Research On Ultrasonic Physiotherapy Based On Phased Array Technology

Currently,ultrasonic physiotherapy equipment usually utilize a single probe,so this method has setbacks that the are neither able to emit flexible and controllable ultrasonic sound beams,and it is not possible to change the treatment position in time.Targeting at the problems,this paper proposes an ultrasonic physiotherapy method based on phased array technology to substitute the existing method: manual mechanical scanning through ultrasonic physiotherapy instruments,so as to achieve rapid control of the treatment area and the direction of force application.Firstly,the basic theory of phase-controlled ultrasonic therapy is discussed.The principle of transmitting and receiving of ultrasonic phased array,basic scanning mode and phased array delay algorithm are analyzed.Secondly,according to the theoretical analysis,a concave spherical acoustic lens focusing phased array transducer for phased ultrasonic physiotherapy is designed.The geometric design of the transducer,important parameters,and theoretical derivation of the radiated sound field of the transducer are introduced,and finite element simulation analysis.The simulation results show that the transducer can perform effective phase-controlled focus deflection within a certain range.Thirdly,the ultrasonic phased array transmitting system is designed based on FPGA digital control technology.The phase-controlled focusing deflection with delay accuracy of 2.5 ns is realized by using the multiplier and phase shifting technology of PLL(phase-locked loop)inside the FPGA.The MAX4940 chip is used to design the excitation pulse transmitting circuit,and the Gigabit Ethernet communication technology is used to realize high-speed real-time data transmission between the upper computer and the lower computer.Finally,the functional test and experimental verification of the FPGA-based ultrasonic phased array launch system and phase-controlled ultrasonic physiotherapy experiments were carried out.The test results show that the ultrasonic phased array transmitting system can transmit data at high speed and real time,and drive the phased array transducer to emit ultrasonic waves with phased focus deflection.The effective sound intensity of each focused point in a certain range in space is in line with the ultrasonic physiotherapy.The standard proves that phase-controlled ultrasonic physiotherapy,which can flexibly change the position of the treatment point without moving the probe position,is feasible;and flexible treatment can be performed in different shaped lesion areas,which improves the flexibility of ultrasound therapy.