Automatic frequency tracking system for needle actuating device

Resonant frequency shift can occur during operation in the application of ultrasonic actuating device. It affects the resonance amplitude and therefore the performance of the device. To solve this problem, an automatic frequency tracking system based on embedded technology was developed. It has the ability to automatically track the resonant frequency shift in response to the load and adjust the excitation frequency accordingly to optimize the performance of the ultrasonic actuating device. The tracking algorithm realized by stm32 ARM processor ensures flexibility to suit different transducers and load conditions. The data acquisition module and serial port can achieve real time operation parameters monitoring and storage on PC. The effectiveness of this frequency tracking system is tested in a trial study of needle visualization during anesthesia procedure using needle actuating device. Results show that the visibility of the needle is greatly improved throughout needle insertion.