Preliminarily Measurement and Analysis of Sawing Forces in Fresh Cadaver Mandible Using Reciprocating Saw for Reality-Based Haptic Feedback

Purpose The aim of the study was to preliminarily measure and analyze the cutting forces in fresh Chinese cadaver mandible using a clinically widely used reciprocating saw for reality-based haptic feedback. Methods Eight mandibles were taken from fresh Chinese cadavers, 4 females and 4 males, aged between 59 and 95 years. A set of sawing experiments, using a surgery Stryker micro–reciprocating saw and Kistler piezoelectric dynamometer, was carried out by a CNC machining center. Under different vibration frequencies of saw and feeding rates measured from orthognathic surgery, sawing forces were recorded by a signal acquisition system. Results Remarkably different sawing forces were measured from different cadavers. Feed and vibration frequency of the reciprocating saw could determine the cutting forces only on 1 body. To reduce the impact of bone thickness changes on the cutting force measurements, all the cutting force data should be converted to the force of unit cutting length. The vibration frequency of haptic feedback system is determined by main cutting forces. Fast Fourier transform method can be used to calculate the frequency of this system. To simulate surgery in higher fidelity, all the sawing forces from the experiment should be amended by experienced surgeons before use in virtual reality surgery simulator. Conclusions Sawing force signals of different ages for force feedback were measured successfully, and more factors related to the bone mechanical properties, such as bone density, should be concerned in the future.