Robot Bone Drilling Assessment

Last updated: 5/18/2017


Design and conduct experiments to evaluate the performance of the Galen System in the bone drilling task.

  • Students: Shain Bannowsky, Yifan Zhang
  • Mentors: Yunus Sevimli, Paul Wilkening, Dr. Russell Taylor, Dr. Matt Stewart

Background, Specific Aims, and Significance

A mastoidectomy is a type of surgery that involves the removal of a portion of the mastoid bone. It is most commonly performed to remove diseased mastoid air cells that result from ear infections. It is also performed to approach other structures in the ear such as during the insertion of a cochlear implant. Bone drilling in a mastoidectomy procedure requires a high degree of precision and accuracy as to avoid damages of critical structures near the drilling site (including the facial nerve, the tympanic membrane, major blood vessels, etc).

When performing the procedure, the surgeon holds the surgical drill free-handedly, and is thus prone to the negative effects of hand tremors. The Galen Robot was developed here at Johns Hopkins to address the issue of operating in tight spaces near sensitive anatomy in minimally invasive Head and Neck surgeries. It is a cooperatively controlled robot that can assist the surgeon in tool manipulation. Surgical tools can be attached to the robot’s tool holder, which is at the end of the robot arm, and the surgeon then holds the tool directly when operating. The force sensor, also at the end of the robot arm, will detect the surgeon’s intended movements and move to comply. Thus, although the surgeon is the one to guide the tools, the robot is able to sense and remove undesirable movements such as hand tremors. A foot pedal is used to modulate control gains. Asides from being able to stabilize the surgeon’s movements by mitigating hand tremors, the system can also set virtual fixtures that limit the robot’s movement to a predefined axis or plane.

To test the effectiveness of this system in assisting the bone drilling process, we plan to design and conduct surgical studies comparing the use of the system to free hand use of the drill.


  • Minimum: Expected by April 4
    1. Design and fabrication of phantom
    2. Study design
  • Expected: Expected by April 28
    1. Get IRB approval for mock surgeries
    2. Collect videos and photos of mock surgeries
  • Maximum: Expected by May 15
    1. Develop virtual fixture mode
    2. Evaluation report
      1. Algorithm to quantify under-drilling and over-drilling of predefined workspace
      2. Algorithm to determine closest distance drill approaches facial nerve during procedure

Technical Approach


The goal of the study is to assess the performance of the Galen robot in the drilling task in terms of safety, effectiveness and speed. Three groups of people will be recruited to test the safety of the device: laymen, surgeons in training, and senior surgeons. These subjects will perform the procedure under three conditions: without robotic assistance, with hand tremor elimination only, and with hand tremor elimination plus virtual fixtures. Participants will be asked to drill away as much of a pre-defined portion of the phantom as possible without overdrilling and without contacting the synthetic facial nerve that’s incorporated into the phantom.

More Information



Milestones and Status

  1. Milestone name: Finalized design of study
    • Planned Date: 3/17/2017
    • Status: Completed
  2. Milestone name: Finalized design of phantom
    • Planned Date: 4/4/2017
    • Status: Completed
  3. Milestone name: Phantom fabrication
    • Planned Date: 4/14/2017
    • Expected Date: 5/2/2017
    • Status: Completed
  4. Milestone name: Finish data collection from mock surgeries
    • Planned Date: 4/23/2017
    • Expected Date: 5/7/2017
    • Status: Completed
  5. Milestone name: Develop algorithm to quantify under-drilling and over-drilling of predefined workspace
    • Planned Date: 5/9/2017
    • Status: In Progress
  6. Milestone name: Develop algorithm to determine closest distance drill approaches facial nerve during procedure
    • Planned Date: 5/14/2017
    • Status: In Progress
  7. Milestone name: Develop virtual fixture mode
    • Planned Date: 5/12/2017
    • Status: Completed. We communicated our ideas with our mentor Paul, and he implemented the virtual fixtures for us.

Reports and presentations

Project Bibliography

  • Olds, Kevin. Robotic Assistant Systems for Otolaryngology-Head and Neck Surgery. Thesis.
  • Strauss, Gero, Kirill Koulechov, Mathias Hofer, Elmar Dittrich, Ronny Grunert, Hendrick Moeckel, Eva Muller, Werner Korb, Christos Trantakis, Thomas Schulz, Juergen Meixensberger, Andreas Dietz, and Tim Lueth. “The Navigation-Controlled Drill in Temporal Bone Surgery: A Feasibility Study.” The Laryngoscope 117.3 (2007): 434-41.
  • Grunert, R., G. Strauss, H. Moeckel, M. Hofer, A. Poessneck, U. Fickweiler, M. Thalheim, R. Schmiedel, P. Jannin, T. Schulz, J. Oeken, A. Dietz, and W. Korb. “ElePhant - An anatomical Electronic Phantom as simulation-system for otologic surgery.” 2006 International Conference of the IEEE Engineering in Medicine and Biology Society (2006)
  • Hofer, Mathias, Elmar Dittrich, Christian Baumberger, Mario Strauß, Andreas Dietz, Tim Lüth, and Gero Strauß. “The influence of various registration procedures upon surgical accuracy during navigated controlled petrous bone surgery.” Otolaryngology - Head and Neck Surgery 143.2 (2010): 258-62

Other Resources and Project Files

Here give list of other project files (e.g., source code) associated with the project. If these are online give a link to an appropriate external repository or to uploaded media files under this name space.

1st Iteration

2nd Iteration

3rd Iteration

4th Iteration

Outer frame design

Image analysis code

courses/446/2017/446-2017-19/project.txt · Last modified: 2019/08/07 12:01 (external edit)