JPH0411226B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to improvements in pulsatile blood pumps.

In recent years, progress has been made in the development of artificial hearts to supplement and temporarily replace the functions of the heart outside the body during open-heart surgery and other surgeries.

The present invention is an improved form of a blood pump serving as an artificial heart. The blood pump in the present invention includes a blood introduction pipe 4 and a blood discharge pipe 5.
A bag-like blood chamber 2 made of a flexible polymeric elastic body is formed in communication with a pressure-resistant housing outer case 1 having a port 9 for introducing and discharging fluid through a collar 3. The housing is airtightly housed, and a fluid such as air, nitrogen, carbon dioxide, helium, or water is introduced or discharged from the port between the housing outer case and the blood chamber, and pressurization and depressurization are alternately repeated. Blood is pumped by compressing or expanding the blood chamber 2.

When a blood pump is used for an artificial heart, one of the characteristics required is excellent mechanical properties and durability. A particularly important factor governing the mechanical properties and durability is the joint between the blood chamber 2 and the pressure-resistant housing outer case 1.

The present invention improves the form of this joint, which is a collar, and communicates with a blood inlet pipe and a blood discharge pipe within a pressure-resistant housing outer case provided with ports for introducing and discharging fluid. A bag-shaped blood chamber made of an elastic polymer material formed by the above-mentioned method is housed, the blood introduction tube and the blood discharge tube are arranged, and the brim portion in which the blood chamber is connected is airtight with the housing outer case. The pump is a sac-type blood pump which is connected to the housing and which introduces and discharges blood by pulsating the blood chamber due to a change in fluid pressure within the housing outer case, and wherein the collar part is made of a material forming the collar part. This invention relates to a pulsating blood pump formed by embedding a highly rigid core material.

The housing outer case 1 of the blood pump according to the present invention has poor mechanical durability because positive pressure (approximately 200 mmHg) and negative pressure (approximately 40 mmHg) are impulsively and alternately applied at a rate of 60 to 120 times per minute. required. In addition, if the housing outer case is deformed due to the application of positive or negative pressure, the pressure waveform delivered by the blood pump will become dull, so the material for the housing outer case needs to be hard, and polycarbonate resin is usually the best material. It is used as.

In addition, as shown in the attached FIG. 1, the sac type that is commonly used as a blood pump has a flange portion 3 provided together with a blood inlet tube 4 and a blood discharge tube 5 when housing a blood chamber 2 in a housing outer case 1. is hermetically joined to the housing outer case. The brim, which is made of an elastic material such as polyurethane or soft polyvinyl chloride, is formed integrally with or in close contact with the blood chamber, and is therefore subject to large shocks due to repeated large stress concentrations caused by the pulsations of the blood chamber. It had the disadvantage of being deformed. This not only significantly reduces the function of the blood pump, but also poses a risk of separation of the joint between the collar and the housing outer case, which is a major problem from a quality assurance and clinical perspective. The present invention solves the above problem by suppressing deformation of the collar by embedding a highly rigid core material in the collar.

The flange part 3 is the first part in the sac type blood pump.
As shown in the figure, a blood inlet tube 4 and a blood outlet tube 5 communicating with a blood chamber 2 are arranged almost parallel in the upper part, and the bag-shaped blood chamber made of an elastic polymer is connected in the lower part. These are integrally formed.

The collar 3 is made of polyurethane, soft vinyl chloride, etc. as described above, but may be made of the same material as the blood chamber described later.

As the highly rigid core material 8, a metal such as stainless steel or brass may be used, and in the case of brass, it is preferable to apply chrome plating. For materials other than metals, polycarbonate,
Hard polymeric materials such as ABS, hard polyvinyl chloride, polymethyl methacrylate, polysulfone, polyamide, and polyester are used.

The method of embedding the core material in the brim 3 is to embed it within the brim during molding of the brim.
It may be inserted over the entire brim (excluding the introduction tube and discharge tube), or it may be embedded and disposed along the outer circumferential portion of the blood chamber. Further, a reinforcing material may be further provided on the collar portion in which the core material is embedded by adhesion, fixing with screws, or the like.

The housing outer case 1 and the flange portion 3 are joined together by adhesion, fusion, fastening, or the like.

The blood chamber 2 must be made of a flexible and elastic material for smooth pulsation, and is preferably made of a material with excellent mechanical properties and antithrombotic properties, so polyether-type polyurethane, plastic Polyvinyl chloride containing an agent is preferably used. Polyether-type polyurethane is a combination of long-chain polyether glycol with OH groups at both ends, such as polytetramethylene glycol (PTMG), and diisocyanate, such as diphenylmethane diisocyanate (ADI), or 2,4-toluene diisocyanate. refers to polyurethane produced by the polyaddition reaction of
Those containing PTMG and MDI as main components are preferably used in terms of mechanical properties and in-vivo deterioration. Furthermore, when polyvinyl chloride is used, it preferably contains a non-toxic plasticizer such as dioctyl phthalate. The degree of polymerization of polyvinyl chloride is 500~
2000 is used, and the amount of plasticizer used is 40 to 120 parts by weight per 100 parts by weight of polyvinyl chloride. If the inner surface of the blood chamber is coated with an antithrombotic material, the antithrombotic properties of the blood pump can be further improved and it is preferably used.

Embodiments of the present invention will be described below based on the accompanying drawings.

FIG. 1 is an exploded perspective view of a sac-type blood pump, and FIG. 1a shows a blood inlet pipe 4 and a blood discharge pipe 5 disposed almost parallel in the upper part, and the blood inlet pipe and the blood discharge pipe in the lower part. A collar portion 3 is integrally formed with an elastic bag-like blood chamber 2 that communicates with a tube. In this example, the collar, blood chamber, blood inlet tube, and blood outlet tube were all made using polyvinyl chloride (Zeon 121, manufactured by Nippon Zeon Co., Ltd.) containing 70% by weight of dioctyl phthalate.
Figure 1b shows a housing outer case 1 having a port 9 made of polycarbonate, and since the flange and the housing outer case are fastened together using screws, any number of screws can be used. A screw hole 10 is provided in each of the collar and the housing outer case. FIG. 2 shows the blood pump shown in FIG. 1, in which the core material 8 is embedded inside the collar 3 at the time of molding the collar. The core material used in this example is a 2.5mm thick brass plate with chrome plating.
The housing is embedded not only at the peripheral edge where it joins with the outer case, but also over almost the entire surface except for the portion occupied by the blood introduction tube 4 and the blood discharge tube 5. Using the blood pump according to the present invention manufactured in the above embodiment, positive pressure (300 mm
Pulsation tests were conducted over two months by repeatedly applying negative pressure (40mmHg) and negative pressure (40mmHg). As a result of this test, no deformation due to pulsation was observed in this example reinforced with a core material. For comparison, a similar pulsation test was conducted using the pump-type blood pump shown in FIG. 1 without a core material attached. As a result, when the blood pump pulsated and the inside of the housing outer case was pressurized, the collar swelled shockingly and violently, and leakage (gas leakage) was observed at the adhesive point of the collar after two weeks of use.

As can be seen from the above results, the sac-type blood pump according to the present invention, which is formed by embedding the core material in the collar, has the core material integrally embedded in the collar, so the blood chamber speed increases. It has features such as preventing impact deformation of the collar due to repeated large stress concentration caused by motion, and also preventing separation of the joint from the housing outer case, thus improving mechanical strength and durability. It has the characteristics of being excellent and safe for clinical use.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of a sac-type blood pump according to the present invention, in which FIG. 1a shows a blood chamber portion having a flange, FIG. 1b shows a housing outer case portion, and FIG. 2 shows a housing outer case portion. FIG. 2 is a longitudinal cross-sectional view of a blood chamber portion formed by embedding a core material in the collar of a sac-type blood pump. In the figure, reference numeral 1 indicates a housing outer case, 2 indicates a blood chamber, 3 indicates a collar, and 8 indicates a core material.

Claims (1)

[Claims] 1 In a pressure-resistant housing outer case provided with ports for introducing and discharging fluid,
A bag-shaped blood chamber made of an elastic polymer body formed in communication with a blood introduction tube and a blood discharge tube is housed, and the blood introduction tube and blood discharge tube are disposed,
A sac type in which the brim portion with the blood chamber connected thereto and the housing outer case are hermetically joined, and the blood chamber is pulsated by changes in fluid pressure within the housing outer case to introduce and discharge blood. What is claimed is: 1. A pulsating blood pump, which is formed by embedding a core material having higher rigidity in the brim portion than the constituent materials of the brim portion.