Concentric Multipixel Silicon Photodiode Array Probes for Spatially Resolved Diffuse Reflectance Spectroscopy

Senlik, Ozlem; Jokerst, N.M.

doi:10.1109/jstqe.2015.2505733

Cited by 9 publications

(7 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Diffuse reflectance imaging was performed with high spatial resolution, large field-ofview (∼20 mm 2 ), and SNR comparable to that of previously developed instruments. 14,18 A dedicated coupling system involving a FOP was developed to provide access to source-detector separations as short as 480 μm. Absorption coefficients (μ a ) and reduced scattering coefficients (μ 0 s ) of phantoms were determined with 4.2% and 7.0% error, respectively, demonstrating the ability of the system for accurate quantification of tissue optical properties.…”

Section: Resultsmentioning

confidence: 99%

“…Various ways to implement srDRS have been reported in the literature. 1,5,[12][13][14][15][16] Most common srDRS instruments involve a broadband source and a spectrophotometer, both coupled to a fiber-optic probe ensuring light delivery and collection directly in contact with tissue. This approach has led to the development of portable instruments that have been deployed in a variety of clinical and preclinical studies.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Contact, high-resolution spatial diffuse reflectance imaging system for skin condition diagnosis

et al. 2018

View full text Add to dashboard Cite

Spatially resolved diffuse reflectance spectroscopy (srDRS) is a well-established technique for noninvasive, in vivo characterization of tissue optical properties toward diagnostic applications. srDRS has a potential for depth-resolved analysis of tissue, which is desired in various clinical situations. However, current fiber-based and photodiode-based systems have difficulties achieving this goal due to challenges in sampling the reflectance with a high enough resolution. We introduce a compact, low-cost architecture for srDRS based on the use of a multipixel imaging sensor and light-emitting diodes to achieve lensless diffuse reflectance imaging in contact with the tissue with high spatial resolution. For proof-of-concept, a prototype device, involving a commercially available complementary metal-oxide semiconductor coupled with a fiber-optic plate, was fabricated. Diffuse reflectance profiles were acquired at 645 nm at source-to-detector separations ranging from 480 μm to 4 mm with a resolution of 16.7 μm. Absorption coefficients (μ a ) and reduced scattering coefficients (μ 0 s ) of homogeneous tissue-mimicking phantoms were measured with 4.2 AE 3.5% and 7.0 AE 4.6% error, respectively. The results obtained confirm the potential of our approach for quantitative characterization of tissue optical properties in contact imaging modality. This study is a first step toward the development of low-cost, wearable devices for skin condition diagnosis in vivo.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Contact, high-resolution spatial diffuse reflectance imaging system for skin condition diagnosis

et al. 2018

View full text Add to dashboard Cite

show abstract

“…The p-n junction Si photodiode array was fabricated on a 600 µm thick, n-type epitaxial Si wafer using standard Si micro-fabrication technology; the fabrication details can be found in our previous work [6]. The diameter of the CMPA illumination aperture reported in this work is 400 µm, and was etched (through the Si substrate) using the Bosch process in a deep reactive ion etching system.…”

Section: Concentric Multi-pixel Si Photodiode Array Probementioning

confidence: 99%

“…In this work, we conducted SRDR measurements on two-layer PDMS skin tissue-mimicking phantoms of varying top layer thicknesses (200 µm-1000 µm) and optical properties using our previously reported [6] CMPA probe. The CMPA probe was fabricated using standard fabrication technology, and it incorporates 24 semi annular Si photodiodes (PD) positioned around a central illumination aperture.…”

Section: Introductionmentioning

confidence: 99%

Spatially resolved diffuse reflectance spectroscopy of two-layer turbid media by densely packed multi-pixel photodiode reflectance probe

et al. 2016

Self Cite

View full text Add to dashboard Cite

Spatially-resolved diffuse reflectance (SRDR) measurements provide photon path information, and enable layered tissue analysis. This paper presents experimental SRDR measurements on two-layer PDMS skin tissue-mimicking phantoms of varying top layer thicknesses, and bulk phantoms of varying optical properties using concentric multi-pixel photodiode array (CMPA) probes, and corresponding forward Monte Carlo simulations. The CMPA is the most densely packed semiconductor SRDR probe reported to date. Signal contrasts between the single layer phantom and bi-layer phantoms with varying top layer thicknesses are as high as 80%. The mean error between the Monte Carlo simulations and the experiment is less than 6.2 %.

show abstract

“…However, the reliance of conventional DRS systems on optical fibers for reflectance collection limits system performance, limits scalability, and constrains the design options. In contrast, custom thin film silicon (Si) photodetectors (PDs) offer a high performance, scalable, and highly customizable alternative to optical fibers for reflectance collection in tissue DRS applications [14][15][16][17][18]. Si PDs improve performance over optical fibers since they have higher numerical apertures (NAs) and collect light from a larger fraction of the probe surface, they are highly scalable due to Si manufacturing technology, they can be geometrically optimized for specific applications, they can be implemented on a variety of substrates, including flexible or conformal, and they can be implemented in the instrument channel or as an attachment to an endoscope.…”

Section: Introductionmentioning

confidence: 99%

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

LaRiviere

Ferguson

Garman

et al. 2019

Biomed. Opt. Express

Self Cite

View full text Add to dashboard Cite

Spatially resolved diffuse reflectance spectroscopy (SRDRS) is a promising technique for characterization of colon tissue. Herein, two methods for extracting the reduced scattering and absorption coefficients (µ s (λ) and µ a (λ)) from SRDRS data using lookup tables of simulated diffuse reflectance are reported. Experimental measurements of liquid tissue phantoms performed with a custom multi-pixel silicon SRDRS sensor spanning the 450-750 nm wavelength range were used to evaluate the extraction methods, demonstrating that the combined use of spatial and spectral data reduces extraction error compared to use of spectral data alone. Additionally, SRDRS measurements of normal and tumor ex-vivo human colon tissue are presented along with µ s (λ) and µ a (λ) extracted from these measurements.

show abstract

Concentric Multipixel Silicon Photodiode Array Probes for Spatially Resolved Diffuse Reflectance Spectroscopy

Cited by 9 publications

References 28 publications

Contact, high-resolution spatial diffuse reflectance imaging system for skin condition diagnosis

Contact, high-resolution spatial diffuse reflectance imaging system for skin condition diagnosis

Spatially resolved diffuse reflectance spectroscopy of two-layer turbid media by densely packed multi-pixel photodiode reflectance probe

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

Contact Info

Product

Resources

About