Analysis of hemodynamics in human skin using photothermal radiometry and diffuse reflectance spectroscopy

Verdel, Nina; Marin, Ana; Vidovič, Luka; Milanič, Matija; Majaron, Boris

doi:10.1117/12.2286043

Cited by 6 publications

(12 citation statements)

References 13 publications

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“…The applied optical model of skin assumes four optically homogeneous layers, representing the epidermis, papillary and reticular dermis, and subcutis (adipose; see figure 1). Determination of the absorption properties of each layer in relation to the fractional contents of the included chromophores was described in detail earlier [1][2][3]6].…”

Section: Discussionmentioning

confidence: 99%

“…The applied light is absorbed well by both epidermal melanin and hemoglobin in dermal vasculature. The radiant exposure was estimated to ∼0.30 J/cm at the effective spot size of ~5 mm [1][2][3].…”

Section: Methodsmentioning

confidence: 99%

“…Mid-IR emission from the tissue surface was recorded with a fast IR camera (SC7500 by FLIR Systems Inc.; λ = 3.5-5.1 µm) at a rate of 1000 frames per second. PPTR signals were obtained by lateral averaging of the radiometric data over a suitable area of interest (typically 1 x 1 mm 2 ) and subtracting the baseline value [1][2][3]. The manufacturer provided calibration system (Hypercal TM ) was used for conversion of raw signal amplitudes to radiometric temperature values.…”

Section: Methodsmentioning

confidence: 99%

“…The experimental data are fitted with predictions of a dedicated numerical model of light transport in strongly scattering medium (Monte Carlo) using a four-layer model of skin. This approach allows assessment of the epidermal and dermal thickness, chromophore contents (e.g., melanin, oxy-and deoxy-hemoglobin), as well as scattering properties of both skin and subcutis [1][2][3].…”

Section: Introductionmentioning

confidence: 99%

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Monitoring of Hemodynamics in Human Skin Using Pulsed Photothermal Radiometry and Optical Spectroscopy

Verdel¹,

Majaron²

2018

Proceedings of the 2018 International Conference on Quantitative InfraRed Thermography

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We present a test of our novel methodology for noninvasive quantitative characterization of human skin in vivo involving a customary pressure-cuff test in healthy volunteers at different cuff pressures. Our experimental approach combines time-resolved measurements of mid-infrared emission from sample surface after exposure to a short light pulse and diffuse reflectance spectroscopy in visible part of the spectrum. Both data sets are fitted simultaneously with predictions of a dedicated numerical model of light transport in a four-layer skin model (i.e., inverse Monte Carlo). This approach allows assessment of, e.g., blood contents and oxygenation levels in papillary and reticular dermis.

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Monitoring of Hemodynamics in Human Skin Using Pulsed Photothermal Radiometry and Optical Spectroscopy

Verdel¹,

Majaron²

2018

Proceedings of the 2018 International Conference on Quantitative InfraRed Thermography

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“…The tissue optical parameters for all three wavelengths were obtained by a thorough literature review and selected values for the above skin model are presented in Table 3. In the interest of space, a detailed explanation of the optical properties calculation is not presented here, but can be found in references [45][46][47].…”

Section: Numerical Simulation Parametersmentioning

confidence: 99%

Temperature Depth Profiles Induced in Human Skin In Vivo Using Pulsed 975 nm Irradiation

et al. 2019

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Background and Objectives The aim of this study was to determine the temperature depth profiles induced in human skin in vivo by using a pulsed 975 nm diode laser (with 5 ms pulse duration) and compare them with those induced by the more common 532 nm (KTP) and 1,064 nm (Nd:YAG) lasers. Quantitative assessment of the energy deposition characteristics in human skin at 975 nm should help design of safe and effective treatment protocols when using such lasers. Study Design/Materials and Methods Temperature depth profiles induced in the human skin by the three lasers were determined using pulsed photothermal radiometry (PPTR). This technique involves time‐resolved measurement of mid‐infrared emission from the irradiated test site and reconstruction of the laser‐induced temperature profiles using an earlier developed optimization algorithm. Measurements were performed on volar sides of the forearms in seven volunteers with healthy skin. At irradiation spot diameters of 3–4 mm, the radiant exposures were 0.24, 0.36, and 5.7 J/cm2 for the 975, 532, and 1,064 nm lasers, respectively. Results Upon normalization to the same radiant exposure of 1 J/cm 2, the assessed maximum temperature rise in the epidermis averaged 0.8 °C for the 975 nm laser, 7.4 °C for the 532 nm, and 0.6 °C for the 1,064 nm laser. The characteristic subsurface depth to which 50% of the absorbed laser energy was deposited was on average 0.31 mm at 975 nm irradiation, and slightly deeper at 1,064 nm, and 0.15 mm at 532 nm. The experimentally obtained relations were reproduced in a dedicated numerical simulation. Conclusions The assessed energy deposition characteristics show that the pulsed 975 nm diode laser is very suitable for controlled heating of the upper dermis as required, for example, for nonablative skin rejuvenation. The risks of nonselective overheating of the epidermis and subcutis are significantly reduced in comparison with irradiation at 532 and 1,064 nm, respectively. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

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Noninvasive assessment of skin structure by combined photothermal radiometry and optical spectroscopy: coregistration with multiphoton microscopy

et al. 2018

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We are combining two optical techniques, pulsed photothermal radiometry (PPTR) and diffuse reflectance spectroscopy (DRS), for noninvasive assessment of the structure and composition of human skin in vivo. The analysis involves simultaneous multidimensional fitting of the measured PPTR signals and DRS spectra with predictions of a numerical model of light transport (Monte Carlo) in a four-layer model optical model of human skin, accounting for the epidermis, papillary and reticular dermis, and subcutis. The assessed epidermal thickness values were tested by coregistration with a multiphoton microscope, which provides vertical sectioning capability based on two-photon excited fluorescence and second-harmonic generation in selected skin components. The comparison shows that these values correspond well to the maximal epidermal thicknesses measured in the multiphoton microscopy images, the rete ridges.

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Analysis of hemodynamics in human skin using photothermal radiometry and diffuse reflectance spectroscopy

Cited by 6 publications

References 13 publications

Monitoring of Hemodynamics in Human Skin Using Pulsed Photothermal Radiometry and Optical Spectroscopy

Monitoring of Hemodynamics in Human Skin Using Pulsed Photothermal Radiometry and Optical Spectroscopy

Temperature Depth Profiles Induced in Human Skin In Vivo Using Pulsed 975 nm Irradiation

Noninvasive assessment of skin structure by combined photothermal radiometry and optical spectroscopy: coregistration with multiphoton microscopy

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