Methods of extraction of optical properties from diffuse reflectance measurements of ex-vivo human colon tissue using thin film silicon photodetector arrays

LaRiviere, Ben; Ferguson, N. Lynn; Garman, Katherine S.; Fisher, Deborah A.; Jokerst, N.M.

doi:10.1364/boe.10.005703

Cited by 7 publications

(4 citation statements)

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“…Achieving specificity in measurement inference to avoid misattribution of a change in scattering measurement to, for instance, aerosol number density, requires a method that can distinguish between linear changes in scattering and absorption strengths due to aerosol density, and nonlinear changes in the optical scattering and absorption cross-sections due to ink composition and droplet size distribution. Based on work on related problems in other fields of property extraction from turbid media, it is likely that an approach using both spatial and spectral variation will yield the most robust outcomes [28,34]. In this study, spatial variation is achieved by implementing an optical measurement cell with scattering measurements at multiple angular positions relative to an illumination source, and spectral variation is achieved by multiplexing two LEDs with distinct emission wavelengths.…”

Section: Aerosolized Ink Optical Propertiesmentioning

confidence: 99%

An Optical Aerosol Sensor for Process Monitoring of Aerosol-Jet Printing

LaRiviere,

Groth,

Joshi

et al. 2023

IEEE Access

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Aerosol-Jet Printing (AJP) is a fabrication technology for 3D printed electronic applications ranging from conformal metallization to system-in-package hybrid devices. The desire to achieve improved control of the AJP process has spurred the development of strategies for in-line estimation of key AJP process variables. This paper describes the design and initial testing of a novel optical light scattering sensor for enabling in-line process monitoring and control of aerosolized ink properties for future process control strategies. The sensor measures optical scattering by the AJP aerosol at nine angular positions using silicon photodetectors and LED light sources, providing a path for a compact, cost-effective in-line monitoring solution. An experimental evaluation of the sensor response to varied AJP ink compositions and process parameters was performed. Finally, the optical response of the system is modeled, and a general framework for extracting quantitative measurements of the scattering and absorption coefficients of the AJP transport mist is provided.

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Section: Aerosolized Ink Optical Propertiesmentioning

confidence: 99%

An Optical Aerosol Sensor for Process Monitoring of Aerosol-Jet Printing

LaRiviere,

Groth,

Joshi

et al. 2023

IEEE Access

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“…Thus, reflected l ight c ontains l ess i nformation about deep layers. 1,2 The aim of this work is to develop a spatially resolved diffuse r eflectance sp ectroscopy system to calculate the optical properties between 850 and 1000 nm. A set of 3x4 optical epoxy phantoms serves for validation.…”

Section: Introductionmentioning

confidence: 99%

Development of a portable diffuse reflectance spectroscopy system between 850 and 1000nm

Wagner,

Zimmermann,

Fugger

et al. 2023

Diffuse Optical Spectroscopy and Imaging IX

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We aim to develop a LED-based precise method to determine the optical properties of scattering media between 850 and 1000 nm. For this purpose, we designed a portable device based on spatially resolved diffuse reflection spectroscopy. The approach uses a spectrometer and fiber-coupled N IR-LEDs. We apply an inverse Monte Carlo model to determine the optical properties. A set of 3x4 phantoms serves for validation. The optical properties determined with our sensor and with an standard integrating sphere device agree well. The accuracy of µ ′ s and µ a is around three percent. Furthermore we theoretically analyse the influence o f t emperature c hange o f the LEDs on the optical properties.

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“…The absorption is directly related to the concentration of chromophores such as reduced hemoglobin and oxyhemoglobin, and the scattering coefficient reflects the size and density of scattering structures such as cellular nuclei, collagen fibers, and the surrounding components of the tissue. 20 Studies reported that DRS has been used for patient monitoring in ICUs for various applications like monitoring oxygen saturation changes in the brain, 21 evaluation of the severity of psoriasis, 22 and photodynamic therapy and its assessment. 23 In addition, DRS has also been explored to distinguish the normal and malignant states of different types of tissues by measuring the oxygenation level.…”

Section: Introductionmentioning

confidence: 99%