Method and apparatus for noninvasively measuring concentration o

Details Method and apparatus for noninvasively measuring concentration o Method and apparatus for noninvasively measuring concentration o

1994-06-17

1995-10-17

Kamm, William E.

Surgery

Truss

Pad

128633, 128664, 128665, 356 39, A61B 600

Patent

active

054581281

ABSTRACT:
The method of noninvasively measuring concentration of a dye in a circulatory system includes measuring an optical density of an arterial blood-dye mixture in an artery as a function of time at a wavelength .GAMMA..sub.1 and at another different wavelength .GAMMA..sub.2 ; calculating ratios of optical density at the wavelength .GAMMA..sub.1 to that at wavelength .GAMMA..sub.2 of arterial blood in the artery at a time before a predetermined initial time and of the arterial blood-dye mixture at at least one time t after the predetermined initial time; injecting a dye absorbing electromagnetic radiation at at least one of the wavelengths into the circulatory system at the predetermined initial time, t=0, to form the arterial blood-dye mixture; measuring a hemoglobin concentration in a blood sample from the living organism; and calculating a concentration C(d,t) of the dye in the arterial blood-dye mixture as a function of time, t, from the hemoglobin concentration, Hb; from extinction coefficients, .epsilon..sub.d1 and .epsilon..sub.d2, of the dye at the wavelengths .GAMMA..sub.1 and .GAMMA..sub.2 ; and from the ratio R(0) at the time before the predetermined initial time and the ratio R(t) at the at least one time, t according to the following formula: ##EQU1## wherein .epsilon..sub.r1 and .epsilon..sub.r2 are reduced hemoglobin extinction coefficients at wavelengths .GAMMA..sub.1 and .GAMMA..sub.2 respectively and .epsilon..sub.o1 and .epsilon..sub.o2 are oxyhemoglobin extinction coefficients at wavelengths .GAMMA..sub.1 and .GAMMA..sub.2 respectively.

REFERENCES:
patent: 3769966 (1973-11-01), Youdin et al.
patent: 3998550 (1976-02-01), Konishi et al.
patent: 4281645 (1981-08-01), Jobsis
patent: 4361049 (1982-11-01), Volgyesi
patent: 4372294 (1983-02-01), Straus et al.
patent: 4759369 (1988-07-01), Taylor
patent: 4819752 (1989-04-01), Zelin
patent: 5024231 (1991-06-01), Feldschuh et al.
patent: 5148022 (1992-09-01), Kawaguchi et al.
patent: 5178142 (1993-01-01), Harjunmaa et al.
patent: 5284137 (1994-02-01), Kessler et al.
patent: 5372135 (1994-12-01), Mendelson et al.
patent: 5377674 (1995-01-01), Kuestner
patent: 5379764 (1995-01-01), Barnes et al.
Measurement of Cardiac Output in man by Dye Dilution Curves . . . , M. McGregor, et al, Circulation Research, vol. IX, Sep. 1961, pp. 1083-1088.
Use of Dichromatic Earpiece Densitometry For Determination Of Cardiac Output, John H. Reed, et al, 1966, pp. 373-380.

Affiliated with

Also associated with

Rating

Method and apparatus for noninvasively measuring concentration o does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method and apparatus for noninvasively measuring concentration o, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for noninvasively measuring concentration o will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-590131