US 2008/0188726 A1 · Blood Flow Sensor

Abstract

The present invention relates to a method for measuring blood flow in living tissue and a device for performing the method. The device comprises a laser and a photo sensor. The laser is arranged to illuminate (10) the tissue in such a way that a portion of the light beam, scattered by the tissue, re-enters the laser in order to obtain a self-mixing effect. The resulting light, that is registered (11) as an electric signal by the photo sensor, contains a speckle pattern that is depending on blood cell movement in the tissue. A Fourier transform is applied (12) to this signal and an exponential fit is applied (13) to the resulting frequency domain spectrum. Thereby parameters corresponding to the amount of blood cells and the average velocity of these cells may be obtained.

Claims13

Dependent claims

A method for measuring the blood flow in living tissue, comprising the following steps:

illuminating (10) the tissue with a laser beam, using a laser, and allowing a part of the laser beam, scattered by the tissue, to re-enter into the laser;
measuring (11), using a photo sensor, light emitted from the laser, thus obtaining a signal which varies in accordance with the interference between the original laser beam and the scattered laser beam;
applying a Fourier transform (12) to said signal in order to provide the spectrum of the signal;
and
applying an exponential fit (13) to said spectrum, thereby obtaining parameters corresponding to the average blood cell velocity in the tissue and the amount of blood in the tissue.

2 more elements

Dependencies are inferred from the claim text.

Blood Flow Sensor

Life of this patent

Blood Flow Sensor

Life of this patent

Abstract

Claims13