JP2006204343A - Auxiliary artificial heart - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an auxiliary artificial heart dispensing with a special processing or means and having superior antithrombogenicity in a simple structure. <P>SOLUTION: This auxiliary artificial heart is provided with a spherical segment body 11, a diaphragm 20 partitioning the interior of the body into a blood chamber and a fluid chamber, an inflow duct 31 and an outflow duct 32 opened to the blood chamber, and a driving source feeding the fluid for driving the diaphragm to the fluid chamber through a driving fluid deed pipe 38; and is formed by having a semispherical projection part at the top of the diaphragm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an auxiliary artificial heart using a diaphragm, and more particularly, to an auxiliary artificial heart excellent in antithrombogenicity capable of preventing a stagnation portion of blood flow and obtaining a smooth flow of blood flow.

  An auxiliary artificial heart using a diaphragm has a simple structure, excellent volumetric efficiency, and little damage to blood, and thus has been studied for many clinical applications. One of the important problems in the practical application of this auxiliary artificial heart is the generation of thrombus.

  As a means for preventing the occurrence of thrombus, for example, Patent Document 1 discloses that a blood contact surface of an auxiliary artificial heart includes a functional group contained in an oxide of a substrate surface generated by ozone treatment, an amino group of heparin, However, assistive artificial hearts have been proposed that have an antithrombogenic surface that is covalently bonded, either directly or via at least one coupling agent.

  Patent Document 2 proposes a decomposable auxiliary artificial heart that can easily and quickly remove and clean a thrombus, assuming that thrombus is inevitable.

Japanese Patent Laid-Open No. 06-105902 JP 2002-102333 A

  However, in the auxiliary artificial heart proposed in Patent Document 1, it is easy to form an antithrombogenic layer on all inner surfaces that come into contact with blood of the auxiliary artificial heart, including the check valve portion having a complicated shape. However, there is a problem that it is difficult to ensure a homogeneous antithrombogenic layer. In addition, the auxiliary artificial heart proposed in Patent Document 2 has a problem that it takes time to disassemble, clean and reassemble the auxiliary artificial heart.

  An object of the present invention is to provide an auxiliary artificial heart that has a simple structure and excellent antithrombogenicity without requiring any special treatment or means in view of such conventional problems.

  An auxiliary artificial heart according to the present invention includes a spherically-shaped main body, a diaphragm that divides the inside of the main body into a blood chamber and a fluid chamber, an inflow conduit and an outflow conduit that open to the blood chamber, and a drive to the fluid chamber An auxiliary artificial heart having a drive source for supplying a fluid for driving the diaphragm through a fluid supply pipe, wherein a hemispherical convex portion is provided on the top of the diaphragm.

  In the above-mentioned auxiliary artificial heart, it is preferable that the inflow conduit and the outflow conduit are arranged on a parallel line sandwiching a hemispherical convex portion provided in the diaphragm, and the inflow conduit and the outflow conduit are located with respect to the main body attachment portion of the diaphragm. Are preferably provided parallel or inclined.

  The artificial heart according to the present invention has a simple structure and does not require any special treatment or means, can prevent the occurrence of stagnation of blood flow in the blood chamber and obtain a smooth blood flow, and prevent the occurrence of thrombus. Can be prevented.

  An auxiliary artificial heart according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of the auxiliary artificial heart, and FIG. 2 is a cross-sectional view taken along the line AA in FIG. As shown in FIGS. 1 and 2, the auxiliary artificial heart includes a main body 11, a diaphragm 20 that divides the body 11 into a blood chamber 16 and a fluid chamber 18, an inflow conduit 31 and an outflow conduit 32 that open to the blood chamber 16. And a drive fluid supply pipe 38 that opens to the fluid chamber 18, and a drive source (not shown) that supplies the drive fluid of the diaphragm through the drive fluid supply pipe 38.

  The main body 11 has a spherical shape, and a blood chamber 16 is formed in the spherical portion at the top. The main body 11 is preferably made of a polyurethane resin having high antithrombogenicity. An acrylic resin coated with a polyurethane resin may be used. Further, the main body 11 may be integrally formed and cannot be disassembled, and the upper spherical portion and the lower portion may be integrally disassembled by, for example, screw connection provided at the peripheral portion thereof. You can also.

  As shown in FIG. 3, the diaphragm 20 has a medium-high disk shape, and in the present invention, a hemispherical convex portion 25 is provided at the top thereof. A flange 23 is formed at the peripheral edge of the diaphragm 20, and the diaphragm 20 is fixed to the main body 11 by being sandwiched between the attachment portions 12 of the main body 11 as shown in FIG. 2. The main body 11 is partitioned by the diaphragm 20 into an upper blood chamber 16 and a lower fluid chamber 18. The diaphragm 20 can be fixed to the main body 11 by a method such as adhesion, fusion, or fastening by screws.

  For the diaphragm 20, silicon rubber and polyurethane rubber having elasticity and high toughness can be used. The material of the diaphragm 20 is preferably the same as that of the main body 11 and both are made of polyurethane resin. Thereby, mutual adhesion etc. can be performed easily and the auxiliary artificial heart excellent in antithrombogenicity can be shape | molded.

  The inflow conduit 31 opens into the blood chamber 16 of the main body 11 as shown in FIG. An inflow check valve 35 is provided in the vicinity of the opening 13 of the inflow conduit 31, and blood can flow into the blood chamber 16 through the inflow conduit 31 but cannot flow out of the blood chamber 16. An outflow conduit 32 opens into the blood chamber 16 of the main body 11, and an outflow check valve 36 is provided in the vicinity of the opening 14 of the outflow conduit 32. Thereby, blood can flow out of the blood chamber 16 through the outflow conduit 32, but cannot flow into the blood chamber 16.

  In this example, the inflow conduit 31 and the outflow conduit 32 are disposed in parallel, and are disposed on parallel lines that sandwich the hemispherical convex portion 25 of the diaphragm 20. As a result, the blood flowing into the blood chamber 16 from the inflow conduit 31 circulates around the hemispherical convex portion 25 along the peripheral wall portion of the main body 11, and then easily flows out from the outflow conduit 32, thereby forming a smooth blood flow. Is done.

  The driving fluid supply pipe 38 is open to the fluid chamber 18, and a fluid for driving the diaphragm 20 is supplied from a driving source through the driving fluid supply pipe 38. The driving fluid can be a gas or a liquid. As the drive source, for example, a simplified drive device for an auxiliary artificial heart described in Japanese Patent Application Laid-Open No. 2004-275302, which can repeatedly perform air supply and suction, for example, can be preferably used.

  The state of blood flow in such an auxiliary artificial heart is shown in FIG. Each of (a) shows the direction of blood flow in the early stage of pump expansion, (b) shows the direction of blood flow in the middle stage of pump expansion, a long arrow shows a fast flow rate, and a short arrow shows a slow flow rate. (C) shows the streamline of blood flow at the end of diastole. The denser the streamline, the stronger the flow in a certain direction. (D) shows the direction of blood flow in the initial stage of pump contraction.

  As a comparative example of the present invention, the state of blood flow in the case of an auxiliary artificial heart that differs only in that the diaphragm does not have a hemispherical convex portion 25 is shown in FIG. FIGS. 5A to 5D correspond to the case of FIG. 4 and 5, it can be seen that the artificial heart of the present invention has a constant strong flow direction throughout the blood chamber 16 and no stagnation of blood flow.

  Comparing FIG. 4 (d) and FIG. 5 (d) showing the direction of blood flow in the initial stage of pump contraction, in the present invention example, the opening 14 of the outflow conduit 32 extends from the center of the blood chamber 16 along the peripheral wall of the main body 11. A swirling blood flow swirling towards is seen. On the other hand, in the comparative example, blood flow that collides with the peripheral wall of the main body 11 opposite to the opening 14 of the outflow conduit 32 from the center of the blood chamber 16 is seen.

  4 and 5 show that in the example of the present invention, the blood flow flows around the hemispherical convex portion 25 of the diaphragm. On the other hand, in the comparative example, it is understood that a spiral blood flow is difficult to be generated, and even if a spiral blood flow is generated, the central portion of the spiral is not clear and the flow tends to be a weak spiral.

  As described above, in the auxiliary artificial heart according to the present invention, a swirling blood flow is easily generated over the entire blood chamber 16 around the hemispherical convex portion 25 of the diaphragm. In addition, it is easy to form a smooth blood flow in which blood flowing in from the inflow conduit 31 circulates around the hemispherical convex portion 25 along the peripheral wall portion of the main body 11 and then easily flows out from the outflow conduit 32. For this reason, in this auxiliary artificial heart, it turns out that the stagnation part of a blood flow is hard to be produced and it is hard to produce a thrombus.

  4 and 5 were obtained using the PIV method in which the flow is visually analyzed from the change in the intensity of the laser beam in which the visualization agent and the laser light sheet are combined. As the laser light sheet, 35 mW He-Ne and 10 mW He-Ne laser light sheet were used. The tracer used was 200-400 μm polystyrene beads. We used a 100fps NTSC type high sensitivity CCD camera.

  As described above, this auxiliary artificial heart is unlikely to have a stagnation part due to blood flow, can obtain a smooth blood flow throughout the blood chamber, and thrombus is unlikely to occur. In order to obtain such an effect sufficiently, it is necessary to optimize the shape, maximum diameter, height, etc. of the hemispherical convex portion 25 of the diaphragm 20 by the analysis using the PIV method described above for each auxiliary artificial heart. is there.

  The present invention is not limited to the above embodiments. For example, as shown in FIG. 6, the inflow conduit 31 and the outflow conduit 32 can be attached to the main body attachment portion 12 of the diaphragm in an inclined manner. In this case, a stagnation portion is less likely to occur in the blood flow, and a smooth blood flow can be obtained throughout the blood chamber 16. The angle θ of the inflow conduit 31 and the outflow conduit 32 with respect to the diaphragm main body attachment portion 12 (the bottom surface of the main body 11) is preferably 45 ° or less, and preferably 30 ° to 45 °.

It is a front view of the auxiliary artificial heart according to the present invention. It is AA sectional drawing of FIG. It is a perspective view of a diaphragm. It is a schematic diagram showing the state of the blood flow of the auxiliary artificial heart. It is a schematic diagram showing the state of the blood flow of the auxiliary artificial heart of a comparative example. It is a perspective view which shows the Example which inclined and attached the inflow conduit and the outflow conduit to the main body attachment part of the diaphragm.

Explanation of symbols

11 Body
12 Body attachment
13, 14 opening
16 Blood chamber
18 Fluid chamber
20 Diaphragm
23 Flange
25 Hemispherical convex part
31 Inflow conduit
32 Outflow conduit
35 Inflow check valve
36 Outflow check valve
38 Drive fluid supply pipe

Claims (3)

A spherically-shaped main body, a diaphragm that divides the inside of the main body into a blood chamber and a fluid chamber, an inflow conduit and an outflow conduit that open to the blood chamber, and a drive fluid supply pipe to the fluid chamber for driving the diaphragm An auxiliary artificial heart having a drive source for supplying fluid,
An auxiliary artificial heart comprising a hemispherical convex portion at the top of the diaphragm.   The auxiliary artificial heart according to claim 1, wherein the inflow conduit and the outflow conduit are arranged on a parallel line sandwiching a hemispherical convex portion provided in the diaphragm.   The auxiliary artificial heart according to claim 1 or 2, wherein the inflow conduit and the outflow conduit are provided parallel to or inclined with respect to the main body attachment portion of the diaphragm.

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