TY - JOUR

T1 - Temporal bone borehole accuracy for cochlear implantation influenced by drilling strategy

T2 - an in vitro study

AU - Kobler, Jan Philipp

AU - Schoppe, Michael

AU - Lexow, G. Jakob

AU - Rau, Thomas S.

AU - Majdani, Omid

AU - Kahrs, Lüder A.

AU - Ortmaier, Tobias

N1 - Funding information: Acknowledgments The authors would like to thank Robert F. Labadie, MD, Ph.D. and Ramya Balachandran, Ph.D. (Vanderbilt University Medical Center, Nashville, TN, USA) for gratefully providing comprehensive information on the drill bits used in their studies. The co-author Thomas S. Rau would like to thank Prof. Witte (Ilmenau University of Technology, Ilmenau, Germany) for the motivating and guiding discussion about industrial deep-hole drilling and its transfer to clinical application. This work was funded by the German Research Foundation (DFG). The project numbers are OR 196/10-1 and MA 4038/6-1. Responsibility for the contents of this publication lies with the authors.

PY - 2014/11

Y1 - 2014/11

N2 - Methods: The experimental setup to evaluate the borehole accuracy comprises a drill handpiece attached to a linear slide as well as a highly accurate coordinate measuring machine (CMM). Based on the specific requirements of the minimally invasive cochlear access, three drilling strategies, mainly characterized by different drill tools, are derived. The strategies are evaluated by drilling into synthetic temporal bone substitutes containing air-filled cavities to simulate mastoid cells. Deviations from the desired drill trajectories are determined based on measurements using the CMM.Purpose: Minimally invasive cochlear implantation is a surgical technique which requires drilling a canal from the mastoid surface toward the basal turn of the cochlea. The choice of an appropriate drilling strategy is hypothesized to have significant influence on the achievable targeting accuracy. Therefore, a method is presented to analyze the contribution of the drilling process and drilling tool to the targeting error isolated from other error sources.Conclusions: A single-flute gun drill combined with a pilot drill of the same diameter provided the best results for simulated minimally invasive cochlear implantation, based on an experimental method that may be used for testing further drilling process improvements.Results: Using the experimental setup, a total of 144 holes were drilled for accuracy evaluation. Errors resulting from the drilling process depend on the specific geometry of the tool as well as the angle at which the drill contacts the bone surface. Furthermore, there is a risk of the drill bit deflecting due to synthetic mastoid cells.

AB - Methods: The experimental setup to evaluate the borehole accuracy comprises a drill handpiece attached to a linear slide as well as a highly accurate coordinate measuring machine (CMM). Based on the specific requirements of the minimally invasive cochlear access, three drilling strategies, mainly characterized by different drill tools, are derived. The strategies are evaluated by drilling into synthetic temporal bone substitutes containing air-filled cavities to simulate mastoid cells. Deviations from the desired drill trajectories are determined based on measurements using the CMM.Purpose: Minimally invasive cochlear implantation is a surgical technique which requires drilling a canal from the mastoid surface toward the basal turn of the cochlea. The choice of an appropriate drilling strategy is hypothesized to have significant influence on the achievable targeting accuracy. Therefore, a method is presented to analyze the contribution of the drilling process and drilling tool to the targeting error isolated from other error sources.Conclusions: A single-flute gun drill combined with a pilot drill of the same diameter provided the best results for simulated minimally invasive cochlear implantation, based on an experimental method that may be used for testing further drilling process improvements.Results: Using the experimental setup, a total of 144 holes were drilled for accuracy evaluation. Errors resulting from the drilling process depend on the specific geometry of the tool as well as the angle at which the drill contacts the bone surface. Furthermore, there is a risk of the drill bit deflecting due to synthetic mastoid cells.

KW - Accuracy

KW - Cochlear implants

KW - Drill bit geometry

KW - Drilling

KW - Surgical robotics

UR - http://www.scopus.com/inward/record.url?scp=84937710220&partnerID=8YFLogxK

U2 - 10.1007/s11548-014-0997-9

DO - 10.1007/s11548-014-0997-9

M3 - Article

C2 - 24728770

AN - SCOPUS:84937710220

VL - 9

SP - 1033

EP - 1043

JO - International journal of computer assisted radiology and surgery

JF - International journal of computer assisted radiology and surgery

SN - 1861-6410

IS - 6

ER -