Experimental measurements of temperatures in drilling cortical bone using thermocouples

A high speed cutting process of bone such as drilling produces heat, and can result in thermal damage (death) of bone tissue. Temperature measurement in bone drilling is a primary step in establishing threshold level for thermal damage (necrosis). Advanced understanding of techniques for acquiring reliable thermal data on bone drilling is important to avoid traumatic incision. Currently, thermocouples are the main source in the experimental determination of temperature elevation during bone drilling. In an effort to overcome uncertainties in temperature measurements with thermocouples, a new approach was used which includes inserting a thermocouple either attached to the cutting edge of a drill or inserted into the bone. The leading idea in this study was to investigate how temperature data obtained from the two mentioned systems are inherently different. Temperature measurements were observed to vary considerably with both types of measurement systems. Experimental results identified drilling speed and depth of drilling as the critical parameters for inducing higher temperatures in bone drilling. The results presented in this study can be used to select the right method for acquiring temperature data for shallow and deep drilling in bone.