Surgical instrument having self-regulating dielectric heating of its cutting edge and method of using the same
OwnerRobert F. Shawinventor
Life of this patent
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Abstract
The cutting edge of a scalpel blade is heated to an elevated preselected constant operating temperature for cutting tissue with simultaneous hemostasis by dielectric heating of the internal structure of the blade in the region along the cutting edge. Selective heating of regions of the cutting edge that are locally cooled by contact with tissues during surgical cutting is provided for by constructing the heating elements of the blade of ferroelectric materials that have a Curie point in the operating temperature range and that provide large increases in loss factor (the product of relative dielectric constant times the ratio of loss current to charging current) for temperature decrements below the Curie point.
Claims16
A blade comprising:
- a cutting means including a cutting edge and a dielectric means disposed in the region along said cutting edge for dissipating power in inverse relation to temperature over a portion of a temperature range, said power so dissipated being generated in response to an alternating electric field applied to said dielectric means;
- and
- electrode means disposed adjacent said dielectric means for applying said alternating electric field to said dielectric means.
A method of cutting using a blade having a cutting edge operating at an elevated temperature and a dielectric means disposed in the region along the cutting edge, said method comprising the steps of:
- establishing an alternating electric field within the dielectric means;
- and
- dissipating power in the dielectric means near the cutting edge in inverse relation to temperature over a portion of a temperature range, said power so dissipated being used to heat the cutting edge via dielectric losses associated with said alternating electric field established in the dielectric means.
The method of cutting as in clain 10 wherein the step of dissipating power, the dielectric material exhibits a Curie point about which a transition in loss factor with temperature occurs.
A surgical blade for cutting tissue with simultaneous hemostasis, said surgical blade comprising:
- a cutting means including a cutting edge and a dielectric means disposed in the region along said cutting edge for dissipating power in inverse relation to temperature over a portion of the temperature range between approximately 300.degree. C. and 1000.degree. C., said power so dissipated being generated in response to an alternating electric field applied to said dielectric means;
- and
- electrode means for applying said alternating electric field to said dielectric means.
Dependencies are inferred from the claim text.