JP2023178157A - Wireless assistance artificial heart system - Google Patents

Abstract

To provide an artificial heart system that can solve a problem with a transcutaneous energy transmission system, which is a mainstream technology of a wireless artificial heart, such as positional deviation, increase in a coil temperature, and difficulty in dealing with a machine failure, and a problem with a magnetic drive pump, which is another wireless artificial heart, that an extracorporeal device restricts activities of a user.SOLUTION: Two kinds of artificial hearts operated by magnetic force and electric power are used. In the magnetic artificial heart, positional deviation hardly occurs thanks to suction force acting between magnets. An intracorporeal battery is recharged while the magnetic artificial heart is being driven. Low output power transmission does not affect output of the artificial heart so that increase in a coil temperature can be suppressed. Furthermore, since the magnetic artificial heart is of a simple structure that does not use electronic equipment, a failure hardly occurs. Also, while the electric power artificial heart is being driven by the intracorporeal battery, an extracorporeal device is not required and a user's activities are not restricted.SELECTED DRAWING: Figure 1

Description

The present invention relates to an implantable wireless ventricular assist device system that eliminates the need for power supply cables extending percutaneously from a patient's body.

Existing implantable ventricular assist devices (for example, the left ventricular assist device (LVAD), which is a type of auxiliary circulatory device used to treat patients with end-stage heart failure) are rechargeable. Powered by electrical current, possibly from an implanted internal battery or a power source external to the body. Typically, in these devices, a power supply external to the patient's body is directly connected to the auxiliary artificial heart through a power supply cable line that extends percutaneously from within the patient's body.

However, with this method, there is a risk of driveline infection, which is a bacterial infection from areas around the driveline such as cable lines, and associated complications such as sepsis and coagulopathy, which significantly reduces the patient's quality of life. let
Therefore, a wireless ventricular assist device that does not use a percutaneous drive line such as a cable line is desired.

One of the wireless ventricular assist devices that do not use a drive line such as a cable line uses an electromagnetic induction method that transmits energy and supplies power through the skin (transcutaneous energy transfer system (TETS)). There is.
The main methods include using an external transmitter to transmit radio-frequency energy to power the implanted device, and using an electromagnetic transmitter coil. The former is not very good because of the loss of energy transfer efficiency through the skin. The latter uses electromagnetic induction between a primary coil installed on the body surface and a secondary coil implanted inside the body to transmit electrical energy transcutaneously into the body. This electrical energy can be used to charge an internal battery and drive an auxiliary artificial heart within the body (for example, Patent Document 1).

Another type of wireless artificial heart assist system is a magnetically driven pump in which an implantable artificial heart that has an impeller combined with a permanent magnet is rotated by a rotating magnetic body placed on the body surface (for example, Patent Document 2). ).

Special Publication No. 2000-505681 International Publication No. 2012-008383

The transcutaneous energy transfer system described in Cited Document 1 etc. cannot supply power if there is a distance between the coils. Therefore, although it is used near the epidermis, it is necessary to continuously supply a large amount of power of nearly 15 W to the auxiliary artificial heart during operation, resulting in a drop in output due to positional deviation of the coil and heat generation of the coil. There are problems such as skin burns caused by Additionally, implanted devices are prone to failure, and in the event of a failure, it cannot be dealt with without invasive procedures such as thoracotomy. These problems hinder the practical application of wireless ventricular assist devices using transcutaneous energy transfer systems.

On the other hand, the implantable magnetically driven pump described in Cited Document 2 does not cause any burns and has a simple structure, so there is no possibility of failure, but it requires a rotating magnetic body that applies an external magnetic field to be carried around at all times. This restricts activities such as sports and bathing, which impairs the patient's quality of life.

The present invention solves the above problems by implanting an artificial heart driven by magnetic force in addition to the conventional artificial heart driven by electric power, thereby overcoming the problems of transcutaneous energy transfer systems and magnetically driven pumps. The objective is to provide a new wireless ventricular assist device system.

The wireless ventricular assist device of the present invention includes an electrically driven pump that is connected to the heart via an artificial blood vessel and assists the activity of the heart, and an electrically driven pump that is connected to the artificial blood vessel via the aorta and the artificial blood vessel. The pump has a magnetically driven pump that is connected to the magnetically driven pump, and a control section that controls the output of the magnetically driven pump and the electrically driven pump.

The wireless ventricular assist device system of the present invention can provide a patient with a safe wireless ventricular assist device that does not impair the patient's quality of life.

FIG. 1 is a configuration diagram of a wireless ventricular assist device system 100 in an embodiment of the present invention. FIG. 2 is a schematic diagram of a magnetically driven pump 31 and an electrically driven pump 21 in the ventricular assist device 1 of the present invention. FIG. 1 is a schematic diagram when the wireless ventricular assist device system 100 according to the present invention is actually connected to a patient. The impeller 33 of the magnetically driven pump 31 in the present invention, the permanent magnet 34 coupled to the impeller, the housing 35, the rotating magnetic body 46 that becomes part of the power supply control device 4, the rotating drive section 47, and the vicinity of the magnetically driven pump 31 during the tabletop test This is an actual photo. It is an actual photograph of the impeller 23, housing 24, coil 25, casing 28, and electrically driven pump 21 of the electrically driven pump 21 in the present invention. It is an actual photograph during a tabletop durability test using the wireless ventricular assist device system 100 of the present invention. 1 is a table summarizing the results of a desktop durability test using the wireless ventricular assist device system 100 of the present invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. Note that the embodiments of the present invention are not limited to the matters described below, and can be modified as appropriate depending on the situation in which the invention is applied within the scope of the invention described in the claims.

[Auxiliary artificial heart system according to the first embodiment]
FIG. 1 is a configuration diagram of a wireless ventricular assist device system 100 according to the present invention.
As shown in FIG. 1, the wireless artificial heart system 100 includes a ventricular assist device 1 and a power supply control device 4.

First, the ventricular assist device 1 will be explained.
The ventricular assist device 1 is for a left ventricular assist device (LVAD), and includes an artificial blood vessel 10, two types of pumps: an electrically driven pump 21, a magnetically driven pump 31, and an electrically driven pump 21 and a magnetically driven pump 31. It consists of an internal control unit 50 that controls the internal control unit 50 , an internal battery 51 , and an internal coil 52 that receives energy transmitted from the power supply control device 4 .

The artificial blood vessel 10 has an electrically driven pump 21 and a magnetically driven pump 31 connected in series, and the one that is not connected to the electrically driven pump 21 and the magnetically driven pump 31, as shown in FIG. One end is connected to the aorta 16 near the heart, and the other end is connected to the left ventricle 12 of the heart. Note that the order of connection of the electrically driven pump 21 and the magnetically driven pump 31 may be reversed. When installing the current auxiliary artificial heart, the electrically driven pump 21 is generally installed near the left ventricle 12, and if the mounting position of the magnetically driven pump 31 is also taken into account, considering the space inside the body, Although it is preferable to connect the left ventricle 12, the electrically driven pump 21, the magnetically driven pump 31, and the aorta 16 in this order, the order in which the electrically driven pump 21 and magnetically driven pump 31 are connected is not particularly limited as long as there is no problem with the mounting position.
As the material of the artificial blood vessel 10, stable biocompatible materials such as polyester and tetrafluoroethylene are used.

FIG. 2 is a schematic diagram of the magnetically driven pump 31 and the electrically driven pump 21 in the ventricular assist device 1 of the present invention.
2(a) is a sectional view of the magnetically driven pump 31 along the central axis, and FIG. 2(b) is a sectional view of the electrically driven pump 21 along the central axis.
FIG. 4 shows the impeller 33 (FIG. 4A) of the magnetically driven pump 31 of the present invention, the permanent magnet 34 coupled to the impeller (FIG. 4B), the housing 35 (front: FIG. 4C, bottom: FIG. 4D), and the power supply control device 4. It is an actual photograph (right view of FIG. 4) of the rotating magnetic body 46 (FIG. 4E), the rotational drive unit 47 (FIG. 4F), and the vicinity of the magnetically driven pump 31 during the desktop test.
FIG. 5 shows the impeller 23 (FIG. 5G), housing 24 (front view: FIG. 5H, bottom surface: FIG. 51), coil 25, casing 28 (bottom left diagram in FIG. 5), and the electric drive pump 21 in the present invention. This is an actual photograph (Figure 5, bottom right).

As shown in FIGS. 2(b) and 5, the electrically driven pump 21 includes an electrically driven pump impeller 23, an electrically driven pump housing 24, an electrically driven pump coil 25, and a casing 28 that holds the coil 25. Become.

[Electric drive pump]
The electrically driven pump 21 is an electrically driven centrifugal pump. Power is supplied from the internal battery 51.

The impeller 23 shown in FIG. 2(b) and FIG. 5G includes a permanent magnet holding part 27 provided at the upper part that holds a plurality of permanent magnets 26, and a rotating part provided at the lower part with a gap serving as a flow path. A rotor consisting of a shaft and a portion in which a plurality of blades are arranged radially. The permanent magnet holding section 27 has a plurality of parts that hold a plurality of permanent magnets 26 radially around the rotation axis. In the permanent magnet 26, S poles and N poles are alternately embedded in each holding portion adjacent in the circumferential direction. The permanent magnet 26 is provided at a position facing the coil 25 provided in the casing 28 and serving as an electromagnet when the casing 28 accommodates the housing 24 . As a result, when current is passed through the coil 25, rotational force is applied based on the principle of a brushless motor, and the impeller 23 rotates. The number of permanent magnets 26 may be any number. The number may be the same as the number of coils 25, more or less, and the number is not limited as long as it operates as a rotor.

The blades of the impeller 23 may have any shape as long as they can function as a pump. The impeller 23 is preferably made of acrylic resin, but is not limited to this, and any biocompatible material can be used.
The impeller 23 plays the role of a pump by passing current through the coil 25 and driving the impeller to rotate within the housing 24 of the electrically driven pump on the principle of a motor.

The housing 24 shown in FIGS. 2(b), 5H, and 5I includes an inlet port extending in the axial direction and a discharge port extending in the centrifugal direction, forms the outer shape of the electrically driven pump 21, and houses the impeller 23. The suction port is provided at the center of the central axis, and the discharge port is provided in the centrifugal direction around the blades of the impeller 23. Although acrylic resin is preferably used as the material, the material is not limited to this, and any biocompatible material can be used.

The coil 25 shown in FIG. 2(b) and the lower left diagram in FIG. 5 is held and provided within the casing 28. A plurality of electromagnetic coils 25 are provided within the casing 28.
The coil 25 is constructed by winding a copper wire around an iron core. A conventional motor such as an electromagnetic motor may be used.

Further, as shown in FIG. 2(b), a first rotation speed detection means 22 for detecting the rotation speed of the impeller 25 is provided near the coil 25. The first rotational speed detecting means 22 may be any device such as a Hall element as long as it detects the rotational speed of a motor or the like. The first rotation speed detection means 22 is connected to the internal control section 50 and sends the rotation speed of the electrically driven pump 21 to the internal control section 50 .

As shown in the lower right view of FIG. 5, the casing 28 holds the plurality of coils 25 therein, and covers the upper part of the impeller 23 in which the permanent magnet 26 is held in the housing 24 of the electrically driven pump 21. The casing 28 encloses the plurality of coils 25 so as to be located at positions facing the permanent magnets 26 in the impeller 23 when the casing 28 covers the housing 24 . Any number of coils 25 may be provided within the casing 28. The number may be the same as the number of permanent magnets 26, more or less, and the number is not limited as long as the impeller 23 can be rotated.

When electric current is passed through the coil 25, the electrically driven pump 21 rotates the impeller 23 on the same principle as an existing brushless motor, and functions as a centrifugal pump. An artificial heart is created by attaching an artificial blood vessel to a predetermined location near the left ventricle 12 and allowing blood to flow through the electrically driven pump 21.

Although a preferred example of the electrically driven pump 21 has been described above, the electrically driven pump 21 is not necessarily limited to this form. Although the present invention has been described using a centrifugal pump, an axial type pump may also be used. Any electric pump may be used as long as it can be rotated by external electric power and performs the function of an auxiliary artificial heart.

[Magnetic drive pump]
As shown in FIGS. 2A and 4, the magnetically driven pump 31 includes a magnetically driven pump impeller 33, a magnetically driven pump permanent magnet 34, and a magnetically driven pump housing 35.
The magnetically driven pump 31 is a centrifugal pump that does not require an electric circuit (electrical driving force) and is driven by rotating a permanent magnet 34 from the outside with a rotating magnetic body 46 of the power supply control device 4. In addition, although it may be separate from the magnetically driven pump 31, a second rotational speed detection means 32 that is arranged near the magnetically driven pump 31 and detects the rotational speed of the magnetically driven pump 31 is provided. .

The impeller 33 shown in FIGS. 2(a) and 4A is a rotor in which a plurality of blades are attached to a rotating shaft with a gap in which the upper part serves as a flow path, and a part for holding a permanent magnet 34 is provided in the lower part. be. The shape of the vanes is not particularly limited, and may be any shape as long as it can fulfill the function of a pump. Acrylic resin is preferably used as the material for the wings, but the material is not limited to this, and any biocompatible material can be used.

The permanent magnet 34 shown in FIGS. 2A and 4B is provided inside a member that is integrally joined to the lower part of the blade portion of the impeller 33, etc. A permanent magnet is a permanent magnet whose magnetic pole is a north pole on one half of the rotating surface, and a permanent magnet whose magnetic pole is an south pole on the other half, and is used by joining two permanent magnets with different magnetic poles on the rotating surface. Although two permanent magnets 34 are used in this embodiment, two or more permanent magnets may be used. As the permanent magnet 34, a magnet having strong magnetic force such as a neodymium magnet is used.
The permanent magnet 34 is rotationally driven by the magnetic force of the rotating magnetic body 46 of the power supply control device 4 .

The housing 35 shown in FIGS. 2A, 4C, and D includes an inlet port extending in the axial direction and a discharge port extending in the centrifugal direction, forms the outer shape of the magnetically driven pump 31, and houses the impeller 33 and the like. The suction port is provided at the center of the central axis, and the discharge port is provided in the centrifugal direction around the blades of the impeller 33. Although acrylic resin is preferably used as the material, the material is not limited to this, and any biocompatible material can be used.

The second rotation speed detecting means 32, which is provided near the magnetically driven pump 31 shown in FIG. The rotational speed of the magnetically driven pump 31 is detected by detecting the alternating current generated by the electromotive force. The second rotation speed detection means 32 is connected to the internal control section 50 and sends the rotation speed of the magnetically driven pump 31 to the internal control section 50 .

The magnetically driven pump 31 is fixed to the back side of the sternum or between the ribs with the magnetic pole surface of the permanent magnet 34 of the magnetically driven pump facing outward. The rotary magnetic body 46 of the power supply control device 4 installed on the outer surface of the skin 11 is rotated by the rotary drive mechanism 45, and the impeller 33 of the magnetically driven pump 31 is rotated by synchronizing the permanent magnet 34 of the magnetically driven pump 31 with this rotation. It rotates and functions as a centrifugal pump.
An artificial heart is created by attaching an artificial blood vessel to a predetermined site and causing blood to flow through the magnetically driven pump 31.

As mentioned above, although a preferred example of the magnetically driven pump 31 has been described, the magnetically driven pump 31 is not necessarily limited to this form. Although the present invention has been described using a centrifugal pump, an axial type pump may also be used. Any magnetically driven pump may be used as long as it can perform the function of an auxiliary artificial heart by being rotationally driven by external magnetic force without power supply.

[Internal control section]
The internal control unit (controller) 50 is a part that controls the electrically driven pump 21. The internal control unit 50 is composed of a one-board microcomputer such as a central processing unit (CPU). The internal control section 50 is not limited to the CPU, but may be any other device that can perform similar control. Further, the internal control unit 50 may include a storage medium such as a memory (not shown). The storage medium may store a control program, control information for the electrically driven pump 21, rotation speed information from the first rotation speed detection means 22, rotation speed information from the second rotation speed detection means 32, etc. .

The internal control section 50 controls the electrically driven pump 21 and detects the rotational speed of the electrically driven pump 21 from the first rotational speed detection means 22 connected to the internal control section 50 . The internal control unit 50 is further connected to the second rotation speed detection means 32 and obtains the rotation speed of the magnetically driven pump 31 from the second rotation speed detection means 32 . The internal control unit 50 controls the electric current so that the output of the auxiliary artificial heart falls within a predetermined range, and the sum of the rotation speeds of the electrically driven pump 21 and the magnetically driven pump 31 falls within a predetermined value range. Controls the drive pump 21.
The internal control unit 50 includes or is connected to an internal battery 51, and is driven by the electrical energy of the internal battery 51.

The internal battery 51 supplies power to the electrically driven pump 21 and the internal control unit 50, and is also charged by receiving power from the internal coil 52. Specifically, the internal battery 51 is desirably a small rechargeable and dischargeable secondary battery with a large capacity, and preferably a lithium ion secondary battery is used.

The internal coil 52 is connected to the internal battery 51 and receives power for charging the internal battery 51 from the power supply control device 4 . The internal coil 52 can transcutaneously receive energy and supply power using electromagnetic induction between the internal coil 52 and the external coil 42 of the power supply control device 4 .

[Power supply control device]
Next, the power supply control device 4 will be explained.
The power supply control device 4 includes an external power source 41 , an external coil 42 that transmits electrical energy to an internal coil 52 , a rotational drive mechanism 45 , and a rotating magnetic body 46 .
The power supply control device 4 uses the external coil 42 to charge the internal battery 51 via the internal coil 52, and uses the rotating magnetic body 46 to rotate the permanent magnet 34, so that the magnetically driven pump 31 can be operated without electric power. It is something that is driven.

The external power supply 41 is a power supply for the power supply control device 4, and may be any type of power supply as long as it can supply power. A battery or the like may be used to increase portability.

The external coil 42 is connected to an external power source 41 and brought close to the skin 11 where the internal coil 52 implanted in the body is present, so that the electromagnetic induction effect between the external coil 42 and the internal coil 52 is transcutaneously induced. It is used to transmit electricity. As this method, one currently used in transcutaneous energy transfer systems (TETS) may be used.

However, in the conventional method, it was necessary to continuously apply a large power of nearly 15W. However, in the present invention, since the magnetically driven pump 31 is provided, there is no problem even if the electrically driven pump 21 is stopped, so the external coil 42 can be operated at a low power of 5 W or less without becoming much larger than the body temperature. It can supply power and charge. Therefore, the risk of burns to the patient can be almost eliminated.

The rotational drive mechanism 45 is a mechanism that rotates using electric power from the external power source 41, as shown in FIG. 4E. The rotation allows the rotating magnetic body 46 to rotate. The rotational drive mechanism 45 can be composed of, for example, an electric motor.

The rotating magnetic body 46 is a member that is rotated by the rotational drive mechanism 45, as shown in FIG. 4E. The rotating magnetic body has two embedded permanent magnets shown in FIG. 4F. The two embedded permanent magnets are arranged so that the magnetic fields on the surface of the magnets pressed against the skin 11 have different poles, such as the south pole and the north pole. Preferably, the permanent magnet has a strong magnetic force, such as a neodymium magnet. Note that two or more magnets may be embedded.
The rotating magnetic body 46 is brought close to the skin 11 where the permanent magnet 34 of the magnetically driven pump 31 implanted in the body exists, and is magnetically coupled to the permanent magnet 34 by applying a magnetic field transcutaneously. It drives the magnetically driven pump 31. Therefore, the magnetically driven pump 31 does not require electric power.

[Actual use of the auxiliary artificial heart system according to the first embodiment]
FIG. 3 is a schematic diagram when the wireless ventricular assist device system 100 according to the present invention is actually connected to a patient.

The skin 11 shown in FIG. 3 shows the skin in the vicinity where the ventricular assist device 1 is implanted, and the right side means the inside of the body and the left side means the outside.
Reference numerals 12 to 17 in FIG. 3 are schematic diagrams of the surroundings of the heart, and represent the left ventricle 12, right ventricle 13, left atrium 14, right atrium 15, aorta 16, and pulmonary artery 17.

In FIG. 3, the opposite end of the artificial blood vessel 10 of the ventricular assist device 1 of the present invention connected to the electrically driven pump 21 is connected to the left ventricle 12, and the opposite end of the artificial blood vessel 10 connected to the magnetically driven pump is connected to the left ventricle 12. The end is connected to the aorta 16.

In the example of FIG. 3, the electrically driven pump 21 is connected to the vicinity of the left ventricle 12 via the artificial blood vessel 10.
As described above, the magnetically driven pump 31 fixes the surface of the permanent magnet 34 on the back side of the sternum or between the ribs.

In FIG. 3, by connecting the artificial blood vessel 10 of the auxiliary artificial heart device 1 of the present invention between the left ventricle 12 and the aorta 16, blood flows to the artificial blood vessel 10, the electrically driven pump 21, and the magnetically driven pump 31. .
In this state, by driving the electrically driven pump 21 and the magnetically driven pump 31 by the method described above, each becomes a centrifugal pump and plays the role of an auxiliary artificial heart.

At this time, it is necessary to ensure that the output of the entire auxiliary artificial heart device 1 as a pump is constant. In other words, the sum of the output of the electrically driven pump 21 and the output of the magnetically driven pump 31 needs to be constant.

As one method, the output is determined by the sum of the rotation speed of the electrically driven pump 21 and the rotation speed of the magnetically driven pump 31. When the magnetically driven pump 31 rotates at a high speed, the electrically driven pump 21 rotates at a low speed or does not rotate, and when the magnetically driven pump 31 rotates at a low speed or does not rotate, the electrically driven pump 21 rotates at a high speed.
The internal control unit 50 controls the total number of rotations of the electrically driven pump 21 and the magnetically driven pump 31 to be within a certain range.

The rotation speed is controlled by the internal control section 50, as described above. The internal control unit 50 detects the electrically driven pump based on information from the first rotational speed detection means 22 that detects the rotational speed of the electrically driven pump 21 and the second rotational speed detection means 32 that detects the rotational speed of the magnetically driven pump 31. 21 and the magnetic drive pump 31 so that the total number of rotations is within a predetermined range.

The internal control unit 50, which has obtained information on the rotation speed of the magnetically driven pump 31 by the second rotation speed detection means 32, calculates the difference between the rotation speed within a predetermined range in which the overall output is maintained, and 21, sends a rectangular pulse wave signal with a duty ratio to control the electric drive pump 21, and controls the rotation speed of the electric drive pump 21 at the rotation speed of the signal according to the duty ratio of the rectangular pulse wave. The rotational speed of the electrically driven pump 21 and the magnetically driven pump 31 is controlled so that the overall rotational speed is within a predetermined range.

Power supply to the internal battery 51 requires a large amount of power when charging the internal battery 51 and discharging it when the electrically driven pump 21 is driven. 21) is preferably performed by a transcutaneous energy delivery system.

[Auxiliary artificial heart system according to the second embodiment]
In the wireless artificial heart system 100 according to the first embodiment of the present invention, the electrically driven pump 21 and the magnetically driven pump 31 of the artificial heart device 1 are connected in series.

However, the electrically driven pump 21 and the magnetically driven pump 31 of the auxiliary artificial heart device 1 are not limited to being connected in series, but the problems of the present invention can be achieved even if they are connected in parallel.
In this case, the artificial blood vessel 10 has a branch part on the side not connected to the aorta 16 near the heart, and an electrically driven pump 21 and a magnetically driven pump 31 are connected to each of the artificial blood vessels 10 extending from the branch part. . The artificial blood vessels 10 are connected to the other connection parts of the electrically driven pump 21 and the magnetically driven pump 31, respectively, and each artificial blood vessel 10 joins at another branch part, and the ends extending from the branch part are connected to each other. It is connected to the left ventricle 12 of the heart. Note that each branch portion may be provided with a valve for switching the flow path.

As in the first embodiment, the auxiliary artificial heart device 1, which has an electrically driven pump 21 and a magnetically driven pump 31 connected in parallel, provides assistance by controlling the rotational speed using the internal control unit 50 so that the overall output is constant. It can act as an artificial heart.

On the other hand, in the auxiliary artificial heart device 1 in which an electrically driven pump 21 and a magnetically driven pump 31 are connected in parallel, if one of the driving pumps is completely stopped, the blood flowing on the stopped side may stagnate and cause blood clots. Therefore, it is necessary to continue driving even with a weak output in a way that creates a flow without stopping completely. Alternatively, a circulation flow mechanism may be provided on the side where the driving pump is stopped to suppress blood stagnation.
Alternatively, maintenance may be performed by stopping the flow on the driving pump side using a valve provided at the branching portion.

The auxiliary artificial heart device 1 in which the electrically driven pump 21 and the magnetically driven pump 31 are connected in parallel can obtain the same effect as in the first embodiment, but if there is an abnormality in either the electrically driven pump 21 or the magnetically driven pump 31. Even if something happens, one of the drive pumps can be stopped and maintenance can be performed, reducing the possibility of endangering the patient.

[Example of the auxiliary artificial heart system according to the first embodiment]
Examples of the present invention will be described below. Note that the items described in the Examples are preferred examples for implementing the present invention, and the size and shape are not limited to those described in the Examples.

A magnetically driven pump 31 was created using the following members.
As shown in FIG. 4A, the impeller 33 of the magnetically driven pump was made of acrylic resin. The impeller 33 of the magnetically driven pump can accommodate a permanent magnet 34 in the lower part of FIG. 4A. It also has a plurality of blades of an impeller 33 on the top. The diameter of the impeller was 25.2 mm, and the height of the permanent magnet 34 from the housing part was 24.2 mm.

As shown in FIG. 4B, the permanent magnet 34 of the magnetically driven pump is made by joining two semicircular permanent magnets, and the two magnetic poles are joined so that they are different from each other. A neodymium magnet was used as the permanent magnet.
The permanent magnet 34 has a diameter of 23.4 mm and a height of 10.5 mm, and is configured to be housed in the impeller 33.

As shown in FIGS. 4C and 4D, the housing 35 of the magnetically driven pump is capable of housing the impeller 33 and is made of acrylic resin. The diameter of the housing 35 including the centrifugal flow path portion was 45.2 mm, and the height was 37.4 mm.

The magnetically driven pump 31 was created by holding a permanent magnet 34 in an impeller 31 and housing the permanent magnet 34 in a housing 35.

A drive mechanism for driving the magnetically driven pump 31 was created as follows.
FIG. 4E shows the rotation drive unit 45 and the rotating magnetic body 46 of the power supply control device 4. A commercially available motor (manufactured by Maxon) was used as the rotation drive unit 45. The rotating magnetic body 46 was attached to the rotating shaft of the rotating drive unit 45. The rotating magnetic body 46 is made of nylon, and two permanent magnets 47 are embedded in a portion facing the permanent magnet 34, the magnetic poles of which are arranged to be different from each other. The rotation drive unit 45 and the rotating magnetic body 46 had a diameter of 38.6 mm and a length of 56.4 mm. FIG. 4F shows a permanent magnet 47 embedded in the rotating magnetic body 46. The permanent magnet 47 was a neodymium magnet (surface magnetic flux density 593 mT) and had a rectangular parallelepiped shape of 10 mm x 20 mm x 15 mm.

The right side of FIG. 4 shows the arrangement of the magnetically driven pump 31 and the power supply control device 4 when implemented on a tabletop. The permanent magnet 34 of the magnetically driven pump 31 and the permanent magnet 47 of the rotating magnetic body 46 were arranged to face each other. The permanent magnet 34 of the magnetically driven pump 31 and the permanent magnet 47 of the rotating magnetic body 46 were placed 20 mm apart to provide a gap similar to the skin.

Next, an electrically driven pump 21 was created using the following members.
As shown in FIG. 5G, the impeller 23 of the electrically driven pump has a permanent magnet 26 fitted into the upper permanent magnet holding part 27. The permanent magnet 26 is held by a permanent magnet holding portion 27 so that S poles and N poles alternately appear on the outer peripheral surface. On the other hand, the lower part has multiple wings. The impeller was made of acrylic resin. The height of the impeller 23 was 27.4 mm, and the outer diameter was 22.8 mm.

The housing 24 of the electrically driven pump is shown in FIGS. 5H and 5I. The housing 24 was made of acrylic resin. The diameter of the housing 24 including the centrifugal flow path portion was 44.8 mm, and the height was 48.4 mm.

In the lower part of FIG. 5, a casing 28 of the electrically driven pump and a plurality of coils 25 arranged in the casing 28 are shown. The coil 25 was created by winding copper wire around an iron core. The coil 25 is configured with a casing 28 to cover the housing 24 of the electrically driven pump. When the casing 28 encloses the housing 24, the coil 25 is provided so that the coil 25 and the permanent magnet 26 of the impeller 23 face each other.

The electrically driven pump 21 was created by enclosing an impeller 23 in a housing 24 and then enclosing it in a casing 28 in which a coil 25 was disposed.

[Experiment using the example of the auxiliary artificial heart system according to the first embodiment]
FIG. 6 shows an actual photograph during a tabletop durability test using the wireless artificial heart assist system 100 of the present invention.

The wireless ventricular assist device system 100 of the present invention was placed in the front (bottom) of FIG. 6 . The electrically driven pump 21 is connected to a portion corresponding to the internal control unit 50, an internal battery 51, and an internal coil 52, and reproduces transcutaneous power supply (transcutaneous energy transfer system (TETS)). Energy was transferred using an external coil 42.

The auxiliary artificial heart device 1 includes a medical tube simulating an artificial blood vessel connected to a sealed acrylic box 120 that resembles a circulatory system around the heart. The closed acrylic box 120 is configured to simulate the conditions of the heart and the circulatory system around the heart. The open acrylic box 114 is likened to the left atrium. The pressure in the open acrylic box 114 was adjusted to the height of the water surface so that the pressure at the inlet of the electrically driven pump 21 was 5 mmHg to 10 mmHg.
In addition, a faucet valve 121 was provided in the sealed acrylic box 120 and controlled to correspond to systemic vascular resistance.

A flow meter 123 was provided at the site of the medical tube used as the artificial blood vessel, and changes in the flow rate of the medical tube were measured.
Additionally, a pressure gauge 122 was provided to measure the pressure inside the sealed acrylic box 120 (corresponding to the pressure inside the circulatory system).
In the experiment, water was used because the density of blood is almost the same as water.

In the experiment, the electrically driven pump 21 was driven for 3 hours, and the magnetically driven pump 31 was driven for the remaining 21 hours. When switching from the electrically driven pump 21 to the magnetically driven pump 31, the rotation speeds of the electrically driven pump 21 and the magnetically driven pump 31 were controlled so that the output was maintained within a predetermined range.

[Results of experiments using the example of the auxiliary artificial heart system according to the first embodiment]
FIG. 7 shows the results of a tabletop durability test using the wireless artificial heart assist system 100, which was subjected to a one-week durability test.

In the table shown in FIG. 7, from the side, the flow rate of the magnetically driven pump 31 measured by the flow meter 123, the pressure range of the magnetically driven pump 31 measured by the pressure gauge 122, the flow rate of the electrically driven pump 21, and the pressure range of the electrically driven pump 21. , the power consumption of the internal battery 51, the power supplied in TETS, the power supply time in TETS, the total power supplied in TETS, the primary coil (external coil 42) temperature, and the secondary coil (internal coil 52) temperature.

In the durability test, there was almost no change in each value over time, so the values were recorded for one week around 20 to 30 minutes after switching from the magnetically driven pump 31 to the electrically driven pump 21. .

During the one-week durability test, there was no obvious damage to the housing or impeller of either the electrically driven pump or the magnetically driven pump. Furthermore, when switching between the magnetically driven pump 31 and the electrically driven pump 21, the switching could be done stably while maintaining the output. Furthermore, as shown in FIG. 7, there was no drop in pump flow rate or pressure during the one-week durability test, and the coil temperature was maintained at 40° C. or lower, close to body temperature, and charging was possible. The transcutaneous energy transmission system was used to charge the body's internal battery without any problems, and an electrically driven pump was responsible for circulation for three hours a day.

As described above, it was confirmed that the wireless artificial heart system 100 of the present invention operates without problems even in a situation simulating the environment around the heart.

〔Effect of the invention〕
In the present invention, with respect to the magnetically driven pump 31, even during rotation, an attractive force due to magnetic force acts between the rotating magnetic body 46 and the permanent magnet 34 of the magnetically driven pump, making it difficult for misalignment to occur.

In the present invention, charging of the internal battery 51 by the transcutaneous energy transmission system is performed while the magnetically driven pump 31 is being driven. There is no need to supply large amounts of power, which was previously the case, and charging can be done over time with low power. Therefore, temperature increases in the internal coil 52 and the external coil 42 are suppressed. Even if the temperature rises, the magnetic drive pump 31 is responsible for blood circulation, so unlike conventional systems, power supply can be stopped. Therefore, the risk of skin burns is small.

In the present invention, the magnetic drive pump 31 has a simple structure in which the rotary magnetic body 46 is rotated by the rotary drive body 45, and the permanent magnet 34 of the magnetic drive pump 31 and the rotary magnetic body 46 are rotated in synchronization. Malfunctions due to malfunctions are less likely to occur. Even if a malfunction were to occur, the problem is due to the positional relationship of the magnets, so there is a high possibility that it can be resolved without invasive procedures that require incisions.

In the present invention, for the electrically driven pump 21, since the internal battery 51 is present in the body, the device outside the body of the power supply control device 4 is not required while the electrically driven pump 21 is being driven, and the user's actions are not restricted. .

1: Assistive heart artificial heart device 4: Power supply control device 10: Artificial blood vessel 11: Skin 12: Left ventricle 13: Right ventricle 14: Left atrium 15: Right atrium 16: Aorta 17: Pulmonary artery 21: Electrically driven pump 22: First rotation Number detection means 23: Impeller 24 of the electrically driven pump: Housing 25 of the electrically driven pump: Coil 26 of the electrically driven pump: Permanent magnet 27: Permanent magnet holding part 28: Casing 31: Magnetically driven pump 32: Second rotation speed detection means 33: Impeller of magnetic drive pump 34: Permanent magnet of magnetic drive pump 35: Housing of magnetic drive pump 41: External power supply 42: External coil 45: Rotation drive mechanism 46: Rotating magnetic body 47: Permanent magnet 50: Internal control unit 51 : Internal battery 52: Internal coil 100: Wireless auxiliary artificial heart system 114: Open acrylic box 120: Sealed acrylic box 121: Faucet valve 122: Pressure gauge 123: Flow meter

Claims (6)

In ventricular assist devices that assist cardiac activity,
An electrically driven pump that connects to the heart via an artificial blood vessel and assists the heart's activity.
a magnetically driven pump connected to the electrically driven pump via an artificial blood vessel and connected to the aorta via the artificial blood vessel;
a control unit that controls outputs of the magnetically driven pump and the electrically driven pump;
Wireless ventricular assist device with. The wireless ventricular assist device according to claim 1, wherein the electrically driven pump and the magnetically driven pump are pumps to be implanted in the body. The electrically driven pump includes a housing having an inlet and an outlet;
an impeller that is rotatably housed in the housing and has permanent magnets arranged so that different poles alternately appear on the outer periphery of the impeller when rotated;
a coil for rotating the impeller, which is disposed radially outward with respect to the rotation axis of the housing;
The ventricular assist device according to claim 1, comprising: The magnetically driven pump includes a housing having an inlet and an outlet;
an impeller rotatably housed in the housing and coupled to a pair of permanent magnets with magnetic poles oriented in opposite directions;
a rotational drive mechanism that rotates the impeller;
rotation speed detection means for detecting the rotation speed of the impeller;
The wireless ventricular assist device according to claim 1, characterized in that it comprises: 5. The wireless artificial heart assistor according to claim 4, wherein the rotational speed detection means includes a coil that detects a change in the magnetic field caused by the rotation of the impeller of the magnetically driven pump and generates an alternating current. Device. The control unit is configured to determine that the total rotational speed of the magnetically driven pump and the electrically driven pump is within a predetermined range with respect to the rotational speed of the impeller of the magnetically driven pump that can be calculated from the frequency of the generated alternating current. 6. The wireless ventricular assist device according to claim 5, wherein a drive signal is sent to the electrically driven pump, and the electrically driven pump is driven at the rotational speed of the sent drive signal.