A single instrument is provided for simultaneously enabling fluid inflow, fluid outflow and pressure sensing during endoscopic surgical procedures. The instrument comprises three concentric tubular members, each of which has a distal end and a proximal end and each of which has a port connected to its...http://www.google.fr/patents/US6086542?utm_source=gb-gplus-shareBrevet US6086542 - Pressure sensing input/output scope sheath
