An in vivo two photon fluorescence endomicroscopic probe based on a 2-axis electrothermal MEMS mirror

Nowadays, the ability to diagnose brain tumors intraoperatively and to delineate their margins, as accurately as possible, is of primordial importance during surgery. However, the exact tumor boundaries and the infiltrated tumor cells outside its solid volume are difficult to be found by the surgeon due to the similar visual appearances especially at the margins, leading in many cases to poor surgical outcomes and a high risk of recurrences. To solve this issue, our group develop a two-photon multimodal endomicroscope to analyze the endogenous fluorescence of cerebral tissues in order to provide reliable informations intraoperatively on the tissues nature at cellular level. For that, and in order to implement the imaging modality in our endomicroscope, we launched a study based on an original miniaturized scanning system to be coupled with our endomicroscope. In this work, we characterize a scanning system prototype based on an electrothermally-actuated scanning micro-mirror. This type of scanning devices can provide a wide linear scan range at a low driving voltage and a high stable scanning speed along a straight scan line which help to acquire high-quality images.