ABSTRACT
【Objective】 The thermal effects of super-pulsed thulium fiber laser (TFL) at different powers,lithotripsy modes and irrigation rates were studied using a 3D kidney model to simulate ureteral lithotripsy in vivo. 【Methods】 A thermal effect model was established in vitro. Under the same conditions of laboratory temperature and equipment,the temperature around the optical fiber was measured and compared when different optical fiber diameters,powers,lithotripsy modes and irrigation rates were used to simulate lithotripsy by TFL. 【Results】 There was significant difference in the temperature around the optical fiber caused by two fibers with different diameters under the same conditions (P<0.05). Under the same conditions,different lithotripsic modes produced different temperatures,and the temperature of "high energy and low frequency" was lower than that of "low energy and high frequency" (P<0.05). When the power was 10 W and the minimum irrigation rate was 10 mL/min,the plateau temperature did not reach the safety threshold (43 ℃). When the power was 20 W and the minimum irrigation rate was 10 mL/min,the platform temperature exceeded the safety threshold. When the irrigation rate was 20 mL/min,the platform temperature did not reach the safety threshold. 【Conclusion】 In the study of ureteral lithotripsy in vitro,the power,mode,irrigation rate and optical fiber diameter are factors affecting the thermal effects of TFL. No matter what kind of lithotripsy mode and fiber diameter,the temperature around the fiber is safe when the lithotripsy power is ≤10 W and the irrigation rate is ≥10 mL/min;when the lithotripsy power is ≤20 W and the irrigation rate is ≥20 mL/min,the temperature around the fiber is safe.
ABSTRACT
Objective To study environmental safety reference standard values of commonly encountered pathogenic microorganisms, and provide the basis for environmental risk assessment of a high-level biosafety laboratory (BSL).Methods Using human exposure dose calculation methods as the basic principle in combination with microbial hazard evaluation methods , an infectious dose calculation model of human exposure to pathogenic microorganisms by breathing was proposed . Based on research on characteristics of commonly encountered pathogenic microorganisms at home and abroad , the environ-mental safety threshold reference standard and environmental risk protection zone for such microorganisms were obtained . Results An the environmental risk assessment standard calculation method for commonly encountered highly pathogenic microorganisms was proposed , and the minimum infectious dose and environmental safety threshold of seven commonly encountered pathogenic microorganisms were obtained , including SARS coronavirus , highly pathogenic avian influenza virus, Mycobacterium tuberculosis, Bacillus anthracis, Yersinia pestis,Francisella tularensis, and epidemic hemorrhagic fever virus.Conclusion The results can be used as a reference standard of infectious aerosols in a high-level BSL for environ-mental risk assessment , laboratory risk control and emergency management .