A catheter (10) is disclosed having a stepped coaxial construction formed by and internal tube (12) and an external tube (14). The internal tube includes a distal pressure lumen (26), a balloon inflation lumen (28), and a sensor lumen (30). The external tube includes the first proximal pressure lumen...http://www.google.ca/patents/US5286259?utm_source=gb-gplus-sharePatent US5286259 - Dual-diameter multifunction catheter
