A Customized Two Photon Fluorescence Imaging Probe Based on 2D scanning MEMS Mirror Including Electrothermal Two-Level-Ladder Dual S-Shaped Actuators

Mehidine, Hussein; Li, Min; Lendresse, Jean-Francois; Bouvet, Francoise; Xie, Huikai; Haidar, Darine Abi

doi:10.3390/mi11070704

Cited by 5 publications

(8 citation statements)

References 31 publications

(78 reference statements)

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“…For that, a customized endoscopic handheld imaging probe head, dedicated to intraoperative use, is under development. This imaging probe head consists of a miniature scanning system based on an electrothermally actuated microelectromechanical system (MEMS) mirror and has already been characterized to be utilized for in vivo imaging essay ( 55 ).…”

Section: Discussionmentioning

confidence: 99%

Comparative Study Between a Customized Bimodal Endoscope and a Benchtop Microscope for Quantitative Tissue Diagnosis

et al. 2022

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Nowadays, surgical removal remains the standard method to treat brain tumors. During surgery, the neurosurgeon may encounter difficulties to delimitate tumor boundaries and the infiltrating areas as they have a similar visual appearance to adjacent healthy zones. These infiltrating residuals increase the tumor recurrence risk, which decreases the patient’s post-operation survival time. To help neurosurgeons improve the surgical act by accurately delimitating healthy from cancerous areas, our team is developing an intraoperative multimodal imaging tool. It consists of a two-photon fluorescence fibered endomicroscope that is intended to provide a fast, real-time, and reliable diagnosis information. In parallel to the instrumental development, a large optical database is currently under construction in order to characterize healthy and tumor brain tissues with their specific optical signature using multimodal analysis of the endogenous fluorescence. Our previous works show that this multimodal analysis could provide a reliable discrimination response between different tissue types based on several optical indicators. Here, our goal is to show that the two-photon fibered endomicroscope is able to provide, based on the same approved indicators in the tissue database, the same reliable response that could be used intraoperatively. We compared the spectrally resolved and time-resolved fluorescence signal, generated by our two-photon bimodal endoscope from 46 fresh brain tissue samples, with a similar signal provided by a standard reference benchtop multiphoton microscope that has been validated for tissue diagnosis. The higher excitation efficiency and collection ability of an endogenous fluorescence signal were shown for the endoscope setup. Similar molecular ratios and fluorescence lifetime distributions were extracted from the two compared setups. Spectral discrimination ability of the bimodal endoscope was validated. As a preliminary step before tackling multimodality, the ability of the developed bimodal fibered endoscope to excite and to collect efficiently as well as to provide a fast exploitable high-quality signal that is reliable to discriminate different types of human brain tissues was validated.

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Section: Discussionmentioning

confidence: 99%

Comparative Study Between a Customized Bimodal Endoscope and a Benchtop Microscope for Quantitative Tissue Diagnosis

et al. 2022

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“…More technical detailed information (pulse duration, pulse compression system, endoscopic fiber) about this endomicroscope characteristics are already published in previous works of our team 38 , 39 . In addition, a handheld miniature imaging probe head is under development and presented in a previous work 40 , and it will be coupled with this endomicroscope, to ensure in-vivo image acquisitions.…”

Section: Discussionmentioning

confidence: 99%

Molecular changes tracking through multiscale fluorescence microscopy differentiate Meningioma grades and non-tumoral brain tissues

Mehidine

Réfrégiers

Jamme

et al. 2021

Sci Rep

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Meningioma is the most common primary intracranial extra-axial tumor. Total surgical removal is the standard therapeutic method to treat this type of brain tumors. However, the risk of recurrence depends on the tumor grade and the extent of the resection including the infiltrated dura mater and, if necessary, the infiltrated bone. Therefore, proper resection of all invasive tumor borders without touching eloquent areas is of primordial in order to decrease the risk of recurrence. Nowadays, none of the intraoperative used tools is able to provide a precise real-time histopathological information on the tumor surrounding areas to help the surgeon to achieve a gross total removal. To respond to this problem, our team is developing a multimodal two-photon fluorescence endomicroscope, compatible with the surgeon tool, to better delimitate tumor boundaries, relying on the endogenous fluorescence of brain tissues. In this context, we are building a tissue database in order to specify each brain tissue, whether healthy or tumoral, with its specific optical signature. In this study, we present a multimodal and multiscale optical measurements on non-tumoral control brain tissue obtained in epilepsy surgery patients and several meningioma grades. We investigated tissue auto-fluorescence to track the molecular changes associated with the tumor grade from deep ultra-violet (DUV) to near infrared (NIR) excitation. Micro-spectroscopy, fluorescence lifetime imaging, two-photon fluorescence imaging and Second Harmonic Generation (SHG) imaging were performed. Several optically derived parameters such as collagen crosslinks fluorescence in DUV, SHG emission in NIR and long lifetime intensity fraction of Nicotinamide Adenine Dinucleotide and Flavins were correlated to discriminate cancerous tissue from control one. While collagen response managed to discriminate meningioma grades from control samples with a 100% sensitivity and 90% specificity through a 3D discriminative algorithm.

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“…A thermal bimorph is a cantilever beam that consists of two or more layers of materials with different coefficients of thermal expansion (CTE). Electrothermal bimorph MEMS mirrors can generate large forces and displacements at low voltages (e.g., less than 10 V), which is ideal for biomedical applications, and they have been implemented in miniature imaging systems, e.g., miniature OCT probes [ 75 ], optical scanning [ 76 ], and TPM probes [ 28 , 77 ].…”

Section: Mems-based Tpmmentioning

confidence: 99%

“…Singh et al developed a MEMS mirror based on Al/Si bimorph actuators and achieved scanning angles up to 17° with voltages less than 2 V and power less than 50 mW [ 79 ]. Compared to Al/Si materials, Al and SiO 2 have a larger CTE difference, so Al/SiO 2 bimorph electrothermal MEMS mirrors are expected to have a larger scan range, and several Al/SiO 2 bimorph electrothermal MEMS mirrors have been developed [ 75 , 77 , 80 , 81 , 82 ]. In 2006, Fu et al first applied an electrothermal bimorph 1D MEMS mirror in endoscopic TPM imaging, where the packaged probe was 3 mm in diameter [ 28 ], as shown in Figure 11 a.…”

Section: Mems-based Tpmmentioning

confidence: 99%

“…However, this mirror had some problems, including hysteresis of the heat response, large initial tilt, and a non-stationary center of rotation, resulting in a slow response time and low image quality [ 80 ]. To address these problems, the same team developed several generations of electrothermal MEMS designs until two-axis electrothermal MEMS mirrors based on an S-shaped inverted-series-connected (ISC) thermal bimorph actuator structure were developed [ 77 , 81 , 82 ], as shown in Figure 11 d, which further increased the fill factor, eliminated both tip-tilt and lateral shift at the end of the folded beam by employing symmetric actuators, and improved the thermal response speed through the removal of the thick, rigid Si beams in the actuator. In 2020, Mehidine et al designed a homemade TPM imaging miniature probe based on an electrothermal MEMS mirror with two-level-ladder double-S-shaped electrothermal bimorph actuators ( Figure 12 a) [ 77 ].…”

Section: Mems-based Tpmmentioning

confidence: 99%

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MEMS Enabled Miniature Two-Photon Microscopy for Biomedical Imaging

Zhou

et al. 2023

Micromachines

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Over the last decade, two-photon microscopy (TPM) has been the technique of choice for in vivo noninvasive optical brain imaging for neuroscientific study or intra-vital microendoscopic imaging for clinical diagnosis or surgical guidance because of its intrinsic capability of optical sectioning for imaging deeply below the tissue surface with sub-cellular resolution. However, most of these research activities and clinical applications are constrained by the bulky size of traditional TMP systems. An attractive solution is to develop miniaturized TPMs, but this is challenged by the difficulty of the integration of dynamically scanning optical and mechanical components into a small space. Fortunately, microelectromechanical systems (MEMS) technology, together with other emerging micro-optics techniques, has offered promising opportunities in enabling miniaturized TPMs. In this paper, the latest advancements in both lateral scan and axial scan techniques and the progress of miniaturized TPM imaging will be reviewed in detail. Miniature TPM probes with lateral 2D scanning mechanisms, including electrostatic, electromagnetic, and electrothermal actuation, are reviewed. Miniature TPM probes with axial scanning mechanisms, such as MEMS microlenses, remote-focus, liquid lenses, and deformable MEMS mirrors, are also reviewed.

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A Customized Two Photon Fluorescence Imaging Probe Based on 2D scanning MEMS Mirror Including Electrothermal Two-Level-Ladder Dual S-Shaped Actuators

Cited by 5 publications

References 31 publications

Comparative Study Between a Customized Bimodal Endoscope and a Benchtop Microscope for Quantitative Tissue Diagnosis

Comparative Study Between a Customized Bimodal Endoscope and a Benchtop Microscope for Quantitative Tissue Diagnosis

Molecular changes tracking through multiscale fluorescence microscopy differentiate Meningioma grades and non-tumoral brain tissues

MEMS Enabled Miniature Two-Photon Microscopy for Biomedical Imaging

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