Study And Optimal Design Of Ultrasonic Horn For Debridement

With the development of social economy, improvement of the living standard,the rate of traffic accidents increased, the trauma is becoming a disease with high rate of mortality and morbidity. Ultrasounds are sound waves with frequencies higher than 20 khz in elastic medium, it can trigger a series of effects.Debridement is a basic operative techniques of woundtreatment, and observably influences the recovery of wounds.combining ultrasonic technology with debridement was applied to clean the contaminated wound.It can shorten the time for wound healing, reduce the pain of trauma patients, and effectively reduce the loss of individuals and nations caused by the trauma.Ultrasound debridement encountered those problems in the clinical using: 1, the cleaning effect needs improve; 2, the disinfection and cleaning of the horn is inconvenience; 3, when the horn was larger, the drilling will be more difficult. The optimization design of the horn was proposed for ultrasonic debridement. First, in order to further improve the effect of ultrasonic debridement, this paper improved the surface structure; secondly, in order to facilitate the replacement and disinfection, the horn-cutting design was proposed, it makes the horn into splicing two section horns. On the one hand, it was requested that the interrupts position must be in its shape variable minimum, to ensure the stability of the horn; on the other hand, the design would adjust the cutoff positions as close as possible to the one-half of the horn, this design could reduce the maximum distance which needs drill, and the machining could be easy.Firstly, ultrasonic performance parameters, physical properties of the liquid medium and the initial radius of cavitation bubble will be related to impact on ultrasonic cavitation, the results of the analysis is used to guide the ultrasonic amplitude end face structure improvement, and design the horn. Next,the simulation calculation of ultrasonic after surface structure of sound field distribution and contrast end surface structure change of acoustic pressure area and the influence of extreme value, select arc concave into the structure of the end face structure in this paper. Newly,performance parameters of typical horns were calculated whenchanging in length by equivalent four-terminal network, The comparison results show that the cone composite horn is the most close to the design requirements in the typical horns. Considering the deficiency of the cone composite horn in the horn-cutting position,the spline curve was used tosimulate the cone composite shape. genetic algorithm be used tooptimize parametric curve shape of the horn, it was based on the shape of typical horns. Four categories, twelve kinds of horns' shape were optimized to ensure that adverse effects on the stability of the hornsminimized when were disconnected from the middle and the drilling distance was minimum. Finally, the optimized spline curve is determined as the best design to meet the requirements of using in debridement by evaluating each optimization horn designs from efficiency, stability, and the difficulty of machining.