Monitoring the Optical Diffuse Transmittance of Skin during Thermo-Hydrotherapy via Spatial Frequency Domain Imaging: A Pilot Study

Abdelazeem, Rania M.; Ahmed, Mahmoud M.; Hamdy, Omnia

doi:10.1364/boda.2021.jw1a.9

Cited by 9 publications

(7 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…According to Equations (7)(8)(9)(10)(11), the absorption and the scattering coefficients of the skin samples were determined and compared with the literature that investigated similar sample and laser wavelength, as summarized in Table 3. As presented in Table 3, scattering coefficient value reported by Firdous et al 46 for hydrated skin at 650 nm is partly in agreement with our measured values, while absorption coefficient is not close but still in the acceptance range.…”

Section: Milk Experiments Resultsmentioning

confidence: 99%

“…SFDI is a noncontact and wide-field imaging technique that utilizes structured illumination patterns, which are spatially modulated. 7,28 Sinusoidal patterns are frequently used to extract a single spatial frequency map. The spatially modulated patterns (I s ) can be expressed as:…”

Section: Methodsmentioning

confidence: 99%

“…Besides, it can greatly affect both physical and mechanical properties of the exposed tissue and/or organ. 2,6,7 Over the last decade, optical imaging has become remarkably impactful in the field of medicine. 8 Typically, the optical absorption and scattering properties of a biological tissue are functionally related to many important physiological changes.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

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: Milk Experiments Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

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

“…13 In the aforementioned method, the wavefront aberrations are represented as a linear combination of orthogonal functions (modes). Using the Thorlabs and Boston micromachines software, the closed-loop feedback system between the DM and SHWFS actuates the DM actuators (at 8 Hz) to reshape its surface (analogy to spatial light modulators which are used to modulate light fields 15,16 ) according to the conjugate of the measured wavefront by the SHWFS.…”

Section: Methodsmentioning

confidence: 99%

Adaptive Shack-Hartmann wavefront system with extended dynamic range for lens characterization

Abdelazeem¹,

Ahmed²,

Agour³

2023

Optical Measurement Systems for Industrial Inspection XIII

View full text Add to dashboard Cite

The adaptive Shack-Hartmann wavefront sensor (SHWFS), which integrates deformable mirror (DM) with SHWFS, is effectively used for measuring and characterizing optical elements such as thick lenses, contact lenses, and intraocular lenses (IOLs). The major advantage of combining the DM with SHWFS is the ability of the DM to implement dynamic corrections of any existing wavefront aberrations. However, the measurement dynamic range of the system is limited by the active area of the DM which has a relatively small bandwidth product. This issue can be physically overcome using compound-lens methodology that uses an additional lens or lens system along with the lens under test. The selection criterion of the compound-lens system is based on the focal length of the tested lens, the effective focal length of the tested lens with the compound lens, and the distance between them. Thus, the optimal selection of the compound-lens system and the setup parameters significantly contribute to readjusting the laser beam diameter to properly fit the DM's active area. Hence, the measurement dynamic range could be successfully extended. To prove the concept, the dynamic range of the used adaptive SHWFS system is first determined. Then, a group of lenses beyond the dynamic range of the system was measured using the compound-lens methodology. The experimental results reveal that the proposed compound-lens methodology can effectively extend the dynamic range of the measurements while keeping the root-mean-square error minimal.

show abstract

“…A polarizer (P) and analyzer (A) are placed before and after the SLM window to select the correct polarization state with respect to the SLM’s slow axis (because the SLM is a birefringent modulator). SLM is a dynamic device that modulates the incident light according to the displayed pattern [ 30 , 31 ], in analogy to the deformable mirror [ 32 ], to provide a predefined light intensity across the observation plane. It is placed at the front focal plane of a Fourier lens FL (f = 125 mm).…”

Section: - Experimental Verificationmentioning

confidence: 99%

Discrimination between normal and cancer white blood cells using holographic projection technique

Abdelazeem

Ibrahim²

2022

PLoS ONE

View full text Add to dashboard Cite

White blood cells (WBCs) play a vital role in the diagnosis of many blood diseases. Such diagnosis is based on the morphological analysis of blood microscopic images which is performed manually by skilled hematologist. However, this method has many drawbacks, such as the dependence on the hematologist’s skill, slow performance, and varying accuracy. Therefore, in the current study, a new optical method for discrimination between normal and cancer WBCs of peripheral blood film (PBF) images is presented. This method is based on holographic projection technique which is able to provide an accurate and fast optical reconstruction method of WBCs floating in the air. Besides, it can provide a 3D visualization map of one WBC with its characterization parameters from only a single 2D hologram. To achieve that, at first, WBCs are accurately segmented from the microscopic PBF images using a developed in-house MATLAB code. Then, their associated phase computer-generated holograms (CGHs) are calculated using the well-known iterative Fourier transform algorithm (IFTA). Within the utilized algorithm, a speckle noise reduction technique, based on temporal multiplexing of spatial frequencies, is applied to minimize the speckle noise across the reconstruction plane. Additionally, a special hologram modulation is added to the calculated holograms to provide a 3D visualization map of one WBC, and discriminate normal and cancer WBCs. Finally, the calculated phase-holograms are uploaded on a phase-only spatial light modulator (SLM) for optical reconstruction. The optical reconstruction of such phase-holograms yields precise representation of normal and cancer WBCs. Moreover, a 3D visualization map of one WBC with its characterization parameters is provided. Therefore, the proposed technique can be used as a valuable tool for interpretation and analysis of WBCs, this in turn could provide an improvement in diagnosis and prognosis of blood diseases.

show abstract

Monitoring the Optical Diffuse Transmittance of Skin during Thermo-Hydrotherapy via Spatial Frequency Domain Imaging: A Pilot Study

Abstract: In this work, the effect of the thermo-hydrotherapy procedure on the immerged skin has been evaluated optically by monitoring the skin diffuse transmittance based on spatial frequency domain imaging technique.

Cited by 9 publications

References 5 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

Adaptive Shack-Hartmann wavefront system with extended dynamic range for lens characterization

Discrimination between normal and cancer white blood cells using holographic projection technique

Contact Info

Product

Resources

About