JP7033578B2 - Pressure detector - Google Patents

Description

The present invention relates to a pressure detector capable of detecting the pressure of a liquid in a flow path by detecting the pressure of the gas phase portion.

Generally, during dialysis treatment, a blood circuit for circulating the collected patient's blood extracorporeally and returning it to the body is used, and the blood circuit is, for example, a dialyzer (blood purifier) provided with a hollow filament membrane. It is mainly composed of an arterial blood circuit and a venous blood circuit that can be connected to. An arterial puncture needle and a venous puncture needle are attached to the tips of the arterial blood circuit and the venous blood circuit, and each of them is stabbed by a patient to perform extracorporeal circulation of blood in dialysis treatment.

In order to detect the pressure of blood circulating extracorporeally in the blood circuit, for example, as disclosed in Patent Document 1, a case connectable to the blood circuit and a case attached to the case and filled with blood in the blood circuit can be used. The liquid phase portion and the gas phase portion that can be filled with air are separated from each other, and a diaphragm (membrane member) that can be displaced according to the pressure of the blood filled in the liquid phase portion is provided, and the pressure of the gas phase portion is provided. A pressure detector that can detect the pressure of blood by detecting the pressure with a pressure detection sensor has been proposed. According to such a conventional pressure detector, since the liquid phase portion and the gas phase portion are partitioned by the membrane member, the blood in the blood circuit while avoiding the blood coming into contact with the air in the gas phase portion. Pressure can be detected accurately.

Special Table 2017-504389 Gazette

However, in the above-mentioned conventional pressure detector, in the process of displacement of the membrane member toward the gas phase portion according to the pressure of the liquid phase portion, there is a possibility that the opening leading to the pressure detection sensor in the gas phase portion is blocked. .. In this case, since the opening is closed before the displacement limit of the membrane member is reached, it is not possible to detect the pressure change due to the displacement of the membrane member any more, and the measurement range is narrowed. On the other hand, by increasing the capacity of the gas phase portion, a predetermined measurement range can be secured even if the opening is closed during the displacement process of the membrane member, but in that case, the capacity of the gas phase portion is larger than necessary. And the case becomes large.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a pressure detector capable of securing a necessary measurement range while suppressing an increase in the capacity of a gas phase portion. ..

The invention according to claim 1 comprises a case that can be connected to a liquid flow path, a liquid phase portion that is attached to the case and can be filled with the liquid in the flow path, and a gas phase portion that can be filled with a gas. A pressure for detecting the pressure of the liquid in the flow path by partitioning and providing a membrane member that can be displaced according to the pressure of the liquid filled in the liquid phase portion and detecting the pressure of the gas phase portion. In the detector, the gas phase portion is formed with an opening through which the gas can flow in or out according to the displacement of the membrane member, and the gas due to the opening is formed in the process of the membrane member being displaced toward the gas phase portion. It is characterized in that the holding portion capable of holding the inflow or outflow of the gas is formed radially around the opening .

According to a second aspect of the present invention, in the pressure detector according to the first aspect, the holding portion comprises a flow passage communicating with the opening, and the flow path is formed in a process in which the membrane member is displaced toward the gas phase portion. It is characterized in that the inflow or outflow of gas through the opening is maintained by allowing the flow of gas in the road.

The invention according to claim 3 is characterized in that, in the pressure detector according to claim 2, the flow passage is formed by a rib or a groove formed around the opening in the gas phase portion.

According to a fourth aspect of the present invention, in the pressure detector according to the second aspect, the flow passage covers the recess formed around the opening in the gas phase portion and the recess while including the opening, and is a gas. It is characterized in that it is composed of a permissible member that allows the passage of gas.

The invention according to claim 5 is characterized in that, in the pressure detector according to claim 4, the permissible member comprises a hydrophobic membrane that allows the passage of a gas but blocks the passage of a liquid.

The invention according to claim 6 is characterized in that, in the pressure detector according to claim 2, the flow passage is formed by ribs or grooves formed on the surface of the membrane member on the gas phase side.

The invention according to claim 7 is a blood circuit, characterized in that the pressure detector according to any one of claims 1 to 6 is connected.

According to the first aspect of the present invention, the gas phase portion is formed with an opening through which gas can flow in or out according to the displacement of the membrane member, and the gas due to the opening is formed in the process of the membrane member being displaced toward the gas phase portion. Since the holding portion capable of holding the inflow or outflow of the gas phase portion is formed, it is possible to secure the necessary measurement range while suppressing the increase in the capacity of the gas phase portion.

According to the invention of claim 2, the holding portion is composed of a flow passage communicating with the opening, and the gas due to the opening is allowed to flow in the flow passage in the process of displacement of the membrane member toward the gas phase portion. Since the inflow or outflow of the gas is maintained, it is possible to reliably prevent the membrane member from closing the opening in the process of being displaced toward the gas phase portion.

According to the invention of claim 3, since the flow passage is formed by ribs or grooves formed around the opening in the gas phase portion, it is possible to surely prevent the opening from being closed by a simple configuration.

According to the invention of claim 4, the flow passage is composed of a recess formed around the opening in the gas phase portion and an allowable member that covers the recess while including the opening and allows the passage of gas. The gas passage area in the allowable member can be set large, the resistance when the gas passes can be reduced, and the deterioration of the pressure detection accuracy can be suppressed.

According to the invention of claim 5, since the permissible member is composed of a hydrophobic film that allows the passage of gas and blocks the passage of liquid, when the liquid leaks from the liquid phase portion, the leaked liquid is the gas phase. It is possible to prevent it from reaching the outside of the part.

According to the invention of claim 6, since the flow passage is formed by ribs or grooves formed on the surface of the membrane member on the gas phase side, it is possible to surely prevent the opening from being closed by a simple configuration. can.

According to the invention of claim 7, it is possible to provide a blood circuit having the effect of any one of claims 1 to 6.

Schematic diagram showing a dialysis apparatus (blood purification apparatus) to which the pressure detector according to the first embodiment of the present invention is applied. Plan view showing the same pressure detector Front view showing the same pressure detector Cross-sectional view taken along the line IV-IV in FIG. 2 (state in which the membrane member is displaced toward the liquid phase portion) IV-IV line sectional view in FIG. 2 (state in which the membrane member is displaced toward the gas phase portion) FIG. 2 is a sectional view taken along line VI-VI. Top view showing the inlet and outlet formed in the liquid phase case of the same pressure detector. Top view showing the gas phase case in the same pressure detector Cross-sectional view showing the flow path in the pressure detector A cross-sectional view showing a pressure detector (a state in which the membrane member is displaced to the liquid phase portion) according to the second embodiment of the present invention. Cross-sectional view showing the same pressure detector (state where the membrane member is displaced to the gas phase part) Top view showing the gas phase case (state before the hydrophobic membrane is attached) in the pressure detector. Top view showing the gas phase case (with the hydrophobic membrane attached) in the pressure detector. Cross-sectional view showing the flow path in the pressure detector Schematic diagram showing a cross section of a hydrophobic membrane in the same pressure detector Sectional drawing which shows the pressure detector (state which the membrane member was displaced to the liquid phase part) which concerns on 3rd Embodiment of this invention. Cross-sectional view showing the same pressure detector (state where the membrane member is displaced to the gas phase part) Cross-sectional view showing the flow path in the same pressure detector Cross-sectional view showing the mounting structure of the hydrophobic membrane

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
The blood purification device applied to the first embodiment comprises a dialysis device for performing dialysis treatment, and as shown in FIG. 1, a blood circuit including an arterial blood circuit 1 and a venous blood circuit 2 and an arterial artery. A dialyzer 3 (blood purifier) that is interposed between the side blood circuit 1 and the venous blood circuit 2 to purify the blood flowing through the blood circuit, a blood pump 4, and air arranged in the venous blood circuit 2. The trap chamber 5, the dialyzer main body 6 that supplies dialysate to the dialyzer 3 and discharges the drainage from the dialyzer 3, and the physiological saline solution supply line L3 (replacement) that can supply the physiological saline solution as a replacement solution to the blood circuit. The liquid supply line) and the accommodating means 7 accommodating the physiological saline solution as a replacement solution are mainly composed.

An arterial puncture needle a can be connected to the tip of the arterial blood circuit 1 via a connector, and an ironing type blood pump 4 is provided in the middle of the arterial blood circuit 1, while the venous blood circuit 2 is provided with an ironing type blood pump 4. The vein-side puncture needle b can be connected to the tip thereof via a connector, and the air trap chamber 5 is connected in the middle. The air trap chamber 5 can capture air bubbles in the liquid and is provided with a filtration net (not shown) so that, for example, a thrombus at the time of returning blood can be captured. In the present specification, the side of the puncture needle for removing blood (collecting blood) is referred to as "arterial side", and the side of the piercing needle for returning blood is referred to as "venous side". "And" vein side "is not defined by either an artery or a vein in which the blood vessel to be punctured is.

The blood pump 4 is composed of a squeeze type pump arranged in the arterial blood circuit 1, is capable of forward rotation drive and reverse rotation drive, and can flow the liquid in the blood circuit in the drive direction. That is, a squeezing tube that is softer and has a larger diameter than the other flexible tubes constituting the arterial blood circuit 1 is connected to the arterial blood circuit 1, and this squeezing tube is connected to the blood pump 4. A roller is provided to squeeze the blood in the liquid feeding direction. When the blood pump 4 is driven in this way, the roller rotates to squeeze the ironing tube (a part of the blood circuit), and the liquid inside can flow in the driving direction (rotation direction of the roller). ..

Then, when the blood pump 4 is driven in the normal direction (rotation to the left in the figure) with the arterial puncture needle a and the venous side puncture needle b punctured in the patient, the patient's blood passes through the arterial blood circuit 1. After reaching the dialyzer 3, blood is purified by the dialyzer 3, and the blood is removed from the air trap chamber 5 while returning to the patient's body through the venous blood circuit 2. That is, the patient's blood is purified by the dialyzer 3 while being circulated extracorporeally from the tip of the arterial blood circuit 1 of the blood circuit to the tip of the venous blood circuit 2. Further, when the blood pump 4 is reversely driven (rotated to the right in the figure), the blood in the blood circuit (between the tip of the arterial blood circuit 1 and the arrangement position of the blood pump 4) can be returned to the patient. ..

The dialyzer 3 is formed in a housing portion thereof with a blood introduction port 3a, a blood outlet port 3b, a dialysate introduction port 3c, and a dialysate outlet port 3d, of which the blood introduction port 3a has an arterial blood circuit 1. However, the venous side blood circuit 2 is connected to each of the blood outlet port 3b. Further, the dialysate introduction port 3c and the dialysate outlet port 3d are connected to the dialysate introduction line L1 and the dialysate discharge line L2 extending from the dialyzer main body 6, respectively.

A plurality of hollow fibers are housed in the dialyzer 3, and the inside of the hollow fibers serves as a blood flow path, and the dialysate flows between the outer peripheral surface of the hollow fibers and the inner peripheral surface of the housing portion. It is said to be a road. A large number of minute holes (pores) penetrating the outer peripheral surface and the inner peripheral surface of the hollow fiber are formed in the hollow fiber to form a hollow fiber membrane, and impurities and the like in blood are dialyzed through the hollow fiber membrane. It is configured to be able to permeate into the liquid.

On the other hand, the dialyzer main body 6 is provided with a liquid feeding means such as a double pump across the dialysate introduction line L1 and the dialysate discharge line L2, and the bypass line bypassing the liquid feeding means is a dialyzer. A water removal pump for removing water from the blood of the patient flowing through the three is provided. Further, one end of the dialysate introduction line L1 is connected to the dialyzer 3 (dialysis fluid introduction port 3c), and the other end is connected to a dialysate supply device (not shown) for preparing a dialysate having a predetermined concentration. Further, one end of the dialysate discharge line L2 is connected to the dialyzer 3 (dialysate outlet port 3d), and the other end is connected to a drainage means (not shown), so that the dialysate supplied from the dialysate supply device is connected. After reaching the dialyzer 3 through the dialysate introduction line L1, it is sent to the drainage means through the dialysate discharge line L2.

An overflow line extends from the upper part of the air trap chamber 5, and a clamping means such as a solenoid valve is arranged in the middle of the overflow line. Then, by opening the clamping means such as the solenoid valve, the liquid (priming liquid or the like) flowing in the blood circuit can overflow through the overflow line.

One end of the physiological saline supply line L3 (replacement solution supply line) is connected by a T-shaped tube or the like between the arrangement position of the blood pump 4 in the arterial blood circuit 1 and the tip of the arterial blood circuit 1. It is composed of a flow path (for example, a flexible tube or the like) capable of supplying a physiological saline solution (replacement solution) for replacing blood in the blood circuit to the arterial blood circuit 1. A storage means 7 (so-called “raw food bag”) containing a predetermined amount of physiological saline is connected to the other end of the physiological saline supply line L3, and an air trap chamber 8 is connected in the middle. ing.

Further, a clamping means 9 (for example, a solenoid valve or the like) is provided on the physiological saline solution supply line L3 according to the present embodiment. The clamping means 9 is provided so that the physiological saline supply line L3 can be opened and closed, and the flow path can be closed and opened. By opening and closing the clamping means 9, the flow of the physiological saline solution supply line L3 can be performed. It is possible to arbitrarily switch between an obstructed state that obstructs the road and a distribution state in which a physiological saline solution (replacement solution) can be distributed. Instead of such a clamping means 9, a general-purpose means such as forceps that can block and open the flow path of the physiological saline solution supply line L3 by manual operation may be used.

Here, the pressure detector 10 is connected to the blood circuit applied to the present embodiment. The pressure detector 10 is connected to a position between the dialyzer 3 and the air trap chamber 5 in the venous blood circuit 2, and is configured to be able to detect the pressure of blood flowing through the venous blood circuit 2 (blood circuit). ing. Specifically, as shown in FIGS. 2 to 6, the pressure detector 10 has a case C and a case that can be connected to a liquid flow path (in this embodiment, the venous blood circuit 2 (blood circuit)). The liquid phase portion S1 which is attached in C and can be filled with the liquid in the flow path (in this embodiment, the blood of the venous blood circuit 2 (blood circuit)) and the gas phase portion S2 which can be filled with air. Along with partitioning, a membrane member M that can be displaced according to the pressure of the liquid (blood) filled in the liquid phase portion S1 is provided, and the pressure of the gas phase portion S2 is detected by the pressure detection sensor P to detect the flow path. The pressure of the liquid in (venous blood circuit 2) can be detected.

The case C is composed of hollow molded parts obtained by molding a predetermined resin material or the like, and includes a liquid phase portion case Ca constituting the liquid phase portion S1 and a gas phase portion case Cb constituting the vapor phase portion S2. It is composed of a combination of. The liquid phase case Ca is integrally formed with an inflow port C1 and an outflow port C2 that can be connected to the liquid flow path and communicate with the liquid phase portion S1, and the gas phase case Cb is a piping portion described later. A connection port C3 that is connectable to one end of K and can communicate with the gas phase portion S2 is integrally formed. The inflow port C1 and the outflow port C2 may have a configuration in which the inflow and outflow of the liquid are reversed (that is, the liquid flows out through the inflow port C1 and the liquid flows in through the outflow port C2).

An annular holding surface m1 (see FIG. 7) is formed on the outer peripheral edge of the liquid phase case Ca, and an annular holding surface m2 (see FIG. 7) is formed on the outer peripheral edge of the gas phase case Cb. 8) is formed, and when the liquid phase case Ca and the gas phase case Cb are assembled together, the outer peripheral portion Ma of the membrane member M is sandwiched between the sandwiching surface m1 and the sandwiching surface m2. , The film member M can be attached while being sealed. The space formed inside the case C is partitioned (defined) into the liquid phase portion S1 and the gas phase portion S2 by the film member M.

The membrane member M is made of a diaphragm mounted in the case C, and is made of a flexible material that can be displaced or deformed according to a pressure change of the liquid phase portion S1 or the gas phase portion S2. That is, when the pressure (hydraulic pressure) of the liquid in the liquid phase portion S1 is small, as shown in FIG. 4, the film member M is displaced toward the liquid phase portion S1 to increase the capacity of the gas phase portion S2, and at the same time, the capacity of the gas phase portion S2 is increased. When the pressure (hydraulic pressure) of the liquid in the liquid phase portion S1 is large, as shown in FIG. 5, the film member M is displaced toward the gas phase portion S2 and the capacity of the gas phase portion S2 is reduced. There is.

Further, the gas phase case Cb has an opening Cb1 (see FIG. 8) formed substantially in the center of the bottom surface thereof. The opening Cb1 is formed on the inner peripheral surface (bottom surface) of the gas phase portion case Cb to communicate the flow path of the connection port C3 with the gas phase portion S2, and the gas phase portion S2 is formed according to the displacement of the membrane member M. Air (gas) can flow in or out. Then, by connecting one end of the pipe K to the connection port C3 and the other end to the pressure detection sensor P, air (gas) flows in or out from the opening Cb1 according to the displacement of the film member M, and the air is introduced. The pressure of the phase portion S2 can be detected by the pressure detection sensor P. The connection port C3 is not limited to the one connected to the pipe K, and may be connected to another means capable of transmitting the pressure of the gas phase portion S2 to the pressure sensor P.

Further, in the gas phase portion case Cb according to the present embodiment, a concave portion Cb4 is formed around the opening Cb1 on the bottom surface thereof, and an annular convex portion Cb3 is formed on the outer peripheral side edge portion of the concave portion Cb4. ing. Further, as shown in FIG. 8, a plurality of ribs Cb2 protruding radially around the opening Cb1 are formed around the opening Cb1 in the recess Cb4 of the gas phase portion S2, and the ribs Cb2 form a flow passage R. (Holding portion) is formed.

The flow passage R (holding portion) according to the present embodiment can hold the inflow or outflow of gas by the opening Cb1 in the process of displacing the membrane member M toward the gas phase portion S2, and as shown in FIG. In a state where the membrane member M is displaced toward the gas phase portion S2 and is in contact with the rib Cb2, it is composed of a space formed around the opening Cb1 and communicating with the opening Cb1 (a space formed by the recess Cb4). That is, in the process of displacement of the membrane member M toward the gas phase portion S2, a flow passage R is formed in the gap created by the rib Cb2, and gas (air in the gas phase portion S2) flows through the flow passage R. By allowing it, the inflow or outflow of gas through the opening Cb1 can be maintained. Instead of the rib Cb2, the flow passage R may be formed by a groove formed around the opening Cb1 in the gas phase portion S2.

The inflow port C1 according to the present embodiment includes a portion (protruding portion) connectable to a liquid flow path (blood circuit), and as shown in FIG. 6, the inflow port Ca1 of the liquid phase portion S1 (see FIG. 7). ), The flow path portion C1a through which the liquid (blood) flows in, and the connection portion C1b that can be connected to the flow path (blood circuit). That is, the flow path portion C1a and the connection portion C1b are formed so as to communicate with each other in the axial direction in the projecting portion constituting the inflow port C1, and the flow path is formed by connecting the tube constituting the flow path to the connection portion C1b. The liquid can be circulated through the flow path portion C1a and flowed into the liquid phase portion S1 from the inflow port Ca1. The inflow port C1 may have a concave shape for connecting the tubes constituting the flow path.

The outflow port C2 according to the present embodiment includes a portion (protruding portion) that can be connected to a liquid flow path (blood circuit), and as shown in the figure, the liquid (blood) that has flowed into the liquid phase portion S1. It is configured to have a flow path portion C2a flowing out from the outlet Ca2 (see FIG. 7) and a connection portion C2b that can be connected to the flow path (blood circuit). That is, the flow path portion C2a and the connection portion C2b are formed so as to communicate with each other in the axial direction in the protruding portion constituting the outflow port C2, and the liquid phase is formed by connecting the tube constituting the flow path to the connection portion C2b. The liquid that has flowed into the portion S1 can be circulated through the flow path portion C2a and flowed out to the downstream flow path (blood circuit). The outflow port C2 may have a concave shape for connecting the tubes constituting the flow path.

According to the present embodiment, the gas phase portion S2 is formed with an opening Cb1 capable of allowing gas to flow in or out according to the displacement of the membrane member M, and the membrane member M is displaced toward the gas phase portion S2. Since the flow passage R (holding portion) capable of holding the inflow or outflow of the gas due to the opening Cb1 is formed, it is possible to secure the necessary measurement range while suppressing the increase in the capacity of the gas phase portion S2. can. Further, the flow passage R (holding portion) according to the present embodiment is composed of a space communicating with the opening Cb1 and allows gas to flow in the flow passage R in the process of displacement of the membrane member M toward the gas phase portion S2. By allowing the gas to flow in or out through the opening Cb1, it is possible to reliably prevent the membrane member M from closing the opening Cb1 in the process of being displaced toward the gas phase portion S2.

In particular, since the flow passage R according to the present embodiment is formed by the rib Cb2 (or groove) formed around the opening Cb1 in the gas phase portion S2, the closure of the opening Cb1 is surely prevented by a simple configuration. can do. In addition, instead of the rib Cb2, the flow passage R may be formed by a convex portion (spiral shape or the like) having another shape. Further, according to the present embodiment, it is possible to provide a blood circuit having the effect of the pressure detector 10 as described above.

Next, the pressure detector according to the second embodiment of the present invention will be described.
The pressure detector according to the present embodiment is applied to the same blood purification device as that of the first embodiment, and as shown in FIG. 1, the tip of the arterial blood circuit 1 (the arterial puncture needle a is attached). It is connected to a position between the connector) and the arrangement site of the blood pump 4, and is configured to be able to detect the pressure of blood flowing through the arterial blood circuit 1.

As shown in FIGS. 10 to 15, the pressure detector 10 according to the present embodiment has a case C that can be connected to a liquid flow path (corresponding to the venous blood circuit 2 in the present embodiment) and a case C inside the case C. The liquid phase portion S1 which is attached to and can be filled with the liquid in the flow path (in this embodiment, the blood of the blood circuit 2 on the venous side) and the gas phase portion S2 which can be filled with air are partitioned and the liquid phase is formed. A membrane member M that can be displaced according to the pressure of the liquid (blood) filled in the portion S1 is provided, and the pressure of the gas phase portion S2 is detected by the pressure detection sensor P to detect the flow path (venous blood circuit 2). ), The pressure of the liquid can be detected. The same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

Here, the flow passage R according to the present embodiment can hold the inflow or outflow of gas by the opening Cb1 in the process of displacement of the membrane member M toward the gas phase portion S2, and the flow passage R of the opening Cb1 in the gas phase portion S2. It is composed of a recess Cb4 formed around the recess Cb4 and a hydrophobic membrane B (allowable member) that covers the recess Cb4 while including the opening Cb1 and allows the passage of gas. The hydrophobic film B is made of a film-shaped member that allows the passage of gas and blocks the passage of liquid, and its outer peripheral edge is welded to the convex portion Cb3 formed around the opening Cb1. It is attached by being (for example, ultrasonic welding, etc.).

More specifically, as shown in FIG. 15, the hydrophobic film B according to the present embodiment is the first layer B1 obtained by molding a resin material made of PTFE (polytetrafluoroethylene) into a sheet shape (film shape). , A second layer B2 made of a non-woven fabric made of PEs (polyester) or the like is provided in the thickness direction. In the present embodiment, the thickness including the first layer B1 and the second layer B2 is about 0.1 to 0.5 mm, and the thickness of the first layer B1 (PTFE) is about one tenth of that. Has been done.

The hydrophobic film B according to the present embodiment uses the second layer B2 as a base material, and PTFE is attached to the surface of the second layer B2 in the form of a sheet to form the first layer B1. However, it may be in another form (a material having a different base material, a material not using a base material, etc.). The first layer B1 is sufficient as long as it has a property of allowing the passage of gas and blocking the passage of liquid, and may be made of, for example, an acrylic copolymer or a polyether sulfone.

Then, in the process of displacement of the film member M toward the gas phase portion S2, as shown in FIG. 14, the flow passage R is held by the hydrophobic film B, and the gas (gas phase portion S2) is held in the flow passage R. By allowing the flow of air) (see the arrow in the figure), the inflow or outflow of gas through the opening Cb1 can be maintained. The hydrophobic membrane B according to the present embodiment blocks the passage of the liquid while allowing the passage of the gas, but may cover the recess Cb4 while including the opening Cb1 and allow the passage of the gas. It's enough.

According to the present embodiment, the gas phase portion S2 is formed with an opening Cb1 capable of allowing gas to flow in or out according to the displacement of the membrane member M, and the membrane member M is displaced toward the gas phase portion S2. Since the flow passage R (holding portion) capable of holding the inflow or outflow of the gas due to the opening Cb1 is formed, it is possible to secure the necessary measurement range while suppressing the increase in the capacity of the gas phase portion S2. can. Further, the flow passage R (holding portion) according to the present embodiment is composed of a space communicating with the opening Cb1 and allows gas to flow in the flow passage R in the process of displacement of the membrane member M toward the gas phase portion S2. By allowing the gas to flow in or out through the opening Cb1, it is possible to reliably prevent the membrane member M from closing the opening Cb1 in the process of being displaced toward the gas phase portion S2.

In particular, the flow passage R according to the present embodiment has a recess Cb4 formed around the opening Cb1 in the gas phase portion S2, and a hydrophobic membrane B (which includes the opening Cb1 and covers the recess Cb4 and allows the passage of gas). Since it is composed of the allowable member), the gas passage area in the hydrophobic membrane B (allowable member) can be set large, the resistance when the gas passes can be reduced, and the deterioration of the pressure detection accuracy can be suppressed. can.

Further, since the permissible member according to the present embodiment is made of a hydrophobic film B that allows the passage of gas and blocks the passage of liquid, when the liquid (blood) leaks from the liquid phase portion S2, the leaked liquid. Can be prevented from reaching the outside of the gas phase portion S2. Further, according to the present embodiment, it is possible to provide a blood circuit having the effect of the pressure detector 10 as described above.

Next, the pressure detector according to the third embodiment of the present invention will be described.
The pressure detector according to the present embodiment is applied to the same blood purification device as that of the first embodiment, and as shown in FIG. 1, the dialyzer 3 and the air trap chamber 5 in the venous blood circuit 2 It is connected to the position between them and is configured to be able to detect the pressure of blood flowing through the venous blood circuit 2 (blood circuit).

As shown in FIGS. 16 to 18, the pressure detector 10 according to the present embodiment has a case C and a case that can be connected to a liquid flow path (in this embodiment, the venous blood circuit 2 (blood circuit)). The liquid phase portion S1 which is attached in C and can be filled with the liquid in the flow path (in this embodiment, the blood of the venous blood circuit 2 (blood circuit)) and the gas phase portion S2 which can be filled with air. Along with partitioning, a membrane member M that can be displaced according to the pressure of the liquid (blood) filled in the liquid phase portion S1 is provided, and the pressure of the gas phase portion S2 is detected by the pressure detection sensor P to detect the flow path. The pressure of the liquid in (venous blood circuit 2) can be detected. The same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

Here, the flow passage R according to the present embodiment can hold the inflow or outflow of gas by the opening Cb1 in the process of displacement of the membrane member M toward the gas phase portion S2, and the gas phase portion S2 in the membrane member M. It is formed by ribs Mb (or may be grooves) formed on the side surface. Specifically, the rib Mb (groove) is composed of a portion formed radially from the center toward the edge portion on the surface of the membrane member M on the gas phase portion S2 side, and the membrane member M is the gas phase portion. In the process of displacement to the S2 side, as shown in FIG. 18, a flow passage R is formed in the gap created by the rib Mb, and a gas (air in the gas phase portion S2) flows through the flow passage R (the same figure). By allowing (see the arrow in the middle), the inflow or outflow of gas through the opening Cb1 can be maintained.

According to the present embodiment, the gas phase portion S2 is formed with an opening Cb1 capable of allowing gas to flow in or out according to the displacement of the membrane member M, and the membrane member M is displaced toward the gas phase portion S2. Since the flow passage R (holding portion) capable of holding the inflow or outflow of the gas due to the opening Cb1 is formed, it is possible to secure the necessary measurement range while suppressing the increase in the capacity of the gas phase portion S2. can. Further, the flow passage R (holding portion) according to the present embodiment is composed of a space communicating with the opening Cb1 and allows gas to flow in the flow passage R in the process of displacement of the membrane member M toward the gas phase portion S2. By allowing the gas to flow in or out through the opening Cb1, it is possible to reliably prevent the membrane member M from closing the opening Cb1 in the process of being displaced toward the gas phase portion S2.

In particular, since the flow passage R according to the present embodiment is formed by ribs Mb (or grooves) formed on the surface of the membrane member M on the gas phase portion S2 side, the opening Cb1 is surely closed with a simple configuration. Can be prevented. In addition, instead of the rib Mb, the flow passage R may be formed by a convex portion (spiral shape or the like) having another shape. Further, according to the present embodiment, it is possible to provide a blood circuit having the effect of the pressure detector 10 as described above.

Although the present embodiment has been described above, the present invention is not limited to this, and the rib Cb2 in the first embodiment is formed on the entire inner peripheral surface of the gas phase case Cb, the third embodiment. The rib Mb in the embodiment may be formed only at a portion facing the opening Cb1. Further, in the first embodiment, the recess Cb4 in which the rib Cb2 is formed may be covered with the hydrophobic membrane B of the second embodiment.

Furthermore, the pressure detector 10 according to the present embodiment is connected to a position between the tip of the arterial blood circuit 1 and the blood pump 4, but is connected to another position in the blood circuit (for example, the arterial blood circuit). It may be connected to the position between the tip and the blood pump 4 in 1 and the position between the blood pump 4 and the dialyzer 3 in the arterial blood circuit 1. The blood circuit to which the pressure detector 10 is connected may be of another form, for example, even if the air trap chamber 5 is not connected and the pressure detector 10 is connected instead. good.

Although it is applied as the pressure detector 10 of the blood circuit in the dialysis treatment in the present embodiment, it may be applied as the pressure detector of another blood circuit capable of purifying and treating the patient's blood. For example, it is used in acetate-free biofiltration (AFBF), continuous slow hemofiltration therapy, blood adsorption therapy, selective blood cell depletion therapy, simple plasma exchange therapy, double membrane filtration plasma exchange therapy, plasma adsorption therapy, etc. It may be applied to a pressure detector of a blood circuit.

The gas phase portion is formed with an opening capable of allowing gas to flow in or out according to the displacement of the membrane member, and is retained so as to be able to hold the inflow or outflow of gas due to the opening in the process of displacement of the membrane member toward the gas phase portion. As long as it is a pressure detector having a formed portion, it can be applied to other forms and applications.

1 Arterial blood circuit 2 Vein blood circuit 3 Dializer (blood purifier)
4 Blood pump 5 Air trap chamber 6 Dialysis machine body 7 Accommodating means 8 Air trap chamber 9 Clamping means 10 Pressure detector L1 Dialysate introduction line L2 Dialysis fluid discharge line L3 Physiological saline supply line C Case Ca Liquid phase part Case Ca1 Flow Inlet Ca2 Outlet Cb Gas phase case Cb1 Opening Cb2 Rib Cb3 Convex Cb4 Recess C1 Inflow port C1a Flow path C1b Connection C2 Outflow port C2a Flow path C2b Connection C3 Connection port M Film member P Pressure detector S1 Liquid Phase S2 Gas phase K Piping B Hydrophobic membrane R Flow passage (holding part)

Claims (7)

A case that can be connected to the liquid flow path and
A liquid phase portion attached in the case and capable of filling the liquid in the flow path and a gas phase portion capable of filling the gas are partitioned, and the liquid phase portion is displaced according to the pressure of the liquid filled in the liquid phase portion. With possible membrane members,
In a pressure detector that detects the pressure of the liquid in the flow path by detecting the pressure of the gas phase portion.
The gas phase portion is formed with an opening through which gas can flow in or out according to the displacement of the membrane member, and the gas inflow or outflow due to the opening is formed in the process of the membrane member being displaced toward the gas phase portion. A pressure detector characterized in that holding portions capable of holding the gas are formed radially around the opening . The holding portion is composed of a flow passage communicating with the opening, and in the process of displacement of the membrane member toward the gas phase portion, gas inflow or inflow through the opening is allowed by allowing gas flow in the flow passage. The pressure detector according to claim 1, wherein the outflow is retained. The pressure detector according to claim 2, wherein the flow passage is formed by ribs or grooves formed around the opening in the gas phase portion. The claim is characterized in that the flow passage is composed of a recess formed around the opening in the gas phase portion and an allowable member that covers the recess while including the opening and allows the passage of gas. Item 2. The pressure detector according to item 2. The pressure detector according to claim 4, wherein the permissible member comprises a hydrophobic membrane that allows the passage of gas while blocking the passage of liquid. The pressure detector according to claim 2, wherein the flow passage is formed by ribs or grooves formed on the surface of the membrane member on the gas phase side. A blood circuit, characterized in that a pressure detector according to any one of claims 1 to 6 is connected.

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