A catheter probe for use in the analysis of gases absorbed in liquids, particularly suitable for the in vivo analysis of blood gases, the probe includes an equilibration chamber disposed within the active length of the probe at the distal end of the probe and which is surrounded by a gas permeable membrane....http://www.google.ca/patents/US4901727?utm_source=gb-gplus-sharePatent US4901727 - Micro-probe for gas sampling
