Development Of Low Intensity Pulsed Ultrasound Equipment For The Study Of Biological Effects Of Cells

LIPUS(Low Intensity Pulse Ultrasound)has beneficial effects(promote cell proliferation,enhance cell membrane permeability,promote blood circulation,etc.on biological tissues)through ultrasonic mechanical effect,thermal effect,cavitation effect,etc.in medical therapeutic field.LIPUS has been applied in different parts of soft tissue,including skin,muscle,tendon,blood vessel,bone and so on in clinic.There are a lot of ultrasound therapeutic instruments in the market at present,but due to the lack of appropriate treatment parameters,neither unified treatment standard,the treatment effect often does not reach the best state.And even more,the instrument being single-functioned,current treatment mode can not satisfiy various treatments.Therefore,it is necessary to develop LIPUS equipment with mechanical moving parts to facilitate the comparative test of different/identical tissue objects.Currently,the parameters of commercial LIPUS equipments are single and fixed,,which can not meet the requirements for various experiments,hereby we design a LIPUS device with continuous adjustable multi-parameters.The features of the design scheme in this paper include:(1)Using MCU + CPLD to realize full digital control mode to avoid the instability of analog mode.(2)The excitation signals with different frequencies,duty cycles and pulse repetition frequencies can be changed for different purposes.The center frequency and supply voltage can be changed online to change the output power intensity,and the average output power can be changed by changing duty cycle.The feasibility of the design is verified by experiments.(3)Changing the supply voltage of power module to adjust the output power can meet the needs of different applications.for the Study of Biological Effects of Cells(4)Machinery moving part: It realizes the movement of mechanical parts by embedded system,realizes the miniaturization and compactness of the movement part,and adjusts the driving current of stepper motor online.(5)Design the circuit diagram,make the circuit board,implement the embedded software and design the CPLD/MCU communication protocol from the whole point of view.(6)The ultrasonic circuit is verified by comparing and testing with biological cells.This paper consists of five chapters.The first chapter is an introduction.The second chapter is the digital part of the system design.The third chapter focuses on the analog circuit part.The fourth chapter mainly introduces the test of the system,including the waveform and sound power test of each part,and the biological effects under LIPUS.The fifth chapter is the summary of the work.