JP2002143322A - Manufacturing method for medical lead - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method improving flexibility of a lead applied to a catheter or the like. SOLUTION: A long lead body 12 of the electrophysiological lead 10 for detecting electroactivity in the body of a patient or applying electric energy to a selected tissue of the body is composed of a polymer. Coil-wound electric wires 18, 20, 22, 24, 26 are embedded inside the lead body 12 along the longitudinal direction of the lead body 12. The wires 18, 20, 22, 24, 26 are electrically connected to electrodes 30, 32, 34, 36, 38 in a distal end 16. The electrodes 30, 32, 34, 36, 38 are configured by laminating an innermost layer 40, a second layer 42, a third layer 44 and an outmost layer 46 from the lead body 12 side. Wall thicknesses of the electrode 30, 32, 34, 36, 38 are not more than about 5 μm. The electrodes 30, 32, 34, 36, 38 don't hinder the bending of the electrophysiological lead 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a medical lead applied to a catheter or the like, and more particularly, to a method for improving the flexibility and followability of a medical lead in a body. It relates to a manufacturing method.

[0002]

2. Description of the Related Art As one of the treatment methods for various arrhythmias, there is known a method in which heart tissue is cauterized at an appropriate site to block a deformable reentrant conduction path. In a normal heart, the sinus node in the right atrium is periodically depolarized, causing radio waves to be transmitted to the atrioventricular node. This radio wave is further transmitted to the left and right legs via the bundle of His, resulting in the coordinated contraction of the ventricles. Arrhythmias, such as atrial fibrillation, atrial flutter, and tachycardia, are often associated with electrical stimuli resulting in depolarization of the sinoatrial node as reentrant pathways from the ventricles into the normal transmission system of the heart This is caused by a false signal being sent to the atrioventricular node.

[0003] When treating these arrhythmias, so-called electrophysiological mapping or ablation electrophysiological therapy is used. That is, first, a catheter having a detection and ablation electrode at a distal end is introduced into a predetermined heart cavity of a patient via a vascular system. The catheter is operated such that the electrodes contact the myocardial tissue to be detected and ablated.

[0004] Detection and ablation are performed through the endocardial surface and through coronary veins or arteries. Mapping is performed to locate deviating pathways and / or focal lesions, where cardiac depolarization signals detected at the electrodes are monitored and analyzed via conductive lines in the leads. Transmitted to the device. After the location of the degenerative reentrant pathways and localized lesions is identified, the electrodes are contacted with the predetermined myocardial tissue to be ablated. Next, for example, a power supply such as a high-frequency power supply connected to the pair of electrodes is activated, thereby performing ablation and cutting off the deformable reentrant conduction path. Or, local lesions are removed.

[0005] The use of catheters for mapping and ablation in treating arrhythmias is discussed in "Catheter Ablation of Atrioventricular Bifurcations with High-Frequency Energy" (Randberg et al., Circulation, Vol. 80, No. 6, pp. 6-35). , December 1989), "High-frequency catheter ablation of atrial arrhythmias" (Resh et al., Circulation, Vol. 89, No. 3, March 1994), "Radiofrequency ablation of atrial tissue in general atrial flutter." Effects "(Kilkorian et al., Naspe, May 1993). Also,
The use of catheters with electrodes to ablate sites within the heart chamber has been disclosed in U.S. Pat. Nos. 4,641,649, 4,892,102, and 5,025,78.
No. 6 discloses it.

[0006] Regarding the electrode configuration of such a catheter, various types have been disclosed. For example, in U.S. Pat. No. 5,676,662 to Flyshhacker et al., A conductive wire is helically wound around an elongated polymeric catheter body, and certain portions of the helix are uncoated, i.e., metal Is exposed to form the electrode surface.

[0007] Also, US Pat.
No. 582,609, separate conductive wires are spirally wound near the distal end of a long and flexible plastic catheter. Here, the reason for spirally winding is to provide the catheter with flexibility so that the catheter can be reliably brought into contact with the surface of the tissue to be cauterized.

Further, in US Pat. No. 5,558,073 to Pomerants et al., The electrodes consist of a metal ring mounted on the outer periphery of the catheter body. In this case, a plurality of conductive wires pass through the lumen of the catheter body, and the metal ring is electrically connected to the terminal located at the proximal end of the catheter body by these conductive wires. Electrodes consisting of metal rings are also disclosed in U.S. Pat. No. 5,487,757 to Trukkai et al.

In these techniques, the electrodes are preformed metal rings. The electrode is attached to the outer surface of the catheter body by gluing, crimping or other method with an adhesive, and is electrically connected to a terminal located at a proximal end by a conductive wire passed through a plurality of lumens of the catheter body. Connected to.

[0010]

By the way, this kind of metal ring is generally large in thickness and, therefore, high in rigidity. Therefore, when about ten electrodes having such shapes and characteristics are mounted on the distal end of the catheter body, for example, at a distance of 1 cm from each other, the flexibility of the distal end is reduced. For this reason, it becomes difficult to bend the catheter, and eventually it becomes difficult to contact the electrode with the tissue to be mapped or cauterized.

To maintain the flexibility of the catheter,
It is envisaged to form an electrode consisting of a thin metal film on the surface of the polymer making up the catheter body. However, in this case, there are the following problems. That is,
First, the metal thin film is easily fixed to the flexible portion of the polymer substrate. Next, since the surface of the metal thin film is oxidized by air, the bonding property of the metal thin film itself is not good. In addition, since cracks occur in the metal thin film, the conductivity decreases,
So-called "spark gaps" occur, in which sparks fly between cracks. Further, when microcracks exist inside the metal thin film, the thickness of the metal thin film is 1 mil (25.4 μm).
If it is less than m), the heat capacity will be insufficient, and heat will be accumulated in the metal thin film. Furthermore, when the metal thin film has a columnar structure, when it is stretched in the longitudinal direction, an intrinsic stress is generated in the metal thin film.

[0012] For the above reasons, it is excellent in flexibility, and can be freely changed in shape so as to be in good contact with the inner surface of the body cavity. Despite its advantages, such as being difficult and thus having a very small energy loss, electrodes made of a metal thin film have not yet been put to practical use in medical leads and catheters.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a method for manufacturing a medical lead having a significantly superior flexibility as compared with a conventional mapping and ablation catheter. With the goal.

[0014]

In order to achieve the above object, the present invention provides a method for manufacturing a lead body having at least one conductor and having an outer surface, and forming at least two layers by film formation. Laminating the metal thin film layers and bonding the at least two metal thin film layers to each other by applying an impact to the metal thin film layers with accelerated ions.

In summary, the present invention supports at least one conductor having a proximal end and a distal end, extending from the proximal end to a predetermined location near the distal end of the lead body, At least one electrode is formed on the outer surface of a long and flexible polymer lead body. The electrode is a conductive pad formed by laminating a plurality of metal thin film layers. The thickness of the electrode can be 5 to 250 μm,
It is preferably 0 μm.

When the electrode has such a small thickness, it is possible to prevent the flexibility of the entire distal end of the lead body from being impaired. That is, a lead that can be easily bent can be configured. Furthermore, by appropriately selecting the shape and arrangement of the electrodes, the electrodes can be satisfactorily adhered to the tissue.

The medical lead manufactured in this manner can be used, for example, for measuring and treating electrical activity in the body of a patient.

That is, according to the present invention, an electrode for a catheter used for mapping and ablation and a catheter used for other electrophysiological applications is constituted by an electrically conductive thin metal film without causing the above-mentioned problems. can do.

Further, since the thickness of the electrode is small, it can be easily bent. For this reason, it is possible to securely adhere to the tissue surface to be mapped and cauterized. Moreover, in this case, the performance as an electrode is not impaired.

The electrodes can be attached to the lead body in various forms. For example, the shape may be concentric, long linear plate, or discontinuous point. The lamination thickness of the electrodes may be, for example, about 5 μm or less.

Of course, the electrodes are connected to electrical conductors, by which signals of the heart depolarization (electrocardiogram) and other nerve impulses captured by the electrodes are transmitted to the analytical instrument. In addition, when performing treatment, in the case of a bipolar lead, a high-frequency voltage is applied between the electrodes of the lead body. On the other hand, in the case of a monopolar lead, a high-frequency voltage is applied between an electrode of the lead body and a human body electrode or a return electrode.

The first metal thin film layer (innermost layer) which is in direct contact with the polymer substrate (lead body) is not particularly limited, but can be made of titanium, chromium, aluminum or nickel. . The thickness of this innermost layer is typically less than about 5 μm.

In order to improve the bonding strength of the innermost layer to the polymer substrate, high energy ions are bombarded in parallel with the film formation. Thereby, the innermost layer is shot-peened on the surface of the polymer substrate. Also,
The structure of the innermost layer changes continuously as if the flat plates in the amorphous, columnar, and nanocrystalline states were stacked. Here, “nanocrystal” means that the metal layer has a myriad of minute plate-like structures (crystals).

The parallel irradiation of such high energy ions is performed by ion beam assisted deposition (IonBeam Assisted Dep.).
osion) is called “IBAD”. Also, instead of IBAD, ion beam enhanced deposition (Ion Beam Enhanced Deposition) for irradiating an ion beam after forming a metal layer, that is, “IBE”
D "may be adopted.

The second metal thin film layer is formed after the innermost layer is formed. The constituent material of the second metal thin film layer is
If the thickness is 1000 ° or less of palladium or platinum, the second metal thin film layer functions as a self-alloying / oxygen diffusion barrier layer. Also in this case, it is preferable that the film is formed in the presence of high energy ions, whereby the bonding between the innermost layer and the second metal thin film layer is promoted, and a preferable non-columnar structure in which no stress remains is obtained. .

Next, a third metal thin-film layer having a predetermined thickness is formed, which mainly functions as a conductive layer. The third metal thin film layer is made of platinum, silver, or an element or alloy having a similar conductivity. Its thickness is 500 ~ 50
μm range, but 0.5-5.0 μm
It is preferably within the range of m. When applied to ablation, to transmit high-frequency electrical signals, a third
The thickness of the metal thin film layer of 2.0 to 3.0 μm is sufficient. The flexibility of the catheter is not impaired even when the thickness of the third metal thin film layer reaches 250 μm.

Finally, a fourth metal thin film layer which is a conductive layer having biocompatibility is laminated on the third metal thin film layer.
As the constituent material of the fourth metal thin film layer, various metals can be adopted, but gold is preferable because it is flexible and, therefore, stress is hardly concentrated. The thickness of the fourth metal thin film layer can be 1000 ° or less, but may be in the range of 500 ° to 50 μm.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a method for manufacturing a medical lead according to the present invention will be described below in detail with reference to the accompanying drawings.

First, the medical lead will be schematically described.

FIG. 1 shows an electrophysiological lead 10.
The use of the electrophysiological lead 10 is not particularly limited, but can be used to treat heart disease. That is, the patient's heart chamber is mapped,
It can be used to treat certain arrhythmias by locating degenerative reentrant pathways and focal lesions and cauterizing tissue accordingly.

It is also possible to use the electrophysiological lead 10 for treating neurological diseases, for example, by performing intracranial mapping and applying stimulation to the deep brain. It can be used for treatment or for treating chronic pain by providing an electrical stimulation impulse by placing it in a sheath lumen around the spinal cord. Further, it can be used in combination with an extracorporeal or implantable pulse generator or defibrillator.

The catheter or electrophysiological lead 10
Comprises an elongated lead body 12 made of a highly flexible polymer having a proximal end 14 and a distal end 16. The lead body 12 can be manufactured by extruding various polymers. In the present embodiment, polytetrafluoroethylene (PTFE), polyethylene terephthalate (PET), polyvinyl chloride (PVC),
Use of polytetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), expanded polytetrafluoroethylene (e-PTFE), polyethylene, silicone rubber, polyurethane, polyamide, polyimide, fluorinated ethylene propylene (FEP), etc. Can be. Further, a mixture thereof or a polymer alloy may be used. By selecting a polymer, the extrudability and the flexibility of the lead body 12 can be adjusted.

As shown in FIG. 2 which is an enlarged cross-sectional view taken along the line II-II in FIG. 1, small coiled electric wires (conductors) 18, 20, 22, 24 and 26 are provided inside the lead body 12.
Is embedded. These coiled electric wires 18, 20,
22, 24, 26 are made of a multi-core wire made of stainless steel, platinum, platinum-iridium or copper, and are disposed near the distal end 16 of the catheter body 12 from the terminal 28 disposed at the proximal end 14 of the lead body 12. Electrodes 30, 3
2, 34, 36, and 38, and electrically connect them to each other.

In FIG. 2, the coil-wound electric wires 18, 20, 2 are embedded inside the polymer constituting the lead body 12.
2, 24, 26 are embedded, but fine ribbon-shaped conductive wires spirally wound along the outer surface of the lead body 12 are electrically connected to the electrodes 30, 32, 34, 36, 38, respectively. You may do so. Preferred constituent materials of the ribbon-shaped conductive wire include Al, Ag, Au, Pd, Ti, and C.
r, Ni, Pt, Pt-Ir, Cu, alumel, chromel, constantan, and alloys thereof. In this case, the ribbon-shaped conductive wire may be covered with an insulator except for portions connected to the electrodes 30, 32, 34, 36, and 38 arranged near the distal end 16.

The diameter of the lead body 12 depends on the application and is not determined uniquely. For example, if used for neurology or myocardial mapping or ablation,
It is set to about 3 French size, and for other uses,
The size is set to about 8 to 12 French size.

The electrodes 30, 32, 34, 36, and 38 have a multilayer structure formed by sequentially depositing a metal thin film on the outer surface of the lead body 12. At the time of film formation, masking is appropriately performed.

As shown in FIG. 3 which is an enlarged cross-sectional view taken along line III-III of FIG. 1, and FIG. 4 which is an enlarged cross-sectional view taken along line IV-IV of FIG. , Also referred to as the innermost layer) 40 is formed directly on the lead body 12 and its thickness is set to about 5 μm or less. The constituent material of the innermost layer 40 is preferably titanium, chromium, aluminum or nickel. As described later, the innermost layer 40 is formed by irradiating a metal with high-energy ions to form a polymer base material (lead body 12).
A film is formed thereon (IBAD method). When a film is formed in the presence of impact ions, the metal thin film is shot-peened in the polymer substrate, so that the bonding force of the innermost layer 40 to the polymer substrate becomes large. Further, the first metal thin film layer 40 is made amorphous,
The structure continuously changes to a columnar structure or a structure having higher crystallinity, and a state is obtained in which the respective flat plates are stacked.

The IBED method may be performed instead of the IBAD method.

After the innermost film 40 is condensed and solidified on the polymer substrate, a second metal thin film layer (hereinafter referred to as
A second layer 42 is also formed. Also at this time, high energy ions are irradiated to the target region, that is, the portion where the electrode is formed. The thickness of the second layer 42 is 500
The thickness may be よ く to 50 μm, and the constituent material is preferably palladium or platinum. This second layer 42
Functions as a self-alloying oxygen diffusion barrier layer. That is, adhesion of a third metal thin film layer (hereinafter, also referred to as a third layer) to be formed next is prevented, and generation of an oxide which also functions as an electrical insulating material is suppressed. The high-energy ions promote the bonding of the innermost layer 40 and the second layer 42 to each other and, as in the case described above, do not concentrate the stress.
Provides a non-columnar preferred structure.

After the second layer 42 is formed, the third layer 44 is formed by performing the IBAD method or the IBED method again. The third layer 44 is a layer that conducts electricity, and has a substantially larger thickness than the innermost layer 40 and the second layer 42.

Preferable examples of the constituent material of the third layer 44 include platinum, silver, gold and copper. These are also good heat carriers.

The thickness of the third layer 44 is about 2 to 250 μm.
m. As described above, the third layer 44 includes the innermost layer 40.
And the second layer 42 can be formed.
It is necessary to have a thickness capable of transmitting an electric signal to be used. This thickness differs depending on the application. For example, when a DC current is applied to map the heart chamber, the thickness is set relatively small. On the other hand, when performing ablation using high-frequency energy, a relatively large thickness is required.

Finally, the fourth metal thin film layer (hereinafter also referred to as the outermost layer) 46 is formed in the presence of high energy ions which bombard the target region during or after the third layer 44 is formed. To form a film. The outermost layer 46 functions as a biocompatible conductive layer.

As the constituent material of the outermost layer 46, the radiating power is high, the thermal characteristics are excellent, and the electrodes 30, 32, 34, 3
It is necessary to have high conductivity so that thermal mismatch does not occur over the entirety of 6, 38. As such a material, various metals can be cited, but since it has good conductivity, has flexibility, and the internal stress in the film formed by this method is extremely low, Gold or platinum is preferred. Electrophysiological lead 10 through an introducer catheter or guide catheter not shown
In the case where the introduction and derivation of
May be made of Pt-Ir which has higher hardness and higher wear resistance than gold.

The thickness of the outermost layer 46 is, for example, 500 to
It can be 50 μm.

As an example, the electrodes 30, 32, 34,
36 and 38 are, from the polymer lead body 12 side, an innermost layer 40 made of titanium with a thickness of about 1000 °, a second layer 42 made of palladium with a thickness of about 1000 °, a third layer 44 made of silver of about 5 μm, and Outermost layer 4 made of gold
6 are laminated. 500 kh
The thickness of the electrode required when using a high-frequency signal of z is 0.2 μm.
Each of 2, 34, 36 and 38 has a sufficient thickness.

The thus obtained electrodes 30, 32,
34, 36, and 38 are well bonded to the lead body 12 made of polymer. In addition, since no or almost no internal stress remains, even if the lead body 12 is extended, no crack is formed in each of the layers 40, 42, 44, 46. For this reason, it is possible to avoid generation of a “spark gap” between cracks and generation of heat due to resistance.

FIG. 5 shows a portion of a lead for mapping and ablation. An electrode 47 formed by laminating a plurality of metal thin films as described above is formed on the surface of the lead. This lead has a relatively long linear shape. A conductive wire 45 for transmitting electric energy to the electrode 47
Is passed through the inside of a catheter body 12 made of a polymer. When the electrode 47 having such a configuration is used, the surface of the myocardium can be cauterized over a long range. Therefore, there is no need to move the electrode 47 over the myocardial tissue.

FIG. 6 shows electrodes 30, 3 made of a metal thin film.
Electrophysiological lead 10 having 2, 34, 36, 38
1 schematically shows an example of an apparatus for producing a. The pressure inside the vacuum chamber 48 can be reduced to about 10 ^-7 torr by a pump. A shutter 50 operable from the outside is arranged in the vacuum chamber 48. By adjusting the position of the shutter 50, it is possible to control the range in which the distal end of the catheter body 12 is exposed to the volatile matter 51 emitted from the container 52 containing the metal material 54 as the film source. it can. Examples of the method for vaporizing the metal material 54 include a method for heating the container 52 and a method known in the semiconductor manufacturing technology, such as electron beam sputtering, high-frequency sputtering, or plasma sputtering. The masking 56 is used to adjust the lengths of the individual electrodes 30, 32, 34, 36, 38 formed on the lead body 12 and the intervals between the electrodes 30, 32, 34, 36, 38.

An ion gun 58 is also disposed inside the vacuum chamber 48. When the shutter 50 is open, the ion gun 58 irradiates the target with the ion beam 60 via the masking 56. The ions are generated by passing a gas, such as argon, nitrogen or oxygen, through a screen held at a high voltage. Although not shown, a bias electrode and a focusing electrode may be provided to adjust the degree of ion bombardment on the thin layer during film formation. Further, a heater 62 may be provided in order to thermally remove stress generated in the electrode during film formation.

FIG. 6 shows only the container 52 as a container for storing the metal to be vaporized.
A plurality of containers accommodating different kinds of metals may be arranged in the inside 8. In this case, if the metal is sequentially heated and vaporized, the stacked electrodes 30 and
32, 34, 36, 38 can be formed.

For example, the electrode 38 and the conductive line 18 are
Can be electrically connected to each other as shown in FIG. That is, a concave portion is provided by removing a part of the polymer constituting the catheter body 12, and the distal end 1 of the conductive wire 18 is provided.
Expose 8 '. As a method for removing the polymer,
Although laser cutting is preferred, the polymer material may be physically or chemically removed.

Next, the recess provided as described above is filled with a conductive substance 64 such as a conductive epoxy resin so that the outer surface of the catheter body 12 is flush.
That is, the recess is filled back.

Thereafter, the conductive material 64 and the lead body 1
2, on each surface 40, 42, 44,
The electrodes 38 and the conductive material 6 are formed by sequentially forming the films 46.
4 are electrically connected, and the electrode 38 is electrically connected to the terminal disposed on the proximal end 14 of the lead body 12 via the conductive wire 18.

Other methods for connecting the electrode 38 to the conductive wire 18 or the ribbon conductive wire (not shown) wound on the surface include soldering, and connecting the electrode 38 to the tip of the long conductive wire 18. Is pressed with an appropriate conductive material. Another method of interconnecting the long conductive wires 18 and the electrodes 38 is to melt the conductive wires 18 inside the catheter body 12 and then remove the lead body 12 to expose the metal surface of the conductive wires 18 Then, a method of directly forming the innermost layer 40 constituting the electrode 38 on the metal surface can also be mentioned.
Of course, on the innermost layer 40, a second layer (oxygen barrier layer) 42,
Third layer (conductive layer) 44 and outermost layer (biocompatible layer) 46
Are sequentially formed.

In FIGS. 1 and 3, the electrodes 30, 32, 3
Although the shapes of 4, 36, and 38 are represented as continuous bands or toroids, discrete annular or dot shapes can be obtained by adjusting the masking arrangement by a vacuum film forming method or by performing laser etching after film formation. The shape may be a shape or a band shape. In addition,
As the masking, a tape, preferably Kapton (registered trademark) manufactured by DuPont High Performance Films, a heat-shrinkable tube, a metal coating, a polymer sleeve, or the like can be used. Whatever masking is employed, it is desirable that the edge of the electrode pad be sharply bent rather than tapered. Electrodes 30, 32 with irregular or tapered edges,
Applying high frequency energy to 34,36,38 will cause heat to propagate along the edges of the film, resulting in non-uniform tissue ablation.

Again, but not limited to, the length of the electrodes 30, 32, 34, 36, 38 can be about 1-10 cm, depending on the use of the lead / catheter 10. Even though the electrodes 30, 32, 34, 36, 38 are continuous strips having a length of up to 10 cm, since the electrodes 30, 32, 34, 36, 38 have a very small wall thickness, the lead / catheter The flexibility of 10 is not compromised.

In a lead / catheter 10 designed for radiofrequency ablation, the electrodes 30, 32, 34, 36,
38 so that the surface temperature of the electrode 38 becomes 48 to 100 ° C.
It is desirable to cool 0, 32, 34, 36, 38.
Referring to FIGS. 1-3, the proximal end 14 of the catheter 10
Cooling can be provided utilizing at least one of the lumens 66 extending from the distal end 16 to the distal end 16. That is, a plurality of openings 68 communicating with the lumen 66 are formed in the wall of the cylindrical catheter body 12. On the other hand, a liquid inlet 70 is provided in the proximal end terminal 28 in order to allow the liquid to flow through the lumen 66. Then, cooled physiological saline is introduced through the luer joint 72 and the liquid inlet 70, flows through the lumen 66, and is then drawn out from the opening 68 of the distal end 16 of the catheter 10. In this process, the electrodes 30, 32, 34, 3
6, 38 are cooled by saline.

When a plurality of electrodes 30, 32, 34, 36, 38 are formed, a plurality of lumens 66 may be provided in the catheter body 12. As a result, the physiological saline can be sent to the electrode pad requiring cooling.

By setting the flow rate of the physiological saline so as to increase when the electrode temperature exceeds a specified value and to decrease when the electrode temperature becomes lower than a predetermined value, the tissue surface can be heated without overheating. A better and deeper penetration profile can be obtained.

Temperature detection and control can also be accomplished with a thermistor material such as constantan, alumel or chromel. These are good conductors forming the third layer 44. That is, in this case, the electrode 30,
32, 34, 36, and 38 function as electrodes for high-frequency ablation and also function as electrodes for temperature detection. Of course, the electrodes 30, 32, 34, 36, 3
Apart from 8, a portion functioning only as a thermistor may be arranged at the tip of the catheter body 12. In any case, by connecting to a computer system and constructing a feedback loop, the high-frequency output is controlled based on the detected temperature so that the electrodes 30, 32, 34, 36, and 38 have a desired temperature. Is done. That is,
There is no need to introduce saline.

[0062] The catheter body 12 can also be designed to provide unique memory characteristics. This allows the distal end 16 to assume a predetermined shape when no external force is applied. The thickness of the electrodes 30, 32, 34, 36, 38 is relatively small and, therefore, the portion of the distal end 16 is sufficiently flexible so that the distal end 16 can conform to the shape of the tissue to be ablated. Position can be adjusted.

Electrodes were formed on each of the seven polymer substrates in order to examine the effect of time and power on electrode performance in the case of cauterizing the heart tissue of a dog without self-harm. The electrodes were unified in the preferred form and configuration described above. The experiments used dog heart tissue.

The test was performed in a monopolar mode using a high frequency generator (Valleylab SSE2L electrosurgical instrument). The frequency was set to 500 MHz and the power was set to 25, 50 and 75 watts. Each electrode 30, 32, 34, 36, 38
A current was applied at intervals of 15 seconds, 30 seconds or 45 seconds. Both cases with and without the introduction of physiological saline were examined. In each case, tissue damage and depth of damage were measured.

Even if the output is low or medium, the ablation may be uneven depending on the electrode.
This phenomenon appeared to be affected by the type of polymer substrate.

With several polymer substrates, tissue could be cauterized at all power levels without electrode degradation. By introducing physiological saline, even in the case of a high output, it was possible to cauterize uniformly to the deep part, and furthermore, the root burning of the electrode was reduced and no damage to the electrode was observed. Ablation depth is 2
From 9 mm, it could be made substantially deeper by the introduction of saline. From this, the electrode according to the present invention can transmit high-frequency energy when an appropriate polymer base material is selected, and can be deeply cauterized with or without the introduction of physiological saline, and That is, it can be said that the electrode itself can be prevented from being damaged.

In the above-described embodiment, the tissue ablation was performed in the monopolar mode using the separated return electrodes. However, a pair of electrodes was selected from the electrodes of the lead 10 itself, and the pair of electrodes was selected. A bipolar mode in which a high-frequency voltage is applied to the electrode may be performed.

The present embodiment has been described in detail with reference to specific examples in order to understand the present invention. However, other arrangements and forms for the electrodes and leads are possible. In addition, the present invention can be implemented with other different devices and processes, and various changes can be made in its physical details and operational functions without departing from the scope of the invention. The description in the present specification is for the purpose of showing specific examples only, and does not limit the present invention except as described in the claims.

[0069]

As described above, according to the method for manufacturing a medical lead of the present invention, an electrode is formed by laminating thin films. Therefore, the obtained medical lead has excellent flexibility.

The medical lead manufactured by the manufacturing method according to the present invention can be used for endocardial mapping and ablation for treating arrhythmia. Further, the present invention can be used for assembling a lead for pacing or a lead for suppressing fibrillation. In addition, it can be placed along the spine and used as a nerve lead to treat chronic pain by applying electrical stimulation to the body.

[Brief description of the drawings]

FIG. 1 is an enlarged perspective view of a medical lead manufactured by a manufacturing method according to the present embodiment.

FIG. 2 is an enlarged cross-sectional view taken along line II-II of FIG.

FIG. 3 is an enlarged cross-sectional view taken along line III-III of FIG. 1;

FIG. 4 is an enlarged cross-sectional view taken along line IV-IV of FIG. 3;

FIG. 5 is a partial view of a catheter having a long linear electrode formed on its surface.

FIG. 6 is a schematic view of an apparatus for performing a manufacturing method according to the present embodiment.

FIG. 7 is an enlarged view of a main part of a partially cutaway portion of the catheter main body, showing a state in which conductive wires and electrodes inside the lead are electrically connected to each other.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Lead (catheter) 12 ... Lead body (catheter body) 14 ... Proximal end 16 ... Distal end 18, 20, 22, 24, 26 ... Coil wound wire (conductor) 30, 32, 34, 36, 38 47, electrode 40, innermost layer 42, 44, metal thin film layer 46, outermost layer 48, vacuum chamber 51, volatile material 54, metal material 56, masking 58, ion gun 60, ion beam 64, conductive material

Claims (11)

[Claims] 1. A step of manufacturing a lead body having at least one conductor and having an outer surface; a step of stacking at least two metal thin film layers by film formation; Bonding the at least two stacked metal thin-film layers by applying an impact to the thin-film layers. 2. The manufacturing method according to claim 1, wherein the innermost metal thin film layer is a metal selected from the group consisting of Ti, Cr, Ni, and Al. . 3. A method according to claim 2, wherein the metal thin film layer laminated on the innermost metal thin film layer is a metal selected from the group consisting of Pd and Pt. Lead manufacturing method. 4. The method for manufacturing a medical lead according to claim 1, wherein the outermost metal thin film layer is a metal selected from the group consisting of Au, Pt, and Pt-Ir. . 5. The method according to claim 4, wherein the metal thin film layer located immediately below the outermost metal thin film layer is made of Ag, P
A method for manufacturing a medical lead, comprising a metal selected from the group consisting of t, Cu, and Au. 6. The manufacturing method according to claim 1, wherein the outer diameter of the lead body is about 2 French to about 1 French.
A method for producing a medical lead, which is within a range of 1.5 French size. 7. The manufacturing method according to claim 1, further comprising a step of masking said lead body in order to provide a plurality of regions on said lead body where said metal thin film layer is formed and separated from each other. A method for manufacturing a medical lead. 8. The method according to claim 1, wherein at least one of the metal thin film layers has a thickness of 500 to 1 μm. 9. The method according to claim 1, wherein at least one of the thin metal layers has a thickness of about 250 μm or less. 10. The manufacturing method according to claim 1, wherein said lead body is made of polytetrafluoroethylene (PTF).
E), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polytetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PF
A), an increased amount of polytetrafluoroethylene (e-P
A method for manufacturing a medical lead, comprising a polymer selected from the group consisting of TFE), polyethylene, silicone rubber, polyurethane, polyamide, polyimide, and fluoroethylene propylene (FEP). 11. The method according to claim 1, wherein the bombardment ions are selected from the group consisting of Ar, N, and O.