DS04 - Vie, santé et bien-être

MicroRobot-assisted Cholesteatoma Surgery – muRoCS

Submission summary

Cholesteatoma is a skin growth that occurs in an abnormal location in the middle ear. It is usually due to repeated infection. It was estimated that one new case per 10,000 citizens occurs each year. Over time, cholesteatoma expands in the middle ear, filling in the empty cavity around the ossicles and then eroding the bones themselves (ossicles, mastoid). Cholesteatoma is often infected and results in chronically draining ears. It also results in hearing losses and may even spread through the base of the skull into the brain. Nowadays, the most effective treatment of cholesteatoma is to surgically remove the infected tissues through a minimally invasive procedure. Therefore, there is a real need for a minimally invasive robotic system able to access the epitympanum cavity, with high accuracy and dexterity.

This project is part of the Challenge 4 – Life, Health and Well-being of the ANR call. It will focus in a surgical protocol breakthrough for the middle ear diseases through basic research in robotics, microrobotics, differential diagnosis methods, and image-guided interventions, following a cross-disciplinary approach.
The objectives of µRoCS are the drastic reduction of recurrence (50% to 10%) and of aggressive wall-down procedures (the most commonly used procedure). Therefore, this project proposes a novel integrated robotic system that will exhaustively and efficiently remove the cholesteatoma, especially in the hardly accessible area located behind the mastoid bone (epitympanic cavity). Ideally, the proposed system will travel through the ear canal, and enter the middle ear by a small incision below the eardrum and/or via a small access tunnel drilled through the mastoid bone.

The proposed surgical tool (used to remove the cholesteatoma) will consist of a flexible microrobot (based on a continuum kinematic and less than 2mm in diameter) able to reach any part of the middle ear thanks to a high bending radius of its distal end. The specificity of this novel system is a free channel through which the surgeon can pass either a fiber-based imaging system and a surgical laser. Furthermore, the microrobotic system and the multimodal diagnosis system will be integrated (macro-micro approach) into the otologic robotic system robOtol (marked CE in 2016) for preclinical experimentations.
Within µRoCS, we will also develop a multimodal in-situ tissue characterization technique which consists of fluorescence spectroscopy coupled with an optical coherence tomography. It will offer to the physicians the possibility to verify in real-time (during the intervention) if the tissue is keratin, normal or pathological one. The diagnosis system will allow acquiring at each position of the robotic arm, a 1-D signal that can be considered as an optical biopsy. The collected data will be used as inputs to real-time classification models in order to recognize the residual cholesteatoma cells. Eventually, again using the robotic arm, the surgeon control the laser probe at the detected pathological cells for vaporization, thanks to an original image-guided control laws.

Finally, through the cited medical goals, breaking with current practices in the cholesteatoma surgery, µRoCS will be a project with a high scientific potential, which can lead to significant breakthroughs (minimally invasive surgery of the cholesteatoma removal, zero risk of recurrence and reoperation). In addition, this may open new perspectives for the management of other tumors of the middle ear (eg. Paraganglioma) and even allow to approach differently the internal auditory canal and the cerebellopontine angle (auditory schwannomas, meningiomas). µRoCS will provide high-level scientific contributions: image guided surgery and surgeon-robot interface, micromechatronics design, biomedical images-based control schemes. Moreover, technological innovations will have the potential to be transferred to other industries.

Project coordinator


The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.


FEMTO-ST Franche-Comté Electronique Mécanique Thermique et Optique- Sciences et Technologies
ISIR Institut des Systèmes Intelligents et Robotiques

Help of the ANR 686,810 euros
Beginning and duration of the scientific project: January 2018 - 48 Months

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