JPS6185952A - blood pump device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a blood pump device, for example, a sac blood pump device for an artificial heart. At the same time, the development of artificial hearts to supplement and temporarily replace the functions of the heart outside the body is progressing. For example, as shown in FIG. 6, a sack blood pump device 11 is connected between the right atrium and the pulmonary artery of the living body's heart 10, and between the left atrium and the aorta.

FIGS. 7 to 9 show the basic form of the sac-type blood pump and blood chamber that constitute the artificial heart shown in FIG. g6. This sack-made blood pump consists of a pressure-resistant (for example, made of polycarbonate or polyurethane) housing outer case l, and a flat sack-like blood chamber 2 that is hermetically housed within the housing outer case. At the upper part of the blood chamber 2, a blood introduction pipe 3 and a blood discharge pipe 4 are formed upwardly and substantially parallel to each other, communicating with the blood chamber.
A flange portion 5 forming a part of the housing is provided around the upper portion of a portion of the blood chamber, and the blood chamber 2 is hermetically housed within the housing outer case 1 by this flange portion 5. In addition, a known backflow valve 6.7 is installed inside each of the blood introduction tube 3 and the blood discharge tube 4 to prevent backflow of the blood 12.
The blood 12 introduced into the blood chamber 2 is pumped out from a blood discharge pipe 4. Blood is pumped out by alternately introducing and discharging fluid, such as compressed air, through a port 8 provided at the bottom of the housing outer case 1, and the blood chamber 2 expands and contracts as the external pressure of the blood chamber changes. This is done by giving back.

FIG. 10 shows an enlarged cross section of the main part of the blood pump described above (a cross section of the main part outside along line XX in FIG. 8). Here, the housing outer case 1 is fixed to the flange part 5 with screws 14 through a metal fixing plate 13, and the blood chamber 2 is connected to the 7-rank part with its outer surface being at a substantially right angle as shown in the figure. 5 are integrally connected.

Regarding the sac-type artificial heart as described above, the present inventors
In a simulation experiment using a mechanical device, we repeatedly tested the durability of the pump and investigated a blood pump that could be used for a long period of time.

As a result, the data shown in Table 1 below was obtained.

Table 1: Status of jar after the above pulsation time elapsed From the results shown in Table 1, the following can be concluded.
That is, if the number of beats is increased or the amount of deformation becomes excessive as in this simulation experiment, cracks will occur in the sac, especially at the base 2a of the blood chamber 2 in FIG. phenomenon was observed.

The inventor investigated this phenomenon and found that it is because the outer surface of the blood chamber 2 is connected to the adjacent part of the lower end surface of the seventh rank part 5 at a nearly right angle, as shown in FIG. It was found that this is because when the blood chamber 2 expands and further contracts as shown by the dashed line, stress tends to concentrate at the base 2aiC, and rupture at this portion tends to proceed.

C. OBJECTS OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and its object is to provide a blood pump device that does not break and has significantly improved durability.

2. Structure of the invention, that is, in the blood pump device according to the present invention, the expandable and contractible sack part forming the blood chamber is arranged in the seventh rank part of the housing part, which is composed of the outer case part surrounding the sack part and the seventh rank part. In the blood pump device, the root region of the sack portion with respect to the housing portion has a taper (for example, an arcuate taper 21 described later) on at least the outer surface thereof, and the taper makes the root region It is characterized in that the cross section is enlarged and is integrally connected to the housing part.

E. Example Hereinafter, an example in which the present invention is applied to a sac-type blood pump device for an artificial heart will be described in detail with reference to FIGS. 1 to 5. However, since the blood pump device according to this embodiment is basically the same in usage and external shape as shown in FIGS. 6 to 9, only its main parts are shown in FIGS. 1 to 5. (Fig. 1 and Figs. 3 to 5 are all sectional views of the same parts as Fig. 10, and Fig. 2 is a corresponding partially enlarged sectional view taken along the line ■-■ in Fig. 9.) It shows.

According to the first embodiment shown in FIGS. 1 to 3, the sac-shaped blood chamber 2 is integrally connected to the adjacent part of the 7-rank part 5 that forms a part of the housing. A groove 20 having a substantially semicircular cross section is formed around the entire circumference of the blood chamber 2 on the outer side of the portion (or root region) 2a. Therefore, an arcuate taper 21 exists on the outer surface of the base 2a of the blood chamber 2, and this taper allows the base 2a to be integrally connected to the housing side while its cross section is continuously enlarged. . Also,
In the area on the inner surface side of the blood chamber 2a, a thick connecting portion 22 connecting the blood inlet tube 3 and the blood discharge tube 4 (see also FIG. 7 for both) described above is connected to the seven flange portions 5. , are integrally provided forming a smooth surface to prevent swirling.

Therefore, in each of the embodiments shown in FIGS. 1 to 5, the structure is such that the blood flow on the inner surface of the chamber is smooth and does not cause thrombus or the like.

In this way, since the root portion 2 & of the blood chamber 2 is connected to the housing side while the cross section is continuously enlarged by the taper 21 (in other words, the wall thickness is gradually enlarged), As shown by the dashed line in , when the sack portion 2 is expanded (furthermore, when it is contracted from the expanded state), the base portion 2a smoothly elastically deforms in the direction of decreasing (or increasing) the curvature of the curved surface of the taper 21. Just do it. Therefore, compared to the case shown in FIG. 10, the stress or concentration of stress applied to the root portion 2a is significantly alleviated, and the durability is greatly improved even under severe driving conditions, and it can last for 5 to 10 times longer. It will be durable for use.

In order to obtain such remarkable effects, the shape and size of the groove 20 or taper 21 described above are desirably set as follows. That is, in FIG. 3, if the diameter of the groove 20 is the distance between the base 2& at the lower edge position of the R1 groove 20 and the fitting position of the case 1 with respect to the 7 flange 5, then Desirably, if the angle is too high, the fixing state of the case 1 to the 7-lung portion 5 will be unstable, and both the fixing stability of the case 1 and the fixing stability of the case 1 can be sufficiently realized under long-term driving conditions. In addition, R may generally be R)0, but specifically R = 4 to 811 to fully obtain the effect of the taper 21.
1Illφ, l=8 to 16IIIllI.
Also, the thickness t of the base portion 2a at the lower edge position of the groove 20
is a maximum of 3 mm (the thickness of the thin portion 2b of the blood chamber 2 is 0.6 to 1.4 mm), and the maximum thickness of the 7-lung portion 5 is t'
may be 7 to 10 mm.

Note that in order to form the above-mentioned groove 20, a rib corresponding to the groove 20 is pre-existing in the mold when molding the upper part of the housing with the seven flange portions 5 integrally with the blood introduction tube and the blood discharge tube. All you have to do is process it like this. Using such a ribbed mold (lower mold), the upper part of the housing is first created by a normal molding process. next,
The upper part of the housing (or the upper lid of the housing) is liquid-tightly attached to a container-shaped slush molding mold, and polyvinyl chloride plastisol is charged into the mold, and by heat transfer from the outside of the mold, The blood chamber 2 described above is integrally molded to the upper part of the housing.

As a method for seamlessly integrating the inner surface of the bag-shaped molded product in this way, it is possible to use the method already proposed by the present inventors in Japanese Patent Application No. 175257/1982.

The effect of providing the groove 20 or the taper 21 described above was confirmed by an experiment shown in Table 2 below using a type with a maximum stroke capacity of 17 cc.

Table 2 In this result, based on the present invention, blood chamber 2
By providing a groove 20 at the base 2 of the
The number of beats is 150 or 200; however, the amount of blood ejected is 2 to 3.
54! /min. ), the number of days until cracks appear in the sack increases by approximately three times, indicating that durability is significantly improved. This fact is surprising when used under such severe conditions as described above, and clearly demonstrates the superiority and sufficient practicality of the blood pump according to the present invention.

FIG. 4 shows a second embodiment of the invention.

In this embodiment, a groove 30 having a linearly inclined taper 31 is formed in place of the groove 20 shown in FIG. However, the angle θ between the outer surface of the blood chamber 2 and the taper 31 should be θ>900, and 130≦
It is desirable that θ≦160. If this angle is 90
If the angle is θ>90° or less, the same drawback as the conventional device shown in FIG. 10 will occur, but by setting θ>90°, that is, an obtuse angle, the root 2a
The wall thickness of the housing is gradually increased and the housing is connected to the housing. As a result, stress concentration at the root portion 2a is alleviated, and durability is significantly improved.

FIG. 5 shows a third embodiment of the invention.

In this embodiment, in the conventional apparatus shown in FIG. 10, a synthetic resin 40 such as soft polyvinyl chloride is placed in the corner between the outer surface of the base 2a of the blood chamber 2 and the lower end surface of the flange 5 using a syringe. As a result, a curved or linear taper 41 is formed on the surface of the synthetic resin coated portion 400 that is integrated with the root portion 2a.

The coating widths w and vr' of the synthetic resin coating portion 40 are set so that the taper 41 is sufficiently formed, and may each be, for example, a minimum of 1 mm. Therefore, this synthetic resin coated part 40 firmly adheres to the blood chamber 2 and the flange part 5 and becomes completely integrated, so the presence of the synthetic resin coated part 40 makes the wall thickness of the base part 2a continuous toward the housing side. As a result, durability can be improved by alleviating stress concentration in the same way as described above.

Further, in FIG. 5, the base portion 2a is connected to the above-mentioned connecting portion 22 with a curved surface, and this curved surface, together with the above-mentioned taper 21 (or 31.41), prevents blood flow. This facilitates smooth elastic expansion and contraction of the chamber 2.

Since it is desirable that the connecting portion 22 originally has sufficient mechanical strength, if the connecting portion 22 is made thicker to the position shown by the dashed line in FIG. 5, the mechanical strength becomes even more sufficient. The thickness increase measure of the connecting portion 22 may be 3 to 4 mm.
However, if it is made too thick, the expansion and contraction of the blood chamber 2 will not occur smoothly, which may cause blood retention points inside and cause blood clotting, so it is necessary to take this into account when determining the above. be.

As described above, it has been confirmed that as a result of making the connecting portion 22 thicker, better durability than the above-mentioned device can be obtained in some cases. For example, the maximum stroke capacity is 17cc, the pulse rate is 150 b, p, m, and the driving pressure is +250I.
II [llHg, -50mmHg, the number of days until cracks appear in the sack (durability) is from 48 days to 85 days
It turns out that it is possible to extend it to a day.

In each of the above-mentioned embodiments, the blood chamber 2 and the conduit 3.4, that is, the parts that come in contact with blood, can be made of an elastic polymeric material, and soft polyvinyl chloride or polyurethane is preferable as the material. There is. in this case,
The soft polyvinyl chloride may be molded from a so-called polyvinyl chloride paste consisting of polyvinyl chloride and a plasticizer composition. A suitable plasticizer that can be used for this flexible polyvinyl chloride is dioctyl phthalate (D
OP), dibutyl phthalate (DBP), butylpenzyl phthalate (BBP), dioctyl adipe) (D
OA), butylphthalyl butyl glycolate (BPBG)
), methyl acetyl lysyl (MAR), and acetyl tributyl cider (ATBC). In this case, the amount of plasticizer mixed is preferably 40 to 100 parts by weight, more preferably 50 to 80 parts by weight, based on the polyvinyl chloride.

The polyvinyl chloride may also contain suitable known stabilizers, such as non-toxic calcium-zinc organic complexes. The degree of polymerization of polyvinyl chloride is 500 to 200
It is preferable to use one with a value of 0.

Polyurethane used as a material can be roughly divided into polyether polyurethane and polyester polyurethane, both of which can be used, but polyether polyurethane is used from the standpoint of elasticity, fatigue resistance, and hydrolysis resistance. is preferable. Since the blood chamber is required to have elastic properties, elastic recovery properties, and fatigue resistance properties, it is optimally constructed from polyether-based polyurethane. As the polyether part of the polyether polyurethane, polyethylene glycol, polypropylene glycol, pentamethylene glycol, diglyme, etc. can be used.

When the blood chamber 2 is made of soft polyvinyl chloride in the above embodiment, the film thickness of the blood chamber 2 is 0.3 to 2.0 m due to its repulsion characteristics and fatigue resistance.
It is preferably 0.6 to 1.2 mm, and more preferably 0.6 to 1.2 mm. Further, when the blood chamber 2 is made of a polyurethane material, the film thickness is preferably 0.2 to 1.5 mm, and more preferably 0.5 to 1.0 mm.
If this thickness is too large, the housing outer case 1
When pressurizing or depressurizing the inside, the timing of the operation of the blood chamber 2 is delayed or the deformation time is prolonged, making it impossible to obtain an appropriate blood pumping behavior. vice versa,
If this film thickness is too thin, the deformation behavior of a portion of the blood chamber becomes sensitive, making it difficult to control it. Furthermore, when driven with excessive pressure, there is a risk that the sack portion will break.

As the reverse valve 6.7 used in the above embodiment, a known or commercially available valve can be used.

Such known or commercially available valves include ball type, disk type, leaflet type, central flow type, and the like.

In the blood pump device of the above embodiment, the surface that comes in contact with blood is coated with a substance having excellent antithrombotic properties.
Compatibility with blood can be improved. For example, surface treatment with dimethylsiloxane, coating treatment with a block copolymer of polyether polycretan-borodimethylsiloxane, etc. may be performed.

Further, since the housing outer case 1 is required to have high strength and transparency, it is made of hard polyvinyl chloride, polycarbonate, polysulfone, or the like.

Although the present invention has been illustrated above, the above-described examples can be further modified based on the technical idea of the present invention.

For example, the shape and size of the tapers 21, 31, 41 described above may be changed in various ways. Furthermore, the present invention is applicable not only to an artificial heart but also to an artificial heart-lung machine. The cross section is enlarged by the taper provided on the outer surface, and it is connected to the 7th rank part of the housing part, so when the sack part expands and contracts, the elastic deformation of the narrow area occurs smoothly, reducing the stress there. It can effectively prevent concentration. Therefore, breakage of the sack portion is prevented, allowing use over a long period of time and greatly improving durability.

[Brief explanation of drawings]

1 to 5 show embodiments of the present invention. FIG. 1 is an enlarged cross-sectional view of the essential parts of the suck blood pump device according to the first embodiment, and FIG. 2 is the same blood pump device. Figure 3 is a cross-sectional view similar to Figure 1 for explaining the operation and size of the main parts of the blood pump device (however, cross-sectional hatching is omitted). ), FIG. 4 is an enlarged cross-sectional view of a main part of a sack-type blood pump device according to a second embodiment, and FIG. 5 is an enlarged cross-sectional view of a main part of a sack-type blood pump device according to a third embodiment. 6 to 10 show conventional examples, in which FIG. 6 is a schematic front view showing the usage state of the sack-type blood pump device, FIG. 7 is an exploded perspective view of the same blood pump device, and FIG. The figure is a front view of a component having a blood chamber, FIG. 9 is a right side view of FIG. 8, and FIG. 10 is an enlarged sectional view of a main part of the sac-type blood pump device. In addition, in the symbols shown in the drawings, 1... Housing outer case 2...
...Blood chamber (sac part) 2a...
・・・・・・Rotation part 3・・・・・・Blood introduction tube 4・・・・・・Blood discharge tube 5・・・・・・・・・7 Rank part 8... ......Port 11...Sac type blood pump device 20.
30・-・−・・Groove 21.31.41・・・・・・Taper 22・・
. . . Connecting portion 40 . . . Synthetic resin coated portion.

Claims (1)

[Claims] 1. The expandable sack part that forms the blood chamber is
In a blood pump device that is integrally connected to the flange portion of a housing portion that includes an outer case portion surrounding the sac portion and a flange portion, a root region of the sac portion with respect to the housing portion is formed at least on an outer surface thereof. A pump device having a taper, the root region being integrally connected to the flange portion while being enlarged in cross section by the taper.