University College Dublin School of Electrical, Electronic and Mechanical Engineering

Effects

Chip Formation

Soft Tissue

Micro Fractures

Thermal

Bone Cells

Variables

Frequency

Amplitude

Force

Cutting tip Design

The Development of Next-Generation Ultrasonic and Vibration Assisted Surgical Tools for Bone Cutting

(VIBONE)Cathal Heavey, Prof. Gerry Byrne, Dr. Eamonn Ahearne

Abstract

Components of an Ultrasonic Bone Cutting System & Challenges

Collaborating Company: Stryker Instruments

Bone cutting is one of the oldest procedures in surgical medicine. However the design of saws and drills has not

advanced significantly in recent decades. Non-conventional processes are being developed to overcome the

shortcomings of today's tools. One such process is ultrasonic/vibration assisted bone cutting. Reported benefits include

reduced reaction forces, and less collateral damage and fiber tearing.

Advanced Manufacturing Science (AMS) Research Centre, Mechanical Engineering, University College Dublin, Belfield, Dublin 4, Ireland

Amplifier andControl System

Conventional Bone Cutting Tools

References:[1] Gleizal, A., J. C. Bera, et al. (2007). "Piezoelectric osteotomy: a new technique for bone surgery-advantages in craniofacial surgery." Childs Nervous System 23(5): 509-513[2] Eggers, G., J. Klein, et al. (2004). "Piezosurgery((R)): an ultrasound device for cutting bone and its use and limitations in maxillofacial surgery." British Journal of Oral & Maxillofacial Surgery 42(5): 451-453[3] Lucas, M., A. Cardoni, et al. (2005). "Temperature effects in ultrasonic cutting of natural materials." Cirp Annals-Manufacturing Technology 54(1): 195-198[4] Cardoni, A., A. MacBeath, et al. (2006). "Methods for reducing cutting temperature in ultrasonic cutting of bone." Ultrasonics 44: E37-E42

Outcomes

Understand the fundamental mechanism of material removal for ultrasonic tools

Design a tool that utilises theoptimum parameters for thecutting of bone

Bone Structure

Horn and VibratingCutting Tip

Ultrasonic Transducer

Shortcomings include;

• Reduced Control• High Cutting Force

• Elevated Temperatures• Soft Tissue Damage due to

snagging

Figure 2. Bone is a composite material. It’s properties are highly variable.

Hard Cortical BoneOsteon

Figure 3. A Current Ultrasonic Cutting Device [1,2]

Figure 1. Examples of conventional bone cutting tools

Figure 4. Thermal Necrosis of Bone[3]

Figure 5. Undesirable

Vibrations[4]

Figure 6. Low Material Removal Rate means Increased Surgical Times

Project Objectives

Spongy Cancellous Bone