Department of Physics, Chemistry and Biology (IFM)

Laser Doppler Flowmeter (PeriScan PIM II imager) was used in the duplex mode to measure the blood flow in the  micro vasculature of  brood patch in Jungle fowl and Zebra finch. The laser light penetrates into the skin and one part of the light gets scattered and the other gets absorbed. The detector detects the scattered light and the signals are processed to extract the information about the movement of RBCs. The basic principle is that when the light particles encounter moving blood cells, the scattered light particles undergo a change in frequency or wavelength (Doppler shift) based on the amount and velocity of the blood cell whereas if it encounters a static particle there won’t be any change in the scattered light signal. Hence the blood flow is measured by using the change in the magnitude of frequency or wavelength of the scattered light. The optimal distance between the instrument and the skin should be 15cm. The instrument is sensitive to motion and hence the bird should be kept still.

Experimental protocol

The study was conducted with 7 Red Jungle-fowls. Initially the LD instrument was calibrated and then switched to duplex mode to record the microcirculatory flow at a specific site in the skin. Klick gel was applied on the skin and started recording for 1 minute. This recording was taken as a control. The recording was then paused and 25µl of Ascorbic acid gel and Sodium Nitrite gel were applied on the specific site using a sterile cotton bud and left for 1 minute. Then the gel was softly wiped out using a tissue without stressing the skin. The recording was then continued for one minute and then stopped. The data was obtained in the form of a graph with time in the X axis and the magnitude of blood flow in arbitrary units in the Y axis.