Determination of arterial blood flow by percutaneously introduced flow sensors in an external magnetic field. I. The method.

A method for determining the rate of blood flow in arteries without surgical intervention is described. It is shown that a probe capable of securing such information about flow in a blood vessel can be introduced into the vascular tree by means of a needle puncture in the skin made by a no. 18-guage hypodermic needle. A snugly-fitting guide wire is passed through the needle, which is then withdrawn. A Teflon catheter is then passed over the wire and pushed through the skin and subcutaneous tissues into the superficial branch artery from which the wire guides it deep into the aorta to a desired location. The guide wire is then withdrawn and a suitable sensing device of wire-like structure can be passed through the catheter into the major arterial trunk and, if desired, into some of its branches. Two types of sensors are used, loop-shaped ones which are used as volume-flow meters, and L-shaped probes used as volume-flow meters when they fir the artery precisely and as velometers when they do not. The sensors are used in conjunction with an apparatus consisting of a flat coil mounted over the animal and a standard electromagnetic sinusoidal flow meter channel.