TW201440824A - Pressure detector, blood circuit and blood purification apparatus with pressure detector - Google Patents

Abstract

The purpose of the present invention is to provide: a pressure-sensing element with a novel structure, said pressure-sensing element measuring the pressure inside an extracorporeal circulation circuit without coming into contact with blood or air, wherein coagulation of blood is better suppressed by minimizing the retention of blood as a result of improving the flow of blood inside the pressure-sensing element; and a blood circuit and a blood purification apparatus provided with the pressure-sensing element. The present invention provides a pressure-sensing element for an extracorporeal circulation circuit for measuring pressure inside an extracorporeal circulation circuit that performs extracorporeal treatment of blood, and is provided with: a chamber member provided with a fluid chamber that has a deforming surface deformed by the pressure inside the extracorporeal circulation circuit, a fluid inlet, and a fluid outlet, and that allows the blood to flow in and out; a fluid inlet joint for linking the fluid inlet to the extracorporeal circulation circuit; and a fluid outlet joint for linking the fluid outlet to the extracorporeal circulation circuit. Flow passages inside the fluid inlet joint and the fluid outlet joint widen in a cone shape toward the fluid chamber.

Description

Pressure detecting body and blood circuit and blood purifying device having the same

The present invention relates to a pressure detecting body and a blood circuit and a blood purifying device including the pressure detecting body.

The extracorporeal circulation therapy refers to a treatment method in which blood is taken out from a patient, blood is externally treated using a blood purification device, and the treated blood is returned to the body to perform blood purification. In this extracorporeal circulation therapy, blood pressure in the extracorporeal circulation must be properly grasped. Therefore, a pressure detecting body that measures pressure is disposed in the extracorporeal circuit. In the case of the pressure detecting body disposed in the extracorporeal circuit, the following two examples are generally used (Patent Documents 1 and 2).

Patent Document 1 discloses a pressure measuring device having a diaphragm which is a flexible thin plate (a film which is deformed in response to pressure in a body fluid circulation circuit) so that blood does not come into contact with air. A box (pressure detector) that is internally divided into a blood chamber and an air chamber. In the case, at least a part of the diaphragm is deformed by the pressure of the blood filled in the blood chamber, so that the pressure in the extracorporeal circuit can be measured by measuring the amount of deformation of the diaphragm.

Patent Document 2 discloses a pressure sensor which is attached The blood is solidified with the retention, and the liquid outflow port and the liquid inflow port which are the flow paths for introducing the liquid into the cartridge (pressure detecting body) are designed such that the liquid outflow port is disposed at a distance from the liquid inflow port. The method of not being able to reach the position of 1 week or more for 2 weeks or more. In the pressure sensor, by arranging the liquid outflow port at a position that is less than one week from the liquid inlet port, the liquid introduced into the casing flows in along the inner circumference of the side surface of the liquid chamber, and is formed and transmitted. The liquid chamber has a concentric flow of the liquid to generate a circulation to relieve the retention due to the sudden expansion of the flow path and to inhibit the coagulation of the blood.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Laid-Open Patent Publication No. 09-024026

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2007-282996

However, in the pressure detecting body described in Patent Document 1, when the blood enters the pressure detecting body, the inlet portion suddenly expands due to the flow path, and the inlet portion is caused to stay in the vicinity of the blood chamber inlet. Therefore, blood flow is stagnant, blood is retained at a certain position, and blood coagulation is prone to occur. Further, in the pressure sensor of Patent Document 2, it is impossible to generate a blood circulation which is assumed in advance due to the viscosity of the circulating blood or the treatment flow rate, and there is a problem that blood is likely to be coagulated due to retention of blood.

Accordingly, it is an object of the present invention to provide a pressure detecting body of a novel configuration which is capable of detecting pressure by detecting pressure in an extracorporeal circuit and in a pressure detecting body in which blood does not come into contact with air. The blood flow inside the body inhibits blood retention and further inhibits blood coagulation.

The inventors of the present invention, after repeated and intensive research, succeeded in discovering that the blood flow is further improved than the conventional pressure detecting body, and the pressure detecting body structure for blood coagulation is more suppressed, and the invention of the present invention is completed. That is, the present invention provides the pressure detecting body of the following (1) to (5), the blood circuit of (7), and the blood purification device of (8).

(1) A pressure detecting body for an extracorporeal circulation circuit, which is a pressure detecting body for measuring a pressure in an extracorporeal circuit that performs extracorporeal treatment of blood, comprising: a chamber member having a pressure due to the pressure in the extracorporeal circuit a deformed deformed surface, a liquid inflow port and a liquid outflow port, and a liquid chamber for inflow and discharge of the blood; a liquid inflow port joint for communicating the liquid inflow port with the extracorporeal circuit by a tube; and a liquid flow The outlet joint is configured to connect the liquid outflow port to the extracorporeal circulation circuit by a tube, and the liquid flow inlet joint and the flow path inside the liquid outflow joint are expanded into a truncated cone shape in a direction of the liquid chamber.

(2) The pressure detecting body for an extracorporeal circulation circuit according to the above aspect, wherein the liquid chamber has a cylindrical shape, and the liquid inflow port and the liquid outflow port are disposed on a cylindrical side surface of the liquid chamber.

(3) The pressure detecting body for an extracorporeal circulation circuit according to the above aspect, wherein the diameter of the liquid inflow port in the circumferential direction is 13.9% or more and 50% or less of the circumferential length of the liquid chamber.

The pressure detecting body for an extracorporeal circulation circuit according to any one of the above aspects, wherein the liquid inflow port and the liquid outflow port The clips are disposed opposite each other through the liquid chamber.

The pressure detecting body for an extracorporeal circulation circuit according to any one of the above aspects, wherein the liquid inflow port joint and the liquid outflow port joint have a truncated cone shape, and The larger bottom surface of the truncated cone shape is coupled to the liquid chamber.

The pressure detecting body for extracorporeal circulation circuits according to any one of the above aspects, wherein the liquid flow inlet joint and the inner flow path of the outlet joint have the same shape.

(7) A blood circuit comprising: the pressure detecting body for an extracorporeal circulation circuit according to any one of the above (1) to (6); and an extracorporeal circulation circuit.

(8) A blood purification device comprising the blood circuit according to (7) above.

According to the pressure detecting body of the present invention, the blood flow rate can be made by allowing the blood flowing from the extracorporeal circulation circuit to flow into the liquid chamber constituting the chamber member to flow through the liquid inlet port joint which is expanded into a truncated cone shape toward the liquid chamber. Uniformity, regardless of blood viscosity or treatment flow rate, can inhibit blood retention, and as a result, blood coagulation can be suppressed.

1‧‧‧Pressure detection body

2‧‧‧Extracorporeal circulation circuit

3‧‧‧Liquid flow inlet

4‧‧‧Liquid outlet

5‧‧‧Liquid room

6‧‧‧ Pressure measuring device

7‧‧ Air Room

8‧‧‧ deformed surface

9‧‧‧ room components

10‧‧‧Liquid flow inlet fittings

11‧‧‧Liquid outlet connector

12‧‧‧Liquid indoor side crotch

13‧‧‧Liquid indoor side crotch

14‧‧‧Liquid indoor side crotch

15‧‧‧ Blood circuit

16‧‧‧Drip room

17‧‧‧Substrate

18‧‧‧ Blood purification device

19‧‧‧Operator panel

20‧‧‧Unit kit

21‧‧‧ blood pump

22‧‧‧drug rack

23‧‧‧cell components for blood purification

24‧‧‧Caliber in the circumferential direction of the liquid inlet

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing the state of the pressure detecting body of the present invention from the side.

Fig. 2 is a schematic view showing the state of the pressure detecting body of the present invention from the above.

Fig. 3 is a schematic view showing another embodiment of the pressure detecting body of the present invention.

Fig. 4 is a schematic view showing a blood circuit embodiment of the pressure detecting body of the present invention.

Fig. 5 is a schematic view showing an embodiment of a blood purification apparatus having the pressure detecting body of the present invention.

Fig. 6 is a schematic view showing the constituent elements of the pressure detecting body of the present invention used in the first embodiment from the above.

Fig. 7 is a view showing various flow states after (b) ink flow and (b) ink flow after the pressure detecting body of the present invention used in the first embodiment.

Fig. 8 is a schematic view showing the constituent elements of the conventional pressure detecting body used in Comparative Example 1 from the above.

Fig. 9 is a view showing the results of confirmation of various flow states after (b) before the ink is circulated and (b) after the ink is circulated, for the conventional pressure detecting body used in Comparative Example 1.

Fig. 10 is a schematic view showing the components of the pressure detecting body used in Comparative Example 2 from the above.

[Formation of the Invention]

The pressure detecting body for the extracorporeal circulation circuit of the present invention is a pressure detecting body for measuring the pressure in the extracorporeal circuit that performs the extracorporeal treatment of blood, and is characterized in that it has a chamber member and is provided in the extracorporeal circuit. a pressure-deformed deformed surface, and a liquid inflow port and a liquid outflow port, and a liquid chamber for inflow and discharge of the blood; a liquid inflow port joint for allowing the liquid inflow port to be The extracorporeal circulation circuit is connected; and the liquid outflow port is configured to communicate the liquid outflow port with the extracorporeal circuit by a tube, and the liquid inflow port and the flow path inside the liquid outflow port are oriented toward the liquid chamber Expanded into a truncated cone shape.

The "extracorporeal circulation circuit" is a tubular flow path through which blood drawn from a human body flows. The "deformed surface" is formed into a surface that is at least partially deformed by the pressure in the extracorporeal circuit and is a part of the chamber member. The "liquid inlet" is an inlet for supplying blood into the liquid chamber in the chamber member, and the "liquid outlet" is an outlet for discharging blood from the liquid chamber in the chamber member. The "liquid inflow port joint" is a flow path that allows the extracorporeal circuit to communicate with the liquid inflow port, and the "liquid outflow port" is a channel that allows the extracorporeal circuit to communicate with the liquid outflow port.

Hereinafter, a preferred embodiment of the pressure detecting body for the extracorporeal circulation circuit will be described with reference to the drawings. 1 and 2 are schematic views showing an embodiment of the pressure detecting body for the extracorporeal circulation circuit.

In Figs. 1 and 2, the pressure detecting body 1 is provided with a chamber member 9 having a connection to the extracorporeal circuit 2, a deformed surface 8 which is deformed by the pressure in the extracorporeal circuit, and a liquid inflow port 3 and a liquid. The outflow port 4, the liquid chamber 5 for supplying and discharging blood, and the air chamber 7 adjacent to the liquid chamber 5 and disposed to sandwich the deformed surface 8. The air chamber 7 is connected to the pressure measuring device 6. Further, a chamber member 9 is provided; a liquid inflow port 10 for communicating the liquid inflow port 3 with the extracorporeal circuit 2; and a liquid outflow port 11 for communicating the liquid outflow port 4 with the extracorporeal circuit 2. Here, the flow path and liquid inflow port joint 10 in the liquid chamber 5 The surface on which the flow paths are connected is such that the diameter of the liquid inflow in the circumferential direction of the liquid chamber is the diameter 24 in the circumferential direction of the liquid inflow port. Further, in order to suppress the liquid flowing in the pressure detecting body 1 from remaining in the liquid chamber 5, the shape of the liquid inflow port joint 10 and the liquid outflow port joint 11 is preferably such that the liquid inflow port 3 and the liquid outflow port 4 can be smoothly connected. The shape of the liquid chamber 5. Although the specific shape can be appropriately designed according to the liquid flow rate or viscosity, it is preferable that the flow path inside the liquid inflow port joint 10 and the liquid outflow port joint 11 is configured to expand in a frustum shape toward the liquid chamber 5 side.

The means for measuring the pressure is a deformed surface 8 which is disposed so as to sandwich the liquid chamber 5 and the air chamber 7, which is deformed by the blood pressure flowing in the liquid chamber 5, and is measured by indirectly detecting the amount of deformation thereof. The pressure inside the extracorporeal circuit 2. Specifically, in the air chamber 7 formed as a hermetic space between the deformed surface 8 and the pressure measuring device 6, a pressure change occurs in the air chamber 7 as the deformed surface 8 is deformed, and a pressure measuring device is used. 6 The pressure change is measured, and the pressure in the extracorporeal circuit 2 is measured indirectly.

As a pressure measuring method, as shown in FIG. 3, a method of measuring the pressure in the extracorporeal circuit 2 by directly measuring the amount of deformation of the deformed surface 8 by a load sensor or a strain gauge or the like may be used. The pressure measuring method is not particularly limited as long as the pressure in the extracorporeal circuit can be accurately measured.

In FIG. 2, although the liquid chamber 5 has a cylindrical shape, the shape of the liquid chamber 5 is not limited, and may be, for example, a polygonal column shape such as a hexagonal column liquid chamber. Further, the arbitrary cross-sectional shape of the liquid chamber 5 parallel to the deformed surface 8 and the deformed surface 8 are not different in shape and size. There will be special problems. However, in order to prevent blood from escaping and to form a smooth blood flow, it is preferable that the liquid chamber 5 is formed into a cylindrical shape while the deformed surface 8 is formed as a circular film having the same circular radius as that of the liquid chamber 5.

Further, in Fig. 1, the side surface of the liquid chamber 5 is linear in cross section, but there is no problem in tilting at an arbitrary angle.

Further, as shown in Fig. 1, although the liquid chamber side dams 12, 13, and 14 belonging to the inner crotch portion of the liquid chamber 5 are at right angles, the crotch portion may have an arc. In order to form a smoother flow, the inner crotch portion of the liquid chamber 5 preferably has a certain degree of circular shape.

Further, in Fig. 1, although the shape of the deformed surface 8 is a flat plate-shaped film, there is no problem even if it is wavy or the like from the cross section. Further, the deformed surface 8 does not have to be deformed by the entire surface, and the area or shape of the deformed portion of the deformed surface 8 is not particularly limited as long as the pressure can be accurately measured.

In addition, in FIG. 2, the flow path of the liquid inflow port joint 10 and the liquid outflow port joint 11 which are tapered toward the liquid inflow port 3 and the liquid outflow port 4 flow in parallel to the deformed surface 8, but it is also possible. An angle is formed on the deformed surface 8. However, in order to form a smoother blood flow, the fritted liquid inflow port joint 10 and the liquid outflow port joint 11 are preferably arranged such that blood flows into the chamber member 9 at an angular range of 0 to 30 degrees with respect to the deformed surface 8. More preferably in the range of 0 to 15 degrees, it is preferably configured in a parallel inflow manner.

As shown in Fig. 1, although the liquid inflow port 3 and the liquid outflow port 4 are provided at an intermediate position with respect to the height direction of the side surface of the liquid chamber 5, the position of the liquid inflow port may be shifted from the intermediate position with respect to the height direction of the side surface. Furthermore, the positions of the liquid inflow port 3 and the liquid outflow port 4 can also be made. The height direction with respect to the side surface of the liquid chamber 5 is deviated from the same axis on the side of the liquid chamber 5. However, in order to form a smoother liquid flow, it is preferable that the liquid inflow port 3 and the liquid outflow port 4 are positioned at an intermediate position with respect to the height direction of the side surface of the liquid chamber 5, and further, the liquid flow with respect to the height direction of the liquid chamber 5 The positions of the inlet 3 and the liquid outflow port 4 are preferably located on the same axis on the side of the liquid chamber 5.

As shown in Fig. 2, the liquid inflow port joint 10 for communicating the liquid inflow port 3 and the extracorporeal circulation circuit 2 by means of a tube has its inner flow path expanded into a truncated cone shape toward the liquid chamber 5. Thus, the portion of the liquid inflow port 10 that is connected to the liquid chamber 5, that is, the circumferential direction 24 of the liquid inflow port 3 is preferably larger than the extracorporeal circuit 2. Further, in any cross section of the liquid flow inlet joint 10 having a truncated cone shape, in order to form a flow resistance equivalent to that of the extracorporeal circulation circuit 2, it is preferable to conform to the relationship of the following formula 1.

De=4Af/Wp‧‧‧(Form 1)

Here, De represents the inner diameter of the extracorporeal circuit, Af represents the cross-sectional area of the liquid flow inlet joint at any position, and Wp represents the cross-sectional circumference of the liquid flow inlet joint at any position.

Although the liquid inflow port 3 is constituted by the connection surface of the liquid inflow port joint 10 and the liquid chamber 5, the connection surface, that is, the circumferential direction diameter 24 of the liquid inflow port 3 may be in accordance with the relationship of Formula 1. However, in order to form a more uniform and smooth flow in the liquid chamber 5, the diameter 24 of the liquid inlet 3 in the circumferential direction is preferably 13.9% or more of the circumference of the liquid chamber 5. On the other hand, when the circumferential direction diameter 24 of the liquid inflow port 3 is 50% or more with respect to the circumference of the liquid chamber 5, the fluid inflow port joint 10 cannot be in a truncated cone shape. That is, the circumferential direction diameter 24 of the liquid inflow port 3 is preferably a liquid The circumference of the chamber 5 is in the range of 13.9% or more and 50% or less.

As shown in Fig. 2, although the liquid inflow port 3 and the liquid outflow port 4 are disposed at a relative position with respect to the chamber member 9, they may be shifted from the relative position. However, in order to create a smoother flow, the relative position is still optimal. The relative position referred to here is a case where the center of the liquid chamber 5 is in a symmetrical relationship.

Further, as shown in FIG. 2, although the liquid inflow port 3 and the liquid outflow port 4 are formed in the same shape, even if the installation area of the liquid outflow port 4 and the liquid chamber 5 is smaller than the liquid inflow port 3, the above invention is not caused. The efficacy is reduced. However, the fluid inflow port 3 and the liquid outflow port 4 preferably have the same shape in terms of moldability of the pressure detecting body 1 and prevention of mounting error of the extracorporeal circuit 2, and in order to form a smoother and more uniform liquid flow.

Although the material of the liquid chamber 5 and the air chamber 7 is not particularly hard or soft, the liquid chamber 5 and the liquid chamber 5 may be caused by environmental factors such as an external force that deforms the liquid chamber 5 or the air chamber 7 due to liquid temperature or temperature. When the shape of the air chamber 7 changes, it becomes difficult to accurately measure the pressure in the extracorporeal circuit 2. Therefore, the material of the liquid chamber 5 and the air chamber 7 is preferably hard, and since it directly or indirectly contacts the blood of the patient, it is preferable to use a material having biocompatibility. For example, vinyl chloride, polycarbonate, polypropylene, polyethylene, polyurethane, etc. may be mentioned, and any of them are suitable for use. In addition, although the manufacturing method is not particularly limited, for example, injection molding, air blowing molding, cutting processing, or the like can be used.

If the material of the deformed surface 8 is hard, the amount of deformation by the pressure becomes small, and it is difficult to accurately measure the pressure in the extracorporeal circuit 2, so that a soft material which can softly deform the pressure is preferable. and Since the blood of the patient is directly or indirectly contacted, it is preferable to use a material having biocompatibility. For example, although polyvinyl chloride, a decyloxy resin, a styrene-based thermoplastic rubber, a styrene-based thermoplastic rubber compound, or the like can be used, it is not limited thereto, and any material can be used as long as it is biocompatible. Be applicable.

The material of the extracorporeal circuit 2 can be any material such as synthetic resin, metal, or glass. However, from the viewpoints of production cost, workability, and workability, it is preferred to use a synthetic resin, particularly a thermoplastic resin. For the thermoplastic resin, for example, a polyolefin resin, a polyamide resin, a polyester resin, a urethane resin, a fluorine resin, a fluorene resin, or the like can be used, and an ABS resin or a polyvinyl chloride resin can also be used. Polycarbonate, polystyrene, polyacrylic acid, polyacetal, and the like. Among them, the soft material is excellent in bending resistance, fracture resistance, and the like, and is excellent in flexibility at the time of handling, and is preferably excellent in soft vinyl chloride from the viewpoint of assemblability.

The material of the liquid inflow port joint 10 and the liquid outflow port joint 11 is not hard or soft. Although any of synthetic resin, metal, glass, and the like can be used, since the patient's blood is directly or indirectly contacted, A material with biocompatibility is preferred. Further, from the viewpoints of production cost, workability, and assembly property, it is preferable to use the same material as the liquid chamber 5 and the air chamber 7. For example, vinyl chloride, polycarbonate, polypropylene, polyethylene, polyurethane, or the like can be used. Further, although the production method thereof is not particularly limited, specifically, injection molding, blow molding, cutting processing, or the like can be used. Further, the extracorporeal circuit 2 and the liquid inflow port 10 and the liquid outflow port 11 may be integrally formed.

The bonding method of each of the liquid chamber 5, the air chamber 7, the deformed surface 8, the liquid inflow port joint 10, the liquid outflow port joint 11, and the extracorporeal circulation circuit 2 is not particularly limited, but in general, the joining of the synthetic resin is exemplified. Heat fusion or bonding. For example, in the thermal fusion bonding, methods such as high-frequency welding, induction heating welding, ultrasonic welding, friction welding, friction welding, hot plate welding, and hot wire welding can be cited. Examples of the bonding method include a bonding method using a cyanoacrylate type, an epoxy type, a polyurethane type, a synthetic rubber type, an ultraviolet curing type, a denatured acryl resin, and a hot melt type.

In addition, generally, in the joining of a hard material and a soft material, a mechanical seal which seals a soft material by pressing a hard material, or a heat fusion joint as disclosed above or Bonding, etc.

Such a pressure detecting body 1 can be directly used in this state after molding and joining, and is particularly used in medical use of extracorporeal circulation therapy after sterilization. The sterilization method can be sterilized by a sterilization method of a general medical device, and can be sterilized by a chemical liquid, gas, radiation, high-pressure steam, heating, or the like.

If the size of the liquid chamber 5, the air chamber 7, and the deformed surface 8 of the pressure detecting body 1 is too large, the volume will increase, and as a result, a problem of an increase in the priming volume will occur; Small, since the pressure in the extracorporeal circuit becomes a negative pressure, the deformed surface 8 is convex toward the liquid chamber side, causing the deformed surface 8 to block the liquid inflow port 3 or the liquid outflow port 4, thereby causing a problem that blood does not flow. Therefore, the size of the liquid chamber 5 is preferably about 1 to 10 cm ³ , more preferably about 1 to 5 cm ³ , and most preferably about 1 to 3 cm ³ . If the size of the air chamber 7 is too large, the deformed surface 8 will be largely deformed toward the liquid chamber side during the negative pressure, and the deformed surface 8 will block the liquid inflow port 3 or the liquid outflow port 4, causing a problem that blood does not flow. Furthermore, conversely, if it is too small, the deformed surface 8 will easily come into contact with the inner wall surface of the air during positive pressure, so that the accuracy of pressure measurement is lowered. Thus, the size of the air chamber 7, in terms of volume, preferably 0.2 to 1.0cm ^3, more preferably from 0.3 to 0.8cm ^3.

Furthermore, the blood circuit of the present invention is characterized by comprising: the pressure detecting body for the extracorporeal circulation circuit; and the extracorporeal circulation circuit.

As an embodiment of the blood circuit described above, FIG. 4 shows a blood circuit 15 having a pressure detecting body 1 and an extracorporeal circuit 2. The blood circuit 15 is configured to connect the pressure detecting body 1 or the dripping chamber 16 or the like by the extracorporeal circulation circuit 2. Here, the connection may be simply connected to each other, or the pressure detecting body 1, the dropping chamber 16, and the extracorporeal circulation circuit 2 may be attached to the substrate 17 made of hard or soft material at a predetermined position. In the case of using the substrate 17, it is preferable to use a hard material from the viewpoint of attachment to the blood purification device or the detachment thereof, or the attachment and detachment of the pressure detecting body 1 or the extracorporeal circulation circuit 2 or the like. Specifically, ABS resin, polypropylene, nylon, polyvinyl chloride, polycarbonate, polyether oxime, and ethylene terephthalate can be used.

Furthermore, the blood purification device of the present invention is characterized by having the blood circuit described above.

As an embodiment of the blood circuit described above, FIG. 5 shows a blood purification device 18 having a blood circuit 15. The blood purification device 18 is configured such that an operation panel 19, a module holder 20, a blood pump 21, a drug solution rack 22, and the like are disposed at predetermined positions, and a blood circuit 15 and a blood purification unit are provided there. Component 23, etc., and each unit Connected. The blood purification device 18 is used for blood purification therapy after being set by the blood purification unit unit 23 used in combination.

[Examples]

Since the effect of the above-described pressure detecting body has been confirmed by the embodiment, it will be specifically described below.

(Example 1)

The liquid flow condition was confirmed by the following methods 1) to 5) using the pressure detecting body configured as shown in Fig. 6 .

1) As the first liquid system in which the simulated blood flows through the extracorporeal circulation circuit and the pressure detecting body, an aqueous solution of xthane gum (concentration: 750 mg/L) was used, and the liquid was supplied at a flow rate of 30 ml/min using a liquid feeding pump. The extracorporeal circuit and the pressure detector are filled.

2) After the liquid-filled pump is kept in operation (30 ml/min), an appropriate amount of ink flows from the extracorporeal circulation circuit on the liquid inlet side of the pressure detecting body.

3) After carrying out the above 1) and 2), the ink flow state in the liquid chamber of the pressure detecting body was visually confirmed.

4) A soft vinyl chloride tube having an inner diameter of about 3.0 mm is connected to the liquid inflow port and the liquid outflow port as an extracorporeal circulation circuit, and the liquid supply pump is disposed on the extracorporeal circuit on the liquid inflow side.

5) The volume of the blood chamber of the pressure detecting body is set to be about 2.3 cm ³ , and the flow path connecting the extracorporeal circuit and the liquid chamber is in the shape of a truncated cone, and the circumferential direction of the liquid inflow port A is set with respect to the circumference of the liquid chamber. It is 33.3%. The liquid inflow port and the liquid outflow port are disposed at opposite positions with respect to the chamber member as a pressure detecting body. Further, in the pressure detecting system of the present embodiment, for the purpose of confirming the flow state of the liquid chamber, since the pressure measurement is not performed, the liquid chamber is made only of polycarbonate.

As a result of the test, when the ink flows into the liquid chamber filled with the aqueous solution of the Sanxian gum shown in Fig. 7(a), as shown in Fig. 7(b), it can be confirmed that the ink can be supplied from the liquid inflow port to the liquid outflow port. Evenly fill and circulate between them.

(Comparative Example 1)

On the other hand, as Comparative Example 1, a pressure detecting body as shown in Fig. 8 was used, and the flow state was confirmed by the following method. The liquid chamber has the same size as that of the first embodiment, and the liquid inflow port and the liquid outflow port are directly connected (in the liquid chamber) by an extracorporeal circulation circuit having an inner diameter of about 3.0 mm, and, as shown in FIG. 8, a liquid inflow port is provided. And the liquid flow outlets are arranged in the vicinity of each other. Further, in the pressure detecting system of the comparative example, for the purpose of confirming the flow state of the liquid chamber, since the pressure measurement was not performed, the liquid chamber was made only of polycarbonate.

As a result of the test, when the ink flows into the liquid chamber filled with the aqueous solution of Sanxian gum as shown in FIG. 9(a), as shown in FIG. 9(b), the ink does not form a liquid flow by the inner circumference of the side surface of the liquid chamber, and It is a flow (short path) that produces a direct flow from the liquid inlet to the liquid outlet. That is, in the liquid chamber, the ink does not flow to a position deviating from the liquid inflow port and the liquid outflow port.

From the above results, it is understood that the liquid inflow port and the liquid outflow port connecting the blood circulation circuit and the liquid chamber are arranged in a frustum shape to the liquid chamber, and a short path is not generated, thereby improving the retention of blood in the liquid chamber. , can achieve blood coagulation inhibition.

(Example 2)

Next, the effect at the time of changing the diameter A in the circumferential direction of the liquid chamber of the liquid inlet shown in FIG. 6 was confirmed.

1) With respect to the present embodiment, the liquid chamber flow velocity distribution was compared using the results obtained by computer simulation. In addition, the standard deviation of the flow velocity distribution in the liquid chamber of each of the examples is disclosed in Table 1.

The computer simulation was performed using the fluid analysis software "STAR-CD" of IDAJ Co., Ltd. In addition, with this simulation model, since the pressure evaluation is not performed, only the liquid chamber is modeled, and the liquid chamber circumferential direction diameter A of the liquid inflow port is set to 8.3% of the liquid chamber circumference length, and on this basis, The flow rate of the model was set to 30 ml/min, which flowed into the liquid chamber from the liquid inflow port and was discharged from the liquid outflow port.

As a result of the simulation, as shown in Table 1, the standard deviation of the flow velocity distribution in the liquid chamber was 0.004903 (m/sec).

(Example 3)

Next, the effect of the liquid chamber circumferential direction diameter A of the liquid inflow port being 16.7% of the liquid chamber circumference length was confirmed. The simulation results are shown in Table 1. The standard deviation of the flow velocity distribution of the liquid chamber was 0.003468 (m/sec).

(Example 4)

Next, the liquid chamber circumferential direction diameter A of the liquid inflow port is set to The effect of 25% of the circumference of the liquid chamber was confirmed. The simulation results are shown in Table 1. The standard deviation in the liquid chamber flow velocity distribution was 0.002608 (m/sec).

(Comparative Example 2)

On the other hand, a pressure-detecting body having the structure shown in Fig. 10 was used as Comparative Example 2, and the flow state was confirmed by the following method. The liquid chamber is the same size as in the first embodiment, and the liquid inflow port joint and the liquid outflow port joint which do not transmit through the truncated cone shape are used, and the extracorporeal circulation circuit having an inner diameter of about 3.0 mm is directly connected to the liquid inflow port and the liquid outflow port. In addition, the liquid inflow port and the liquid outflow port are arranged so that the liquid chambers are arranged to face each other. This design was modeled and flowed into the liquid chamber from the liquid inflow port by the same method as in Examples 2 to 4, and discharged from the liquid outflow port to confirm the flow velocity distribution of the liquid chamber.

The simulation results are shown in Table 1. The standard deviation of the liquid chamber flow velocity distribution of Comparative Example 2 was 0.007163 (m/sec). As described above, by setting the liquid inflow port joint and the liquid outflow port joint to a truncated cone shape, the liquid chamber flow velocity distribution (degree of speed unevenness) can be reduced.

(Comparative Example 3)

Next, a mold having the structure shown in Fig. 8 was produced, and the flow velocity distribution of the liquid chamber was confirmed by the same method as in Examples 2 to 4. The simulation results are shown in Table 1. The standard deviation of the liquid chamber flow velocity distribution was 0.003967 (m/sec).

The standard deviation of the liquid chamber flow velocity distribution derived from the results obtained in Examples 2 to 4 is related to the ratio of the circumferential direction of the liquid chamber in the liquid flow inlet to the circumferential length of the liquid chamber, such as setting the standard deviation of the liquid chamber flow velocity distribution to Y. , liquid chamber inlet liquid chamber circumferential direction caliber and liquid When the ratio of the circumference of the chamber is set to X, the relationship of XY can be expressed by the following formula 2.

Y=0.0311X ² -0.0243X+0.0067‧‧‧(Form 2)

It can be seen from Equation 2 that if the liquid chamber circumferential direction diameter A of the liquid inflow port is set to 13.9% of the liquid chamber circumference length, the standard deviation of the liquid chamber flow velocity distribution is smaller than that of Comparative Example 2, so that the liquid chamber that passes the liquid inflow port is passed. The diameter A in the circumferential direction is set to be 13.9% or more of the circumference of the liquid chamber, and a better effect can be obtained.

In this manner, by setting the diameter A in the circumferential direction of the liquid chamber of the liquid inflow port to be 13.9% or more and 50% or less of the circumference of the liquid chamber, not only the blood retention can be improved, but also the short path can be prevented, and the flow velocity distribution can be suppressed. The standard deviation reduces the disorder of blood flow, which in turn inhibits blood coagulation.

[Industrial availability]

The pressure detecting body of the present invention and the blood circuit and blood purification device including the pressure detecting body can suppress blood coagulation more than the conventional pressure detecting body. Therefore, it is safe to measure the pressure in the extracorporeal circuit and can be used in extracorporeal circulation therapy.

1‧‧‧Pressure detection body

5‧‧‧Liquid room

6‧‧‧ Pressure measuring device

7‧‧ Air Room

8‧‧‧ deformed surface

9‧‧‧ room components

10‧‧‧Liquid flow inlet fittings

11‧‧‧Liquid outlet connector

12‧‧‧Liquid indoor side crotch

13‧‧‧Liquid indoor side crotch

14‧‧‧Liquid indoor side crotch

Claims (8)

A pressure detecting body for an extracorporeal circulation circuit for measuring a pressure in an extracorporeal circuit for performing extracorporeal treatment of blood, comprising: a chamber member having a deformed surface deformed by pressure in the extracorporeal circuit, and a liquid flow An inlet and a liquid outlet, and a liquid chamber for inflow and discharge of the blood; a liquid inflow joint for communicating the liquid inlet with the extracorporeal circuit by means of a tube; and a liquid outflow joint for using the tube The liquid outflow port is in communication with the extracorporeal circulation circuit; and the liquid inflow port joint and the flow path inside the liquid outflow port joint are expanded into a truncated cone shape toward the liquid chamber. The pressure detecting body for an extracorporeal circuit according to claim 1, wherein the liquid chamber has a cylindrical shape, and the liquid inflow port and the liquid outflow port are disposed on a cylindrical side surface of the liquid chamber. The pressure detecting body for an extracorporeal circuit according to claim 2, wherein the circumferential direction of the liquid inflow port is 13.9% or more and 50% or less of the circumferential length of the liquid chamber. The pressure detecting body for an extracorporeal circulation circuit according to any one of claims 1 to 3, wherein the liquid inflow port and the liquid outflow port are disposed to face each other with respect to the liquid chamber. The pressure detecting body for an extracorporeal circuit according to any one of claims 1 to 4, wherein the liquid inflow port joint and the liquid outflow port joint have a truncated cone shape and are larger in the shape of the truncated cone. Bottom surface and The liquid chamber is connected. The pressure detecting body for an extracorporeal circuit according to any one of claims 1 to 5, wherein the liquid flow inlet joint and the inner flow path of the outlet joint have the same shape. A blood circuit comprising: a pressure detecting body for an extracorporeal circulation circuit according to any one of claims 1 to 6; and an extracorporeal circulation circuit. A blood purification device comprising the blood circuit of claim 7.