Abstract: A probe for use within a catheter is disclosed. The probe transducer portion is constructed of a crystal hollow cylinder with an inside lead attached to the inner surface of the crystal cylinder. One end of the outside lead is positioned close to the outer surface, in a plane tangential to the outer surface, and is coupled to the outer surface of the crystal cylinder by a thin sputtered layer of conductive material. The probe transducer also includes a layer of acoustically absorbing material on the proximal end of the crystal, and layer of acoustically coupling material on the distal end of the crystal cylinder. The transducer element simultaneously generates an axially oriented signal beam at one frequency and a radially oriented signal beam at 2 different frequency. The signal beams are analyzed to calculate the blood flow area and the blood flow velocity, the product of which is the blood flow rate.

Abstract: A method of sequentially analyzing various body conditions with a plurality of probes is disclosed. Also disclosed, is a catheter which can be used to practice the method. The catheter has several independent lumens extending longitudinally therethrough for accepting probes and for introducing fluid therethrough and into a body cavity. The catheter outer body has a cross-sectional maximum outer dimension. The first lumen is circular in cross-section, and has a cross-sectional dimension of approximately half the maximum outer dimension of the catheter body. The first lumen is capable of accepting various probes, as well as allowing simultaneous fluid flow through the lumen. The second lumen is crescent-shaped in cross-section and occupies at least a quarter of an arc around the cross-section of the catheter body. The large cross-section of the second lumen allows for a high fluid flow rate through the lumen.