate of feed-back flow is 2%-5%.展开更多
Objective: to investigate the value of self-made negative pressure aspirator combined with ureteroscopic lithotripsy (URL) in the treatment of upper urinary calculi. Methods: 178 patients with upper urinary calculi we...Objective: to investigate the value of self-made negative pressure aspirator combined with ureteroscopic lithotripsy (URL) in the treatment of upper urinary calculi. Methods: 178 patients with upper urinary calculi were divided into two groups according to different treatment methods, 89 cases in each group. Patients in the control group were treated with conventional URI, and patients in the observation group were treated with self-made negative pressure suction device combined with URI. The surgical indicators, complications and therapeutic effects of patients in the two groups were observed. Results: the renal pressure, operation time, postoperative hospital stay, intraoperative blood loss, WBC count, neutrophil percentage, PCT value and CRP value in the observation group were significantly lower than those in the control group (P < 0.01), and the differences were statistically significant (P < 0.05). The primary stone clearance rate in the observation group was higher than that in the control group (P < 0.05), and the intraoperative stone escape rate, postoperative fever incidence and postoperative septic shock incidence in the observation group were significantly lower than those in the control group (P < 0.05), with statistically significant differences. Conclusion: the self-made negative pressure suction device combined with URL can significantly reduce the intraoperative calculus escape rate and the incidence of septic shock, and can significantly improve the primary calculus clearance rate with good effect.展开更多
Objective:We aimed to study the effect of flexible ureteroscopy(FURS)for renal stones using a flexible and navigable suction ureteral access sheath(FANS)on intraoperative radiation dose and time.Methods:This was a mul...Objective:We aimed to study the effect of flexible ureteroscopy(FURS)for renal stones using a flexible and navigable suction ureteral access sheath(FANS)on intraoperative radiation dose and time.Methods:This was a multicenter study of adults who underwent FURS with FANS.The correlation analysis was done to identify factors affecting radiation dose and time measured by the C-arm fluoroscopy intraoperatively.Results:We analyzed 110 patients,with a median age of 50 years.Of them,72%were pre-stented prior to the procedure.The median stone volume was 1503 mm3 and the median operative time was 39 min.The median radiation dose was 7.4 mSv and median radiation time was 0.6 min.Totally,91%of patients achieved stone-free status(Grade A or B)on the non-contrast CT scan within 30 days postoperatively.There were no cases of postoperative sepsis.Body mass index,stone volume,and total operation time were associated with a higher radiation dose.Procedures performed under general anesthesia had a lower radiation dose and time than those performed under spinal anesthesia.Disposable scopes were associated with higher radiation time than reusable scopes but not dose.A low-power holmium laser had longer radiation time than other laser sources,but only the thulium fiber laser was associated with a significantly lower radiation dose.Conclusion:Our study is the first to highlight the multitude of factors affecting radiation exposure in FURS with FANS.Although not a direct measure of surgeons'actual exposure,it has important implications for the As Low As Reasonably Achievable principle which is commonly used to minimize radiation exposure to patients and operating room staff.展开更多
The model describing the forces acting on rice seeds within seed metering systems significantly impacts the design and structural parameters of rice pneumatic seed metering mechanisms.To formulate a mathematical repre...The model describing the forces acting on rice seeds within seed metering systems significantly impacts the design and structural parameters of rice pneumatic seed metering mechanisms.To formulate a mathematical representation of the device during seed suction,a DEM-CFD bidirectional coupling approach was utilized to simulate and model the seed-suction process.The dynamic behavior of rice seeds under the airflow at the suction port was examined,and force models for various seed-suction positions were developed.Simulation analyses were conducted under varying conditions,including different rotation speeds of the seed-suction plate and different levels of negative suction pressure.The effects of these variables on seed suction were investigated,leading to the development of a drag force model.Optimal seeding parameters and precision were determined from the simulation results.Verification and analysis were conducted through empirical experiments,and the optimal seeding performance was attained at a negative suction pressure of 1.6 kPa and a plate rotation speed of 30 r/min.The results indicated a seeding qualification rate of 95.7%,a reattachment rate of 2.4%,and a leakage suction rate of 1.9%.The simulation findings were consistent with experimental data,demonstrating that the seed-metering device satisfies the requirements for field seeding.展开更多
文摘Improving the suction performance of centrifugal pumps by using jetting device is presented. The theoretical analysis, experimental study and engineering implementation show that suction performance of centrifugal pump can be improved with jetting device and be used for delivering the liquid media requiring high suction performance, whereas the efficiency and head of the pump will decrease a little. The effect of feed-back jetting on suction performance is the most obvious at design point. The suitable rate of feed-back flow is 2%-5%.
文摘Objective: to investigate the value of self-made negative pressure aspirator combined with ureteroscopic lithotripsy (URL) in the treatment of upper urinary calculi. Methods: 178 patients with upper urinary calculi were divided into two groups according to different treatment methods, 89 cases in each group. Patients in the control group were treated with conventional URI, and patients in the observation group were treated with self-made negative pressure suction device combined with URI. The surgical indicators, complications and therapeutic effects of patients in the two groups were observed. Results: the renal pressure, operation time, postoperative hospital stay, intraoperative blood loss, WBC count, neutrophil percentage, PCT value and CRP value in the observation group were significantly lower than those in the control group (P < 0.01), and the differences were statistically significant (P < 0.05). The primary stone clearance rate in the observation group was higher than that in the control group (P < 0.05), and the intraoperative stone escape rate, postoperative fever incidence and postoperative septic shock incidence in the observation group were significantly lower than those in the control group (P < 0.05), with statistically significant differences. Conclusion: the self-made negative pressure suction device combined with URL can significantly reduce the intraoperative calculus escape rate and the incidence of septic shock, and can significantly improve the primary calculus clearance rate with good effect.
文摘Objective:We aimed to study the effect of flexible ureteroscopy(FURS)for renal stones using a flexible and navigable suction ureteral access sheath(FANS)on intraoperative radiation dose and time.Methods:This was a multicenter study of adults who underwent FURS with FANS.The correlation analysis was done to identify factors affecting radiation dose and time measured by the C-arm fluoroscopy intraoperatively.Results:We analyzed 110 patients,with a median age of 50 years.Of them,72%were pre-stented prior to the procedure.The median stone volume was 1503 mm3 and the median operative time was 39 min.The median radiation dose was 7.4 mSv and median radiation time was 0.6 min.Totally,91%of patients achieved stone-free status(Grade A or B)on the non-contrast CT scan within 30 days postoperatively.There were no cases of postoperative sepsis.Body mass index,stone volume,and total operation time were associated with a higher radiation dose.Procedures performed under general anesthesia had a lower radiation dose and time than those performed under spinal anesthesia.Disposable scopes were associated with higher radiation time than reusable scopes but not dose.A low-power holmium laser had longer radiation time than other laser sources,but only the thulium fiber laser was associated with a significantly lower radiation dose.Conclusion:Our study is the first to highlight the multitude of factors affecting radiation exposure in FURS with FANS.Although not a direct measure of surgeons'actual exposure,it has important implications for the As Low As Reasonably Achievable principle which is commonly used to minimize radiation exposure to patients and operating room staff.
基金the support from the National Key Research and Development Project of China(2024YFF0505400)National Natural Science Foundation of China(52478530,52321165649)the Fundamental Research Funds for the Central Universities(NC2024006)。
基金funding from the National Natural Science Foundation of China(Grant No.32201669)the Guangzhou Science and Technology Plan Project(Grant No.2023A04J0865)+5 种基金Key Discipline Research Capability Enhancement Project in Guangdong Province(Grant No.2024ZDJS081)Guangdong Provincial Junior Innovative Talents Project for Ordinary Universities(Grant No.2022KQNCX122)the project was supported by Open Fund of State Key Laboratory of Agricultural Equipment Technology,South China Agricultural University(Grant No.SKLAET-202405)Guangzhou College of Commerce Campus Project(Grant No.2021XJYB06)Guangdong Provincial Key Laboratory of Agricultural Artificial Intelligence Open Plan Project(Grant No.GDKL-AAI-2022002GDKL-AAI-2022003).
文摘The model describing the forces acting on rice seeds within seed metering systems significantly impacts the design and structural parameters of rice pneumatic seed metering mechanisms.To formulate a mathematical representation of the device during seed suction,a DEM-CFD bidirectional coupling approach was utilized to simulate and model the seed-suction process.The dynamic behavior of rice seeds under the airflow at the suction port was examined,and force models for various seed-suction positions were developed.Simulation analyses were conducted under varying conditions,including different rotation speeds of the seed-suction plate and different levels of negative suction pressure.The effects of these variables on seed suction were investigated,leading to the development of a drag force model.Optimal seeding parameters and precision were determined from the simulation results.Verification and analysis were conducted through empirical experiments,and the optimal seeding performance was attained at a negative suction pressure of 1.6 kPa and a plate rotation speed of 30 r/min.The results indicated a seeding qualification rate of 95.7%,a reattachment rate of 2.4%,and a leakage suction rate of 1.9%.The simulation findings were consistent with experimental data,demonstrating that the seed-metering device satisfies the requirements for field seeding.
