Patent ID: 6695837
Filing Date: 2004-02-24
Classification: A61B

Abstract:
A system for performing thermal cautery comprising:at least one group of thermal cautery devices, wherein each group of thermal cautery devices comprises a plurality of thermal cautery devices, wherein each of the thermal cautery devices in each group comprises a resistive heating element; a power supply capable of providing power to any particular thermal cautery device in each group, wherein the power supply further comprises a means for identifying a thermal cautery device, said means for identifying a thermal cautery device capable of identifying the group to which a particular thermal cautery device belongs when the particular device is electrically connected to the power supply, and wherein each of the thermal cautery devices is designed to operate with the power supply; wherein each thermal cautery device comprises an identification resistor electrically connected thereto, wherein the identification resistors within a particular group of devices have the same resistance, and wherein the identification resistors of the devices of one group have a distinct resistance from the identification resistors of the devices of all other groups; wherein the means for identifying a thermal cautery device comprises: a reference resistor placed in series with the identification resistor when the identification resistor is electrically connected to the power supply, said reference resistor also electrically connected to ground such that an identifying voltage develops across the reference resistor when power is applied to the system; a resistor ladder comprising a plurality of comparison resistors electrically connected to each other in a resistor ladder, said resistor ladder electrically connected to the power supply and to ground, wherein a corresponding plurality of reference voltages develops across the resistor ladder when power is applied to the system; a plurality of comparators, wherein the positive terminal of each of the plurality of comparators is electrically connected to the identifying voltage, wherein the negative terminal of a particular comparator is electrically connected to a particular reference voltage, and wherein each of the reference voltages is applied to the negative terminal of a corresponding comparator; wherein each particular comparator produces an output signal if the voltage at the positive terminal of the particular comparator is higher than the voltage at the negative terminal of the particular comparator; and wherein a combination of all comparator outputs uniquely identifies the group to which a particular thermal cautery device belongs when the particular thermal cautery device is electrically connected to the system and power is applied to the system.