Abstract: Improved method for in situ visual examination of cardiovascular system comprises feeding a catheter having at least one afferent fiber-optic bundle for transmitting light from the proximal end of the catheter to the distal end thereof and at least one efferent fiber-optic bundle for returning light from the distal end to the proximal end, into the cardiovascular system until the distal end is in the vicinity of the region of cardiovascular system to be examined; illuminating the region by illuminating the proximal end of the catheter; injecting a clear physiologically innocuous fluid in front of the distal end of the catheter to increase clarity of blood in the region being examined; and observing the image returned to the proximal end of the efferent fiber-optic bundle. Fiber-optic catheter system and improved catheter for carrying out method are also disclosed.

Abstract: Improved method for in situ visual examination of cardiovascular system comprises feeding a catheter having at least one afferent fiber-optic bundle for transmitting light from the proximal end of the catheter to the distal end thereof and at least one efferent fiber-optic bundle for returning light from the distal end to the proximal end, into the cardiovascular system until the distal end is in the vicinity of the region of cardiovascular system to be examined; illuminating the region by illuminating the proximal end of the catheter; injecting a clear physiologically innocuous fluid in front of the distal end of the catheter to increase clarity of blood in the region being examined; and observing the image returned to the proximal end of the efferent fiber-optic bundle. Fiber-optic catheter system and improved catheter for carrying out method are also disclosed.

Abstract: Improved bladder catheter for insertion in a body cavity comprises a tubular member having a distal end and a proximal end, a longitudinally extending lumen open for drainage at the proximal end, and a plurality of circumferentially spaced longitudinally extending slits adjacent the distal end. At least the portion of the tubular member intermediate the extremities of the slits is flexible and at least one longitudinally extening spring element is disposed in each of the intermediate portions, the spring elements being unstressed when the intermediate portions are flush with the adjacent unslitted portions of the tubular member for biasing the intermediate portions to the flush position. The improved catheter also includes means within the tubular member for releasably retracting the distal end relative to the proximal end to flex the intermediate portions outwardly from the adjacent portions for retaining the catheter in the bladder.