Catheter for determining carbon@ di-oxide partial pressure in internal organ

摘要

The catheter comprises a catheter tube (1) which contains tonometer tubes which are watertight and do not allow CO2 to pass at certain sections. Tonometer chambers (10,12) formed from spiral tubing wound around the catheter are used for undertaking the test. The walls of the tonometer chambers are water tight but do allow CO2 to pass. One end of the tonometer tubes are positioned such that they project into the tonometer chambers and the other end leads away from the chambers. This exit part of the tubes (2,6) is parallel to the entry part of the tubes (4,8). Both proximal ends of the entry and exit parts of the tube are connected to a pump arrangement external to the patient's body. The pump maintains a fluid or gas for circulation within the circuit for the test to be undertaken on a continual basis.