Thermal cautery system
First Claim
1. A thermal cautery system comprising:
- a thermal cautery probe having a heat-transfer portion adapted to be placed in contact with tissue to be cauterized;
a diode mounted in said probe in thermal contact with said heat-transfer portion so that heat is transferred from said diode to said heat-transfer portion by conduction, said diode having a predetermined breakdown voltage at a predetermined temperature;
a pair of electrical conductors; and
a power supply connected to said diode through said electrical conductors, said power supply applying an output voltage to said diode that is substantially equal to the predetermined breakdown voltage of said diode at said predetermined temperature so that the current through said diode is substantially reduced as the temperature of said diode approaches said predetermined temperature.
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Accused Products
Abstract
A thermal cautery system having an endoscopically deliverable probe connected to a power supply and display unit. The power supply and display unit, when triggered by a footswitch, energizes a voltage regulator having a current limited output that supplies power to the probe. The current limiting function of the voltage regulator is disabled for a predetermined period that power is initially applied to said probe to minimize the heating time of said probe. The current through said probe is sensed and used to increase the voltage at the output of the voltage regulator as the current increases to compensate for the voltage drop in the conductors connecting the probe to the power supply. A manually selected portion of the sensed current through the probe is also integrated and used to terminate the flow of current through the probe when the integral of the current with respect to time has reached a predetermined value. A tone generator provides an audible indication when power is being applied to the probe and for a predetermined period thereafter to allow the probe to cool before the absence of the tone signals the removal of the probe from tissue being coagulated. The probe is heated by current flowing through an internal diode having a predetermined breakdown voltage at a predetermined temperature. The temperature of the probe is self-regulated by applying a voltage to the probe that is substantially equal to said predetermined voltage so that the current through the probe is reduced at said predetermined temperature.
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Citations
9 Claims
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1. A thermal cautery system comprising:
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a thermal cautery probe having a heat-transfer portion adapted to be placed in contact with tissue to be cauterized; a diode mounted in said probe in thermal contact with said heat-transfer portion so that heat is transferred from said diode to said heat-transfer portion by conduction, said diode having a predetermined breakdown voltage at a predetermined temperature; a pair of electrical conductors; and a power supply connected to said diode through said electrical conductors, said power supply applying an output voltage to said diode that is substantially equal to the predetermined breakdown voltage of said diode at said predetermined temperature so that the current through said diode is substantially reduced as the temperature of said diode approaches said predetermined temperature. - View Dependent Claims (2, 3, 4, 5, 6)
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- 7. A method of regulating the temperature of a thermal cautery probe having a diode in thermal contact with a heat transfer portion of said probe, said diode having a predetermined breakdown voltage at a predetermined temperature, said method comprising applying a voltage to said diode that is substantially equal to the predetermined breakdown voltage at said predetermined temperature so that the current through said diode is substanially reduced as the temperature of said diode approaches said predetermined temperature.
Specification