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:
Jun. 20, 1995
Filed:
Mar. 12, 1993
Steven A Daniel, Fremont, CA (US);
Mark J Cowell, San Carlos, CA (US);
Metcal, Inc., Menlo Park, CA (US);
Abstract
An instrument for cutting, ablating and coagulating tissue has a rod of ferromagnetic material fusion welded to the base of a conical tip of copper with the rod adjacent the base of the conic being of lesser diameter than the base to provide a region to accept a potted coil of wire about the rod whereby when the coil is connected to a constant current high frequency source the rod and tip are heated to a temperature approaching the Curie temperature of the ferromagnetic rod. As Curie temperature is approached the rod becomes essentially non-magnetic heating decreases to produce a temperature below Curie temperature and the cycle repeats. As a result of the excellent heat exchange interfaces produced by fusion welding the energy delivered to the tissue or other load which may be non-biological is closely controlled by temperature which is self regulated. A ferromagnetic sleeve is placed about the coil to concentrate magnetic flux in the rod. An outer sleeve spaced radially from the ferromagnetic sleeve and of relatively non-heat conductive material extends from the base of the tip away from the tip to provide a handle for the instrument.