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Transferring Technologies to the Marketplace – Percutaneous Cochlear Implantation

Cochlear implantation is the accepted method for restoration of hearing in people with sensorineural hearing loss. An electrode-tipped implant is placed in the patient’s cochlea; the electrodes collectively stimulate hair cells in the cochlea at different frequencies, whereupon the auditory nerve is activated. During the delicate surgical procedure, the surgeon accesses the cochlea thru the skull. At present, this requires the mastoid bone to be first removed. This step is obviously fairly invasive; the follow on insertion of the implant is preceded by very precise drilling of the cochlear wall.

A multidisciplinary team of Vanderbilt researchers, Drs. Robert Labadie, Michael Fitzpatrick and Benoit Dawant, have developed a process for simplification and semi-automation of this procedure. Clinical trials for this technology are currently supported by a NIH grant. It is anticipated that a commercial partner will be engaged to bring this technology to the marketplace.

Robert F. Labadie, MD, Ph.D. and J. Michael Fitzpatrick, Ph.D.

What’s New in CAOS?

World’s First Robotic Mastoidectomy Performed at Vanderbilt University on October 16, 2009

Using image-guided surgical techniques, a robotic system was designed to perform mastoidectomy.

The robotic system incorporates a custom robot-control software that interfaces with an industrial robot, Mitsubishi RV-3S (Mitsubishi Electric & Electronics USA, Inc., Cyprus, CA) and a commercially-available Polaris Spectra optical tracking system (Northern Digital Inc., Waterloo, Ontario, Canada).

Desired path of the drill was contoured on clinically-applicable temporal bone CT scans using planning software and then exported to the robotic system. The robot under the guidance of the robot-control software then achieved the desired path.

We demonstrated that we can perform a robotic mastoidectomy on a dried cadaveric skull on October 16, 2009 at Vanderbilt University. Click here for video of the demonstration.

To the best of our knowledge, this is the first time that a robot has been used to perform a mastoidectomy. While significant hurdles remain to translate this to clinical use, we have shown that it is feasible.

This work is a result of collaboration between Vanderbilt University and Leibniz Universität Hannover and is funded by National Institutes of Health Grant #NIH/NIBIB-R21EB006044-01A1.

Robotic Insertion Tool for Placing Cochlear Implant Electrode Arrays

Working in collaboration with Leibniz Universität Hannover, our team has begun bench top testing of a robotic insertion tool for cochlear implant electrode arrays.  This device – the core unit of which was designed by Daniel Schurzig and developed by Andreas Hussong in Hannover (Hussong A, Rau T, Eilers H, Baron S, Heimann B,Leinung M, Lenarz T, Majdani O, Conception and Design of an Automated Insertion Tool for Cochlear Implants. 30th Annual International IEEE EMBS Conference,Vancouver, 2008) – is able to duplicate advance off-stylet (AOS) insertion technique.

The first video shows the motion of the tip of a cochlear implant electrode with AOS.

The second video shows how the insertion tool, essentially a single degree of freedom robot, was envisioned to duplicate AOS.  Since the initial design, the CAOS team has modified the tool by attaching strain gauges to the housing, such that forces can be measured during insertion.

Initial studies in cochlear models (video 3) show that the insertion tool is at least as good as a human operator being more consistent with fewer peak forces (Majdani O, Schurzig D, Hussong A, Rau T, WittkopfJ, Lenarz T, Labadie RF, Force measurement of insertion of cochlear implant electrode arrays in-vitro: Comparison of surgeon to automated insertion tool. Acta Oto-Laryngolocia, 2009-In Press).

The next step is to move this study to cadaveric specimens, analyzing the histologic effects of robotic insertion. Following confirmation of atraumatic insertion of temporal bones, the team will pursue clinical implementation. The hope is that this device will provide more consistent, low force, atraumatic insertion allowing better hearing outcomes in cochlear implantations.  It also provides the potential solution for insertion down a long narrow lumen, such as that required for percutaneous implantation.

Ultimately, the team envisions a six degree of freedom robot lining up this one degree of freedom robot to automate cochlear implant surgery.