JPH0613738Y2 - Blood reservoir - Google Patents

Description

[Detailed description of the device]

[0001]

[Industrial applications]

The present invention relates to a blood reservoir installed in an extracorporeal blood circulation circuit.

[0002]

[Prior art]

For example, in cardiac surgery, an extracorporeal blood circulation is performed, in which a blood pump is operated to remove blood from a patient's vein, gas is exchanged with an artificial lung, and then this blood is returned to the patient's artery. Be done. In this artificial lung extracorporeal blood circulation circuit, a blood storage tank for temporarily storing the removed blood and a heat exchanger for adjusting the temperature of the blood are installed.

The blood reservoir has a buffering function for adjusting the blood volume in the circuit and keeping the blood return volume constant, and also has a defoaming ability for the blood removed. In addition, the heat exchanger may change the temperature of blood to 2
It is used to cool the blood to about 0 ° C and warm the blood to return it to the body temperature at the end of surgery.

In such an extracorporeal blood circulation circuit,
In order to reduce the burden on the patient, it has been an issue to reduce the amount of blood priming in the circuit as much as possible. Therefore, a blood reservoir containing a heat exchanger has been developed. This blood storage tank has a housing having a blood storage space therein, a coiled metal tube is installed in the blood storage space, and a medium for heat exchange (hereinafter referred to as a heat medium) is passed through the metal tube, By exchanging heat between the heat medium and blood via the tube wall of the tube, the blood in the blood storage space is heated or cooled.

In order to further improve the heat exchange efficiency,
A blood reservoir having a heat exchanger using a plurality of metal straight tubes arranged in parallel instead of the coiled metal tube has also been developed.

On the other hand, in such a blood reservoir, backflow may occur from the tube connected to the blood outlet of the blood reservoir into the blood reservoir at the start of operation immediately after priming or when the pump pulsates. At this time, relatively large bubbles that have accumulated in the tube may enter the blood reservoir. In such a case, in the heat exchanger using a plurality of straight pipes, the pipe density of the straight pipes is high, and therefore bubbles that have entered the blood reservoir cannot escape upward between the straight pipes.

As a result, the air bubbles are mixed in the blood returned to the artery, resulting in a very dangerous situation for the living body. For this reason, it is possible to increase the gap between the inner wall of the housing and the pipe adjacent thereto, and to remove the bubbles from this gap, but in this case, channeling occurs and the heat exchange rate decreases.

[0008]

[Problems to be solved by the device]

An object of the present invention is to quickly eliminate air bubbles that have accumulated below the heat exchanger in the blood storage tank, and to provide a blood storage tank that has less air bubbles accumulated inside.

[0009]

[Means for Solving the Problems]

Such an object is achieved by the present invention of the following (1) to (3).

(1) A blood storage space is formed inside, a housing capable of ventilating between the blood storage space and the outside, a blood inlet and a blood outlet communicating with the blood storage space, and a blood storage space A blood reservoir having a heat exchanger for heating or cooling blood, wherein the heat exchanger is installed in the blood storage space and has a plurality of tubular bodies mainly composed of straight pipe parts; A heat medium supply unit that supplies a heat medium to the pipe body, and a heat medium discharge unit that discharges the heat medium that has passed through the pipe body, and an arrangement of a lowermost pipe body group of the plurality of pipe bodies. A blood reservoir characterized in that an inclined portion that is inclined with respect to the liquid surface is configured by.

(2) Each of the pipes is a straight pipe arranged in parallel, and both ends of each straight pipe are supported by partition walls without blocking openings at both ends of each straight pipe. Blood reservoir described in.

(3) The blood reservoir according to (1) or (2) above, wherein the inclination angle of the arrangement of the lowermost tubular body is 3 to 60 ° with respect to the liquid surface.

[0013]

[Action]

According to the present invention having such a configuration, since the arrangement of the lowermost pipes among the plurality of pipes installed in the blood storage space is inclined with respect to the liquid surface, the bubbles that have entered from the blood outlet are Is
It is guided to the inner wall of the blood storage space along an inclined portion composed of a group of pipes arranged in an inclined manner.

Further, since the inner wall is a surface which is continuous in the vertical direction, the bubbles can easily float up through the gap between the inner wall surface and the tubular body along the inner wall and escape, and the bubbles can be formed on the lower side of the tubular body. Does not accumulate.

[0015]

[Constitution of device]

Hereinafter, the blood reservoir of the present invention will be described in detail with reference to the preferred embodiments shown in the accompanying drawings.

FIG. 1 is a perspective view showing a constitutional example of a blood reservoir of the present invention, FIG. 2 is a sectional view taken along the line AA in FIG. 1, and FIG.
It is sectional drawing in the BB line in FIG. As shown in these figures, the blood reservoir 1 of the present invention has a housing 2 composed of a housing body 3 and a lid body 4. A blood storage space 5 for storing blood is formed inside the housing 2.

The housing body 3 has a box shape having a protrusion 31 on the upper right side in FIG.

The lid 4 is placed so as to cover the upper opening of the housing body 3, and does not seal the blood storage space 5, but, for example, via the gap between the housing body 3 and the lid 4 stores blood. The space 5 and the outside can be ventilated. As a result, the amount of blood stored in the blood storage space 5 can be increased or decreased. A ventilation port (not shown) may be provided in the housing 2 to connect the blood storage space 5 to the outside.

A tubular blood inlet 6 communicating with the blood storage space 5 is fixed to the lid 4. This blood inlet 6 is
For example, it is connected to the tube of the blood removal line in the extracorporeal blood circulation circuit.

A tubular blood outlet 7 communicating with the blood storage space 5 is formed in the lower portion of the housing body 3. This blood outlet 7 is connected to, for example, a tube to an artificial lung or the like in an extracorporeal blood circulation circuit.

Although the volume of the blood storage space 5 is not particularly limited,
For example, about 3000 to 5000 ml for adults and about 1000 to 2000 ml for infants are preferable.

Further, a space for storing blood (described later) (a space between the pipes 10 and a space between the pipe 10 and the inner wall of the housing) and a space 51 below the space are combined to form a blood storage space. Substantial volume less than about 300 ml, especially,
It is preferably about 100 to 200 ml (for adults).
The reason why such a small volume can be achieved is that the heat exchanger 9 is small and has high performance, as will be described later, and thus the minimum limit blood storage amount of the blood storage tank can be made smaller than in the conventional case. , Contributes to the reduction of the priming amount of the circuit.

The constituent materials of the housing body 3 and the lid 4 are polycarbonate, acrylic resin, polyethylene terephthalate, polyethylene, polypropylene,
Examples thereof include polystyrene, polyvinyl chloride, acryl-styrene copolymer, acryl-butadiene-styrene (ABS) copolymer, and among these, polycarbonate and polyvinyl chloride are particularly preferable.

The housing body 3 and the lid 4 are
It is preferably transparent so that the blood storage amount can be visually confirmed.

A scale (not shown) indicating the amount of stored blood may be provided on the side surface of the housing body 3.

An inclined surface 32 is formed below the projecting portion 31 of the housing body 3 in the figure, and is inclined by, for example, about 1 to 45 ° with respect to the horizontal plane.

Further, in the blood storage space 5 in the protruding portion 31, a defoaming member 8 for removing air bubbles contained in the blood flowing from the blood inlet 6 is installed. This defoaming member 8
Are fixed by inserting both side ends thereof between ribs 33 formed in pairs on opposite inner walls of the housing body 3. The lower end of the defoaming member 8 is
It contacts the inclined surface 32.

As the defoaming member 8, for example, foamed polyurethane, foamed polyethylene, foamed polypropylene,
Examples thereof include foams such as expanded polystyrene, woven cloth, non-woven cloth, mesh, and porous materials such as porous ceramics. Among them, foamed polyurethane,
Foamed polyethylene is preferred.

When a foam or a porous material is used as the defoaming member 8, the pore diameter is about 20 μm to 5 mm, especially 30.
It is preferable that the thickness is about μm to 2 mm.

Such a blood storage tank 1 has a heat exchanger 9 for heating or cooling the blood stored in the blood storage space 5 as needed.
Have. The heat exchanger 9 includes a plurality of heat exchanging pipes 10 installed in the blood storage space, a pair of partition walls 11 supporting the pipes 10, and heat for supplying a heat medium into each pipe 10. The medium supply unit 12 and the heat medium discharge unit 13 that discharges the heat medium that has passed through each tube body 10 are provided. Hereinafter, each component of the heat exchanger 9 will be described.

The tubular body 10 is mainly composed of a straight pipe portion, and is a straight pipe in the illustrated configuration example. The tubular body according to the present invention is not limited to a straight pipe, but may be, for example, a U-shaped pipe in which a straight pipe is bent so as to be folded back, or a straight pipe having an opening angle of about 160 to 175 °. Any one may be used as long as the straight pipe portion occupies most of it, such as a V-shaped pipe bent at the same time.

The tubes 10 are installed in parallel. The tubular body 10 is made of a material having a high thermal conductivity, for example, a metal such as stainless steel, aluminum, copper or titanium. The dimensions of the tubular body 10 are
The outer diameter is preferably about 0.5 to 10 mm, particularly about 2 to 5 mm, and the effective length (length in the blood storage space) is 50 to 30.
It is preferably about 0 mm, particularly about 70 to 150 mm.

The number of pipes 10 to be arranged is preferably about 10 to 2000, and more preferably about 50 to 1000.

The arrangement density of the pipes 10 is preferably uniform throughout, and the minimum gap distance between the adjacent pipes 10 is about 0.3 to 3.0 mm, particularly about 0.6 to 2.0 mm. Is preferred. Further, it is preferable that a spiral member (not shown) for causing a swirl flow in the heat medium is disposed inside the tube body 10.

By setting the conditions of the tube body 10 as described above, the heat exchanger 9 having a small size and a high heat exchange efficiency can be obtained.

The tubular bodies 10 arranged with the density as described above.
As shown in FIG. 3, the arrangement direction of the lowermost tube group constitutes an inclined portion 90 inclined with respect to the liquid surface.

In the example shown in the figure, it is inclined upward toward the inner wall 34 where the blood outlet 7 is provided. Thus, by providing the inclined portion 90, the blood outlet 4
The bubbles that have entered the blood storage space 5 from are contacted with the inclined portion 90 and are guided to the inner wall 34.

Then, bubbles are accumulated at a position where the inclined portion 90 and the inner wall 34 intersect, and the bubbles escape along the inner wall 34 onto the liquid surface. In this way, each tubular body 10 arranged at the bottom stage
By arranging incliningly, the bubbles accumulated under the heat exchanger 9 are gathered at one place, thereby increasing the volume of the bubbles and increasing the buoyancy. In addition, by bringing bubbles into contact with the inner wall 34, which is a flat surface that is continuous upward, the bubbles easily travel along the inner wall 34 and come off. Due to these two effects, the air bubbles accumulated on the lower side of the pipe body 10 can easily escape to the upper liquid surface.

As described above, in order to allow air bubbles to float and escape between the inner wall 34 and the pipe body 10, the inner wall 34
And the distance from the tube body 10 adjacent to the inner wall 34 is 0.5
It is about 3.0 mm, preferably about 0.6 to 2.0 mm. This is because if it is narrower than this range, the escape of air bubbles becomes worse, and if it becomes wider, channeling occurs between the inner wall 34 and the pipe body 10, and the heat exchange rate becomes worse.

The inclination angle θ is preferably about 3 to 60 °, more preferably about 10 to 45 °. The inclination angle is
It is the angle on the side including the pipe body among the angles formed by the surface including the pipe body 10 arranged in the lowermost stage and the liquid surface.

Further, in order to keep the heat exchange rate high, it is desirable that the distance between the inner wall 34 and the tube body 10 is narrow as long as they do not come into contact with each other. Therefore, in order to further improve the escape of bubbles, a groove 35 is vertically formed in the inner wall 34. 4 is a plan sectional view of the inner wall 34 showing the shape of the groove 35, and FIG. 5 is a front view thereof. Groove 35
Bottom surface 351 is continuous with the inner wall surface of the space 51, which will be described later, and the inner wall surface of the blood storage space 5 located above the heat exchanger 9 so that bubbles can easily float up through the groove 35. Has been done. Further, the lower end portion of the groove 35 has a width that widens downward, and floating bubbles are configured to be able to fly while being guided to the groove 35 where the distance between the inner wall 34 and the pipe body 10 is the largest. . When the groove 35 is provided in this manner, since the flow rate of blood flowing through the groove 35 is small, channeling is small and the heat exchange rate is hardly reduced.

The cross-sectional area of such a groove 35 is 2 to 40.
mm ² approximately, and more preferably ² about 3 to 20 mm. This is because if it is larger than this level, channeling occurs in the groove 35 and a sufficient heat exchange rate cannot be obtained, and if it is smaller, bubble escape becomes worse. The groove 35
May be formed in two steps in the width direction.

In the configuration example shown in FIG. 3, the bubbles entering from the blood outlet 7 reach the upper end of the inclined portion along the inner wall 34, so that the bubbles can easily escape to the liquid surface. .

In addition, as shown in FIGS. 6 and 7, the inclination angles of the tubular bodies 10 in the arrangement direction may be inclined in the opposite directions, or in a V shape inclined in both directions. It may be a mold.

By providing the inclined portion 90 by inclining the arrangement direction of the tubes 10 as described above, it is preferable that there is a space 51 near the blood outlet 7 where the tubes 10 do not exist. This reduces pressure loss when blood flows out from the blood outlet 7, and prevents blood from circulating and staying in the blood storage space 5.

The tubular body 10 is not limited to one having a circular cross section, and may be, for example, an ellipse, a polygon such as a triangle, a quadrangle, a hexagon, or an octagon.

In such a tube body 10, both ends thereof are buried in the pair of partition walls 11 without closing the openings at both ends,
It is supported by being fixed in a liquid-tight manner. This partition 1
It is preferable that 1 is composed of a potting material made of a polymer material such as polyurethane, silicone rubber or epoxy resin. As a result, the tubes 10 are securely fixed, and the liquid tightness of the partition wall 11 is maintained.

The thickness of the partition wall 11 is preferably about 15 to 50 mm, more preferably about 10 to 30 mm.

A heat medium supply unit 12 is provided on one end side of the tubular body 10, and a heat medium discharge unit 13 is provided on the other end side.

The heat medium supply unit 12 has a housing 14 fixed to the side surface of the housing body 3 in a liquid-tight manner.
The heat medium chamber 16 is regulated by the partition wall 11 and the partition wall 11. Also,
A tubular heat medium inlet 18 communicating with the heat medium chamber 16 is installed in the housing 14.

The heat medium discharge portion 13 has a housing 15 fixed to the side surface of the housing body 3 in a liquid-tight manner.
The heat medium chamber 17 is regulated by the partition wall 11 and the partition wall 11. Also,
The housing 15 is provided with a tubular heat medium outlet 19 that communicates with the heat medium chamber 17.

The constituent materials of the housings 14 and 15 are:
The same as the housing body 3 may be used.

The volumes of the heat medium chambers 16 and 17 are not particularly limited, but are preferably about 10 to 200 ml, particularly about 30 to 150 ml.

As the heat medium, a liquid such as water or alcohol adjusted to a predetermined temperature is preferably used, but a gas such as air may be used.

The total amount (heat medium supply amount) of the heat medium flowing in each tube 10 is the pressure loss of the heat medium passage of the heat exchanger 9,
It is appropriately determined depending on the capacity of the heat medium pump, etc.
5 to 30 liters / minute, especially 8 to 20 liters / minute
It is preferably about a minute.

Next, the operation of the blood storage tank 1 will be described.

For example, the blood that has flowed into the housing 2 through the blood removal port 6 through the blood removal line first passes through the defoaming member 8 to be defoamed, and then flows down along the inclined surface 32.
It is stored in the blood storage space 5. In addition, the blood in the upper part of the blood storage space 5 may be separated from the gap between the pipes 10 or the pipes 10 and the inner wall of the housing by suction of a pump (not shown) installed in a line connected to the blood outlet 7. Through the gap between the housing 2 and the housing 2. After reaching the space 51, the blood flows out of the housing 2 through the blood outlet 7. Due to such a balance of the inflow and outflow of blood, the blood in the blood storage space 5 is maintained at the liquid level L, for example.

On the other hand, when the heat medium is supplied from the heat medium inlet 18 to the heat medium chamber 16, the heat medium is transferred to the inside of each tube 10.
After passing through the heat medium chamber 17, the heat medium is discharged from the heat medium outlet 19. When the heat medium passes through each tube 10, the tubes 10
Heat is exchanged between the heat carrier and blood through the tube wall of
The blood in the blood storage space 5 is heated or cooled.

For example, in the case of the blood storage tank 1 installed in the extracorporeal blood circulation circuit, cold water is used as a heating medium during surgery,
The temperature of the blood is cooled to about 20 ° C., and at the end of the operation, warm water is used as a heat medium to heat the blood at about 20 ° C. to return it to the body temperature.

[0060]

【Example】

 Hereinafter, a specific embodiment of the present invention will be described.

Example A blood reservoir having the structure shown in FIGS. 1, 2 and 3 was prepared. The conditions of each part of the blood reservoir are as follows. Housing volume: 4000 ml Volume of the tube installation part and the space below it: 200 ml in total Housing material: Polycarbonate (transparent) Partition material: Polyurethane (two liquid mixture type) Defoaming member: Polyurethane foam (pore diameter 1000 μm) Tubular shape: cross section Round straight tube Body material: Stainless steel Body inner diameter: 2.00 mm Body outer diameter: 2.28 mm Body length: 116 mm (Length in blood storage space 75 m
m) Minimum gap distance between adjacent pipes: 0.9mm on average Number of pipes arranged: 405 Arrangement angle of bottom pipes (tilt angle to liquid surface): 30
° No groove was formed on the inner wall.

Comparative Example A blood reservoir similar to that of the above-described example was produced except that the arrangement direction of the lowermost tubular body was set horizontally (arrangement angle of the lowermost tubular body = 0).

For each blood reservoir of the above-mentioned Examples and Comparative Examples, physiological saline was supplied from the blood inlet to the blood storage space for priming, and 10 ml of bubbles were introduced from the blood inlet to observe the degree of bubble escape. did.

In the blood reservoir of the embodiment of the present invention, the bubbles easily escaped from between the inner wall and the tube to reach the liquid surface.

On the other hand, in the blood reservoir of the comparative example, the air bubbles remained at the lower side of the tubular body and did not escape to the liquid surface.

[0066]

[Effect of device]

As described above, according to the blood reservoir of the present invention, the bubbles that have entered the lower side of the heat exchanger can be easily discharged to the liquid surface during priming and the like, and the heat exchange rate is also high.

[Brief description of drawings]

FIG. 1 is a perspective view showing a constitutional example of a blood reservoir of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG.

3 is a cross-sectional view taken along the line BB in FIG.

FIG. 4 is a plan sectional view of an inner wall showing the shape of a groove.

FIG. 5 is a front view of the inner wall similarly showing the shape of the groove.

FIG. 6 is a side view of the arranged pipes, showing another inclination mode in the arrangement direction of the pipes.

FIG. 7 is a side view of the arranged pipes, showing another inclination mode in the arrangement direction of the pipes.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Blood reservoir 2 Housing 3 Housing main body 31 Projection part 32 Sloping surface 33 Rib 34 Inner wall 35 Groove 351 Bottom surface 4 Lid body 5 Blood storage space 51 Space 6 Blood inflow port 7 Blood inlet / outlet 8 Defoaming member 9 Heat exchanger 90 Inclination part 10 Tube Body 11 Partition wall 12 Heat medium supply part 13 Heat medium discharge part 14, 15 Housing 16, 17 Heat medium chamber 18 Heat medium inlet 19 Heat medium outlet L Liquid level

Claims (3)

[Scope of utility model registration request] 1. A blood storage space is formed inside, a housing capable of ventilating between the blood storage space and the outside, a blood inlet and a blood outlet communicating with the blood storage space, and a blood storage space stored in the blood storage space. A blood reservoir having a heat exchanger for heating or cooling blood, wherein the heat exchanger is erected in the blood storage space, and a plurality of tubular bodies mainly configured by straight pipe portions,
A heat medium supply unit that supplies a heat medium to the pipe body and a heat medium discharge unit that discharges the heat medium that has passed through the pipe body are provided. A blood reservoir characterized in that an inclined portion that is inclined with respect to the liquid surface is formed by the arrangement. 2. The pipes are straight pipes arranged in parallel, and both ends of each straight pipe are supported by partition walls without blocking openings at both ends of each straight pipe. Blood tank. 3. The blood reservoir according to claim 1, wherein the inclination angle of the array of the lowermost tube is 3 to 60 ° with respect to the liquid surface.