DESIGN OF HIGH POWER ULTRASONIC DEVICES FOR BONE SURGERY AND MANUFACTURING THROUGH CONTROL OF PARAMETRIC AND NONLINEAR VIBRATIONS

This proposed research tackles the current gaps in the understanding of the nonlinear vibration behaviour of power ultrasonic systems in order to overcome the limitations of this technology in bone surgery. The study stems from successful previous work by the proposer in ultrasonic cutting of food products and recent work on ultrasonic cutting of bone, to improve the performance of current ultrasonic devices and identify a new generation of ultrasonic instruments for osteotomy and osteoplasty in implantology, periodontology, endodontics, orthodontic and orthopaedic surgery.Research by the PI has shown that nonlinear phenomena such as tuned frequency shifts and multi-modal responses are characteristic of ultrasonic cutting devices driven at high power. He has demonstrated that the vibration behaviour of these devices is qualitatively similar to theoretical models of autoparametric and nonlinear dynamic systems. In this proposed work, nonlinear phenomena will be characterised in a range of ultrasonic bone cutting systems with the aim of controlling, eliminating or enhancing the responses as benefits of each surgical application. A validated theoretical methodology for ultrasonic component design, based on the control of nonlinear vibration effects will be proposed. Hence, single-mode or multi-mode surgical devices will be designed either by constraining or by exploiting the inherent nonlinear behaviour of system components. The research outcomes will also provide insights and solutions for the control of nonlinear vibration characteristics in a wider range of ultrasonic systems including tuned devices used for manufacturing and chemical-biological processes.