JPH0538722Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention consists of an electrode that is provided on the front surface of the tip of the catheter body guided into the heart chamber and that contacts the endocardial surface, and an electrode that is placed on the circumferential surface of the tip. The present invention relates to a MAP (Monophasic Action Potential) catheter that detects the action potential of a pair of myocardial cells with an electrode that is provided and positioned within the heart chamber.

[Conventional technology]

This type of push-type MAP catheter has recently begun to be developed as an alternative to the suction-type catheter, which can damage the endomyocardium during long-term measurements and is complicated in operation and structure.

Figure 5 shows such an electrode.
-Although AgCl is used, it is lumpy, and one electrode 1 with a spherical tip surface partially protrudes from the tip of the catheter body 2, and the other electrode 3 pierces the tip circumferential surface 2a. Cement 4
It was formed by solidifying it. Further, the guiding operation of the MAP catheter was performed using a guide wire 5 specially inserted into the sheath 6.

[The problem that the idea aims to solve]

For this reason, expensive Ag had to be used in a corresponding amount, and there was also a concern that the perforations 2b in the peripheral surface 2a of the distal end would become clogged with foreign matter, resulting in poor blood contact with the electrodes. Furthermore, in consideration of manufacturing convenience, it is preferable that the catheter main body also functions as a guide wire.

Therefore, an object of the present invention is to provide a guide wireless MAP catheter of the type mentioned at the beginning, which uses less Ag and has high measurement reliability.

[Means to solve the problem]

In order to achieve this objective, the present invention was developed in such a way that, although the contact area with the endocardium can be increased by forming a block as in the past, since the polarization voltage increases accordingly, the apparent contact resistance increases. After confirming this, I configured it as follows.

That is, Ag-AgCl wires are protruded as a pair of electrodes from the front surface and the circumferential surface of the distal end of the catheter body, which is directly guided at the rear end, and
A lead wire is followed by each wire and led out from the rear end of the catheter body, and the Ag is attached to the distal end of the catheter body.
- An insulating catheter closure part was provided to fix the non-protruding part of the AgCl wire in a sealed state, and an elastic body was inserted behind this catheter closure part.

[Effect]

The catheter body is guided into the heart chamber along the blood vessel with a certain degree of flexibility with a predetermined stiffness by direct manipulation at its rear end. And Ag−AgCl
The protruding part of the lead from the front of the catheter tip contacts the intracardial wall as one electrode, the protruding part from the circumferential surface of the tip is positioned within the heart chamber as the other electrode and comes into contact with blood, and the rear end of the lead wire Detect action potentials from In this case, the elastic body behind the catheter closure serves as a buffer against excessive pressing forces on the catheter body.

[Example of idea]

FIG. 1 shows a MAP catheter 9 according to an embodiment of the present invention, in which a catheter body 10 made of a polyurethane synthetic resin tube with a diameter of, for example, 2 mm has a woven Dacron 15 inserted therein, and the center of the front end 10a of the distal end thereof. From the position, Ag-AgCl wire 11 with a wire diameter of 0.3 mm, which is an Ag wire plated with AgCl.
However, one electrode of approximately 0.5 mm is made to protrude as it is. For example, 5mm from the front of this tip.
Ag-
Similarly, the AgCl wire 12 is made to protrude by about 0.5 mm in the orthogonal direction. This distal end region of the catheter body 10 is filled with epoxy cement 13 as a catheter closure part and connected to the Ag-AgCl wire 1.
1 and 12 are fixed in position, and their non-protruding portions are completely sealed to prevent blood from entering, and the protruding portions 11a and 12 of the Ag-AgCl wires 11 and 12 are
A pair of electrodes 21 and 22 are formed by forming substantially hemispherical surrounding portions 13a and 13b around the epoxy cement 12a.

Ag-AgCl wires 11 and 12 are epoxy cement 1
It is guided along the inner wall of the catheter body 10 from the filled part 3, and led out from the rear end of the catheter body 10 through the inside of the woven Dacron 15 with conducting wires 11b and 12b following along the way. The catheter body 10 has a length of about 1 to 1.5 m, but the first
The figure shows only the main part at the front. Silicone rubber 14 is filled as an elastic material over an area of, for example, 30 mm between the catheter body 10 and the woven Dacron 15 at the rear of the portion filled with the epoxy cement 13. In this way, the catheter body 10 into which the woven Dacron 15 is inserted is
It is flexible and is formed so that pressing force and rotational force generated by direct manipulation at the rear end are transmitted to the tip.

During measurement, the MAP catheter 9 is directly operated at the rear end in this way, and is guided into the blood vessel and inserted into the heart chamber. In particular, since the electrode 21 includes the hemispherical surrounding portion 13a, the protruding portion 11a extends along the spherical surface.
The slightly exposed portion of the tube is guided and brought into contact with the endocardium. Further, since the electrode 22 also includes the hemispherical surrounding portion 13b, the catheter 9 can be smoothly guided into the heart chamber without being damaged. When the side electrodes 22 are positioned in the heart chamber, the exposed portions of the protruding portions 12a of the side electrodes 22 protrude from the circumferential surface of the catheter body 10.
Unlike the case of the side electrode 3 in FIG. 5, the foreign matter does not adhere to the electrode 3 and the electrode 3 reliably contacts the blood.
Woven Dacron 15 and Epoxy Cement 13
By interposing the silicone rubber 14 in between,
It expands in response to excessive pressing force during operation, cushioning the impact, and ensuring safety.

Action potentials at the measurement site supplied from conductive wires 11b and 12b led out from the rear end (not shown) of the catheter body 10 are amplified in an output device and recorded on recording paper, and are also monitored on a cathode ray tube if necessary. Ru. It is safe to perform measurements at one location or multiple locations over a long period of time, and the polarization voltage can be suppressed to a small amount, making it possible to achieve not only high sensitivity but also high fidelity.
Enables detection of MAP waveforms.

FIG. 3 shows another embodiment, in which the same reference numerals as in FIG. 1 indicate the same parts.

That is, in the MAP catheter 9, ring-shaped electrodes 25 and 26 made of stainless steel or platinum and having a width of, for example, 1 mm for pacing are embedded in the catheter body 10 by cutting out the peripheral surface of the distal end thereof so as to be flush with each other. And lead wires 25a, 26 on the inner surface.
A is connected and led out from the rear end of the catheter body 10 so that it can be connected to a pacing device, thereby forming a MAP catheter with a pacing electrode. As a result, MAP measurement is performed with a single catheter while performing pacing and sensing as necessary, and local myocardial activity status in response to changes in heart rate can also be precisely monitored.
Moreover, since the ring-shaped electrodes 25 and 26 can be brought closer to the electrodes 21 and 22 by integrating, higher precision can be achieved.

FIG. 4 shows still another embodiment, in which the catheter body 2 is shown in a schematic side view in FIG.
0, the area A from the tip is approximately 50 mm and is previously formed into a curved shape. The catheter main body 20, including the hemispherical surrounding portions 20a and 20b, is integrally molded from the same synthetic resin material in which electrodes and lead wires are embedded from the tip to the distal end. As shown in the enlarged cross-sectional view in Figure b, the protruding portion 11 of the AgCl wire at the tip
Exposed portion 11c from the hemispherical surrounding portion 20a of a
are rounded for greater safety.

In addition, in the above-mentioned examples, Ag-
Hemispherical surrounding portion 13a, 1 of the protruding portion of the AgCl wire
Even if 3b is abolished, the intended purpose will still be achieved. The pacing electrode has a ring shape to ensure contact, but in some cases it can also have a point shape. A variety of catheter bodies without a guide wire can be formed by considering the material and structure on the premise that direct guidance operation at the rear end is propagated.

[Effect of idea]

As described above, according to the present invention, the amount of Ag used can be reduced,
Furthermore, it is possible to detect myocardial action potentials with higher sensitivity and higher fidelity while generating only a small amount of polarization voltage. In addition, since it is a pressing type and the side electrodes are of a protruding needle type, there is no problem of foreign matter adhering to the electrode surface, making it possible to carry out measurements over a longer period of time.

The elastic body behind the catheter closing portion can reliably prevent mistakes such as perforation of the endocardial wall due to excessive pressing force applied to the catheter body, and is particularly effective when the tip electrode is needle-shaped.

Furthermore, by adding a pair of pacing electrodes to the circumferential surface of the catheter tip, highly accurate MAP measurement in a pacing state is possible with a single catheter.

With such a practical MAP catheter, it is expected that clinical applications for heart diseases will become more active.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the main parts of a MAP catheter according to an embodiment of the present invention, Fig. 2 is a front view of the tip of the catheter main body of the same embodiment, and Fig. 3 is a MAP catheter according to another embodiment of the present invention. Main part sectional view, 4th
The figure shows a MAP catheter according to yet another embodiment of the present invention, and FIG. 5 is a sectional view of a main part of a conventional MAP catheter. 9...MAP catheter, 10, 20...Catheter body, 10a...Tip front, 10b...
Tip peripheral surface, 11, 12...Ag-AgCl wire, 11
a, 12a...Protruding portion, 11b, 12b, 25
a, 26a... Lead wire, 13... Epoxy cement, 13a, 13b, 20a, 20b... Surrounding part, 14... Silicone rubber, 15... Woven Dacron, 21, 22... Electrode, 25, 26... Ring-shaped electrode.

Claims (1)

[Claims for Utility Model Registration] 1) Ag-AgCl wires are made to protrude as a pair of electrodes from the front surface and the circumferential surface of the distal end of the catheter body, which is directly guided at the rear end, and a lead wire is attached to each of the wires. Subsequently, the Ag is guided out from the rear end of the catheter main body, and the Ag
- A MAP catheter characterized in that an insulating catheter closing part is provided to fix the non-protruding part of the AgCl wire in a sealed state, and an elastic body is inserted behind the catheter closing part. 2) A pair of electrodes for pacing are added to the circumferential surface of the distal end of the catheter body.
MAP catheter.