Electrically heated surgical blade and methods of making
First Claim
1. A blade for use in a surgical instrument for hemostatically cutting tissue to reduce bleeding, the instrument including a handle having an electrical terminal, the blade comprising:
- a first region of a laminate material having a cutting edge and two lateral sides, the laminate comprising a core of a high strength hardenable material and a pair of outer layers of a material having a high thermal conductivity, each of the pair of outer layers disposed on opposite sides of the core and in thermal communication therewith;
a second region comprising a low thermal conductivity metallic material, the second region metallurgically joined to the first region at a longitudinal joint, the longitudinal joint being mechanically finished to provide a smooth surface, the second region having a portion adapted to engage the handle;
a heating element for heating the first region to a temperature in the range from about 100°
C. to about 500°
C., the heating element secured to first region in thermal communication therewith and electrically isolated therefrom; and
an electrical lead for connecting the heating element to the electrical terminal, the electrical lead disposed on the first and second regions and extending continuously across the longitudinal joint.
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0 Petitions
Accused Products
Abstract
A hemostatic surgical blade and methods of manufacturing such blades are provided, wherein the blade comprises a laminate region having a hardenable center layer and highly thermally conductive outer layers, joined to a second region of a low thermal conductivity material. A heating element is secured to the laminate region and in thermal communication therewith to thermally reform the collagen of tissue as it is incised. The heat generated by the heating element is conducted to the cutting edge of the blade to maintain the cutting edge temperature within 20° C. to 70° C. of a user-selected operating temperature. The second region reduces the conduction of heat to the handle of the instrument. The heating element comprises a thermally conductive dielectric layer attached to an outer surface of the laminate region, resistive conductive elements deposited on the dielectric, a second dielectric layer covering the resistive conductor elements, and an abherent coating disposed thereon to reduce coagulum buildup on the blade.
239 Citations
29 Claims
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1. A blade for use in a surgical instrument for hemostatically cutting tissue to reduce bleeding, the instrument including a handle having an electrical terminal, the blade comprising:
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a first region of a laminate material having a cutting edge and two lateral sides, the laminate comprising a core of a high strength hardenable material and a pair of outer layers of a material having a high thermal conductivity, each of the pair of outer layers disposed on opposite sides of the core and in thermal communication therewith; a second region comprising a low thermal conductivity metallic material, the second region metallurgically joined to the first region at a longitudinal joint, the longitudinal joint being mechanically finished to provide a smooth surface, the second region having a portion adapted to engage the handle; a heating element for heating the first region to a temperature in the range from about 100°
C. to about 500°
C., the heating element secured to first region in thermal communication therewith and electrically isolated therefrom; andan electrical lead for connecting the heating element to the electrical terminal, the electrical lead disposed on the first and second regions and extending continuously across the longitudinal joint. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A blade for a hemostatic surgical instrument comprising:
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a first region including a portion defining a cutting edge, the first region of a laminate comprising a core of a high strength hardenable material having lateral faces, and first and second outer layers of a high thermal conductivity material, each one of the first and second outer layers joined to one of the material faces of the core; a second region of a low thermal conductivity material welded to the first region at a longitudinal joint, the longitudinal joint mechanically finished to provide a smooth surface, the blade being heat treated while in blank form by passing it through a reducing atmosphere at an elevated temperature and then being cooled to obtain a high hardness level in the core of the first region; a first layer of a high expansion dielectric material coated on the first and second regions, the first layer having a thermal expansion coefficient in the range of the thermal expansion coefficient of one of the pair of outer layers of the first region and the low thermal conductivity material of the second region; a resistive conductor material deposited in a first pattern of the first layer of dielectric material so that the first pattern is superimposed over the first region, the resistive conductor material having a specific sheet resistance in the range of from about 10 to about 50 milliohms per square mm at 20°
C.;a conductor material deposited in a second pattern on the first dielectric layer superimposed over the second region, the second pattern overlapping the first pattern of first dielectric material so that the resistive conductor material and the conductor material are in electrical contact; and a second layer of dielectric material deposited over all of the first pattern and the second pattern except for a portion adapted for completing an electrical contact between the conductor material and the hemostatic surgical instrument. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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Specification