TY - JOUR

T1 - An automated insertion tool for cochlear implants with integrated force sensing capability

AU - Kobler, Jan Philipp

AU - Beckmann, Daniel

AU - Rau, Thomas S.

AU - Majdani, Omid

AU - Ortmaier, Tobias

N1 - Funding information: Acknowledgments The authors would like to thank Peter Erfurt (Department of Otolaryngology, Hannover Medical School) for preparing the scala tympani phantom, Andreas Hussong (former Institute of Mechatronic Systems) for his preliminary work on the previous insertion tool prototypes, and Cochlear Ltd. for providing Nucleous 24 Contour Advance electrodes. This work was funded by the German Federal Ministry of Education and Research. The project numbers are 01EZ0832, 01EZ0833, 16SV3943, and 16SV3945. Responsibility for the contents of this publication lies with the authors.

PY - 2014/5

Y1 - 2014/5

N2 - Purpose: Minimally invasive cochlear implantation and residual hearing preservation require both the surgical approach to the cochlea as well as the implant insertion to be performed in an atraumatic fashion. Considering the geometric limitations of this approach, specialized instrumentation is required to insert the electrode while preserving intracochlear membranes carrying the sensory hair cells. Methods: An automated insertion tool for cochlear implants, which is capable of sensing insertion forces with a theoretical resolution of 30 μN , is presented. In contrast to previous designs, the custom force sensor is integrated in the insertion mechanism. Moreover, a test bench for insertion studies under constant and reproducible boundary conditions is proposed. It is used to experimentally validate the force sensing insertion tool, which is achieved by comparing the acquired forces to a ground truth measurement. The results of insertion studies on both an acrylic cochlear phantom and temporal bone specimen are given and discussed. Results: Results reveal that friction, occurring between the electrode carrier and the inside of the insertion tool guide tube, is likely to affect the force output of the proposed sensor. An appropriate method to compensate for these disturbances is presented and experimentally validated. Using the proposed approach to friction identification, a mean accuracy of (4.0 ± 3.2 ) mN is observed. Conclusions: The force information provided by the proposed, automated insertion tool can be used to detect complications during electrode insertion. However, in order to obtain accurate results, an identification of frictional forces prior to insertion is mandatory. The insertion tool is capable of automatically executing the appropriate trajectories.

AB - Purpose: Minimally invasive cochlear implantation and residual hearing preservation require both the surgical approach to the cochlea as well as the implant insertion to be performed in an atraumatic fashion. Considering the geometric limitations of this approach, specialized instrumentation is required to insert the electrode while preserving intracochlear membranes carrying the sensory hair cells. Methods: An automated insertion tool for cochlear implants, which is capable of sensing insertion forces with a theoretical resolution of 30 μN , is presented. In contrast to previous designs, the custom force sensor is integrated in the insertion mechanism. Moreover, a test bench for insertion studies under constant and reproducible boundary conditions is proposed. It is used to experimentally validate the force sensing insertion tool, which is achieved by comparing the acquired forces to a ground truth measurement. The results of insertion studies on both an acrylic cochlear phantom and temporal bone specimen are given and discussed. Results: Results reveal that friction, occurring between the electrode carrier and the inside of the insertion tool guide tube, is likely to affect the force output of the proposed sensor. An appropriate method to compensate for these disturbances is presented and experimentally validated. Using the proposed approach to friction identification, a mean accuracy of (4.0 ± 3.2 ) mN is observed. Conclusions: The force information provided by the proposed, automated insertion tool can be used to detect complications during electrode insertion. However, in order to obtain accurate results, an identification of frictional forces prior to insertion is mandatory. The insertion tool is capable of automatically executing the appropriate trajectories.

KW - Automated insertion tool

KW - Cochlear implants

KW - Surgical robotics

UR - http://www.scopus.com/inward/record.url?scp=84902370441&partnerID=8YFLogxK

U2 - 10.1007/s11548-013-0936-1

DO - 10.1007/s11548-013-0936-1

M3 - Article

C2 - 23959671

AN - SCOPUS:84902370441

VL - 9

SP - 481

EP - 494

JO - International journal of computer assisted radiology and surgery

JF - International journal of computer assisted radiology and surgery

SN - 1861-6410

IS - 3

ER -