Photobiomodulation consists in using light, in the visible/near infrared range, to treat or slow down the evolution of a pathology. In the case of Parkinson’s disease, a neurodegenerative disease without any curative treatment so far, the brain region responsible for symptoms is located in the midbrain area, deep in the brain, which requires neurosurgery to position the optical implant. At Clinatec, 3 patients have been implanted with such an active implantable medical device so far, following years of preclinical research that showed the potential of the technique. At the moment the photon propagation in brain is mostly driven by scattering; therefore scattered photons reach regions of the brain that should not be stimulated and that also limits the yield. In this context, the PhD goal will be to develop wavefront shaping for a clinical use to restrain scattering to go towards a clinical use.
The technique has been published in 2007 by Vellekoop and consists in acting on the amplitude and phase of a coherent light source to compensate for scattering and therefore focus light in tissue. The final goal is to illuminate exclusively the desired brain region. The PhD work will include experimental and fundamental developments in optics, particularly for the feedback control (photoacoustics signal generated by the light pulse), but also in numerical simulation. The PhD will be located between Clinatec and Optics and Photonics lab of CEA LETI, and directed by LiPhy at UGA.