JPH06237990A - Artificial heart - Google Patents

Abstract

PURPOSE:To realize the artificial heart having a shaft sealing mechanism which completely prevents the infiltration of blood into a driving section over a long period. CONSTITUTION:This artificial heart has a pump section 4, a driving section 5 and a nozzle section 6 and is used by inserting the pump section into the cardiac ventricle. The artificial heart is provided with the sealing mechanism 31 for shaft sealing of a driving shaft 26 which drives the pump section from the driving section. Tetrafluoroethylene (PTFE) and its deriv. are codeposited in the metallic plating film on the surface of the driving shaft. As a result, the PTFE and its deriv. particles are held on the metallic plating film and, therefore, a secure lubricant is formed. The driving shaft having excellent lubricity, wear resistance, durability and water repellency and good bioadaptability is obtd. Consequently, the sealing and lubricating characteristics of the sealing mechanism are greatly improved and the infiltration of the blood from the pump side to the driving section side is surely prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an implantable auxiliary artificial heart which is used by being implanted in the ventricle of the human body, that is, the left ventricle or the right ventricle.

[0002]

2. Description of the Related Art Conventional artificial hearts include various types such as a diaphragm type, a sack type, an axisymmetric type, a centrifugal type and a pusher plate type. However, both of them are of a type that sends blood in place of the heart of the human body or bypassing the heart of the human body.

By the way, recently, an auxiliary heart has been developed, which is buried in the ventricle of the human heart and sends blood in the ventricle into the aorta from the tip of a nozzle penetrating the aortic valve or the like. Such an artificial heart does not impair the function of the heart even if it is embedded, and is configured to send blood, which is insufficient only by the beating of the heart, to the arteries. In such an artificial heart, blood is also sent by the heartbeat,
Even if the artificial heart stops, blood is sent by the beating of the heart, so there is an advantage that the safety is high and the burden on the patient is small.

In such an artificial heart as described above, the volume of the part of the heart to be inserted into the ventricle must be smaller than the minimum contraction volume of the ventricle. Therefore, in such an artificial heart, the pump body has a cylindrical axial flow type pump portion, and a nozzle portion provided at the tip thereof,
It is composed of a drive unit provided at the base end of this pump. Then, the apex of the ventricle of the heart is incised and a short cylindrical apex ring is embedded, and the pump portion and nozzle portion are inserted into the ventricle through the apex ring, and the tip portion of the nozzle portion is inserted. The drive unit having a large volume is configured to penetrate the aortic valve and the like and be inserted into the aorta, and to be embedded in the thoracic cavity outside the heart.

However, in the artificial heart as described above, the shaft seal mechanism between the pump section and the drive section poses a problem. That is, in such an artificial heart, a motor or the like is built in the drive unit, and the rotor of the pump unit is driven via the drive shaft extending from the drive unit to the pump unit. Then, blood circulates in the pump portion, and blood pressure acts on the blood. On the other hand, blood is not allowed to flow into the space inside the drive unit.
If blood invades the space inside the drive unit, the blood coagulates and the operation of the motor or the like is hindered.

In order to prevent such infiltration of blood into the drive unit, it is necessary to provide a seal mechanism for liquid-sealing the drive shaft between the drive unit and the pump unit. However, since such an artificial heart is embedded in the human body, it is necessary to operate reliably without maintenance for a long period of time, and a shaft seal mechanism that maintains a perfect seal for such a long period of time. It is not easy to provide with current technology.

[0007]

The present invention has been made based on the above circumstances, and in the artificial heart as described above, it is possible to completely prevent blood from entering the drive section for a long period of time. A shaft seal mechanism is provided. Furthermore, the present invention provides the above drive shaft having excellent wear resistance, excellent lubricity, and excellent durability.

[0008]

In order to solve the above-mentioned problems, the seal mechanism of the present invention maintains the shaft seal of the drive shaft between the pump part and the drive part, and from the pump side. An oil seal for preventing blood from flowing into the drive unit side is provided, and a sealed liquid chamber formed around the drive shaft is formed in the drive unit side of the oil seal. The sealing liquid chamber is filled with the sealing liquid. The oil seal is made of an elastic material and is in close contact with the periphery of the drive shaft due to elastic deformation. And, a hard lubricating film on the surface of the drive shaft,
Specifically, tetrafluoroethylene and its derivative are co-deposited in a nickel or nickel alloy plating film.

[0009]

The seal mechanism of the present invention is equipped with the oil seal and elastically adheres to the outer peripheral surface of the drive shaft to reliably prevent the infiltration of blood, but there is no maintenance for a long period of time. Need to work reliably. Therefore, wear resistance, lubricity, and durability are required for both the oil seal and the drive shaft.

The tetrafluoroethylene and its derivatives used for the surface treatment of the drive shaft of the present invention are usually particles of 0.1 to 1.0 micron or less and are taken into the plating film, and the exposed portion on the surface is Exhibits lubrication performance and low surface tension performance.

In general, the particles are easily condensed in the plating solution when the particle size is 0.1 μm or less, and easily settled in the plating solution when the particle size is 1.0 μm or more.

The particles can be formed into a film by firing at a temperature above the melting point of tetrafluoroethylene and its derivatives. Since this film is held by the plating film by the anchor effect, it has excellent adhesion. Furthermore, the tetrafluoroethylene particles are evenly dispersed in the film, and the durability is excellent.

Further, in the sealing mechanism of the present invention, the sealing liquid chamber is formed, and the sealing liquid chamber is filled with a sealing liquid such as heparin or physiological saline. Therefore, the sealing liquid ensures the sealing and lubrication of the sealing mechanism, and blood is surely prevented from entering the drive unit side from the sealing mechanism. Moreover, it is designed such that the sealing liquid formed between the oil seal and the outer peripheral surface of the drive shaft forms a lubricating film and is unilaterally sent to the pump side as the lubricating liquid. Therefore, it is possible to reliably prevent blood from entering the drive unit side for a long period of time without maintenance.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show an embodiment of the present invention. FIG. 1 shows a state where the artificial heart of the present invention is embedded in the left ventricle B of the human heart A. C is the apex, D is the left atrium, E is the mitral valve, F is the aortic valve, and G is the aorta.

The artificial heart 1 is composed of an apex ring 2 and an artificial heart body 3. The apex ring 2 is in the form of a short cylinder having a brim, the apex C of the heart A is incised, and the apex C is penetrated and implanted.
Further, the main body 3 includes a pump unit 4 and the pump unit 4
It is composed of a nozzle portion 6 provided at the tip end portion of the pump and a drive portion 5 provided at the base end portion of the pump portion 4. Then, the pump portion 4 and the nozzle portion 6 are inserted into the left ventricle B through the apex ring 2 described above, and the nozzle portion 6 is further inserted into the aorta G through the central portion of the aortic valve F. ing. A liquid-tightness is secured between the apex portion ring 2 and the main body portion 3 by an ordinary sealing mechanism, for example, a sealing member 8.

The pump section 4 has a relatively small cylindrical shape, and its volume is formed to be smaller than the minimum volume of the left ventricle B at the minimum contraction, so that it does not interfere with the natural beating of the heart. ing. A small axial pump is built in the pump unit 4 and is driven by the motor built in the driving unit 5. And this pump part 4
Is configured to inhale the blood in the left ventricle B from the suction port 7 formed on the outer peripheral surface thereof, to bypass the aortic valve F from the tip of the nozzle portion 6 at the tip and discharge the blood into the aorta G. There is.

The nozzle portion 6 is made of a soft synthetic resin material and is flexible. The nozzle portion 6 penetrates the central portion of the aortic valve F and does not impair the function of the aortic valve F. It is constructed so as not to damage the valve F.

The drive unit 5 is embedded in the chest cavity outside the heart A. A motor and the like are built in the drive unit 5, and a battery and control electronic parts are built in as needed. This drive unit 5 is connected to a non-contact type electrode 10 via an electric wire 9,
0 is buried near the skin H of the human body. Then, via this electrode 10, necessary power is supplied from an external power supply device (not shown).

The drive unit 5 is connected to the sealed liquid bag 12 via a flexible tube 11. The sealing liquid bag 12 is made of a flexible material and is filled with a sealing liquid such as physiological saline. Then, the sealing liquid bag 12 is buried in an appropriate site in the chest or abdomen, for example.

Next, the structure of the main body 3 will be described with reference to FIG. The pump section 4 is a cylindrical casing 2
1, the front end of the casing 21 is reduced in diameter to form the nozzle portion 6, and the base end is connected to the drive portion 5 through the extension portion 24. . An axial flow type pump, for example, a propeller 22 and a plurality of guide vanes 23 that perform a rectifying function are arranged in the casing 21. And this casing 2
The suction port 7 is formed on the outer peripheral surface of the No. 1, and the propeller 22 and the guide vane 23 are provided through the suction port 7.
A smooth blood flow path is formed inside the casing 21 up to the nozzle portion 6 at the tip end via the.

A drive shaft 26 is attached to the propeller 22.
The tip of is connected. The drive shaft 26 passes through the inside of the extension portion 24 and extends to the inside of the drive portion 5.

A motor is built in the drive unit 5, 32 is a stator coil thereof, and 33 is a rotor. The base end of the drive shaft 26 is connected to the rotor 33. Reference numeral 34 is a lid member for sealing the drive unit 5.

The tip end of the drive shaft 26 is supported by a bearing 28 made of a ceramic material, and the base end portion thereof is a dynamic pressure bearing 35, 36 made of a ceramic material in the drive unit 5.
Supported by. A seal mechanism 31 is provided at the tip of the drive shaft 26, and the seal mechanism seals the shaft between the inside of the pump unit 4 and the inside of the drive unit 5 so that the blood inside the pump 4 is It is configured to prevent intrusion into the drive unit 5.

A sealing liquid chamber 30 is formed surrounding the drive shaft 26 in a portion closer to the drive unit 5 than the sealing mechanism 31, for example, in the extension portion 24 of the casing 21. The sealing liquid chamber 30 is filled with a sealing liquid, such as physiological saline. If necessary, an anticoagulant such as heparin and other necessary chemicals are added to the saline.

Next, the sealing mechanism 31 will be described. In this embodiment, an oil seal is used as the sealing mechanism 31. The oil seal is a member that is formed of an elastic material such as synthetic rubber and has a lip portion that can be elastically reduced in diameter. The lip portion contacts the outer peripheral surface of the drive shaft 26 to maintain liquid tightness. To do. This oil seal is characterized in that a lubricating film of the above-mentioned sealing liquid is formed between the oil seal and the drive shaft 26. The lubricating film exhibits a reliable sealing property, and the oil seal prevents the oil seal from the outer periphery of the drive shaft 26. Direct contact is prevented and wear is prevented over a long period of time.

FIG. 3 shows a preferred structure of the sealing mechanism 31. This is an oil seal 4 made of synthetic rubber, etc.
1, the oil seal 41 has an elastically deformable lip portion 42. And this lip portion 42
The inner peripheral surface of is in contact with the outer peripheral surface of the drive shaft 26.
Further, this one is provided with a garter spring 43 in order to stabilize the contact pressure between the lip portion 42 and the outer peripheral surface of the drive shaft 26. Such an oil seal 41
As described above, the inner peripheral surface of the lip portion 42 and the drive shaft 26
It is designed so that a thin lubricating film of the sealing liquid is formed between the outer peripheral surface and the outer peripheral surface. The sealing liquid intervening as the lubricating film is designed to circulate in the seal surface by the rotation of the drive shaft 26. Further, in this embodiment, the sealing liquid intervening as the lubricating film is designed so as to flow unilaterally to the pump portion 4 side, and to flow into the pump portion 4 in small amounts. Therefore, such behavior of the sealing liquid surely prevents blood from entering the sealing surface between the oil seal 41 and the drive shaft 26 from the pump portion 4 side.

Further, the surface treatment of the drive shaft 26 will be described with reference to FIG. Since the oil seal 41 is elastically brought into close contact with the outer peripheral surface of the drive shaft 26, the invasion of blood is reliably prevented. Both the seal 41 and the drive shaft 26 are required to have wear resistance, lubricity, and wear resistance. Therefore, in this embodiment, a composite plating film 52 is formed on the surface of the drive shaft 26, in which Teflon fine particles 51 are uniformly dispersed and co-deposited in a nickel electroless plating film. The amount of eutectoid Teflon is about 25%. As the material of the drive shaft 26, for example, stainless steel is used, and for degreasing and activation treatment for forming a film, nickel phosphor plating in which Teflon fine particles 51 hydrophilized with a surfactant and dispersed with a surfactant is dispersed is used for several microns. Give. If the drive shaft 26 is quenched, the hardness of the coating will be HV500-600. The drive shaft 26 thus produced has the following features.

(1) Since the plated film is held by the anchor effect, the adhesion of the film is excellent.

(2) Since the coefficient of friction is low, it has excellent lubricity and wear resistance.

(3) The Teflon fine particles are uniformly dispersed in the coating, which is excellent in durability.

(4) Since the surface tension of the Teflon fine particles is high, the water repellency is excellent.

(5) Since Teflon itself serves as a lubricant, it has good biocompatibility.

Due to the above-mentioned characteristics, even if the oil seal 41 of FIG. 3 is elastically adhered to the outer peripheral surface of the drive shaft 26, a reliable shaft sealing effect can be achieved without maintenance for a long period of time. Can be expected.

The lubrication effect according to the present invention is not limited to metal as a base material, but can be applied to materials such as ceramics and polymer materials by pretreatment.

In the present embodiment, the oil seal and the drive shaft have been described as being coated for the purpose of improving lubricity, wear resistance and durability, but the above five characteristics are the artificial heart of the present invention. Of all components, such as a cylindrical casing 21, a nozzle portion 6, a propeller 22, and a guide vane 23.
It goes without saying that it is effective for all parts that come into contact with blood.

[0036]

As described above, according to the present invention, since the tetrafluoroethylene and its derivative particles are held by the nickel or nickel alloy plating film by the anchor effect, a strong lubricant is formed and the lubricity and wear resistance are improved. It is possible to provide a part which is excellent in durability, durability and water repellency and is also excellent in biocompatibility.

As a result, if an oil seal is elastically brought into close contact with the outer peripheral surface of the drive shaft coated with this lubricating film, the sealing performance and the lubrication characteristics of the seal mechanism are significantly improved, and the pump side to the drive side is improved. It is possible to more reliably prevent the infiltration of blood for a long period of time without maintenance.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a state in which the artificial heart of the embodiment is mounted in the left ventricle.

FIG. 2 is a vertical cross-sectional view of the main body portion of the artificial heart.

FIG. 3 is a vertical cross-sectional view of a seal mechanism portion.

FIG. 4 is an enlarged view in which a metal plating film on which tetrafluoroethylene and a derivative thereof of the present invention are co-deposited is formed on the surface of a drive shaft.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Artificial heart 2 ... Apex ring 3 ... Body part 4 ... Pump part 5 ... Drive part 6 ... Nozzle part 7・ ・ ・ ・ ・ Suction port 8 ・ ・ ・ Seal member 9 ・ ・ ・ Electric wire 10 ・ ・ ・ Electrode 11 ・ ・ ・ Pipe 12 ・ ・ ・ Sealing liquid bag 21 ・ ・ ・-Casing 22-propeller 23-guide vanes 24-extension 26-driving shaft 28-bearings 30-sealing liquid chamber 31 ... Sealing mechanism 32 ... Stator coil 33 ... Rotor 34 ... Lid member 35 ... Dynamic pressure bearing 36 ... Dynamic pressure bearing 41 ・.... Oil seal 42 ... Lip part 43 ... Garter spring 51 ... Teflon fine particles 52 ... composite plating film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenji Yamazaki 3-7-15 Honmachi, Koganei-shi, Tokyo (72) Inventor Toshio Mori 3148 Tamagawa 6, Chino-shi, Nagano Prefecture 6

Claims (2)

[Claims] 1. An artificial heart in which tetrafluoroethylene and its derivative are co-deposited in a metal plating film on the surface of a component used for the artificial heart. 2. The artificial heart is a supplementary artificial heart that is used by inserting it into the ventricle of the human heart, and is a cylindrical axial flow pump that is inserted into the ventricle of the human heart. Department,
A drive unit that drives the pump unit via a drive shaft provided at the base end of the pump unit is provided, and the shaft seal of the drive shaft is maintained between the pump unit and the drive unit. A sealing mechanism is provided to prevent blood from entering the pump section side, and the tetrafluoroethylene and its derivative are co-deposited in the metal plating film on the surface of the drive shaft. heart.