Increasing the penetration depth for ultrafast laser tissue ablation using glycerol based optical clearing

2016 ◽  
Author(s):  
Ilan Gabay ◽  
Kaushik G. Subramanian ◽  
Chris Martin ◽  
Murat Yildirim ◽  
Valery V. Tuchin ◽  
...  
Keyword(s):  
Penetration Depth ◽  
Ultrafast Laser ◽  
Tissue Ablation ◽  
Optical Clearing

A STUDY ON PENETRATION DEPTH OF POLARIZATION IMAGING

2010 ◽  
Vol 03 (03) ◽  
pp. 177-181 ◽  
Author(s):  
RAN LIAO ◽  
NAN ZENG ◽  
DONGZHI LI ◽  
TIANLIANG YUN ◽  
YONGHONG HE ◽  
...  
Keyword(s):  
Penetration Depth ◽  
Free Path ◽  
Path Length ◽  
Free Path Length ◽  
Mean Free Path ◽  
Optical Measurements ◽  
Degree Of Polarization ◽  
Polarization Imaging ◽  
Optical Clearing ◽  
Different Response

Optical clearing improves the penetration depth of optical measurements in turbid tissues. Polarization imaging has been demonstrated as a potentially promising tool for detecting cancers in superficial tissues, but its limited depth of detection is a major obstacle to the effective application in clinical diagnosis. In the present paper, detection depths of two polarization imaging methods, i.e., rotating linear polarization imaging (RLPI) and degree of polarization imaging (DOPI), are examined quantitatively using both experiments and Monte Carlo simulations. The results show that the contrast curves of RLPI and DOPI are different. The characteristic depth of DOPI scales with transport mean free path length, and that of RLPI increases slightly with g. Both characteristic depths of RLPI and DOPI are on the order of transport mean free path length and the former is almost twice as large as the latter. It is expected that they should have different response to optical clearing process in tissues.

scholarly journals A tunable refractive index matching medium for live imaging cells, tissues and model organisms

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Tobias Boothe ◽  
Lennart Hilbert ◽  
Michael Heide ◽  
Lea Berninger ◽  
Wieland B Huttner ◽  
...  
Keyword(s):  
Refractive Index ◽  
Image Quality ◽  
Light Microscopy ◽  
Penetration Depth ◽  
Cell Cultures ◽  
Model Organisms ◽  
Optical Clearing ◽  
Index Matching ◽  
Refractive Index Matching ◽  
Tunable Refractive Index

In light microscopy, refractive index mismatches between media and sample cause spherical aberrations that often limit penetration depth and resolution. Optical clearing techniques can alleviate these mismatches, but they are so far limited to fixed samples. We present Iodixanol as a non-toxic medium supplement that allows refractive index matching in live specimens and thus substantially improves image quality in live-imaged primary cell cultures, planarians, zebrafish and human cerebral organoids.

scholarly journals Improving sampling depth of laser speckle imaging by topical optical clearing: A theoretical and in vivo study

2019 ◽  
Vol 13 (02) ◽  
pp. 2050004
Author(s):  
D. Li ◽  
Y. Zhang ◽  
B. Chen
Keyword(s):  
Blood Flow ◽  
Penetration Depth ◽  
Laser Speckle ◽  
Skin Tissue ◽  
Laser Speckle Imaging ◽  
Sampling Depth ◽  
Speckle Imaging ◽  
Optical Clearing ◽  
Peg 400

The effect of optical cleaning method combined with laser speckle imaging (LSI) was discussed to improve the detection depth of LSI due to high scattering characteristics of skin, which limit its clinical application. A double-layer skin tissue model embedded with a single blood vessel was established, and the Monte Carlo method was used to simulate photon propagation under the action of light-permeating agent. 808[Formula: see text]nm semiconductor and 632.8[Formula: see text]nm He–Ne lasers were selected to study the effect of optical clearing agents (OCAs) on photon deposition in tissues. Results show that the photon energy deposition density in the epidermis increases with the amount of tissue fluid replaced by OCA. Compared with glucose solution, polyethylene glycol 400 (PEG 400) and glycerol can considerably increase the average penetration depth of photons in the skin tissue, thereby raising the sampling depth of the LSI. After the action of glycerol, PEG 400, and glucose, the average photon penetration depth is increased by 51.78%, 51.06%, and 21.51% for 808nm, 68.93%, 67.94%, and 26.67% for 632.8 nm lasers, respectively. In vivo experiment by dorsal skin chamber proves that glycerol can cause a substantial decrease in blood flow rate, whereas PEG 400 can significantly improve the capability of light penetration without affecting blood velocity, which exhibits considerable potential in the monitoring of blood flow in skin tissues.

Mechanical Compression for Dehydration and Optical Clearing of Skin

2008 ◽  
Author(s):  
Chris W. Drew ◽  
Christopher G. Rylander
Keyword(s):  
Refractive Index ◽  
Light Scattering ◽  
Penetration Depth ◽  
Biological Tissue ◽  
Structural Modification ◽  
Incident Light ◽  
Optical Clearing ◽  
Treatment Techniques ◽  
Index Distribution ◽  
Tissue Optical Clearing

The highly disordered refractive index distribution in biological tissue causes multiple-scattering of incident light and inhibits optical penetration depth. “Tissue optical clearing” increases penetration depth of near-collimated light in biological tissue, potentially resulting in improved optical analysis and treatment techniques. Numerous methods of tissue optical clearing have been hypothesized using hyperosmostic agents [1]. These methods propose reduction in light scattering by means of dehydration of tissue constituents, replacement of interstitial or intracellular water with higher refractive agents, or structural modification or dissociation of collagen fibers [2,3]. It has been suggested that dehydration of tissue constituents alone can reduce light scattering by expulsing water between collagen fibrils, increasing protein and sugar concentrations, and decreasing refractive index mismatch [4].

Cartilage shaping using the Holmium: YAG laser without tissue ablation

1998 ◽  
Vol 23 (3) ◽  
pp. 286-286
Author(s):  
Jones ◽  
Viridov ◽  
Sobol
Keyword(s):  
Tissue Ablation ◽  
Yag Laser
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