VASCULAR COAGULATION FORCEPS

Abstract

A surgical, vascular coagulation forceps (1) comprising two mutually displaceable jaws (3, 4) bearing flat electrodes (12, 13) connected to different terminals of an hf source (16), or one of said jaws being fitted with an ultrasonic oscillator, characterized in that a coil unit (18) connected to an eddy current sensor (20) is mounted on at least one of the jaws (3, 4).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sideview of a bipolar forceps fitted with an eddy current sensor, and

FIG. 2 is a section along line 2-2 of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

In a much simplified embodiment mode, the Figures show a bipolar forceps 1 with two jaws 3, 4 which extend proximally into handles 5, 6 and are articulating with each other by a pivot pin 7. The forceps also may be designed with another kind of pivot, to form a laparoscopic stem forceps while retaining essentially the same jaws 3, 4.

The two forceps elements 3, 5 and 4, 6 shown in the present embodiment are entirely metallic. Electrically insulating plates 10, 11 rest on the engaging surfaces 8, 9 that are displaced toward each other when the forceps 1 is closing and in turn support metal electrode plates 12, 13 connected by electrical conductors 14, 15, installed at the jaws 3,4 and the handles 5, 6, to the two terminals of a high frequency source 16.

As shown in FIG. 1, the bipolar forceps 1 is used to seal a blood vessel, for instance an artery 17 shown sectionally in FIG. 1. As further shown in FIG. 1, the artery is seized between and squeezed by the jaws 3, 4 of the forceps 1 until its lumen has been closed. Thereupon and while maintaining the sealing compression, the hf source is turned ON and a current passes between the electrode plates 12 and 13 through the tissue of the artery 17. This current heats and coagulates the said tissue.

After a given time, coagulation has progressed enough that the superposed artery surfaces have fused into each other and the artery henceforth shall stay closed even in the presence of substantial internal pressure. At this time the hf current may be turned OFF and the forceps 1 may be released. Using separate scissors or an omitted cutting element on the bipolar forceps 1, the artery now can be severed at the center of the zone of coagulation.

The progressing coagulation is monitored at the shown bipolar forceps 1 in order to attain optimal coagulation and optimal mechanical tissue strength.

For that purpose a coil 18, which rectangularly encloses the electrode plate 12 and rests on the electrically insulating plate 10, is mounted on the jaw 3 and is connected by a two-conductor cable 19 to an eddy current sensor 20.

The eddy current sensor 20 transmits through the cable 19 an AC current into the coil 18. Said coil generates an AC magnetic field which in turn generates eddy currents about said coil's axis that is perpendicular to the gripping surface 8, said eddy currents being situated in the zone of coagulation, that is in the tissue of the artery 17. These eddy currents influence the current in the coil 18. This phenomenon can be measured by appropriate elements in the eddy current sensor 20. The inductive reaction foremost depends on the electrical conductivity of the arterial tissue, which in turn depends foremost on the tissue's water content. Said water content drops as coagulation progresses, whereby the eddy current sensor 20 is able to monitor said progress and display it (omitted).

In the embodiment mode shown, a coil 18 is connected by a two-conductor cable 19 to the eddy current sensor. A double-coil unit also may be used, wherein the coil 18 consists of two superposed coil parts each connected by a two-conductor cable to the eddy current sensor 20. One of these coil elements may be a generator coil and the other the sensing coil. Sensitivity of measurement may be increased in this manner. The coil unit 18 moreover may contain still other coil elements used for compensation.

In the shown embodiment mode, the tissue of the artery 17 is heated by an hf current. In another, omitted embodiment mode, the forceps also may heat said tissue ultrasonically. For that purpose one of the electrode surfaces 12, 13 may be designed as the surface of an ultrasonic oscillator which is fed from an ultrasonic generator at one of the handles 5, 6 for instance by means of an ultrasonic guide. The eddy current sensor may be designed in this instance in the manner discussed in relation to the shown bipolar forceps.

Claims

1. A surgical, vascular coagulation forceps (1) comprising: two mutually displaceable jaws (3, 4) bearing flat electrodes (12, 13);said flat electrodes (12, 13) being connected to different terminals of an hf source (16), or one of said jaws being fitted with an ultrasonic oscillator, andwherein a coil unit (18) connected to an eddy current sensor (20) is mounted on at least one of the jaws (3, 4).

2. Forceps as claimed in claim 1, wherein the coil unit (18) is configured parallel to the gripping surface (8) of a jaw (3).

3. Forceps as claimed in claim 2, wherein the coil unit (18) encloses the electrode (12).