Colonic polyp discrimination by tissue fluorescence and fiberoptic probe
A system and method for the in situ discrimination of healthy and diseased tissue. A fiberoptic based probe is employed to direct ultraviolet illumination onto a tissue specimen and to collect the fluorescent response radiation. The response radiation is observed at three selected wavelengths, about 403 nm, about 414 nm, and about 431 nm. The intensities of the 403 nm and 414 mn radiation are normalized using the 431 nm intensity. A score is determined using the ratios in a linear discriminant analysis (LDA). The tissue under examination is resected or not, based on the outcome of the LDA.
1. A method of identifying a state of health of a tissue in vivo, the method comprising the steps of:
illuminating a tissue in vivo with light having a wavelength of about 337 nanometers;
receiving from the tissue a response comprising fluorescent light having wavelengths of about 403 nanometers, about 414 nanometers, and about 431 nanometers;
computing a first ratio, the first ratio being an intensity of the fluorescent light having a wavelength of about 403 nanometers divided by an intensity of the fluorescent light having a wavelength of about 431 nanometers;
computing a second ratio, the second ratio being an intensity of the fluorescent light having a wavelength of about 414 nanometers divided by the intensity of the fluorescent light having a wavelength of about 431 nanometers; and
deducing a state of health of the tissue depending on the magnitude of the first ratio and the magnitude of the second ratio to a linear discrimination function.
2. The method of claim 1 , wherein illuminating the tissue involves contacting the tissue with an illumination optical fiber.
3. The method of claim 1 , wherein receiving from the tissue a response comprising fluorescent light involves contacting the tissue with a receiving optical fiber.
4. The method of claim 1 , wherein the tissue in vivo comprises a polyp under about 10 millimeters in size.
5. The method of claim 1 , wherein deducing a state of health of the tissue comprises deducing the state of health in real time.
6. A system for identifying a state of health of a tissue in vivo, comprising:
an illumination source for illuminating a tissue in vivo with light having a wavelength of about 337 nanometers, the source comprising an illuminating optical fiber;
a detector for receiving from the tissue a response comprising fluorescent light having wavelengths of about 403 nanometers, about 414 nanometers, and about 431 nanometers, the detection system comprising at least one optical fiber for receiving the fluorescent light;
a wavelength dispersive element for separating the fluorescent light into different wavelengths;
a computation system for computing a first ratio and a second ratio, the first ratio being an intensity of the fluorescent light having a wavelength of about 403 nanometers divided by an intensity of the fluorescent light having a wavelength of about 431 nanometers, the second ratio being an intensity of the fluorescent light having a wavelength of about 414 nanometers divided by the intensity of the fluorescent light having a wavelength of about 431 nanometers; and
an analysis module for deducing a state of health of the tissue depending on the magnitude of the first ratio and the magnitude of the second ratio to a linear discrimination function.
7. The system of claim 6 , wherein the illuminating optical fiber contacts the tissue.
8. The system of claim 6 , wherein the at least one optical fiber for receiving the fluorescent light contacts the tissue.
9. The system of claim 6 , wherein the tissue in vivo comprises a polyp under about 10 millimeters in size.
10. The system of claim 6 , wherein the analysis module produces information about the state of health in real time.