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Cauterizing hemostatic equipment

  • US 4,759,362 A
  • Filed: 04/21/1987
  • Issued: 07/26/1988
  • Est. Priority Date: 11/28/1984
  • Status: Expired due to Term
First Claim
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1. A cauterizing hemostatic device comprising:

  • a probe adapted to be inserted into a body cavity through a channel provided in an endoscope for insertion of a treating tool, said probe having at a front end (12) thereof a semiconductor heating element (22) of small heat capacity which has an electron avalanche characteristic, a voltage drop across said heating element at a constant current being dependent on the temperature thereof; and

    a current supply circuit connected to said heating element through a rear end connector of said probe, said current supply circuit including a constant current circuit means (21) for applying a constant heating current to said heating element at a set current level, and a heating control circuit means (23) connected to said constant current circuit means (21) for adjustably setting and controlling said level of constant current applied to said heating element (22);

    said current supply circuit constant current circuit means (21) including a first resistance means (21r1, ra) connected in series with said heating element (22) and a transistor (21b) such that a voltage across said first resistance means varies in proportion to variations in said applied heating current, a reference voltage source (23r4), and a voltage regulator (21a) to compare said first resistance means voltage with voltage of said reference voltage source and to control current through said first resistance means (21r1, ra) so as to apply a constant current to said heating element; and

    said heating control circuit means (23) including a second resistance means (23r1) connected in series with said transistor (21b), said first resistance means (21r1, ra) and said heating element (22), and a comparator (23a) connected to both ends of said second resistance means (23r1) to compare a voltage drop of said second resistance means with a voltage of said reference voltage source (23r4), an output of said comparator (23a) being connected to said transistor (21b) to control current therethrough so that, by positive feedback of the heating current as measured by the voltage drop across said second resistance means (23r1) the level of constant current from the constant current circuit means (21) will be set to make the sum of the voltages of the heating element (22) and the first resistance means (21r1, ra) constant such that heating current will be increased with an increase of heat dissipation within said body cavity to maintain the temperature of said heating element (22) constant.

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