Master’s Thesis Proposal – 15.07.2015
Thermal conductivity of cortical and cancellous bone Background The demographic development of society demands for less invasive surgical methods. Moreover, smaller incisions and the use of robotic tools are becoming more common in many surgical procedures. New problems like the drilling of deep holes close to vulnerable structures and the heat development in a closed environment will arise. The research aims at getting a better understanding of the thermal conductivity of bone in order to predict if vulnerable structures (e.g. nerves) may be damaged by the heat produced along a drilling path. The thermal conductivity of cortical bone has already been investigated, but the results vary greatly. The reasons are the different test settings, which were not up to today’s standard and the lack of characterization of the bone samples’ microstructure and composition. Aim A previously designed experimental setup allows the precise measurement of thermal conductivity at ISTB. The aim is to plan, prepare and execute an experimental study to determine the thermal conductivity of bone specimen as a function of bone density, orientation and marrow space composition. Additionally, a simple micro Finite Element (FE) analysis, based on the microstructure of bone samples, will be used to validate the experiments. Materials and Methods First, a small literature review has to be conducted in order to get familiar with bone and the experimental methods. Afterwards, the experiments will be planned and bone samples have to be prepared. Micro-CT images of samples have to be taken and experiments will be conducted with the state of the art experimental setup shown in Figure 1. An FE simulation of cancellous bone samples will provide additional validation and further insight into the heat transfer mechanisms of bone. We provide a clearly defined task, cooperation in an international team and the freedom to realize own ideas. Finally, the thesis combines an interesting mixture of experimental and computational tasks, which allow the student to participate in scientific research.
Nature of the Thesis: Literature Review: 10% Preparation and experimentation: 60% FE simulation: 30% Requirements: Basic knowledge about bone No prior FE knowledge needed Supervisors: Dipl.-Ing. Arne Feldmann Prof. Philippe Zysset Institutes: ISTB, University of Bern
Fig.1 Experimental setup for measuring thermal conductivity.
References: S. R. Davidson and D. F. James, “Measurement of thermal conductivity of bovine cortical bone,” Medical engineering & physics, vol. 22, no. 10, pp. 741–7, Dec. 2000 Contact: Dipl.-Ing. Arne Feldmann,
[email protected], Stauffacherstrasse 78, CH-3014 Bern
Master’s Program Biomedical Engineering