JP5295015B2 - Dialysate supply / discharge device - Google Patents

Description

  The present invention relates to a dialysate supply / discharge device in a hemodialysis apparatus, and more particularly to an improvement of a so-called chamber-type dialysate supply / discharge device using a flexible chamber membrane.

  A hemodialysis apparatus using a chamber-type dialysate supply / discharge device, which is an object of improvement in the present invention, is known (for example, Patent Document 1). This hemodialysis apparatus is configured, for example, as shown in FIG. FIG. 1 illustrates one state during normal hemodialysis. In FIG. 1, reference numeral 1 denotes a hemodialysis element (dialyzer) including a dialysis membrane 2 made of, for example, a hollow fiber. In element 1, hemodialysis is performed via the dialysis membrane 2 between a blood circuit 3 for circulating blood between the patient's body and a dialysate circuit 4 for circulating dialysate. The blood circuit 3 includes an arterial blood circuit 5 connected to the patient's artery side and a venous blood circuit 6 connected to the vein side. In the dialysate circuit 4, flexible chamber membranes 11 and 12 made of a material having elasticity, such as silicon rubber, having a spherical bulging portion whose bulging direction can be reversed, and each chamber membrane 11 and 12 are provided with a pair of chamber pieces 13a, 13b and 14a, 14b having spherical concave portions corresponding to the spherical bulges, and the pair of chamber pieces 13a, 13b and 14a. 14b, the spherical concave portions of 14b are arranged to face each other to form a membrane working space in which the bulging direction of the spherical bulging portions of the chamber membranes 11 and 12 can be reversed, and the membrane working space with respect to the membrane working space. Chamber-type dialysate supply / discharge devices 15 and 16 (hereinafter sometimes simply referred to as “chambers”) having supply / exhaust ports facing the working space are provided. The membrane working spaces in the chambers 15 and 16 are partitioned into chambers on both sides by the chamber membranes 11 and 12, and in the illustrated example, the chamber 15 is divided into a fresh dialysate side chamber 17a and a used dialysate side chamber 17b, and a chamber 16 Are divided into a fresh dialysate side chamber 18a and a used dialysate side chamber 18b, respectively.

  At the time of hemodialysis, for example, as shown in FIG. 1, the fresh dialysate accommodated in the fresh dialysate side chamber 18a of the chamber 16 is pushed out to the chamber membrane 12 and sent into the hemodialysis element 1 for hemodialysis. The used dialysate is returned to the used dialysate side chamber 18b. This circuit is formed in a closed circuit, and the amount of liquid fed and the amount of return are substantially the same, and the amount of movement of the chamber film 12 that can reverse the bulging direction of the spherical bulging portion (the movement of each chamber due to movement). (Volume change amount). The circulation of the dialysate is performed by a circulation pump 21 provided in the return side circuit. In addition, the dialysate circuit 4 is provided with a flow switch 22, and a water removal pump 23 is connected to the upstream side of the circulation pump 21. 24 can be removed. When the chamber 16 side is used for hemodialysis, on the chamber 15 side, fresh dialysate is supplied into the fresh dialysate-side chamber 17a by the deaeration pump 25 via the flow switch 26. The inside of the side chamber 17a is filled with fresh dialysate. At the same time, the used dialysate stored in the used dialysate side chamber 17 b is discharged out of the system through the drain circuit 27. For each of the fresh dialysate side chambers 17a and 18a and the used dialysate side chambers 17b and 18b of the chambers 15 and 16, a pair of switching valves 28 (normally closed two-way solenoid valves) are arranged. By switching on and off the switching valve 28, a chamber used for hemodialysis and a chamber for receiving fresh dialysate can be switched alternately. By this switching, the dialysate can be supplied to the hemodialysis element 1 substantially continuously.

  As described above, the chamber-type dialysate supply / discharge devices 15 and 16 include the flexible chamber membranes 11 and 12 having spherical bulges that can reverse the bulging direction, and the chamber membranes 11. , 12 and a pair of chamber pieces 13a, 13b and 14a, 14b having spherical recesses corresponding to the spherical bulges. FIG. As illustrated in the half cross section of the device 15, the spherical concave portion 52 of the chamber piece 13 b is disposed so as to face the spherical bulging portion 51 of the flexible chamber membrane 11, and the spherical shape of the chamber membrane 11 is obtained. A fresh dialysate-side small chamber 17a whose volume can be enlarged and reduced is formed between the bulging portion 51 and the spherical concave portion 52 of the chamber piece 13b. The fresh dialysate side chamber 17a is connected to the chamber piece 13b so that a supply / exhaust port 53 through which fresh dialysate is supplied and discharged faces the fresh dialysate side chamber 17a. Although not shown, the chamber piece 13a on the opposite side is connected so that a supply / exhaust port for supplying and discharging the used dialysate to the used dialysate side chamber 17b faces the used dialysate side chamber 17b. ing. The dialysate supply / discharge device 16 side is configured in the same manner. In the chamber-type dialysate supply / discharge devices 15 and 16 configured as described above, fresh dialysis is performed by moving the chamber membrane accompanied by reversing the bulging direction of the spherical bulging portion in the membrane working space in the chamber. The supply and discharge of the liquid and the supply and discharge of the used dialysate are performed at the same time.

JP 2008-093193 A

  The dialysate supply / discharge device having the basic configuration as described above currently has the following problems. That is, for example, in the form shown in FIG. 6, when the spherical bulging portion 51 of the chamber film 11 is further bulged, the chamber film 11 eventually comes into contact with the spherical concave portion 52, and on the upper side in FIG. The thus-formed chamber membrane 11 contacts the opening (flow channel opening) of the supply / exhaust port 53 into the fresh dialysate side small chamber 17a. At this time, if the chamber film made of the current silicon rubber is used, an abnormal noise (chattering noise) may occur in the state where the chamber film is in contact with the channel opening. Dimple processing is applied to the chamber membrane part that contacts the part to prevent the generation of abnormal noise, but the dimple processing locally reduces the durability of the part, and the part tends to crack. This causes a decrease in the lifetime of the film. The cause of chatter noise is that the portion of the chamber film 11 where the spherical bulge 51 is formed is formed slightly smaller than the portion of the chamber piece 13b where the spherical concave portion 52 is formed. The membrane is stressed in the state where the chamber membrane 11 is bulged and the force balance between the stress and the acceptance or discharge pressure of the dialysate supplied or discharged through the flow passage opening of the supply / exhaust port is just the above chamber. It is considered that the film becomes unstable in the state of whether or not the film abuts the flow path opening, and the film vibrates slightly due to minute vibrations. In order to prevent the occurrence of chattering noise, the upper part of the film was subjected to demble processing as described above. However, since tensile stress was easily applied thereto, it is considered that the generation of cracks was promoted.

  As a countermeasure, aiming to improve the chemical resistance of the chamber membrane, the material of the chamber membrane was changed from silicon rubber to fluorine rubber, and the shape of the chamber membrane, especially the outer diameter size of the spherical bulge, was changed to the chamber. A chamber film (curvature-modified fluorine-based chamber film) with a modified film curvature was manufactured to match the shape of the piece, especially the spherical recess, but this improved the chemical resistance and eliminated nasal noise, but a new problem A point occurred. That is, when the liquid is received in the normal operation, the membrane is gradually pushed to the opposite chamber piece wall surface side, and when the liquid is filled, the membrane hits the chamber piece wall surface. In the middle of receiving and discharging the liquid, the champ membrane closes the flow path opening, which may cause malfunction (changing of champs). Thus, the present invention has been reached as a result of intensive studies on an improved structure further advanced from the chamber film made of the above-described curvature-modified fluorine-based rubber.

  That is, the problem of the present invention is that no abnormal noise is generated during the operation of the chamber membrane, the chamber membrane can have sufficient durability, and malfunctions such as abnormal switching of the champ are generated. It is also an object of the present invention to provide an improved chamber type dialysate supply / discharge device capable of stable operation.

  In order to solve the above-described problems, a dialysate supply / discharge device according to the present invention is disposed on both sides of a flexible chamber membrane having a spherical bulging portion whose bulging direction can be reversed. And a pair of chamber pieces having spherical concave portions corresponding to the spherical bulging portions, and the spherical concave portions of the pair of chamber pieces are arranged to face each other, and the spherical bulging of the chamber film is disposed inside. A chamber-type dialysate supply / exhaust device in a hemodialysis apparatus, wherein a membrane working space capable of reversing the bulging direction of the protruding portion is formed and a supply / exhaust port facing the membrane working space is provided to the membrane working space The center position of the spherical bulging portion of the chamber film is offset with respect to the center position of the spherical concave portion of the chamber piece in a direction opposite to the position where the supply / exhaust port exists. Consists of things.

  In such a chamber-type dialysate supply / exhaust device according to the present invention, the center position of the spherical bulging portion of the chamber membrane is on the side opposite to the supply / discharge port installation side with respect to the central position of the spherical concave portion of the chamber piece. Since the offset is performed by a predetermined amount, when the chamber membrane is moved, the gap space between the spherical bulging portion of the chamber membrane and the spherical concave portion of the chamber piece is not offset on the supply / exhaust port installation side. Compared to the case, it is intentionally enlarged. Therefore, in the improved structure according to the present invention, the bulging of the chamber membrane proceeds, and the spherical bulging portion of the chamber membrane is in contact with the spherical concave portion of the chamber piece on the side where the supply / discharge port is installed. On the supply / discharge port installation side, a predetermined gap is secured (remained) between the spherical bulge portion of the chamber film and the spherical concave portion of the chamber piece, and the bulged chamber film Is reliably prevented from closing the supply / exhaust port (however, when the movement of the chamber membrane is completed, the flow channel opening of the supply / exhaust port is closed). As a result, it is possible to reliably prevent the failure of the champ membrane closing the flow path opening in the middle of liquid reception and discharge, and to prevent malfunctions such as abnormal switching of the chamber, and stable operation. Secured. Further, on the supply / discharge port installation side, as a result of securing a predetermined gap between the spherical bulge portion of the chamber membrane and the spherical concave portion of the chamber piece, whether or not the chamber membrane abuts on the spherical concave portion. Thus, the appearance of a state in which chatter noise is likely to occur is avoided, and excellent performance can be obtained in terms of preventing the generation of abnormal noise.

  In the dialysate supply / discharge device according to the present invention, it is preferable that the outer diameter of the spherical bulging portion of the chamber membrane is set smaller than the inner diameter of the spherical concave portion of the chamber piece. By doing so, as described above, the center position of the spherical bulge portion of the chamber film can be easily offset by a predetermined amount in a predetermined direction, and such a desirable design can be easily performed. Will be able to.

  Further, the radius of curvature on the side where the supply / discharge port of the spherical bulged portion of the chamber film is set larger than the radius of curvature on the side opposite to the position where the supply / discharge port exists. Preferably it is. That is, the spherical bulge portion of the chamber film does not have a shape that forms a part of a complete spherical surface, and it is preferable to have a difference in the radius of curvature if possible at the stage of forming the chamber film. In this way, when the spherical bulge of the chamber membrane is in contact with the spherical concave portion of the chamber piece on the counter-feed / exhaust installation side, the spherical surface of the chamber film is more reliably formed on the supply / exhaust port installation side. A desired gap space can be formed between the bulging portion and the spherical concave portion of the chamber piece, particularly between the supply / exhaust port.

  The supply / discharge port may be opened as a single flow path to the membrane working space, but at least one of the supply / discharge ports (that is, the supply / discharge port of fresh dialysate and the supply of used dialysate). It is preferable that at least one of the discharge ports is formed of a plurality of small holes. If constituted in this way, the flow of the liquid at the time of supply and discharge can be finely dispersed, the flow state can be stabilized, the supply and discharge operation can be made more stable, and the spherical bulge portion of the chamber membrane can be obtained. Even if it is close to the spherical concave part of the chamber piece and close to a part of the supply / discharge port, the flow from the small holes in the other part of the supply / discharge port is secured. Therefore, the occurrence of a situation in which the chamber film sticks to the spherical concave portion and closes the supply / exhaust port is prevented, and a more stable supply / discharge operation can be ensured more reliably.

  The chamber film is not particularly limited as long as it is a flexible chamber film capable of performing a predetermined spherical bulging portion reversal operation, but in order to perform the above-described series of operations more stably, It is preferable to have elasticity, and from this aspect, the chamber film is preferably made of rubber. In particular, from the viewpoint of chemical resistance and durability, it is preferably made of a fluorinated rubber.

  In addition, the amount of the offset is such that the spherical bulge portion of the bulged chamber membrane contacts the spherical concave portion located on the opposite side of the one chamber piece from the position where the supply / exhaust port exists. Then, on the position side where the supply / exhaust port exists, between the spherical bulging portion of the chamber film and the spherical concave portion of the chamber piece, the outer diameter of the spherical bulging portion of the chamber film is 1% to It is preferably set so that a gap having a dimension corresponding to 20% is formed. However, the specific numerical value of this gap may be determined according to the size of the chamber and the rubber elastic modulus of the chamber membrane. In practice, several chamber membranes with different shapes were tested and the best results were obtained. What is necessary is just to design to what obtained.

  Further, if the chamber membrane has a flange-like attachment portion around the spherical bulge portion, and the pair of chamber pieces have a sandwiching portion for sandwiching the chamber membrane attachment portion, It is possible to easily attach the chamber membrane and assemble the entire apparatus into a predetermined form. In this case, it is particularly preferable that the mounting portion and the clamping portion are formed in shapes corresponding to each other. Especially, it is preferable that the shape corresponding to each other is formed in a non-target shape with respect to a plane that defines the position side where the supply / exhaust port exists and the opposite position side. For example, a configuration (so-called shell-shaped configuration) in which the mounting portion and the clamping portion are formed in a shape having skirt portions corresponding to each other on the position side opposite to the position side where the supply / exhaust port exists. Can be adopted. In other words, in the present invention, the center position of the spherical bulge portion of the chamber film is required to be offset by a predetermined amount toward the counter-feed / discharge port installation side with respect to the center position of the spherical concave portion of the chamber piece. However, since the chamber film and each chamber piece are separate parts before assembly, if the chamber film has a structure that can be erroneously assembled with respect to the chamber piece, the above-described necessary configuration may not be achieved. Remains. However, if the shapes corresponding to each other as described above, particularly the position side where the supply / exhaust port exists and the opposite position side are formed in non-target shapes, the possibility of erroneous assembly is completely eliminated. The

  As described above, according to the dialysate supply / discharge device according to the present invention, the chamber membrane can be smoothly and stably operated for dialysate supply / discharge, and the occurrence of malfunction such as an abnormal switching of the champ can be caused. It can be surely prevented. In addition, it is possible to prevent the generation of abnormal noise during operation of the chamber membrane and to achieve sufficient durability of the chamber membrane.

It is an equipment system diagram showing an example of a hemodialysis apparatus using a chamber type dialysate supply / discharge device to which the present invention is applicable. It is the external appearance front view (FIG. 2A) and internal schematic perspective front view (FIG. 2B) of the dialysate supply / discharge device which concerns on one embodiment of this invention. It is the front view (FIG. 3A) and longitudinal cross-sectional view (FIG. 3B) of the chamber membrane in the dialysate supply / discharge device of FIG. FIG. 3 is a half vertical cross-sectional view of the dialysate supply / discharge device of FIG. 2 in an assembled state and a chamber membrane bulging toward one chamber piece. FIG. 3 is a flow rate change characteristic diagram at the time of chamber switching for comparing the case of using the dialysate supply / discharge device of FIG. 2 and the case of using a curvature-changing fluorine-based chamber membrane in the course of the examination of the present invention. It is a half longitudinal cross-sectional view of the conventional dialysate supply / discharge device.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
The basic form of the hemodialysis apparatus and the basic form of the arrangement of the chamber-type dialysate supply / discharge apparatus in the hemodialysis apparatus are as shown in FIG. As shown in FIG. 1, at least a pair of dialysate supply / discharge devices are switchably arranged. Here, a structural example of one dialysate supply / discharge device will be described.

  2 shows an external front view (FIG. 2A) and a schematic perspective front view (FIG. 2B) of the dialysate supply / discharge device according to one embodiment of the present invention, and FIG. 3 shows the dialysate supply / discharge device. FIG. 4 shows a front view (FIG. 3A) and a longitudinal sectional view (FIG. 3B) of the chamber membrane in FIG. 4, and FIG. 4 shows a state in which the chamber membrane bulges to one chamber piece side in the assembled state of the dialysate supply / discharge device FIG. In the figure, the dialysate supply / drainage device 31 has a spherical bulging portion 32 whose bulging direction can be reversed (FIG. 3B, the bulging direction can be reversed in the left-right direction in FIG. 4). A plastic or a flexible chamber film 33 made of fluorine-based rubber having excellent chemical properties and durability, and a spherical recess 34 disposed on both sides of the chamber film 33 and corresponding to the spherical bulge 32 A pair of chamber pieces 35 made of metal. As shown in FIG. 1, the pair of chamber pieces 35 are arranged so that the spherical concave portions 34 face each other, and the membrane working space 37 in which the bulging direction of the spherical bulging portion 32 of the chamber film 33 can be reversed is provided. (Shown in FIG. 4) is assembled with the chamber film 33 sandwiched therebetween. The assembly is performed by co-fastening via an appropriate fastener (not shown) such as a bolt inserted into the fastener insertion hole 36, for example. The membrane working space 37 formed in the pair of chamber pieces 35 is provided with a supply / exhaust port 38 (shown in FIG. 4) facing the membrane working space 37. As described above with reference to FIG. 1, the membrane working space 37 is divided into two chambers, a fresh dialysate side chamber and a used dialysate side chamber, by the chamber membrane 33. Exhaust ports 38 are provided, and the respective supply / exhaust ports 38 are arranged at positions where the flow path openings 39 to the respective small chambers substantially face each other. The supply / exhaust port 38, particularly the flow path opening 39 to each small chamber, is preferably composed of a plurality of small holes, thereby finely dispersing the flow of liquid during supply / discharge as described above. Thus, the supply / discharge operation can be made more stable, and the occurrence of a situation where the chamber film 33 sticks to the spherical recess 34 and blocks the supply / discharge port 38 is easily prevented.

  As shown in FIG. 2B, the outer diameter of the spherical concave portion 34 of the chamber film 33 is set smaller than the inner diameter of the spherical concave portion 34 of the chamber piece 35. In the present invention, the position of the center 41 of the spherical bulging portion 32 of the chamber film 33 (in the illustrated example, the center position in the vertical direction in FIGS. 2B and 4) is the chamber piece. The position of the center 42 of the spherical recess 34 of 35 (in the illustrated example, the center position in the vertical direction in FIGS. 2B and 4 in FIG. 4) is opposite to the position where the supply / exhaust port 38 exists. Is offset by a predetermined amount δ. In the illustrated example, the supply / exhaust port 38 is disposed on the upper side of the chamber piece 35, so that the offset of the position of the center 41 of the spherical bulge portion 32 of the chamber film 33 is directed downward. It is not limited to this, and it may be offset to the side where the supply / discharge port 38 is installed according to the position where the supply / discharge port 38 is provided.

  As the offset amount δ, as shown in FIG. 4, the spherical bulge portion 32 of the bulged chamber film 33 is opposite to the position side of one chamber piece 35 where the supply / discharge port 38 is present. 4 on the position side (upper side portion in FIG. 4) where the supply / discharge port 38 exists, the spherical bulging portion 32 of the chamber film 33 and A predetermined amount of gap G is formed between the chamber piece 35 and the spherical recess 34. The predetermined amount of the gap G may be appropriately selected from 1% to 20% with respect to the outer diameter of the spherical bulging portion 32 of the chamber film 33 so that the gap is surely formed in the above state. Should be set. For example, in a preferred test example of the present invention, the position of the center 41 of the spherical bulging portion 32 of the chamber film 33 is offset 1.6 mm downward from the position of the center 42 of the spherical concave portion 34 of the chamber piece 35. As a result, a gap of 3.4 mm was formed as the gap G in the above state. Due to the presence of the gap space S (shown in FIG. 4), a smooth dialysate supply / discharge operation is possible.

  Further, in the above embodiment, the chamber film 33 has the flange-shaped attachment part 43 (FIG. 3) around the spherical bulge part 32, and the pair of chamber pieces 35 are attached to the attachment part 43 of the chamber film 33. A flange-shaped sandwiching portion 44 having a shape corresponding to the mounting portion 43 is provided. The mounting portion 43 of the chamber film 33 is assembled in a predetermined form simply by being sandwiched and fixed by a pair of flange-shaped sandwiching portions 44 having a corresponding shape, so that the assembly is easily performed. In this case, as described above, the mounting portion 43 of the chamber film 33 and the sandwiching portion 44 of the chamber piece 35 corresponding to each other form a plane that defines the position side where the supply / exhaust port 38 exists and the opposite position side ( The neutral surface is preferably formed in a non-target shape, thereby reliably preventing errors in the offset direction and misassembly. In the present embodiment, the attachment portion 43 of the chamber film 33 and the sandwiching portion 44 of the chamber piece 35 are formed in a shell shape having skirt portions 45a and 45b having shapes corresponding to each other, and erroneous assembly is reliably prevented. It has become so.

  By adopting the structure as described above, that is, by offsetting the center position of the spherical bulging portion 32 of the chamber film 33 in a predetermined direction by a predetermined amount, the bulging of the chamber film 33 proceeds and the supply / discharge is performed. When the spherical bulging portion 32 of the chamber film 33 comes into contact with the spherical concave portion 34 of the chamber piece 35 on the mouth installation side (when the state shown in FIG. 4 is reached), The predetermined gap S is surely secured between the spherical bulging portion 32 of the chamber film 33 and the spherical concave portion 34 of the chamber piece 35, and the bulged chamber film 33 is supplied to the supply / discharge port. 38 is reliably prevented, and a smooth and stable supply / discharge operation of the dialysate is ensured. In addition, by appropriately setting the gap S, it is possible to reliably prevent chatter noise when the chamber film 33 approaches the supply / discharge port 38. Furthermore, the durability of the apparatus is sufficiently ensured by using a fluorine rubber having excellent chemical resistance and durability as the material of the chamber film 33.

  Such a smooth predetermined operation of the chamber film 33 causes a problem that the chamber film 33 sticks to (is in close contact with) the spherical concave portion 34 of the chamber piece 35 at or near the installation portion of the supply / discharge port 38. Since generation is also prevented, for example, as shown in FIG. 1, two chambers (dialysate supply / discharge devices) are provided, and a chamber for hemodialysis and a chamber for receiving fresh dialysate can be switched alternately. In the above configuration, switching can be performed smoothly in a shorter time.

  Incidentally, the hemodialysis apparatus using the dialysate supply / discharge apparatus according to the above-described embodiment (the hemodialysis apparatus having the configuration shown in FIG. 1) and the spherical shape of the chamber membrane compared to the conventional type, which was prototyped during the examination of the present invention. A flow rate sensor at the time of chamber switching (for example, a hemodialysis machine using a dialysate supply / discharge device incorporating the above-described curvature-changing fluorine-based (made of fluorine-based rubber) chamber membrane in which the radius of curvature of the bulging portion is increased) FIG. 5 shows the result of comparing the flow rate (flow rate change) characteristics measured by the flow switch 22) in FIG. As is clear from FIG. 5, in the chamber membrane of the present invention, the switching time is 0.6 seconds, which is greatly reduced compared to the switching time of 0.8 seconds for the curvature-changing fluorine-based chamber membrane. Compared with the curvature-modified fluorine-based chamber membrane, which has a characteristic that is distorted and causes slight switching unevenness, the present invention chamber film has a smooth and stable flow rate change characteristic that does not cause switching unevenness. .

  The dialysate supply / discharge device according to the present invention is applicable to any chamber-type dialysate supply / discharge device using a chamber membrane.

DESCRIPTION OF SYMBOLS 1 Hemodialysis element 2 Dialysis membrane 3 Blood circuit 4 Dialysate circuit 5 Arterial side blood circuit 6 Venous side blood circuit 11, 12 Chamber membrane 13a, 13b, 14a, 14b Chamber piece 15, 16 Dialysate supply / discharge device 17a, 18a Fresh Dialysate side chambers 17b, 18b Used dialysate side chamber 21 Circulating pump 22 Flow switch 23 Dewatering pump 24 Female cylinder 25 Deaeration pump 26 Flow switch 27 Drain circuit 28 Switching valve 31 Dialysate supply / discharge device 32 Spherical expansion Outlet portion 33 Chamber membrane 34 Spherical concave portion 35 Chamber piece 36 Insertion hole 37 for fasteners Membrane operating space 38 Supply / exhaust port 39 Channel opening portion 41 Center of spherical bulge portion 42 Center of spherical concave portion 43 Attachment portion 44 Parts 45a, 45b Skirt part 51 Spherical bulge part 52 Spherical concave part 53 Supply / exhaust port δ Offset G Gap S Gap space

Claims (10)

  A flexible chamber membrane having a spherical bulge that can be reversed in bulge direction, and a pair of spherical recesses disposed on both sides of the chamber membrane and corresponding to the spherical bulge A chamber working space, and the spherical concave portions of the pair of chamber pieces are arranged facing each other to form a membrane working space in which the bulging direction of the spherical bulging portion of the chamber membrane can be reversed, A chamber-type dialysate supply / exhaust device in a hemodialysis apparatus having a supply / exhaust port facing the membrane operation space with respect to the membrane operation space, wherein the chamber piece has a central position of the spherical bulging portion of the chamber membrane A dialysate supply / discharge device characterized in that it is offset in the direction opposite to the position where the supply / discharge port is present with respect to the center position of the spherical recess.   The dialysate supply / discharge device according to claim 1, wherein an outer diameter of the spherical bulging portion of the chamber membrane is set smaller than an inner diameter of the spherical concave portion of the chamber piece.   The curvature radius on the position side where the supply / discharge port of the spherical bulging portion of the chamber film is set is larger than the curvature radius on the position side opposite to the position side where the supply / discharge port exists, The dialysate supply / discharge device according to claim 1 or 2.   The dialysate supply / discharge device according to any one of claims 1 to 3, wherein at least one of the supply / discharge ports is formed of a plurality of small holes.   The dialysate supply / discharge device according to claim 1, wherein the chamber membrane is made of rubber.   The dialysate supply / discharge device according to claim 5, wherein the chamber membrane is made of a fluorine-based rubber.   The amount of the offset is determined when the spherical bulge portion of the bulged chamber membrane comes into contact with a spherical concave portion located on the opposite side of the one chamber piece from the position where the supply / exhaust port exists. On the side where the supply / discharge port is present, the outer diameter of the spherical bulging portion of the chamber film is 1% to 20% between the spherical bulging portion of the chamber film and the spherical concave portion of the chamber piece. The dialysate supply / drainage device according to claim 6, wherein the dialysate supply / drainage device is set so that a gap having a dimension corresponding to is formed.   8. The chamber film according to claim 1, wherein the chamber film has a flange-shaped attachment part around the spherical bulge part, and the pair of chamber pieces have a sandwiching part for sandwiching the chamber film attachment part. The dialysate supply / discharge device according to any one of the above.   The dialysate supply / drainage device according to claim 8, wherein the attachment portion and the clamping portion are formed in shapes corresponding to each other.   10. The dialysate supply / drainage according to claim 9, wherein the shapes corresponding to each other are formed in a non-target shape with respect to a plane that defines a position side where the supply / exhaust port exists and an opposite position side thereof. apparatus.

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