The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 19, 1983
Filed:
Aug. 17, 1981
Ronald S Newbower, Acton, MA (US);
Massachusetts General Hospital, Boston, MA (US);
Abstract
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 current through the vascular fluid between one pair of electrodes, and voltage sensing means is provided for measuring the voltage between the other pair of electrodes. In the preferred embodiment, the electrodes are closely spaced, substantially parallel electrodes oriented along the longitudinal direction of the catheter and transversely spaced apart by a distance which is small compared to the diameter of the catheter. The longitudinal length of the electrodes is chosen to be large as compared to the transverse spacing. The preferred current source is an isolated AC source, and the preferred voltage detection means is a phase sensitive voltage detector selectively responsive to the frequency and phase of the current source.