Dual modality multiphoton-OCT flexible endomicroscope with an integrated electromagnetic z-actuator for optical field-of-view switching and a piezo-fiber-scanner for image acquisition

Messerschmidt, Bernhard; Matz, Gregor; Flämig, Sven; Reichwald, Karl; Pshenay-Severin, Ekaterina; Kamm, Andreas; Reinlein, Claudia; Kopf, Teresa; Korn, Beatrice; Kühnert, Karsten; Vasquez, David Fernando Reyes; Heilmann, Marianne; Frank, Thomas; Sattel, Thomas; Ströhla, Tom; Lu, Xiang; Groß, Herbert

doi:10.1117/12.2543382

Cited by 3 publications

(6 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For our endoscope, the presented collection method outperforms the DCF collection, particularly at higher imaging depths. Collection efficiency limitations at increased imaging depths with DCF collection is discussed also in 9 , where a 3.3 % simulated collection efficiency at the surface was obtained with a DCF with cladding diameter of 100 μm.…”

Section: Figure 2: Simulation Results For the Collection Arm Collecti...mentioning

confidence: 97%

“…Many applications require development of specialized imaging endoscopy systems to perform diagnosis at locations that can be hard to access. So far, several endoscope systems with 2p autofluorescence imaging capability were shown in the literature [4][5][6][7][8][9][10] . Main challenge in development of 2p autofluorescence imaging systems has been the effective collection of naturally weak autofluorescence signals.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

2p autofluorescence imaging endoscope for clinical observation of metabolic changes in cervical tissue

Camli

Andrus²,

Roy³

et al. 2023

Endoscopic Microscopy XVIII

View full text Add to dashboard Cite

Imaging modalities capable of detecting functional changes over small areas can increase sensitivity and specificity of early cancer detection. Label-free imaging of metabolic activity at cellular level resolution over full thickness of cervix epithelium is possible with 2p imaging. However, low probability of 2p excitation and scattering nature of tissues limit autofluorescence levels in 2p imaging. We present a 2p autofluorescence imaging endoscope system for detection of metabolic changes in cervix in a clinical setting, with an increased collection efficiency in scattering media. Collection of autofluorescence signals is done with a multitude of high NA fibers arranged around a miniaturized excitation objective. By cleaving the collection fibers at a specific angle, we increase the directivity of the collection and the collection efficiency per fiber. The endoscope performs imaging at 775 nm, which is capable of exciting NAD(P)H and FAD molecules. Laser pulses of 100 fs duration are delivered to the sample with an air core photonic bandgap fiber. Fiber is scanned in spiral pattern via a piezo actuator tube. Scanning at different tissue depths is possible with the axial actuation of the endoscope via a linear stepper motor. Benchtop tests indicate that the endoscope system has lateral and axial resolutions of 0.65 μm and 4.33 μm, respectively. Fluorescence images of pollen cores are presented to demonstrate the imaging quality of the endoscope system.

show abstract

Section: Figure 2: Simulation Results For the Collection Arm Collecti...mentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

2p autofluorescence imaging endoscope for clinical observation of metabolic changes in cervical tissue

Camli

Andrus²,

Roy³

et al. 2023

Endoscopic Microscopy XVIII

View full text Add to dashboard Cite

show abstract

“…Based on the λ -1.2 dependence of scattering length for soft tissues [ 49 , 50 ], at the average emission wavelength of 500 nm, we used the emission scattering lengths of 15 µm and 59 µm in the simulation model. For comparison, we also simulated a hypothetical scenario where our system employed DCF fluorescence collection for the objective design finalized above in conjunction with a DCF (F-SMM900, Fibercore), used in previous studies [ 24 , 28 ].…”

Section: Probe Design and Simulationsmentioning

confidence: 99%

“…Several probe systems with 2p autofluorescence imaging capability demonstrated in the literature handle autofluorescence collection mainly in two ways [ 22 – 33 ]. The first way uses double clad fibers (DCFs) in a way that the fiber core is dedicated to delivery of the excitation pulses and the inner cladding is reserved for autofluorescence collection [ 22 – 24 , 26 – 28 , 31 , 33 ]. The advantage here is to have the collection element axially aligned with the focal spot.…”

Section: Introductionmentioning

confidence: 99%

“…The advantage here is to have the collection element axially aligned with the focal spot. However, sizes of commercially available DCFs limit the overall achievable collection area, which can limit the collection efficiency and the imaging depth [ 28 ]. The necessity that the collection elements must interface with the tissue through the distal optics can put additional complexity in design of the distal optics also.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Two photon imaging probe with highly efficient autofluorescence collection at high scattering and deep imaging conditions

Camli,

Andrus,

Roy

et al. 2024

Biomed. Opt. Express

View full text Add to dashboard Cite

In this paper, we present a 2-photon imaging probe system featuring a novel fluorescence collection method with improved and reliable efficiency. The system aims to miniaturize the potential of 2-photon imaging in the metabolic and morphological characterization of cervical tissue at sub-micron resolution over large imaging depths into a flexible and clinically viable platform towards the early detection of cancers. Clinical implementation of such a probe system is challenging due to inherently low levels of autofluorescence, particularly when imaging deep in highly scattering tissues. For an efficient collection of fluorescence signals, our probe employs 12 0.5 NA collection fibers arranged around a miniaturized excitation objective. By bending and terminating a multitude of collection fibers at a specific angle, we increase collection area and directivity significantly. Positioning of these fibers allows the collection of fluorescence photons scattered away from their ballistic trajectory multiple times, which offers a system collection efficiency of 4%, which is 55% of what our bench-top microscope with 0.75 NA objective achieves. We demonstrate that the collection efficiency is largely maintained even at high scattering conditions and high imaging depths. Radial symmetry of arrangement maintains uniformity of collection efficiency across the whole FOV. Additionally, our probe can image at different tissue depths via axial actuation by a dc servo motor, allowing depth dependent tissue characterization. We designed our probe to perform imaging at 775 nm, targeting 2-photon autofluorescence from NAD(P)H and FAD molecules, which are often used in metabolic tissue characterization. An air core photonic bandgap fiber delivers laser pulses of 100 fs duration to the sample. A miniaturized objective designed with commercially available lenses of 3 mm diameter focuses the laser beam on tissue, attaining lateral and axial imaging resolutions of 0.66 µm and 4.65 µm, respectively. Characterization results verify that our probe achieves collection efficiency comparable to our optimized bench-top 2-photon imaging microscope, minimally affected by imaging depth and radial positioning. We validate autofluorescence imaging capability with excised porcine vocal fold tissue samples. Images with 120 µm FOV and 0.33 µm pixel sizes collected at 2 fps confirm that the 300 µm imaging depth was achieved.

show abstract

Intraoperative Fluorescent Image Guidance for Nerve-Sparing Prostatectomy: A Review of Historical Context and Current Research

Mandel,

Das,

Ting

et al. 2024

Journal of Endourology

View full text Add to dashboard Cite

Dual modality multiphoton-OCT flexible endomicroscope with an integrated electromagnetic z-actuator for optical field-of-view switching and a piezo-fiber-scanner for image acquisition

Cited by 3 publications

References 15 publications

2p autofluorescence imaging endoscope for clinical observation of metabolic changes in cervical tissue

2p autofluorescence imaging endoscope for clinical observation of metabolic changes in cervical tissue

Two photon imaging probe with highly efficient autofluorescence collection at high scattering and deep imaging conditions

Intraoperative Fluorescent Image Guidance for Nerve-Sparing Prostatectomy: A Review of Historical Context and Current Research

Contact Info

Product

Resources

About