JPH06296684A - Blood pump and its production - Google Patents

Abstract

PURPOSE:To provide the diaphragm type blood pump having the durability and excellent antithrombotic property by smoothing the joint part of its housing and a diaphragm. CONSTITUTION:This blood pump has an extremely smooth joint part of a diaphragm and a housing. This process for production of the blood pump consists of forming the joint part by pouring a blank material soln. of the same compsn. as the compsn. of the diaphragm housing in joining of the joint part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an artificial organ for maintaining the systemic circulation of a patient whose heart function is deteriorated and for recovering the heart function, and to a blood pump for maintaining the circulation and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, as a blood pump for an extracorporeal circulation circuit which is a cardiac assisting circulatory device after open heart surgery, a roller pump type which produces a steady flow, a centrifugal pump type, a tubular type which produces a pulsatile flow, and a pusher plate. A diaphragm type is known in addition to a die type, a sack type, and the like.

This diaphragm-type blood pump draws air into a blood chamber formed by a housing having a blood outflow / inflow port and a diaphragm, and an air chamber formed by a back plate having an air outflow port. It is a blood pump that changes the volume of the blood chamber in response to contraction and expansion of the diaphragm when it is inserted to produce a pulsatile flow.

After the housing and the diaphragm are manufactured in separate steps, the housing and the diaphragm are joined together, and the vicinity of the junction is located at the most driving part of the diaphragm drive.

This diaphragm type blood pump can support circulation for a longer period of time than a steady flow type pump. Among the pulsatile flow type pumps, this diaphragm type has an excellent pumping ability and the flow rate relative to the capacity of the pump. The auxiliary efficiency is high and miniaturization is possible, and there is no hemolysis due to the collision of blood chambers unlike the sack type.

Therefore, the use of this diaphragm type blood pump has been increasing in recent years as a blood pump for a cardiac assist circulation device after open heart surgery because of the length of the circulation support period and the high flow assist efficiency. .

[0007]

When using an auxiliary artificial heart, the most concerned point is the coagulation reaction or thrombus due to the contact of blood with a foreign substance. On the blood contact surface of the auxiliary artificial heart,
Although antithrombogenic materials such as segmented polyether type urethane urea are used and have good antithrombotic properties, it is desirable for the antithrombotic properties that the surface of this material be as smooth as possible.

As a conventional manufacturing method, a solution having the same composition as the solute for forming the housing and the diaphragm is injected into a part of the junction part of the temporarily fixed housing and the diaphragm, and the junction part is gradually dried by repeating a process of drying. Is buried and the two are joined.

According to this method, there is a problem that bubbles are left at the junction and unevenness is seen at the junction on the blood contact surface of the housing and the diaphragm, so that the site tends to become a thrombus-prone site due to lack of smoothness.

There is also a problem in that the diaphragm cannot be maintained stably because of insufficient thickness of the junction portion on the blood contact surface, the diaphragm is ruptured, expanded, or contracted poorly.

The present invention has been made to improve the above circumstances. That is, an object of the present invention is to establish a manufacturing method for obtaining the smoothness and strength of the junction portion on the blood contact surfaces of the housing and the diaphragm.

[0012]

According to the present invention for solving the above-mentioned problems, a solute having the same composition as that of a solute for forming a housing and a diaphragm for joining in a gap found in a portion corresponding to a junction portion before joining the housing and the diaphragm is provided. So that the solution with solute is uniformly filled, by operating under reduced pressure, the bubbles blown in the gap are foamed, and by rapidly returning to normal pressure, the solution is instantly filled into the foaming bubbles. After the air bubbles are filled with the solution and the solution is discharged so as to coat the entire inner surface of the blood pump, the junction part is installed so that the junction part faces the direction of gravity so that the solution remaining in the blood pump collects at the junction part. The blood porosity is characterized in that the wall thickness of the junction part is obtained by spin drying so that a part of the part comes to the bottom. It is a method of manufacturing-flops.

The present invention will be described in detail below. Temporarily fixed to form a blood pump Blood pump Pour the required amount of polyurethane solution into the blood chamber, tilt the pump, etc. to spread the solution over the entire inner surface of the blood pump and coat it to make the inner surface wet and reduce the pressure afterwards. At the time of foaming of the solution below, fine bubbles on the coating surface are also filled with the solution when returning to normal pressure. Bubbles are repeatedly vigorously foamed at the time of depressurization even from the gap corresponding to the junction between the housing and the diaphragm, and when the pressure is rapidly returned to normal pressure, the bubbles are filled with the solution and disappear, and the gap can be completely filled. By the above method, the smoothness of the junction portion after drying can be obtained.

After filling the gaps in the junction portion and confirming that there is no foaming from the junction portion, the solution is discharged while allowing the entire inner surface of the blood pump to be spread with the solution, and an appropriate amount of the solution is intentionally left in the junction portion. By dissolving the polyurethane in the vicinity of the portion corresponding to the junction portion of the housing and the diaphragm, a stronger joining force can be obtained and the thickness of the junction portion can be obtained at the same time.

By coating with a polyurethane solution having the same composition as the solute from which the housing and diaphragm are made, it is possible to integrate the entire inner surface of the blood pump between the housing, the diaphragm and the inner surface coating solution. It was possible to establish an almost completely integrated molded product, rather than the concept of joining parts such as and diaphragm to each other, and the smoothness and durability were remarkably improved from the conventional method, and the yield was also greatly improved.

[0016]

[Example] Diaphragm mold in which a portion of a housing designed to be smaller than the diaphragm mold is dipped in acetone to swell the part corresponding to the joint with the diaphragm, and the film is already cast on the mold surface. Cover the above with the above housing, push it in until the part corresponding to the diaphragm die side pump junction part and the part corresponding to the housing side pump junction part match, and the acetone contained for swelling in a dedicated dryer. Both are temporarily fixed by using the shrinkage of polyurethane while evaporating. The combination of the two forms a blood pump. This matched blood pump is filled with an appropriate amount of a solution having the same composition as the solute that forms the housing and the diaphragm in the blood chamber, and the pump is tilted so that the solution does not overflow from the housing inflow / outflow port. And make the inner surface wet with the solution.

Next, the diaphragm die is placed on a dedicated pedestal so that the entire area of the junction is uniformly immersed in the solution, and the pump is allowed to stand in the defoaming chamber of the vacuum casting machine together with the pedestal. The pressure in the pump is depressurized to defoam the solution in the pump, and the degassing chamber is leaked for a moment so that the solution does not overflow from the housing outflow inlet. Prevent spillage from the housing outlet. The above operation is repeated until the solution does not overflow from the housing outflow port, and the defoaming chamber is returned to normal pressure all at once with clean nitrogen. The pump is taken out of the defoaming chamber, the solution is spread over the entire inner surface of the pump again, and then the solution is gently discharged from the outlet of the housing so as not to foam, and is dried in a dedicated rotary dryer for a predetermined time.

[0018]

INDUSTRIAL APPLICABILITY The present invention, which is operated under reduced pressure, has been a subject of the prior art, and the method of joining the housing and the diaphragm, which is the most critical point of the diaphragm blood pump, is completely different from the conventional method. Is. Removal of bubbles by vacuum defoaming and filling of the solution could dramatically improve smoothness and durability. Further, the present invention is applicable not only to the manufacturing method of the diaphragm type blood pump but also in a wide range.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view showing an example of a blood pump of the present invention.

FIG. 2 is an enlarged sectional view of a blood pump junction portion of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Diaphragm 3 Junction part 4 Blood chamber 5 Blood outflow / inflow port a Junction part according to the present invention b Junction part by conventional method c Junction part by conventional method

Claims (2)

[Claims] 1. A blood chamber is formed by a housing portion having a blood outflow inlet to which a check valve is attached and a thin film diaphragm, and an air chamber is formed by a back plate having an air port portion and the diaphragm.
In a diaphragm type blood pump characterized by pulsating the diaphragm by introducing air into the air chamber to introduce and discharge blood, in the blood chamber, the diaphragm and the junction part of the housing part are seamless and have no steps. A blood pump having a curved surface. 2. When joining the diaphragm of the diaphragm type blood pump and the housing, (1) the housing is closely fixed to a die formed by casting the diaphragm, and (2) the outlet or the inlet of the housing to the diaphragm. And at least the amount of the elastomer solution dissolved in a solvent capable of dissolving the housing so that the diaphragm and the junction part of the housing are immersed, (3) the solution is discharged from the outlet or the inlet, and (4) the solvent is evaporated. A method for manufacturing a blood pump, characterized in that the pump is dried so that the diaphragm and the housing are integrated without any gap.