Laser Doppler flow monitor

Details Laser Doppler flow monitor Laser Doppler flow monitor

1984-12-18

1986-06-24

Howell, Kyle L.

Surgery

Truss

Pad

128691, 356 28, A61B 502

Patent

active

045962545

ABSTRACT:
A method and apparatus for measuring the velocity of moving particles such as red blood cells in a tissue sample is disclosed, characterized by digital processing techniques and autocorrelation. The moving particles are illuminated to produce a spread spectrum optical signal resulting from the Doppler shift occurring when photons are scattered by the moving particles. A spread spectrum electrical signal corresponding with the optical signal and containing spectral and noise components is generated from the optical signal. The electrical signal is filtered to produce the bandpass and DC signals which are subsequently converted to digital form. A first autocorrelation function is calculated from the bandpass signal and a noise autocorrelation function is determined in accordance with the DC signal level. The first and noise autocorrelation functions are compared to produce an autocorrelation function free of a noise component. From the autocorrelation function, the mean frequency of the electrical signal is linearly calculated, the mean frequency corresponding with the average velocity of the moving particles.

REFERENCES:
patent: 3313290 (1967-04-01), Chance et al.
patent: 3511227 (1970-05-01), Johnson
patent: 3532427 (1970-10-01), Paine
patent: 3552855 (1971-01-01), Crosswy et al.
patent: 3584956 (1971-06-01), Hines
patent: 3647299 (1972-03-01), Lavallee
patent: 3709599 (1973-01-01), Iten
patent: 3795447 (1974-03-01), Welch et al.
patent: 3814081 (1974-06-01), Mori
patent: 3830222 (1974-08-01), Chance
patent: 4109647 (1978-08-01), Stern et al.
patent: 4476875 (1984-10-01), Nilsson et al.
Duteil et al., IEEE Trans. Biomed. Engr., vol. BME-32, No. 6, Jun. 1985, pp. 439-447.
Yogamathan et al., Med. & Biol. Eng. & Comput, vol. 17, No. 1, Jan. 1979, pp. 38-44.
Tanaka et al., Applied Optics, vol. 14, No. 1, Jan. 1975, pp. 189-196.
Wunderlich et al., Rev. Sci. Instrum., vol. 51(9), Sep. 1980, pp. 1258-1262.
"In Vivo Evaluation of Microcirculation by Coherent Light Scattering" Nature, vol. 254, Mar. 6, 1975, pp. 56-58.
"High Speed Correlation Techniques," SI Quarterly, vol. VIII, issue 2, Apr.-Jun. 1982, pp. 3-12.
"Model for Laser Doppler Measurements of Blood Flow in Tissue" Applied Optics, vol. 20, No. 12, Jun. 15, 1981, pp. 2097-2107.

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