ELECTRICALLY HEATED SURGICAL CUTTING INSTRUMENT
First Claim
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1. A surgical instrument for cutting tissue with simultaneous hemostasis, the instrument comprising:
- a blade-shaped support wafer of electrically insulating material having disposed thereon an electrically heatable element of electrically conductive material having a resistance which varies as a function of the temperature thereof, the element including a plurality of sections which form segments or portions of a tissue-cutting edge of said support wafer, each of said sections conducting electrical current along said edge for directly heating the edge; and
connection means providing electrical connections to each of said sections for independently supplying electrical power thereto for maintaining the resistance of each of said sections at a substantially constant selected value.
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Abstract
A surgical cutting instrument includes an electrically heated cutting edge and an automatic control system for maintaining the cutting edge at a constant high temperature for sterilizing the blade, cutting tissue, and cauterizing the incised tissue to reduce hemorrhage from the cut surfaces of the tissues (hemostasis).
243 Citations
3 Claims
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1. A surgical instrument for cutting tissue with simultaneous hemostasis, the instrument comprising:
- a blade-shaped support wafer of electrically insulating material having disposed thereon an electrically heatable element of electrically conductive material having a resistance which varies as a function of the temperature thereof, the element including a plurality of sections which form segments or portions of a tissue-cutting edge of said support wafer, each of said sections conducting electrical current along said edge for directly heating the edge; and
connection means providing electrical connections to each of said sections for independently supplying electrical power thereto for maintaining the resistance of each of said sections at a substantially constant selected value.
- a blade-shaped support wafer of electrically insulating material having disposed thereon an electrically heatable element of electrically conductive material having a resistance which varies as a function of the temperature thereof, the element including a plurality of sections which form segments or portions of a tissue-cutting edge of said support wafer, each of said sections conducting electrical current along said edge for directly heating the edge; and
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2. A surgical instrument as in claim 1 comprising:
- means for each of said sections operatively coupled thereto for sensing the electrical resistance of the corresponding section;
circuit means for each of said sections having an input for receiving electrical current from a source and being responsive to the electrical resistance of the corresponding section of said element for altering the electrical power supplied through said connection means to the corresponding section from the signal received at said input to maintain the temperature of the corresponding section substantially at a preselected value independent of the temperature of another section of said element.
- means for each of said sections operatively coupled thereto for sensing the electrical resistance of the corresponding section;
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3. A surgical instrument as in claim 2 wherein each of said circuit means comprises a plurality of circuit elements and said corresponding section connected in a bridge circuit having first and second pairs of bridge terminals, and including control means coupling said input to the first pair of bridge terminals, and bridge-balance sensing means connected to the second pair of bridge terminals and to said control means for altering the electrical power applied through the bridge circuit to said corresponding section for maintaining the resistance thereof substantially at a preselected value.
Specification