Patent ID: 7181260

Claim:
A pulmonary artery catheter adapted to be inserted into a patient's venous system to detect the rate of oxygen consumption in the heart by comparing oxygen levels in the pulmonary artery to oxygen levels in the right atrium, or superior vena cava, the catheter comprising: an elongated flexible tube having an inflatable balloon at a distal end, a syringe positioned at a proximal end of the tube, the syringe allowing an operator to selectively inflate the balloon to thereby allow the catheter to be pulled through the patient's venous system; a thermistor proximal to the balloon, the thermistor measuring blood temperatures and determining cardiac output; a first oxygen sensor located adjacent the distal end of the tube and comprising a series of light emitting diodes and a photodetector, the first oxygen sensor determining blood oxygen content by measuring the blood's absorption of infrared light, the first oxygen sensor adapted to be positioned within a patient's pulmonary artery; a second oxygen sensor positioned proximal to the first oxygen sensor and likewise comprising a series of light emitting diodes and a photodetector, the second oxygen sensor determining blood oxygen content by measuring the blood's absorption of infrared light, the second oxygen sensor adapted to be positioned within a patient's right atrium or superior vena cava; a microprocessor operatively coupled to the first and second oxygen sensors, the microprocessor implementing an algorithm that calculates the rate of oxygen consumption in the heart as a function of the difference between blood oxygen content as measured by the first and second oxygen sensors and the cardiac output as determined by the thermistor.