R. Graaff, A. C. M. Dassel, M. H. Koelink, F. F. M. de Mul, J. G. Aarnoudse, and W. G. Zijlstra, "Optical properties of human dermis in vitro and in vivo," Appl. Opt. 32, 435-447 (1993)
Condensed Monte Carlo simulation results have been used for calculating absorption and reduced scattering coefficients from the literature data on the measured total transmittance and total reflectance of samples of the human skin in υitro. The results of several measuring methods have been compared. We have also estimated the range for absorption coefficients and reduced scattering coefficients at 660 and 940 nm from measured intensities at the skin surface as a function of the distance from the location where the light enters the skin by using condensed Monte Carlo simulations for a homogeneous semi-infinite medium. The in υiυo values for the absorption coefficients and the reduced scattering coefficients appear to be much smaller than the values from the in υitro measurements, that have been assumed until now. The discrepancies have been discussed in detail. Our in υiυo results are in agreement with other in υiυo measurements that are available in the literature.
Frédéric Bevilacqua, Dominique Piguet, Pierre Marquet, Jeffrey D. Gross, Bruce J. Tromberg, and Christian Depeursinge Appl. Opt. 38(22) 4939-4950 (1999)
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
Calculations based on measured data from Prahl (Ref. 13, Fig. 6.6) Rtot = 0.43, Ttot = 0.43, Tcoll = 0.038. Sample thickness = 0.360 mm. Adding–doubling calculation by Prahl.
Jacqnes et al., gHG = 0.817, β = 0.1.
Isotropic.
Henyey–Greenstein g = 0.875.
Table 4
Rayleigh and Rayleigh–Gans Contributions to μs′ for the in Vitro Results at 633 nm for Different Values of β(633 nm)
μs′ (mm−1)
β(633 nm)
g(633 nm)
μs (mm−1)
μs,R (mm−1)
μs,RG′ (mm−1)
2.4
0.00
0.908
29.3
0.0
2.4
2.4
0.05
0.863
17.5
0.9
1.5
2.4
0.10
0.817
13.1
1.3
1.1
5.1
0.10
0.817
27.9
2.8
2.3
5.1
0.15
0.772
22.4
3.4
1.7
5.1
0.20
0.726
18.7
3.7
1.4
Table 5
Intensities I1,I2, and I3 of Remitted Light of Five Male Caucasians as Measured at the Skin Surface at 4.1, 6.9, and 9.4 mm from the Light Source, Respectivelya
LED
Detector
Finger
Abdominal
Calf
Forehead
660 nm
I1
1.00
1.00
1.00
1.00
I2
0.23 ± 0.03
0.24 ± 0.02
0.25 ± 0.03
0.19 ± 0.04
I3
0.062 ± 0.012
0.088 ± 0.014
0.092 ± 0.017
0.058 ± 0.019
I3/I2
0.27
0.37
0.37
0.31
940 nm
I1
1.00
1.00
1.00
1.00
I2
0.21 ± 0.03
0.22 ± 0.02
0.21 ± 0.02
0.16 ± 0.03
I3
0.060 ± 0.016
0.081 ± 0.012
0.071 ± 0.011
0.046 ± 0.019
I3/I2
0.29
0.37
0.34
0.29
Normalized with respect to the first detector.
Table 6
Effect of Additional Shielding of the LED’s and Application of Refractive-Index Matching Oila
660-nm LED
940-nm LED
I2/I1
I3/I1
I2/I1
I3/I1
No matching oil
Normal probe
0.263
0.105
0.262
0.122
Additional shielding
0.270
0.109
0.276
0.132
Matching oil
Normal probe
0.241
0.094
0.216
0.093
Additional shielding
0.264
0.105
0.248
0.112
Measurements on the white Teflon medium.
Table 7
Monte Carlo Simulation of Measured Intensities with the Reflectance Pulse Oximeter Probe when a Semi-infinite Medium is Assumeda
μa (mm−1)
μs′ (mm−1)
c′
I1
I2
I3
0.005
1.4
0.996
1.0
0.24
0.08
0.010
1.2
0.992
1.0
0.24
0.08
0.015
1.0
0.985
1.0
0.24
0.08
0.020
0.9
0.978
1.0
0.24
0.08
0.025
0.8
0.970
1.0
0.24
0.08
0.015
1.3
0.988
1.0
0.21
0.06
0.020
1.1
0.982
1.0
0.21
0.06
0.025
1.0
0.976
1.0
0.21
0.06
0.030
0.9
0.968
1.0
0.21
0.06
0.035
0.8
0.958
1.0
0.21
0.06
0.040
0.7
0.949
1.0
0.21
0.06
Modified Henyey–Greenstein scattering, gHG = 0.91, β = 0.1, nrefr = 1.4. Intensities have been normalized with respect to the first detector. Simulated detectors at 3.7, 6.5, and 9.0 mm from a point source.
Table 8
Estimated Range for Average Absorption and Reduced Scattering Coefficients for the Human Dermis in vivo Based on Average Values: I2/I1 = 0.24 and 0.21 for 660 and 940 nm, Respectivelya
β
μs′ (940nm)
μs′ (mm−1)
μa (mm−1)
μs′ (660 nm)
660 nm
940 nm
660 nm
940 nm
0.00
0.829
0.9–1.3
0.8–1.1
0.007–0.020
0.020–0.035
0.05
0.630
1.2–1.4
0.8–0.9
0.005–0.010
0.030–0.035
0.10
0.527
1.45
0.8
0.003
0.025
0.20
0.416
—
—
—
—
Interpretation with condensed Monte Carlo simulation of a semi-infinite medium with modified Henyey–Greenstein scatterers: gHG = 0.91, β = 0.1, and nrefr = 1.4.
Table 9
Results for the Wavelength Dependence of μs,RG′ and Rayleigh Scattering
x
μs,RG(x)
μs,RG(x)
gRG
μs,RG′(x)
μs,RG(5)
μs,R(5)
μs,RG′(5)
2.0
0.121
0.026
0.6075
0.518
2.5
0.205
0.063
0.7469
0.566
3.0
0.319
0.130
0.7957
0.711
3.5
0.456
0.240
0.8347
0.823
4.0
0.612
0.410
0.8742
0.841
4.5
0.794
0.656
0.8950
0.910
5.0
1.000
1.000
0.9084
1.000
5.5
1.225
1.464
0.9240
1.018
6.0
1.474
2.074
0.9345
1.054
6.5
1.747
2.856
0.9410
1.125
7.0
2.040
3.842
0.9485
1.146
7.5
2.355
5.062
0.9547
1.165
8.0
2.694
6.554
0.9584
1.223
8.5
3.054
8.352
0.9626
1.247
9.0
3.436
0.498
0.9665
1.257
9.5
3.841
13.032
0.9689
1.303
10.0
4.268
16.000
0.9715
1.330
11.0
5.187
23.426
0.9758
1.371
12.0
6.195
33.178
0.9793
1.403
13.0
7.292
45.698
0.9817
1.460
14.0
8.476
61.466
0.9840
1.483
15.0
9.749
81.000
0.9857
1.517
Tables (9)
Table 1
Optical Properties of Human Dermis Samples (633 nm) Obtained from Reflectance and Transmittance Measurements of Jacques et al.a
Calculations based on measured data from Prahl (Ref. 13, Fig. 6.6) Rtot = 0.43, Ttot = 0.43, Tcoll = 0.038. Sample thickness = 0.360 mm. Adding–doubling calculation by Prahl.
Jacqnes et al., gHG = 0.817, β = 0.1.
Isotropic.
Henyey–Greenstein g = 0.875.
Table 4
Rayleigh and Rayleigh–Gans Contributions to μs′ for the in Vitro Results at 633 nm for Different Values of β(633 nm)
μs′ (mm−1)
β(633 nm)
g(633 nm)
μs (mm−1)
μs,R (mm−1)
μs,RG′ (mm−1)
2.4
0.00
0.908
29.3
0.0
2.4
2.4
0.05
0.863
17.5
0.9
1.5
2.4
0.10
0.817
13.1
1.3
1.1
5.1
0.10
0.817
27.9
2.8
2.3
5.1
0.15
0.772
22.4
3.4
1.7
5.1
0.20
0.726
18.7
3.7
1.4
Table 5
Intensities I1,I2, and I3 of Remitted Light of Five Male Caucasians as Measured at the Skin Surface at 4.1, 6.9, and 9.4 mm from the Light Source, Respectivelya
LED
Detector
Finger
Abdominal
Calf
Forehead
660 nm
I1
1.00
1.00
1.00
1.00
I2
0.23 ± 0.03
0.24 ± 0.02
0.25 ± 0.03
0.19 ± 0.04
I3
0.062 ± 0.012
0.088 ± 0.014
0.092 ± 0.017
0.058 ± 0.019
I3/I2
0.27
0.37
0.37
0.31
940 nm
I1
1.00
1.00
1.00
1.00
I2
0.21 ± 0.03
0.22 ± 0.02
0.21 ± 0.02
0.16 ± 0.03
I3
0.060 ± 0.016
0.081 ± 0.012
0.071 ± 0.011
0.046 ± 0.019
I3/I2
0.29
0.37
0.34
0.29
Normalized with respect to the first detector.
Table 6
Effect of Additional Shielding of the LED’s and Application of Refractive-Index Matching Oila
660-nm LED
940-nm LED
I2/I1
I3/I1
I2/I1
I3/I1
No matching oil
Normal probe
0.263
0.105
0.262
0.122
Additional shielding
0.270
0.109
0.276
0.132
Matching oil
Normal probe
0.241
0.094
0.216
0.093
Additional shielding
0.264
0.105
0.248
0.112
Measurements on the white Teflon medium.
Table 7
Monte Carlo Simulation of Measured Intensities with the Reflectance Pulse Oximeter Probe when a Semi-infinite Medium is Assumeda
μa (mm−1)
μs′ (mm−1)
c′
I1
I2
I3
0.005
1.4
0.996
1.0
0.24
0.08
0.010
1.2
0.992
1.0
0.24
0.08
0.015
1.0
0.985
1.0
0.24
0.08
0.020
0.9
0.978
1.0
0.24
0.08
0.025
0.8
0.970
1.0
0.24
0.08
0.015
1.3
0.988
1.0
0.21
0.06
0.020
1.1
0.982
1.0
0.21
0.06
0.025
1.0
0.976
1.0
0.21
0.06
0.030
0.9
0.968
1.0
0.21
0.06
0.035
0.8
0.958
1.0
0.21
0.06
0.040
0.7
0.949
1.0
0.21
0.06
Modified Henyey–Greenstein scattering, gHG = 0.91, β = 0.1, nrefr = 1.4. Intensities have been normalized with respect to the first detector. Simulated detectors at 3.7, 6.5, and 9.0 mm from a point source.
Table 8
Estimated Range for Average Absorption and Reduced Scattering Coefficients for the Human Dermis in vivo Based on Average Values: I2/I1 = 0.24 and 0.21 for 660 and 940 nm, Respectivelya
β
μs′ (940nm)
μs′ (mm−1)
μa (mm−1)
μs′ (660 nm)
660 nm
940 nm
660 nm
940 nm
0.00
0.829
0.9–1.3
0.8–1.1
0.007–0.020
0.020–0.035
0.05
0.630
1.2–1.4
0.8–0.9
0.005–0.010
0.030–0.035
0.10
0.527
1.45
0.8
0.003
0.025
0.20
0.416
—
—
—
—
Interpretation with condensed Monte Carlo simulation of a semi-infinite medium with modified Henyey–Greenstein scatterers: gHG = 0.91, β = 0.1, and nrefr = 1.4.
Table 9
Results for the Wavelength Dependence of μs,RG′ and Rayleigh Scattering