Objective:This study aims to investigate the energy conduction mechanism of holmium laser lithotripsy based on the Gemini platform and validate the optimal lithotripsy parameters under this mechanism using an in vitro...Objective:This study aims to investigate the energy conduction mechanism of holmium laser lithotripsy based on the Gemini platform and validate the optimal lithotripsy parameters under this mechanism using an in vitro ureteral model.Methods:The Lumenis VersaPulse PowerSuite dual-wavelength laser system was employed,with a holmium laser wavelength of 2.1μm,power output of 0-80 W,pulse energy ranging from 0.2 to 3.5 J,and pulse frequency from 5 to 40 Hz.An in vitro thermal effect model of the holmium laser was established to simulate temperature changes in urinary stones under varying power levels,energy ranges,pulse frequencies,and irrigation rates.High-speed cameras and thermal imaging devices were used to observe and record the temperature of the stone and surrounding tissues during laser irradiation.Finite element analysis was integrated to simulate the energy conduction pathways of the holmium laser within the stone and ureteral wall,assessing whether localized high-temperature regions exceeded the thermal injury threshold.Results:Temperature in the stone fragmentation mode decreased significantly with increasing distance from the basket and higher irrigation rates,thereby reducing the risk of thermal injury.In fragmentation mode,both 276μm and 500μm core-diameter fibers generated significantly higher temperatures at the basket site compared to the free-running mode(P<0.05).No thermal injury was observed at irrigation rates≥15 ml/min across all parameter combinations;at 10 ml/min,only high-energy settings(3.5 J)approached the thermal injury threshold(50.3℃);at≤5 ml/min,high-energy settings(>1.5 J)consistently exceeded the danger threshold.The safest parameter combination was 0.5 J+5 Hz(at any irrigation rate).Within 5 min,temperatures at the stone surface-below,middle,and above the basket-reached 151.0℃±1.0℃,62.5℃±0.2℃,and 46.8℃±0.2℃,respectively,whereas the maximum temperature on the ureteral wall surface was only 49.5℃.The FEA results closely matched experimental observations,indicating that with 0.5 J+5 Hz(at any flow rate),laser energy is primarily confined within the stone,generating localized high-temperature zones(80℃-90℃)at the stone-ureter wall interface,which promotes stone fragmentation while effectively minimizing collateral tissue damage.Conclusion:The holmium laser energy conduction mechanism based on the Gemini platform is predominantly concentrated within the stone,exhibiting excellent directionality and depth penetration,enabling efficient lithotripsy while minimizing thermal damage to surrounding tissues.展开更多
文摘Objective:This study aims to investigate the energy conduction mechanism of holmium laser lithotripsy based on the Gemini platform and validate the optimal lithotripsy parameters under this mechanism using an in vitro ureteral model.Methods:The Lumenis VersaPulse PowerSuite dual-wavelength laser system was employed,with a holmium laser wavelength of 2.1μm,power output of 0-80 W,pulse energy ranging from 0.2 to 3.5 J,and pulse frequency from 5 to 40 Hz.An in vitro thermal effect model of the holmium laser was established to simulate temperature changes in urinary stones under varying power levels,energy ranges,pulse frequencies,and irrigation rates.High-speed cameras and thermal imaging devices were used to observe and record the temperature of the stone and surrounding tissues during laser irradiation.Finite element analysis was integrated to simulate the energy conduction pathways of the holmium laser within the stone and ureteral wall,assessing whether localized high-temperature regions exceeded the thermal injury threshold.Results:Temperature in the stone fragmentation mode decreased significantly with increasing distance from the basket and higher irrigation rates,thereby reducing the risk of thermal injury.In fragmentation mode,both 276μm and 500μm core-diameter fibers generated significantly higher temperatures at the basket site compared to the free-running mode(P<0.05).No thermal injury was observed at irrigation rates≥15 ml/min across all parameter combinations;at 10 ml/min,only high-energy settings(3.5 J)approached the thermal injury threshold(50.3℃);at≤5 ml/min,high-energy settings(>1.5 J)consistently exceeded the danger threshold.The safest parameter combination was 0.5 J+5 Hz(at any irrigation rate).Within 5 min,temperatures at the stone surface-below,middle,and above the basket-reached 151.0℃±1.0℃,62.5℃±0.2℃,and 46.8℃±0.2℃,respectively,whereas the maximum temperature on the ureteral wall surface was only 49.5℃.The FEA results closely matched experimental observations,indicating that with 0.5 J+5 Hz(at any flow rate),laser energy is primarily confined within the stone,generating localized high-temperature zones(80℃-90℃)at the stone-ureter wall interface,which promotes stone fragmentation while effectively minimizing collateral tissue damage.Conclusion:The holmium laser energy conduction mechanism based on the Gemini platform is predominantly concentrated within the stone,exhibiting excellent directionality and depth penetration,enabling efficient lithotripsy while minimizing thermal damage to surrounding tissues.
