United States Patent m
 DEVICE AND METHOD FOR
INTRA-VASCULAR OPTICAL RADIAL
 Inventor: Hugh L. Narciso, Jr., Santa Barbara, Calif.
 Assignee: PDT Cardiovascular, Inc., Goleta, Calif.
 Appl. No.: 840,478
 Filed: Feb. 24,1992
 Int.C1.5 A61B 17/32
 U.S. CI 606/15; 606/17;
 Field of Search 606/2, 3, 7, 13-18;
 References Cited
U.S. PATENT DOCUMENTS
4,768,858 9/1988 Hussein 606/7 X
4,850,351 7/1989 Herman et al 606/16 X
4,860,743 8/1989 Abela 606/16
4,917,084 4/1990 Sinofsky 606/16 X
4,993.412 2/1991 Murphy-Chutorian 606/7
5,032,123 7/1991 Katz et al 606/15
iiiiiiiii'iii ii; ill ...
[ii] Patent Number: 5,217,456
 Date of Patent: Jun. 8, 1993
Primary Examiner—Peter A. Aschenbrenner
Attorney, Agent, or Firm—Michael G. Petit
An intra-vascular optical radial imaging system comprising an intra-vascular guidewire-compatible catheter, a source of illumination and a synchronous fluorescence detector. The catheter is inserted into a blood vessel until the tip is adjacent to a section of vessel to be imaged. A narrow beam of light emanating radially from an aperture underlying the segment to be imaged repetitively illuminates segments of the wall of the vessel in a scanning or sweeping manner with the light of a wavelength that induces fluorescence in molecules in the tissue. Fluorescence from molecules in the illuminated tissue enters the catheter through the aperture and is conveyed to a spectral analyzer. Properties of the fluorescence signal are characteristic of the particular tissue and may be used to differentiate healthy tissue from atherosclerotic plaque. The method yields not only the longitudinal position of a lesion along a vessel but also the cylindrical coordinates by determining the circular or angular position of the lesion on the interior wall of the vessel.
7 Claims, 5 Drawing Sheets