Transcript Extended abstract

MONITORING OF MICROCIRCULATION BY FULL FIELD
SPECKLE-CORRELATION TECHNIQUE IN ANIMAL STUDY
Maxim Vilensky, Saratov State University, Russia Oxana V.
Semyachkina-Glushkovskaya, Saratov State University, Russia
Denis A. Alexandrov, Saratov State Medical University, Russia
Valery V. Tuchin, Saratov State University, Russia; Institute of
Precision Mechanics and Control, Russian Academy of Sciences,
RAS, Russia; University of Oulu, Finland
Polina A. Timoshina, Saratov State University, Russia Viktor A.
Kuleshov, Saratov State Medical University, Russia
Igor A. Semyachkin-Glushkovsky, Saratov State University, Russia
Outlines
The results of experimental study of full field laser
speckle imaging in application to cortex and pancreas
microcirculation monitoring of laboratory rats at stressinduced stroke, modeled hemorrhagic pancreatitis and
impact of exogenous agents are presented
The results of phantom study and nail fold capillary
blood flow monitoring are also presented
2
Analysis and computing of speckle images
Vk   I k I k
M
N
I k  1 MN  I k m, n 
(1)
The contrast of speckle-modulated images
(2)
The intensity of the speckle field
m 1 n 1
Ik 
1 MN  I k m, n  I k 2 (3)
M
N
Standard deviation of intensity
m 1 n 1
g 2    exp    c 
(4)
Correlation function of strength fluctuation of
scattering light
 с  K v
(5)
Correlation time of strength
fluctuation
Investigated objects
2 – Capillary bundle with scatters flow
1 - Rats
microcirculation
monitoring
3 – human nail bed
microcirculation
Cortex microcirculation monitoring
Experimental setup
Schematic diagram of experimental setup:1. He–Ne laser GN 5P with the wavelength 633 nm;
2. Optical fiber; 3. Detector (CMOS camera Basler A602f) (in the speckle imaging regime); 4.
Lens tube of the microscope with microscopic objective (LOMO, 10x) and 8 element LEDilluminator (central wavelength ~530 nm); 5. Object of study (in the microscopy regime)
Speckles contrast data fluctuation via blood flow changes
1. Mean contrast values for rats one day after the stress exposure;
2. Mean contrast values for rats immediately after action;
3. Mean contrast values for healthy animals.
Pancreas microcirculation monitoring
The pancreas capillary blood flow studied at different
states of the experimental animal
Contrast variations of time-averaged speckles caused
by pancreas blood flow velocity reperfusion changes
The pancreas capillary blood flow studied by digital image
microscopy at different states of the experimental animal
The pancreas capillary blood flow studied by digital image
microscopy at different states of the experimental animal at
reperfusion
Phantom particles flow visualisation
Speed-contrast relation ship
0,4
0,3
<V>
0,2
0,1
0,0
0
100
200
300
v, m/sec
Speed-contrast relationship for scatters flow;
Tube diameter 3 mm (left curves) & 50 mm (right curve)
400
500
Nail fold speckle images
Speckle contrast variations due to vessels
overcomression
Contrast
Time, sec
Summary
Contrast of time-averaged speckles, used as a diagnostic parameter, characterized by a rather
high sensitivity to changes in blood microcirculation in superficial layers of the internals caused
by pathological changes or external factors
The experimental study of the blood flow velocity dynamics under conditions of stroke in
laboratory rats demonstrates high efficiency of the developed instrument and algorithm for data
acquisition and processing, implementing the method of fullｭfield speckleｭimaging, in
monitoring of the blood microcirculation state in the brain cortex, affected by pathological
changes or action of agents
Monitoring of blood flow during the pancreatitis showed a good correlation between data
obtained from speckle-correlometry monitoring and dynamic microscopic imaging studies. No
significant changes in blood flow existing after prolonged ischemia (10, 15 min), probably
indicate the appearance of the irreversible disorders of pancreas blood flow regulatory
mechanism. In contrast, after 5 min of ischemia, there are significant changes of blood flow
velocity.
Acknowledgments
The research has been made possible by program:
FiDiPro TEKES (40111/11) and grants: RFBR #11-0200560-а, #224014; PHOTONICS4LIFE of FP7-ICT2007-2; Projects: #1.4.09, #2.1.1/4989 and
#2.2.1.1/2950 of RF Ministry of Education and
Science;
RF
Governmental
contracts:
02.740.11.0879, 14.B37.21.0563, 11.519.11.2035