Influence of glucose concentration on blood optical properties in THz frequency range

Transcription

1 Photonics Summer School 2017 Influence of glucose concentration on blood optical properties in THz frequency range Gusev S.I., Simonova A.A., Demchenko P.S., Khodzitsky M.K., Cherkasova O.P. St.Petersburg/Oulu,

2 International Students and Scholars Rock Humanity Diabetes vs.

3 Number of diabetics mil deaths of diabetics per year mil 422 mil 1 death per 10 seconds Worldwide Health Organization,

4 CARBOHYDRATE METABOLISM Insulin

5 Pancreas of healthy man Pancreas of diabetic

6 6

7 Increased mortality from complications heart diseases insult blindness nephropathy gangrene Multiply index of the number of cases with diabetics compared with other diseases 20

8 Insufficient glucose control Complications Death 8

9 Day: 5 times Month: 150 times Year: 1800 times 9

10 1 800 punctures x humans = 10

11 1 800 x =

12 Bracelet GlucoWatch (out of production)

13 Chameleon tattoos

14 CGMS (DexСom, Medtronics, Abbott)

15 Non-invasive control is No pain No punctures 15

16 Non-invasive control is Safe No risk of infection 16

17 Non-invasive control is Easy No test strips 17

18 Non-invasive control is Cost efficient No need for consumables 18

19 Non-invasive control is For all ages Save fingers of babies and seniors 19

20 The Goal Totally non-invasive glucose measuring technique 20

21 Tasks 1. Searching correlation between glucose level and.. Optical properties Debye relaxation times 2. Non-invasive measuring technique implementation 21

22 Transmission THz TDS Reference signal Sample signal Sample

23 Amplitude, a.u. Reference signal Sample signal Time, ps 23

24 Amplitude, a.u. Reference signal Sample signal Time, ps 24

25 Amplitude, a.u. Reference signal Sample signal Feel the difference Time, ps 25

26 S.I. Gusev, et al., Plastic preform 2 Cloth 3 Blood sample 4 Transmission of THz pulse

27

28 Refractive index (n) f is frequency ϕ(f) is phase data c is speed of light in vacuum l is thickness of medium 28

29 Effective refractive index dispersions S.I. Gusev, et al.,

30 S.I. Gusev, et al., 2015 Calibration curves

31 n = THz C = 70 mg/dl 31

32 n = THz C = 235 mg/dl 32

33 Transmission THz TDS pt.2 Reference signal Sample signal Sample

34 Tair Tsam S.I. Gusev, et al., 2016

35 Different media different delays S.I. Gusev, et al., 2016/

36 Blood with different glucose concentrations. nreal(f) S.I. Gusev, et al., 2016/

37 Calibration curves for nreal(c) S.I. Gusev, et al., 2016/

38 Permittivity (ε) nreal is real part of refractive index, nreal is imaginary part of refractive index 38

39 Blood with different glucose concentrations. εreal(f) S.I. Gusev, et al., 2016/

40 Calibration curves for εreal(f) S.I. Gusev, et al., 2016/

41 Permittivity ε feat. relaxation time τ1 ε ω = ε + ε s ε iωτ 1 + ε 2 ε 1 + iωτ 2 ε real ω = ε + ε s ε ω 2 τ ε 2 ε 1 + ω 2 τ 2 2 ε is high frequency limiting dielectric constant εs is static limiting dielectric constant ε2 is an intermediate dielectric value τ1 is calculating relaxation time τ2 is time constant ω is circular frequency Model: M. Hassan Arbab, et al., 2011 Constants: J. Wang, et al., 2013 Constants: ε =4,0 ε s ε 2 = 56,0 ε 2 ε = 5200,0 τ 2 = 132,629 ps 41

42 Relaxation times τ1 S.I. Gusev, et al., not published 42

43 Results Dependences of glucose level from: Refractive index (real part) nreal Permittivity (real part) εreal Debye relaxation times (currently validating) τ1 43

44 Non-invasive measuring 44

45 Reflectance THz TDS 45

46 Reflectance THz TDS Original signal Reference signal Sample signal 46

47 Amplitude, a.u. Reflective signals Time, ps 47

48 Reflectance THz TDS Original signal Reference signal Sample signal 48

49 Reflectance THz TDS Nail bed Nail plate 49

50 Amplitude, a.u. Different time delays Reference signal Sample signal Time, ps 50

51 Amplitude, a.u. I am so different! Time, ps 51

52 Amplitude, a.u. Different absorptions Time, ps 52

53 Amplitude, a.u. We are different too! Time, ps 53

54 Optical properties of nails nreal real part of refr. index nimag imag. part of refr. index α absorption L penetration depth εreal real part of permittivity εimag imag. part of permettivity V.A. Guseva, et al.,

55 55

56 Reflectance THz TDS Original signal Reference signal Sample signal 56

57

58 Acknowledgements This work was supported by the Government of Russian Federation, Grant 074-U01 58

59 Our Lab 59

60 Spectrina software Complex refractive index Absorption Penetration depth Complex permittivity 60

61 Spectrina software Reference signal Sample signal Sample 61

62 Spectrina software Sample 1 Sample signal 1 Sample signal 2 Sample 2 62

63 Spectrina software Reference signal Sample signal 1 Sample 1 Sample signal 2 Sample 1 Sample 2 63

64 Spectrina software Reference signal Sample signal Sample 64

65 Spectrina software Original signal Reference signal Sample signal 65

66 Questions? Sviatoslav Gusev ITMO University, THZ Biomedicine Lab St.Petersburg, Russia fb.com/s.i.gusev 66