14
Effect of external mechanical compression on optical properties of the human skin in vivo Inara A. Nakhaeva, Mohammod R. Mohammod, Olga A. Zyuryukina,Yury P. Sinichkin Saratov State University

Effect of external mechanical compression on optical properties of the human skin in vivo Inara A. Nakhaeva, Mohammod R. Mohammod, Olga A. Zyuryukina,Yury

Embed Size (px)

Citation preview

Page 1: Effect of external mechanical compression on optical properties of the human skin in vivo Inara A. Nakhaeva, Mohammod R. Mohammod, Olga A. Zyuryukina,Yury

Effect of external mechanical compression onoptical properties of the human skin in vivo

Inara A. Nakhaeva, Mohammod R. Mohammod,

Olga A. Zyuryukina,Yury P. SinichkinSaratov State University

Page 2: Effect of external mechanical compression on optical properties of the human skin in vivo Inara A. Nakhaeva, Mohammod R. Mohammod, Olga A. Zyuryukina,Yury

Abstract

This work presents the results of theoretical and experimental studies of the

effect of the nonlocalized external mechanical pressure on human skin diffuse

reflectance spectra in vivo. It was found that spectral changes are a result of

absorption and scattering properties of the human skin decreasing during

compression. The time of stabilization of the human skin optical parameters

during external pressure (~ some minutes) significantly smaller the time of

relaxation of the skin tissue in normal state after compression (~ one hour).

Also blood content and the degree of hemoglobin oxygenation significantly

increase in initial moment after compression.

Page 3: Effect of external mechanical compression on optical properties of the human skin in vivo Inara A. Nakhaeva, Mohammod R. Mohammod, Olga A. Zyuryukina,Yury

Experiment

Method: reflectance spectroscopyObject: the inner forearm human skin in vivo

Experimental setup

Fiber-optic probe

Reflectance spectra: 400-1000 nm USB4000 (Ocean Optics, USA)

Page 4: Effect of external mechanical compression on optical properties of the human skin in vivo Inara A. Nakhaeva, Mohammod R. Mohammod, Olga A. Zyuryukina,Yury

Results of experiment

Dynamics of human skin reflectance under the external mechanical compression (m = 0.5 kg; p = 13.9 kPa)

400 500 600 700 800 9005

10

15

20

25

30

35

40R

efle

ctan

ce,

%

Wavelength, nm

0

205 s392 s

52 s

Page 5: Effect of external mechanical compression on optical properties of the human skin in vivo Inara A. Nakhaeva, Mohammod R. Mohammod, Olga A. Zyuryukina,Yury

Dynamics of human skin reflectance after the external mechanical compression (m = 0.5 kg; p = 13.9 kPa)

400 500 600 700 800 900

5

10

15

20

25

30

35R

efle

ctan

ce,

%

Wavelength, nm

under pressue

22 s

134 s

Results of experiment

Page 6: Effect of external mechanical compression on optical properties of the human skin in vivo Inara A. Nakhaeva, Mohammod R. Mohammod, Olga A. Zyuryukina,Yury

Results of experiment

Dynamics of human skin reflectance under the external mechanical compression (m = 4.0 kg; p = 110 kPa)

500 600 700 800 900

28

30

32

34

36

38

40

42

44R

efle

ctan

ce,

%

Wavelength, nm

15 s

105 s200 s290 s

Withoutpressue

Page 7: Effect of external mechanical compression on optical properties of the human skin in vivo Inara A. Nakhaeva, Mohammod R. Mohammod, Olga A. Zyuryukina,Yury

Results of experiment

Dynamics of human skin reflectance after the external mechanical compression (m = 4.0 kg; p = 110 kPa)

500 600 700 800 900

20

24

28

32

36

40

44R

efle

ctan

ce,

%

Wavelength, nm

40 minWithoutpressue

0 s150 s

10 s

Page 8: Effect of external mechanical compression on optical properties of the human skin in vivo Inara A. Nakhaeva, Mohammod R. Mohammod, Olga A. Zyuryukina,Yury

Results of experiment

Temporal changes of the human skin reflectance coefficients at two wavelengths in the conditions of the external

mechanical compression

0 100 200 300 400 500 600 700 800 90010

15

20

25

30

35

40

Ref

lect

ance

,%

Time, sec

700 nm

450 nm

m=1 kg

m=1 kg

m=2 kg

m=2 kg

m = 8 kg; p = 111 kPa0-225 sec ‑ under compression,

225 sec – 50 min ‑ after compression

Page 9: Effect of external mechanical compression on optical properties of the human skin in vivo Inara A. Nakhaeva, Mohammod R. Mohammod, Olga A. Zyuryukina,Yury

Results of experiment

Erythema index

– apparent optical density.

575560 545 510 610E =100× OD +1.5× OD + OD - 2.0× OD + OD

, [nm]

Dynamics of the human skin eryhema index under (0-290 s) and after (290 s -40 min) the external mechanical compression; m = 4 kg (p = 111 kPa)

Page 10: Effect of external mechanical compression on optical properties of the human skin in vivo Inara A. Nakhaeva, Mohammod R. Mohammod, Olga A. Zyuryukina,Yury

Results of experiment

Hemoglobin oxygenation degree,

= 31, = 1

0 100 200 300 400 500 600-20

0

20

40

60

80

100

Oxy

gena

tion

degr

ee

Time, s

Page 11: Effect of external mechanical compression on optical properties of the human skin in vivo Inara A. Nakhaeva, Mohammod R. Mohammod, Olga A. Zyuryukina,Yury

TheoryThe human skin diffuse reflectance spectrum in the case of diffusion approximation of

radiation transfer theory: source - spot, medium - homogeneous, semi-infinite

(Farrell T.J., Patterson M.S., and Wilson B. A diffuse theory model of spatially resolved, steady-state diffuse reflectance for the noninvasive determination of tissue optical properties in vivo // Med. Phys. 1992. Vol. 19. P. 879-888).

' 4 1'1 exp A 3 12 3 '1 3 1

aR aa

, A = 2.79

Absorption ( ) ( ) ( )C C C C

a hem oxy oxy deoxy deoxy mel mel

2.303 150 ( ),, ( )66500

oxy deoxyoxy deoxya

, (Prahl S. http://omlc.ogi.edu)

( ) 544.936 exp106.207mel

. (Prahl S. http://omlc.ogi.edu)

Scattering12 4 0.22' ( ) 0.55 10 36.85s

(Bashkatov A.N., Genina E.A., Kochubey V.I., Tuchin V.V. Optical properties of human skin, subcutaneous and mucous tissues in the

wavelength range from 400 to 2000 nm // J. Phys. D: Appl. Phys. 2005. Vol. 38. P. 2543-2555).

Page 12: Effect of external mechanical compression on optical properties of the human skin in vivo Inara A. Nakhaeva, Mohammod R. Mohammod, Olga A. Zyuryukina,Yury

Results of modellingEffect of hemoglobin absorption Effect of the scattering

Effect of hemoglobin absorption and scattering

1- normal; 2- absorption was decreased 10 times, scattering was decreased in 1.5 times

Page 13: Effect of external mechanical compression on optical properties of the human skin in vivo Inara A. Nakhaeva, Mohammod R. Mohammod, Olga A. Zyuryukina,Yury

Effect of the transport scattering coefficient on the skin reflectance

10 9 8 7 6 5 4 3

0,52

0,56

0,60

0,64

0,68

Ref

lect

ance

'S ,cm-1

λ

Decreasing of reflection on 15% is result of decreasing of transport scattering coefficient in 2 times

Page 14: Effect of external mechanical compression on optical properties of the human skin in vivo Inara A. Nakhaeva, Mohammod R. Mohammod, Olga A. Zyuryukina,Yury

1. The external mechanical compression decreases the blood content and scattering properties of the human skin.2. The time of blood content stabilization (about 3 minutes) is less than the time of the scattering properties stabilization (about 5 minutes).3. Decreasing of blood content is accompanied with decreasing of hemoglobin oxygenation degree.4. The blood content in the skin sharply increases (about 2.4 times as compared with normal skin) after removing of compression.5. The hemoglobin oxygenation degree also increases (about 2.7 times as compared with normal skin) after removing of compression.6. The time of relaxation of the human skin to normal state after compression ~ one hour.

Conclusions