JPS62155869A - Production of electrode for heart pacemaker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of manufacturing electrodes for cardiac pacemakers.

(Prior art and its problems) A cardiac pacemaker consists of a main body including a control section, electric wires, and electrodes. The performance required for electrodes, especially those for implantable cardiac pacemakers, is that the electrodes should be able to adhere to the heart easily, as well as reduce power consumption and extend the lifespan of the power supply.
It is required to have good responsiveness to signals from the heart, and low impedance (sensing impedance) when responding to signals from the heart.

Among these requirements, in order to suppress power consumption, it is sufficient to reduce the size of the electrode, but in order to improve responsiveness and reduce sensing impedance, it is preferable to have a large surface area.

Therefore, conventionally, the physical size of the electrode was made as small as possible,
The surface was mechanically roughened using sandblasting or glass beads to increase the effective surface area and improve responsiveness and sensing impedance, but this was not sufficient.
There was a demand for electrodes with even greater surface roughness.

(Object of the Invention) The present invention was made in view of the above-mentioned needs, and it minimizes the physical size of the electrode and greatly increases the surface roughness to improve the responsiveness of signals from the heart. The purpose is to reduce sensing impedance.

(Structure of the Invention) One of the methods of manufacturing an electrode for a cardiac pacemaker of the present invention is characterized by coating a Pt group metal or an alloy on the electrode for a cardiac pacemaker by a wire bombardment spraying method.

The wire bomb spraying method used in the manufacturing method of the present invention refers to coating a metal or alloy wire or plate material to be coated.
This is a method to obtain the desired coating layer by applying a large impact current in the atmosphere or atmospheric gas to cause a discharge explosion, and the particles scattered by these collide with the base material at high speed, and melt and scatter due to the discharge explosion. The particles are very small,
In addition, since the scattering speed is very high, the coating film has a low porosity, a high adhesion strength, and a very high surface roughness. Therefore, the electrode for a cardiac pacemaker obtained by applying this beam spraying method has a high surface roughness, so even if the physical size of the electrode is made as small as possible, the response is good (and the sensing impedance can be made small).

In the production method of the present invention, the reason why the Pt group metal or alloy is coated is that the Pt group catalytic ability acts effectively on body fluids containing hydrogen ions and chloride ions, improving responsiveness.

Another method for manufacturing electrodes for cardiac pacemakers according to the present invention
One feature is that the coating layer of the cardiac pacemaker electrode produced as described above is oxidized at an oxygen partial pressure of 0.01 kg/cr1 or more and a temperature of 300 to 900°C.

By oxidizing in this way, the surface of the Pt group metal or alloy in the coating layer is roughened, and this oxide has a small affinity for hydrogen ions and chloride ions in body fluids.
In addition, since it has catalytic ability, the response is further improved.

During oxidation treatment, the oxygen partial pressure is set to 0.01 kg/cn! The reason for this limitation is 0.01kg/CI! ! less than Pt
This is because the group is insufficient to be oxidized. Also, the reason why the oxidation temperature was limited to 300 to 900°C is that 300°C
If it is less than 900℃, oxidation is insufficient, and if it exceeds 900℃, Pt
This is because group acid oxide dissociation begins.

(Example) An example of the method for manufacturing an electrode for a cardiac pacemaker according to the present invention will be described together with a conventional example.

First, to explain a conventional example, a cardiac pacemaker electrode 1 having the dimensions and shape shown in FIG. 1 is made of Pt, and a head 2 is
50μ glass beads were added to increase the effective surface area. The surface roughness at this time was as shown in FIG.

Next, Example 1 will be described. A cardiac pacemaker electrode 1 having the dimensions and shape shown in FIG. 1 was made of stainless steel and coated with 33 wt % of P L -1r by beam spraying. That is, a capacitor of C=80 μF is charged with a charging voltage of V=7.2 KV, and this energy is 20 μF.
73.6 joules with a diameter of 1 mm and a length of 60 mm
t-Ir3:ht% is applied instantly to the wire, melted and scattered, and then attached to the stainless steel cardiac pacemaker electrode.
33 wt% of t-1r was coated.

The spraying distance at this time was 18 mm, and P t -1r33
The wt% coating layer was 5μ. The surface roughness was as shown in FIG.

Next, to explain Example 2, the stainless steel cardiac pacemaker electrode coated with 33 wt% Pt-Ir obtained in Example 1 was heated at an oxygen partial pressure of 9 kg/aa and a temperature of 700°C for 24 hours. Oxidation treatment was performed to change Pt-1r to PL-IrO.

The cardiac pacemaker electrodes of the conventional example and Example 1.2 thus obtained were tested for polarization from the pulse waveform in the test circuit shown in FIG. 4, and for sensing impedance in the test circuit shown in FIG. The results were obtained as shown in Table 1 below.

In Figure 4, 10 is an electrolytic cell, and the solution 11 is pJac19g.
, water 1β, and ethanol 11, the cathode 12 in the solution is a cardiac pacemaker electrode, and the anode 13 is 12 cal T.
It is an i-board, and the distance between the poles is 50 degrees. 14 is a 10 mA constant current power supply, and 15 is an oscilloscope for waveform measurement.

In Figure 5, 10 to 13 indicate the same items as in Figure 4, so
The explanation will be omitted. 16 is a 100 mV, 5011z power supply, and 17 is a 10Ω shunt resistor for measuring the sensing impedance.

The above method for calculating the polarizability is derived from V max of P and 2 of the pulse waveform in FIG. 6 as follows.

Polarizability (%) ”' (Vp / '/may) x
100 The method for calculating the sensing impedance is as follows.

Measurement Voltage As is clear from Table 1 above, the cardiac pacemaker electrode of Example 1.2 has a significantly lower polarizability and an order of magnitude lower sensing impedance than the conventional cardiac pacemaker electrode. I understand.

(Effects of the Invention) As detailed above, according to the method of manufacturing electrodes for cardiac pacemakers of the present invention, the surface roughness can be increased while reducing the physical size as much as possible, resulting in extremely low polarizability. This has the excellent effect of providing an electrode for a cardiac pacemaker that has high responsiveness from the heart, an extremely low sensing impedance, and extremely high reliability.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the shape and dimensions of a cardiac pacemaker electrode, Fig. 2 is a diagram showing the surface roughness of a cardiac pacemaker electrode obtained by the conventional method, and Fig. 3 is a diagram showing the surface roughness of the cardiac pacemaker electrode obtained by the manufacturing method of the present invention. A diagram showing the surface roughness of cardiac pacemaker electrodes, Figure 4 is a diagram showing a test circuit for measuring polarizability, Figure 5 is a diagram showing a test circuit for measuring sensing impedance, and Figure 6 is a diagram for calculating polarizability. FIG. Applicant: Tanaka Kikinzoku Kogyo Co., Ltd. Figure 1, Figure 2, Collection 3, Figure 4, Figure 5] 1 Figure 6 L" Two Sake Cups 'f:t Amendment (spontaneous) March 2, 1986・Day 1, Indication of the case 1985 Patent Application No. 294425 2, Name of the invention Method for manufacturing cardiac pacemaker electrodes 3, Person making the amendment 4, Subject of the amendment Figure 4 of the drawings 5, Contents of the amendment Attached sheet street. 1← 人'i 5ゝ～し'

Claims (1)

[Scope of Claims] 1) A method for manufacturing a cardiac pacemaker electrode, which comprises coating the cardiac pacemaker electrode with a Pt group metal or alloy by beam spraying. 2) The electrode for a cardiac pacemaker is coated with a Pt group metal or alloy by beam spraying, and then oxidized at an oxygen partial pressure of 0.01 kg/cm^2 or more and a temperature of 300 to 900°C. A method for manufacturing electrodes for cardiac pacemakers.