Intravascular oximetry catheter

摘要

Apparatus and a method for monitoring a percentage of the oxygen saturation in the hemoglobin of blood flowing through a blood vessel. An optical sensor that detects the percentage oxygen saturation in blood is disposed proximate a proximal end of the catheter. A thermistor is disposed adjacent to the distal end of the catheter and it is employed to detect changes in blood temperature that indicate the position of the catheter's distal end in the blood vessel. Indicia or marks visible at intervals on the outer surface of the catheter enable a medical practitioner to determine the length of the catheter that has been introduced into the blood vessel. A strain relief that is flexible and resists stretching extends along the length of the catheter. For flushing the distal end of the catheter, a fluid supply may be connected to a lumen running through the catheter to provide the flushing fluid. A removable guide wire is inserted in the lumen when positioning the distal end of the catheter at a location in the blood vessel and provides enhanced rigidity for this purpose. The catheter may be coated with an anticoagulant such as heparin, to prevent blood from coagulating on the exterior surface of the catheter.