scholarly journals Development of a noncontact diffuse optical spectroscopy probe for measuring tissue optical properties

2011 ◽  
Vol 16 (12) ◽  
pp. 120505 ◽  
Author(s):  
Sheldon F. Bish
Keyword(s):  
Optical Properties ◽  
Optical Spectroscopy ◽  
Diffuse Optical Spectroscopy ◽  
Tissue Optical Properties

Extracting optical properties from diffuse optical spectroscopy

2009 ◽  
Author(s):  
Rami Nachabé ◽  
Rik Harbers ◽  
Adrien E. Desjardins ◽  
Marjolein van der Voort ◽  
Guus A. L. Braun ◽  
...  
Keyword(s):  
Optical Properties ◽  
Optical Spectroscopy ◽  
Diffuse Optical Spectroscopy

scholarly journals Characterization of a Time-Resolved Diffuse Optical Spectroscopy Prototype Using Low-Cost, Compact Single Photon Avalanche Detectors for Tissue Optics Applications

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3680 ◽  
Author(s):  
Mrwan Alayed ◽  
Darek Palubiak ◽  
M. Deen
Keyword(s):  
Optical Properties ◽  
Optical Spectroscopy ◽  
Single Photon ◽  
Low Cost ◽  
Oxide Semiconductor ◽  
Tissue Optics ◽  
Time Resolved ◽  
Instrument Response Function ◽  
Diffuse Optical Spectroscopy ◽  
Compact Size

Time-resolved diffuse optical spectroscopy (TR-DOS) is an increasingly used method to determine the optical properties of diffusive media, particularly for medical applications including functional brain, breast and muscle measurements. For medical imaging applications, important features of new generation TR-DOS systems are low-cost, small size and efficient inverse modeling. To address the issues of low-cost, compact size and high integration capabilities, we have developed free-running (FR) single-photon avalanche diodes (SPADs) using 130 nm silicon complementary metal-oxide-semiconductor (CMOS) technology and used it in a TR-DOS prototype. This prototype was validated using assessments from two known protocols for evaluating TR-DOS systems for tissue optics applications. Following the basic instrumental performance protocol, our prototype had sub-nanosecond total instrument response function and low differential non-linearity of a few percent. Also, using light with optical power lower than the maximum permissible exposure for human skin, this prototype can acquire raw data in reflectance geometry for phantoms with optical properties similar to human tissues. Following the MEDPHOT protocol, the absolute values of the optical properties for several homogeneous phantoms were retrieved with good accuracy and linearity using a best-fitting model based on the Levenberg-Marquardt method. Overall, the results of this study show that our silicon CMOS-based SPAD detectors can be used to build a multichannel TR-DOS prototype. Also, real-time functional monitoring of human tissue such as muscles, breasts and newborn heads will be possible by integrating this detector with a time-to-digital converter (TDC).

scholarly journals Machine learning estimation of tissue optical properties

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Brett H. Hokr ◽  
Joel N. Bixler
Keyword(s):  
Neural Network ◽  
Optical Properties ◽  
Biological Tissues ◽  
Homogeneous Layer ◽  
In Vivo Measurement ◽  
Tissue Optical Properties ◽  
The Neural Network ◽  
Spatio Temporal ◽  
Fully Connected

AbstractDynamic, in vivo measurement of the optical properties of biological tissues is still an elusive and critically important problem. Here we develop a technique for inverting a Monte Carlo simulation to extract tissue optical properties from the statistical moments of the spatio-temporal response of the tissue by training a 5-layer fully connected neural network. We demonstrate the accuracy of the method across a very wide parameter space on a single homogeneous layer tissue model and demonstrate that the method is insensitive to parameter selection of the neural network model itself. Finally, we propose an experimental setup capable of measuring the required information in real time in an in vivo environment and demonstrate proof-of-concept level experimental results.

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