Metcal, Inc.

Minnesota Mining and Manufacturing Company

Mark J Cowell

Steven A Daniel

Thomas H McGaffigan

John F Krumme

David F Wirt

Philip S Carter, Jr

James M Taylor

Eric L Gay

Kevin Ladd

James C Swift

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.

Instrument for cutting, coagulating and ablating tissue

A Curie point heater primarily for use in a soldering iron and initially designed to operate with currents in the megahertz range is restructured to operate in the kilohertz range. Further in one embodiment of the heater, the coil exciting the heater is mounted in the handle of the iron.

Temperature self regulating heaters and soldering irons

A peak power measurement as a function of various system parameters is made to determine completion of a proper heating operation; in one embodiment by measuring peak power delivered to a level as a function of temperature within a specified time period for a specific load; and in another embodiment by the plot of peak power and ramp-up and ramp-down levels as a function of time.

Profiles to insure proper heating function

A thermal atherectomy catheter has a tip of high magnetic permeability cylindrical stem with an enlarged head at one end and an enlarged collar at the other end, a coil of wire wrapped about the stem adjacent the head and removed from said collar, a sleeve of ferromagnetic material disposed about the coil and a second sleeve of non-magnetic outer sleeve extending between and of the diameter of the head and collar to define a space between the sleeves whereby the outer sleeve to collar are maintained at a lower temperature than the head.

Thermal atherectomy device

A self regulating heater comprises a non-conductive, magnetic core having a coil wound about it and providing pole pieces extending into contact or very near contact with a surrounding ferromagnetic member which in turn may be surrounded by and in intimate contact with a non-magnetic low resistance member; the magnetic member having an effective Curie temperature at the temperature to be maintained.

Self regulating heater

Provided is a cartridge soldering iron having a hollow cylindrical handle, incorporating an internal coaxial socket assembly, a connection to a power supply, and a cartridge housing support, and a soldering tip bearing cartridge incorporating a tip, a heater assembly, a tubular housing and a coaxial socket assembly adapted to mate with the handle socket assembly in a wiping electrically conductive manner.

Cartridge soldering iron

A self-heating and self-soldering bus bar for use in many applications. The pins of the bus bar are quickly and directly heated to a predetermined autoregulated temperature without significantly raising the temperature of the body of the bus. Thusly a bus bar may be mounted while maintaining thermal balance and mechanical integrity of all work pieces. The present invention avoids the problems normally associated with excess thermal expansion experienced when a bus bar is heated incidental to the heating of its contact points. A majority of this incidental heating is eliminated by direct quick heating of the mounting pins.

Growing community of inventors

San Carlos, CA, United States of America

Mark J Cowell