Claims
- 1. A method for measuring a temporal change in a concentration of an exogenous chromophore in a target tissue in the presence of an endogenous chromophore in the target tissue within the body of an animal comprising the steps of:
- (a) establishing a concentration of the exogenous chromophore within the target tissue of the animal;
- (b) illuminating the target tissue with excitation light having a first wavelength which is absorbed by the exogenous chromophore and the endogenous chromophore and wherein the absorption of the excitation light by the exogenous chromophore and the endogenous chromophore causes the exogenous chromophore to emit fluorescence light having a maximum intensity at a second wavelength and the endogenous chromophore to emit fluorescence light having a third wavelength and wherein the second and third wavelengths are unequal;
- (c) directing the fluorescence light into a fluorescence light detection apparatus operable for separating a portion of the fluorescence light having the second wavelength from a portion having the third wavelength;
- (d) detecting and measuring the intensity of the portions of the fluorescence light emanating from the target tissue at the second wavelength and the third wavelength;
- (e) dividing the intensity of the fluorescence light at said second wavelength by the intensity of the fluorescence light at said third wavelength, the resulting quotient being a measure of the concentration of exogenous chromophore in the target tissue; and
- (f) repeating steps b-e above over an interval of time to measure the rate of change of the quotient with time, the rate of change of the quotient with time providing a measure of the temporal change in the concentration of the exogenous chromophore in the target tissue during the interval of time.
- 2. The method of claim 1 wherein said step of illuminating includes delivering said excitation light having said first wavelength to said target tissue by means of a fiber optic having (a) a proximal end in optical communication with a source of light having said first wavelength; and (b) a distal end in optical communication with said target tissue and further includes maintaining a constant position of the distal end with respect to said target tissue remains constant during said interval of time.
Parent Case Info
This is a continuation-in-part of application Ser. No. 08/308,288 filed 19 Sep. 1994, now abandoned.
US Referenced Citations (4)
Number |
Name |
Date |
Kind |
4718417 |
Kittrell et al. |
Jan 1988 |
|
5074306 |
Green et al. |
Dec 1991 |
|
5318023 |
Vari et al. |
Jun 1994 |
|
5377676 |
Vari et al. |
Jan 1995 |
|
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
308288 |
Sep 1994 |
|