Minimally Invasive Surgery and Interventional Techniques
Department of Biomechanical Engineering - Delft University of Technology
Prof.dr. Jenny Dankelman
Development of a bone tissue-simulating phantom
19 August 2020

Development of a bone tissue-simulating phantom for testing of a DRS-enhanced steerable drill

Spinal fusion is the surgical procedure of stiffening parts of the spinal column to reduce back pain for patients affected by multiple diseases. In conventional spinal fusion procedures, the fused vertebrae are stabilized with the use of metal rods. Pedicle screws run through the pedicle and fixate the metal rods to the vertebrae. The inside of the bone (cancellous bone) is too weak to achieve sufficient grip. Therefore, pedicle screw fixation mainly relies on locations where the screw is in direct contact with the surrounding layer of cortical bone [1].

Increasing the contact area of screws and cortical bone is thought to result in better fixation of the pedicle screws. Therefore, we are developing a novel drill that allows the surgeon to steer through the bone along the cortical bone layer. To help the surgeon find and maintain the right drilling trajectory, an optical sensing system based on Diffuse Reflectance Spectroscopy (DRS) will be integrated into the drill to differentiate the two types of bone tissue in real time based on their respective fat and water contents [2].

Project proposal: In the scope of the proposed graduation project, a bone tissue-simulating phantom should be developed that mimics both mechanical and optical properties of human bone. This phantom will allow for mechanical testing of the steerable drill, as well as for optical testing of the sensing system. Eventually, it will also provide a training environment where surgeons can become accustomed to the novel tool.

Start Date: September 2020 or as early as possible
For further questions or to apply, please contact E. de Kater (  or M. Losch  ( When applying, please provide a short motivation, up to date CV, a transcript of your current degree program and intended start date.

[1] Eswaran, S.K., Gupta, A., Adams, M.F. and Keaveny, T.M., 2006. Cortical and trabecular load sharing in the human vertebral body. Journal of Bone and Mineral Research, 21(2), pp.307-314.
[2] Nachabe, R., Hendriks, B.H., Desjardins, A.E., van der Voort, M., van der Mark, M.B. and Sterenborg, H.J., 2010. Estimation of lipid and water concentrations in scattering media with diffuse optical spectroscopy from 900 to 1600 nm. Journal of biomedical optics, 15(3), p.037015.

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