Tissue blood flow measurement by laser Doppler technique

Continuous measurement of tissue blood flow by laser-Doppler spectroscopy.

Laser light scattered from tissue in vivo is broadened in line width as a result of the Doppler shift produced by moving red cells in the microcirculation. A feasibility study was carried out to demonstrate use of this effect to measure and monitor tissue blood flow. Light from a helium-neon laser illuminated a 1-mm area of tissue (human skin or rat renal cortex), and the backscattered light wa...

Blood Flow Measurement by Laser Doppler Method in Orofacial Region

Laser Doppler is a noninvasive, objective, reproducible and painless method for measuring blood flow in tissue microcirculation. This method is based on the Doppler effect, the change in frequency of light reflecting from blood cells in motion. Light from helium-neon laser through optical fibers and probes is directed to the surface of the tissue in which the flow is measured. Light portion is ...

Laser Doppler measurement of rectal mucosal blood flow.

BACKGROUND Gut mucosal blood flow measurement is used to study a variety of disorders and possibly extrinsic neural function. AIMS To determine optimal measurement criteria and validate this technique as a measure of level of activity of extrinsic autonomic gut innervation. METHODS In 26 healthy volunteers a laser Doppler mucosal probe was applied 10 cm from the anus. Response to inhaled sa...

Non-Invasive Capillary Blood Flow Measurement: Laser Speckle and Laser Doppler

Microcirculation is essential for the proper supply of oxygen and nutritive substances to the biological tissue and the removal of waste products of metabolism. The determination of blood flow in the capillaries is therefore of great interest to clinicians. A comparison has been carried out using the developed non-invasive, non-contact and whole field laser speckle contrast imaging (LSCI) based...

Laser Doppler Displacement Measurement

Existing precision displacement-measuring devices are primarily based on linear encoders (optical or magnetic) or laser interferometers. Most encoders use grating scales and frequency counters, while most interferometers use stabilized lasers and fringe counters. In general, interferometers are more expensive and more accurate than linear encoders. However, there are large gaps in price and per...

Studies of Blood Flow in Human Nasal Mucosa with Xe Washout Technique and Laser Doppler Fiowmetry