Abstract: The cardiac catheter of this invention combines in a single, thin tube, an acoustic transducer for determining blood flow velocity, and a separate lumen with a removable, flexible, radio-opaque guide wire, enabling the surgeon to locate the site of arterial blockage, evaluate the blockage, and assess the effect of the treatment.

Abstract: The present invention comprises a vacuum cup having a concave undersurface on which is mounted a doppler flow transducer. A vacuum tube is in communication with the undersurface of the cup and is capable of removing the air from beneath the suction cup so as to permit the suction cup to be clamped over an artery or other vessel. The device is used by activating the transducer to cause it to transmit a sound signal into the artery. The secondary or echo sounds created by this sound signal are sensed by the transducer and the transducer converts these secondary sound signals into electrical signals which are transmitted to means for analyzing the signals so as to determine the velocity of fluid flow within the vessel.