Thesis: Real-time processing and visualization in the spatio-temporal frequency domain for surgical guidance

Thesis defense: Enagnon (Fabrice) AGUENOUNON

Title: Real-time processing and visualization in the spatio-temporal frequency domain for surgical guidance

Team: IPP

Abstract: Diffuse optical imaging has a significant potential for image-guided surgery. One of its methods called SFDI for Spatial Frequency Domain Imaging allows to extract the optical properties of biological tissue from structured light and using these measurements acquired at several wavelengths we can retrieve physiological and structural information interpretable by the surgeon. This thesis on the development of a real-time imaging instrument for surgery is based on SSOP "Single Snapshot imaging of Optical Properties" the rapid acquisition implementation of SFDI. To achieve our goals, we designed a system that uses spatiotemporal light modulation, where spatially we encode SSOP and temporally we encode wavelengths. Among our developments, we have proposed two methods, one in Fourier domain and one with deep learning for improving the visual quality and accuracy of SSOP results. A two-wavelength system (665nm and 860nm) was designed and we then validated it in vivo to measure the oxygen saturation rate and demonstrate that it can detect the ischemia of a tissue. Finally, to ensure real-time processing and visualization, all algorithms developed were implemented on GPU (Graphics Processing Unit). In conclusion, today we have the first imaging system capable of visualizing saturated oxygenation level in real-time and over a wide field of view.

This thesis was supervised and directed by GIOUX Sylvain (PU, University of Strasbourg) and UHRING Wilfried (PU, University of Strasbourg). GIGAN Sylvain (PU, Sorbonne University) and BLONDEL Walter (PU, University of Lorraine) are the reviewers. The examiners of the jury are DADOUCHE Foudil (MCF, University of Strasbourg) and DEHGHANI Hamid (PU, University of Birmingham). DIANA Michele (DR-HDR, Institute of Image-Guided Surgery, Strasbourg) is the invited member.

Keywords: Diffuse optical imaging, Spatial frequency domain imaging, Multispectral imaging, Image-guided surgery, Real-time system, GPGPU.

The defense will be held in English, on Friday 25 September 2020 at 10:00 am in the Charles Lindbergh amphitheater at IRCAD (Strasbourg).

As the number of seats in the amphitheater is limited due to compliance with the rules related to COVID-19, please register at this link if you would like to attend the defense in person.
For those unable to attend the defense in person you can use the broadcast link.