Apparatus for making cardiac output conductivity measurements

摘要: An improved catheter probe includes a conductivity sensor comprising four electrodes configured and spaced to be electrically coupled together by vascular fluids. A current source is provided for driving through the fluid between one pair of electrodes, voltage sensing means measuring other electrodes. In preferred embodiment, are closely spaced, substantially parallel oriented along longitudinal direction transversely apart distance which small compared diameter catheter. The length chosen large as transverse spacing. an isolated AC source, detection phase sensitive detector selectively responsive frequency source.