Minimally Invasive Surgery and Interventional Techniques
Department of Biomechanical Engineering - Delft University of Technology
Prof.dr. Jenny Dankelman
3D guidance for spinal surgery
16 September 2020


3D guidance for spinal surgery - Development of a DRS-enhanced drill

M.Sc. project proposal at the Medical Instruments & Bio-Inspired Technology Research Group, Department of BioMechanical Engineering, TU Delft


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]. By measuring the fat and water contents in different directions of the tool tip, information about the direction in which a bone boundary is located can be gathered.


Project proposal: In the scope of the proposed graduation project, it will be researched how a DRS system could be integrated into the drill to provide 3D guidance during spinal surgery. After a literature study on current applications of DRS guidance, a prototype of a drill providing directional feedback will be built, and its usability for guidance will be assessed through drilling tests on a bone phantom.


Start Date: as early as possible


For further questions or to apply, please contact M. Losch <>. When applying, please provide an up to date CV and your 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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