Percutaneous inner-ear access via an image-guided industrial robot system

Abstract

Image-guided robots have been widely used for bone shaping and percutaneous access to interventional sites. However, due to high-accuracy requirements and proximity to sensitive nerves and brain tissues, the adoption of robots in inner-ear surgery has been slower. In this paper the authors present their recent work towards developing two image-guided industrial robot systems for accessing challenging inner-ear targets. Features of the systems include optical tracking of the robot base and tool relative to the patient and Kalman filter-based data fusion of redundant sensory information (from encoders and optical tracking systems) for enhanced patient safety. The approach enables control of differential robot positions rather than absolute positions, permitting simplified calibration procedures and reducing the reliance of the system on robot calibration in order to ensure overall accuracy. Lastly, the authors present the results of two phantom validation experiments simulating the use of image-guided robots in inner-ear surgeries such as cochlear implantation and petrous apex access.

Optically tracked multi-robot system for keyhole neurosurgery

“…The residual error, detected as difference from the actual pose of the tip of the surgical probe with respect to the desired position in the optical reference system, is corrected iteratively, first approaching with the gross positioner and then refining the targeting with the fine positioner, before leaving the control to the teleoperation modality. The optical feedback approach proposed by [8] allowed reaching (2.6 ± 0.8) mm as maximum error at the first iteration and (0.60 ± 0.36) mm as final targeting error, while [9] reached 0.5 mm of accuracy in 99.9 % of the cases, without previous calibration. Our approach proved to be independent from the calibration residuals: even if the calibration transformation is inaccurate, the iterative algorithm allows reaching comparable residual errors with the accurate calibrations for both the serial and the parallel robots.…”

“…The tracking system, which provides overall surveillance, allows also increasing the safety of the application since the consistency of the calibration loop, together with the visibility of all DRFs, is continuously checked at 10 Hz by a Safety Check (similarly to what proposed in [9]). Whenever inconsistency is detected, the probe advancement in the brain is stopped and the system placed in safe state.…”

“…In robotic endoscopy applications, in order to decrease the noise in the signals provided by the tracking system and to correct possible robot inaccuracies, Kalman filters were applied to correct the position of the trochar point [8]. Kalman filters were also used for data fusion of redundant sensory information (from encoders and optical tracking systems) [9]. Tracking systems performances for robot control can be improved by the addition of inertial measurements units [10] in order to increase the control robustness with respect to marker occlusions, to compensate for delay of the optical system and to reduce noise.…”

Surgical planning tool for robotically assisted hearing aid implantation

“…To achieve such accuracy, a robotically assisted procedure which overcomes the inability to precisely position the surgical drill using hand held instruments [5] was suggested [6][7][8][9][10]. The safe and effective conduction of an image guided, robotically assisted DCA procedure, strongly relies on the quality of the surgical plan and the accuracy at which the surgical plan can be registered to the physical patient intraoperatively.…”

Feasibility of Using EMG for Early Detection of the Facial Nerve During Robotic Direct Cochlear Access

“…Alternatively, a procedure termed direct cochlear access (DCA) avoids an open mastoidectomy by relying on stereotactic tool guidance to accurately and reproducibly drill a small diameter tunnel to the middle ear cavity. Free hand stereotactic guidance (3,4), patientspecific templates (5,6), and robotic systems (7,8) have been used to guide a drilling tool to a target location on the cochlea. Regardless of the stereotaxic means, each of these methods suffers from the fact that they rely entirely on the navigation system to ensure that the procedure is carried out as planned.…”