10 SURGICAL AND MEDICAL APPARATUS AND INSTRUMENTS, NAMELY, HEAT EXCHANGE SYSTEMS FOR MEDICAL CATHETERS; MEDICAL CATHETERS; MEDICAL CATHETERS CONTAINING FLUIDS, MEDICAL CATHETERS INCORPORATING BALLOONS, MEDICAL CATHETERS CONTAINING STERILE TEMPERATURE-CONTROLLED SOLUTIONS; CATHETER CONTROL APPARATUS AND INSTRUMENTS, NAMELY, TEMPERATURE REGULATORS FOR MEDICAL CATHETERS, ELECTRONIC CIRCUITS FOR REGULATING MEDICAL CATHETER TEMPERATURES; ELECTRONIC CIRCUITS FOR REGULATING FLUID TEMPERATURES INSIDE A MEDICAL CATHETER; HEAT EXCHANGE DEVICES, NAMELY, FLUID TEMPERATURE REGULATORS FOR MEDICAL CATHETERS