Distant-detector versus integrating sphere measurements for estimating tissue optical parameters: A comparative experimental study

Hamdy, Omnia; Solouma, Nahed H.

doi:10.1016/j.ijleo.2021.167981

Cited by 12 publications

(5 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Kubelka-Munk is an inverse model used to relate tissue reflectance and transmittance with its optical parameters by assuming two propagating fluxes inside the tissue. It can be used for that purpose using diffuse measurements obtained with integrating sphere or distant detector, 33 the later approach provides spatially resolved diffuse reflectance-transmittance that is defined as tissue diffuse reflectance-transmittance at different spatial distance from the source. In the present study, we assumed that the spatial frequency-dependent reflectance and transmittances R d f x ð Þ and T d f x ð Þ could be analogues to the common spatially resolved diffuse reflectance and transmittances (R d and T d ) measured using distant detector.…”

Section: Methodsmentioning

confidence: 99%

Utilizing the spatial frequency domain imaging to investigate change in optical parameters of skin exposed to thermal‐hydrotherapy: Ex‐vivo study

Abdelazeem

Hamdy

2022

Int J Imaging Syst Tech

Self Cite

View full text Add to dashboard Cite

Hydrotherapy is a traditional clinical practice that has been widely used for pain relief. However, immersion in hot water influences skin's moisture and morphology. In this study, we investigate the physiological changes of ex-vivo chicken skin immersed in hot water (at 40 and 50 C) via monitoring the change in its absorption and scattering properties using the spatial frequency domain imaging (SFDI) technique. The procedure started by calculating the modulation transfer function of the proposed imaging system over a range of spatial frequencies using a high-resolution test target. Thereafter, structured illumination patterns at different spatial frequencies were projected onto the examined samples via a reflective phase-only spatial light modulator using transmission and reflection modes. The transmission and reflection images were recorded using a digital camera to reconstruct the optical absorption and scattering parameters. Such parameters were calculated using Kubelka-Munk and lookup table methods. For system validation, the optical properties of two kinds of milk (skimmed and full cream), as reference samples, were reconstructed using the proposed SFDI system in the reflection mode via lookup table method. The results revealed an increase in the scattering coefficient of the skin samples immersed in higher water temperature, while the absorption coefficient values were nearly the same. Furthermore, the obtained results were validated using Monte-Carlo method showing absolute errors that range from 0.004 to 0.057. In conclusion, the proposed system was presented to investigate the changes in ex-vivo skin properties under thermalhydrotherapy in the context of measured changes in optical parameters.

show abstract

Section: Methodsmentioning

confidence: 99%

Utilizing the spatial frequency domain imaging to investigate change in optical parameters of skin exposed to thermal‐hydrotherapy: Ex‐vivo study

Abdelazeem

Hamdy

2022

Int J Imaging Syst Tech

Self Cite

View full text Add to dashboard Cite

show abstract

“…It has different ports for light entry and detector placing [39]. Additionally, the studied tissue sample was placed in different positions for collecting reflectance and transmittance separately [21] as demonstrated in Figure 1a,b. Figure 1c demonstrates the experimental configuration for measuring the collimating transmittance T c .…”

Section: Tissue Diffuse Reflectance and Transmittance Measurementsmentioning

confidence: 99%

“…Tissue absorption and scattering coefficients are extracted indirectly using the experimental measurements of light diffuse reflectance and transmittance [17]. Such measurements are obtained via either integrating-sphere-based [18,19] or distant-detector-based systems [20,21]. An inverse mathematical model is then used to retrieve the optical coefficients from the diffuse light measurements [22].…”

Section: Introductionmentioning

confidence: 99%

Ex Vivo Optical Properties Estimation for Reliable Tissue Characterization

Solouma

Hamdy

2023

Photonics

Self Cite

View full text Add to dashboard Cite

: Lasers are demonstrating high impact in many medical and biological applications. They have different interaction mechanisms within tissues depending on operational parameters, particularly the wavelength. In addition, the optical properties of the examined tissue (i.e., absorption and scattering properties) influence the efficacy of the applied laser. The development of optical biomedical techniques relies on the examination of tissues’ optical properties, which describe the viability of tissue optical evaluation and the effect of light on the tissue. Understanding the optical properties of tissues is necessary for the interpretation and evaluation of diagnostic data, as well as the prediction of light and energy absorption for therapeutic and surgical applications. Moreover, the accuracy of many applications, including tissue removal and coagulation, depends on the tissues' spectroscopic characteristics. In the current paper, a set of ex vivo absorption and scattering coefficients of different types of biological samples (skin, skull, liver and muscle) at 650 nm laser irradiation were retrieved using an integrating phere system paired with the Kubelka–Munk model. The obtained optical parameters were utilized to acquire the local fluence rate within the irradiated tissues based on the Monte Carlo simulation method and the diffusion approximation of the radiative transfer equation. The obtained results reveal that the optical absorption and scattering coefficients control the light propagation and distribution within biological tissues. Such an understanding refers to system design optimization, light delivery accuracy and the minimization of undesirable physiological effects such as phototoxicity or photobleaching.

show abstract

“…The technique is called “diffuse” because light propagation in tissues at that optical region follows a diffusion process due to light’s dense and multiple scattering behavior [ 47 , 48 ]. Determining absorption and scattering parameters requires knowledge of tissue reflectance and transmittance, which can be measured using either an integrating sphere or a distant detector [ 49 , 50 ]. The optical parameters were estimated based on the measured diffused light [ 51 ].…”

Section: Introductionmentioning

confidence: 99%

Early cancer detection using the fluorescent Ashwagandha chitosan nanoparticles combined with near-infrared light diffusion characterization: in vitro study

et al. 2023

Self Cite

View full text Add to dashboard Cite

Early cancer diagnosis through characterizing light propagation and nanotechnology increases the survival rate. The present research is aimed at evaluating the consequence of using natural nanoparticles in cancer therapy and diagnosis. Colon cancer cells were differentiated from the normal cells via investigating light diffusion combined with the fluorescence effect of the Ashwagandha chitosan nanoparticles (Ash C NPs). Ionic gelation technique synthesized the Ash C NPs. High-resolution transmission electron microscope, dynamic light scattering, and zeta potential characterized Ash C NPs. Fourier transform infrared spectroscopy analyzed Ash C NPs, chitosan, and Ashwagandha root water extract. Moreover, the MTT assay evaluated the cytotoxicity of Ash C NPs under the action of near-infrared light (NIR) irradiation. The MTT assay outcomes were statistically analyzed by Bonferroni post hoc multiple two-group comparisons using one-way variance analysis (ANOVA). Based on the Monte-Carlo simulation technique, the spatially resolved steady-state diffusely reflected light from the cancerous and healthy cells is acquired. The diffuse equation reconstructed the optical fluence rate using the finite element technique. The fluorescent effect of the nanoparticles was observed when the cells were irradiated with NIR. The MTT assay revealed a decrease in the cell viability under the action of Ash C NPs with and without laser irradiation. Colon cancer and normal cells were differentiated based on the optical characterization after laser irradiation. The light diffusion equation was successfully resolved for the fluence rate on cells’ surfaces showing different normal and cancer cells values. Ash C NPs appeared its fluorescent effect in the presence of NIR laser.

show abstract

Distant-detector versus integrating sphere measurements for estimating tissue optical parameters: A comparative experimental study

Cited by 12 publications

References 23 publications

Utilizing the spatial frequency domain imaging to investigate change in optical parameters of skin exposed to thermal‐hydrotherapy: Ex‐vivo study

Utilizing the spatial frequency domain imaging to investigate change in optical parameters of skin exposed to thermal‐hydrotherapy: Ex‐vivo study

Ex Vivo Optical Properties Estimation for Reliable Tissue Characterization

Early cancer detection using the fluorescent Ashwagandha chitosan nanoparticles combined with near-infrared light diffusion characterization: in vitro study

Contact Info

Product

Resources

About