Study on detection of vibration of a microfabricated ultrasonic Micro-knife

Ultrasonic micro-knife is a new minimally invasive surgical instrument. It was made by using MEMS technology. It works in an ultrasonic vibration mode to realize the precise incision with its sharp tip at one end. We chose the PZT-4 plates whose resonant frequency is close to the natural frequency of the Microknife and used them to excite the micro-knife into vibration. As a micro-driver, its vibration detection is very important. So we studied the optical detection and electrical detection techniques. The entire micro-knives´ vibration was observed and measured by using the high-power digital microscope and CCD equipment in the precision optical platform. We also studied micro-knives vibration signal acquisition system based on DSP and PLL. The hardware circuit and software of the system were designed. The vibration voltage signal result was detected. And we can lock the vibration voltage frequency. These two methods can complement each other and provide an effective method to solve the detecting micro-knife problem.