Design Of Automatic Tracking Frequency Locking Ultrasonic Therapeutic Instrument Based On Neural Network Control

Medical studies have shown that ultrasonic therapy has a remarkable therapeutic effect on chronic pain such as neuralgia and spinal disease and soft tissue diseases such as Meniere’s disease and myoimpotence due to its strong penetration,no side effects and quick effect.At present,the ultrasonic therapeutic instrument developed in the market still has some problems,such as low efficiency,large size,not suitable for carrying and expensive price.At the same time,the resonant frequency of piezoelectric ultrasonic transducer in ultrasonic therapy instrument is easy to drift due to the external environment,temperature change and load change and other factors,as well as the natural frequency factory error caused by the manufacturing process in the production process will make it work on the non-resonant point.When the piezoelectric ultrasonic transducer works at the non-resonant frequency,it will make the treatment waveform of the ultrasonic therapy instrument change,the output power is unstable,thus affecting the therapeutic effect of the ultrasonic therapy instrument.In view of the above problems,this topic proposes a design scheme of automatic tracking frequency locking ultrasonic therapy instrument based on fuzzy neural network PID(Proportion Integration Differentiation)control algorithm.The system uses STM32F103C8T6 as a microcontroller.By using the characteristic principle of reverse piezoelectric effect of piezoelectric ultrasonic transducer and voltage feedback type automatic tracking and locking method,the voltage values at both ends of the piezoelectric ultrasonic transducer are collected and fed back in real time by sweeping frequency.The fuzzy neural network PID control model is established to automatically track and lock frequency and find the maximum voltage value and corresponding resonant frequency.The frequency of ultrasonic excitation signal output by DDS(Direct Digital Frequency Synthesizer)is controlled by a single chip microcomputer so that the piezoelectric ultrasonic transducer always works at the resonant point.In this paper,MATLAB/Simulink and other software simulation and experimental testing,through fuzzy neural network PID control algorithm before and after the automatic tracking frequency-locking experiment to compare,the prototype ultrasonic therapeutic apparatus was used to test and analyze the whole apparatus and its functions.The results show that the automatic tracking frequency locking ultrasonic therapy instrument can maintain a stable output frequency and good waveform,high frequency tracking accuracy and low cost,and can achieve good therapeutic effect.The device has the characteristics of convenience,low cost and good therapeutic effect.It is a convenient ultrasonic therapy instrument suitable for home use.Patients can operate by themselves and effectively relieve pain and relax muscles,so this subject has good innovation and application prospects and wide application value.