Research And Design Of Adaptive Low Intensity Focused Ultrasound Therapeutic Device Based On PID Algorithm

With the continuous development of social economy,the pace of life is accelerating,and the pressure of life is increasing.People are busy working all day and lack of exercise,resulting in a continuous increase in the number of people in sub-health.At present,portable ultrasound treatment equipment on the market generally exists in large volume,expensive,complex functions,and is not easy to carry.Therefore,a portable low intensity focused ultrasound treatment device is developed in this paper.According to the characteristics of the existing ultrasound equipment on the market and the specific conditions of people's lives,the device can be reduced to a size that can be placed in their pockets,output focused ultrasound,replace the traditional way of smearing coupling agent with disposable convenience stickers,which can fix the transducer to the affected area,realize the simultaneous treatment of people's work and soft tissue diseases,and enable the device to realize the real sense of travel carrying.In the aspect of hardware,the design cost of the device is reduced by circuit optimization,and the size and power consumption of the device are reduced.Using 12 V rechargeable lithium battery as power supply and low power STM32L151 MCU as control core,according to the continuous increase of ultrasonic treatment time,combined with PID algorithm,the duty cycle of output PWM wave is automatically adjusted to achieve the control of output ultrasonic intensity.The DDS signal generator generates 2MHz square wave,which is output by frequency dividing circuit.The boost boost circuit is used to supply the power amplifier circuit for power amplification.Then the series inductance impedance matching circuit is used to drive the concave piezoelectric ceramics with output frequency of 1MHz,intensity of 0.3W/cm2,0.5W/cm2,0.7W/cm2 and 1W/cm2.Coupling agent is placed in disposable post-it notes by process.When used,the transducer can be fixed on the surface of human skin by pasting the post-it notes on the transducer and the other side on the skin.The over-current and over-heat protection circuit is used to prevent damage to the device due to the influence of no-load and ambient temperature.Finally,the stability and safety of the device are tested.The test results show that the ultrasonic treatment device is suitable for soft tissue disease patients of working people and other groups.It can abandon the traditional way of smearing coupling agent and achieve fixed treatment.The needling sensation of warm and hot sensation and focusing effect can be obviously felt during the treatment.Among them,the maximum error of output ultrasonic intensity is about 6%,the frequency error is 2%,and the total conversion efficiency is up to 41.81%.