JP5230377B2 - Calibration method of pressure measurement unit - Google Patents

Description

  The present invention relates to a calibration method for a pressure measuring unit that measures a pressure in an extracorporeal circuit through which a liquid, particularly a body fluid or a chemical solution, is circulated.

  For example, in an extracorporeal circulation system that removes blood from a patient's body, performs extracorporeal treatment of the blood, and returns the processed blood to the body, a pressure sensor for measuring the pressure in the extracorporeal circuit is usually disposed. Yes.

  As an example of means for measuring the pressure in the extracorporeal circulation circuit while avoiding contact between the body fluid or the chemical solution and air, Patent Document 1 discloses a pressure sensor that measures the pressure in the extracorporeal circulation circuit through a diaphragm. Have been described.

  FIG. 4 shows an outline of the configuration of this pressure sensor. The pressure sensor 100 is disposed in the middle of the extracorporeal circuit 101. The pressure sensor 100 includes an air chamber 103 having an air inlet / outlet 102, a liquid chamber 106 having a liquid inlet 104 and a liquid outlet 105 connected to the extracorporeal circuit 101, and an air chamber sandwiched between the air chamber 103 and the liquid chamber 106. 103 and the liquid chamber 106, and a pressure measuring unit A including a container 108 having a flexible diaphragm 107 that deforms according to a pressure difference between the air chamber 103 and the liquid chamber 106, and an air inlet / outlet 102 of the air chamber 103 And a pressure measuring means 110 for measuring the pressure in the liquid chamber 106 on the air chamber 103 side via the flexible diaphragm 107. Since the flexible diaphragm 107 is deformed by the change in the pressure in the liquid chamber 106 and the pressure in the air chamber 103 changes in correlation with the pressure in the liquid chamber 106, the pressure measuring means 110 changes the pressure in the air chamber 103. The pressure in the liquid chamber 106 is measured by measuring and converting this value.

  However, since the pressure measuring unit A as described above is normally a disposable disposable product, the expensive pressure measuring unit 110 is configured to be separable from the air inlet / outlet 102 of the pressure measuring unit A. Therefore, the pressure measuring means 110 may be removed from the air inlet / outlet 102 or disconnected during use. In this case, since the air chamber 103 is opened to the atmosphere and the pressure balance between the air chamber 103 and the liquid chamber 106 is changed, the flexible diaphragm when the pressure measurement is resumed even if the pressure measuring means 110 and the air inlet / outlet 102 are reconnected as they are. The position 107 changes every time and is not stable. As a result, the pressure may not be measured within the target pressure measurement range.

  Non-Patent Document 1 describes an example of a method for calibrating a pressure measurement unit that attempts to improve such a problem. FIG. 5 is a schematic configuration diagram for explaining the calibration method. The pressure measurement unit A is configured to be separable from the pressure measurement unit 110 by a connection unit 111 provided in the communication unit 109. The conventional calibration execution system for the pressure measurement unit A includes a pressure measurement unit A arranged in the middle of the extracorporeal circuit 101, and an extracorporeal circulation arranged on the upstream side of the liquid inlet 104 and the downstream side of the liquid outlet 105. It comprises blocking means 120, 121 that closes the circuit 101, a sample port 122 disposed between the two closing means 120, 121, and a syringe 123 that can be connected to the sample port 122. In FIG. 5, the same reference numerals are given to the constituent members having the same functions as the constituent members in FIG. 4.

In the pressure measurement unit A described above, the calibration method when the connection unit 111 of the communication unit 109 is removed is performed according to the following procedure.
1. 1. Stop liquid feeding means (not shown) of extracorporeal circuit 101 2. The inside of the liquid chamber 106 is closed using the closing means 120, 121. 3. Insert the syringe 123 into the sample port 122 and extract 1 cc body fluid or drug solution from the extracorporeal circuit 101 or inject 1 cc physiological saline into the extracorporeal circuit 101. 4. Reconnect the connection means 111 of the communication unit 109. Opening of the closing means 120, 121

  However, in the calibration method as described above, in step 2, the pressure is closed in the extracorporeal circuit 2 when the liquid feeding means is stopped. For example, the pressure in the extracorporeal circuit 101 is negative. In this case, the flexible membrane 107 is closed to the liquid chamber 106 side, and conversely, if it is positive pressure, the liquid chamber 106 is closed by the closing means 120 and 121 while being deformed to the air chamber 103 side. Therefore, the position of the flexible diaphragm 107 fluctuates depending on the pressure in the extracorporeal circuit 101 at the time of occlusion, and is not constant. The position of the sex diaphragm 107 cannot always be returned to an appropriate position at the start of pressure measurement, for example. For example, when the position of the flexible diaphragm 107 when the pressure measurement is resumed moves from the proper position to the liquid chamber 106 side, the variable range of the flexible diaphragm 107 to the liquid chamber 106 side is reduced. The measurement limit on the negative pressure side increases. On the contrary, when the position of the flexible diaphragm 107 is moved from the proper position to the air chamber 103 side when the pressure measurement is resumed, the variable range of the flexible diaphragm 107 to the air chamber 103 side is reduced. The measurement limit on the positive pressure side is lowered. Therefore, even if the operation after the procedure 3 is performed, there is a possibility that the range in which the pressure measurement unit can correctly measure the pressure becomes narrow. Furthermore, when the syringe 123 is inserted into or removed from the sample port 122, there is a risk that body fluid or chemical solution in the extracorporeal circuit 101 leaks out of the extracorporeal circuit 101, or a needle (not shown) attached to the tip of the syringe 123. ) May be accidentally stabbed into the human body when inserted into the sample port 122, which in turn increases the risk of infection.

Japanese Patent Application Laid-Open No. 09-024026 Gambro Plismaflex Operator's manual p.193-p.199

  In view of the above-described problems of the prior art, the present invention provides a pressure measuring unit that measures the pressure in an extracorporeal circuit without contacting air. For example, during the extracorporeal circulation process, the air chamber and pressure measuring means of the pressure measuring unit Calibration of the pressure measurement unit that stably measures the pressure in the extracorporeal circuit even if it is disconnected and then reconnected, without risk of infection due to leakage of bodily fluids or chemicals in the extracorporeal circuit It aims to provide a method.

  As a result of intensive studies to solve the above problems, the present inventors have found that when the connection between the air chamber of the pressure measurement unit and the pressure measurement unit is disconnected, the liquid in the liquid storage unit connected to the extracorporeal circuit The present inventors have found that the above problem can be solved by adjusting the pressure in the liquid chamber when connecting the air chamber and the pressure measuring means by utilizing the pressure due to the difference in water level, and the present invention has been completed. That is, the present invention includes the following configurations.

(1) An extracorporeal circuit, an air chamber formed with an air inlet / outlet, a liquid inlet connected to the extracorporeal circuit, a liquid chamber formed with a liquid outlet, and the air chamber and the liquid chamber are partitioned And a pressure measuring unit comprising a container having a flexible diaphragm that deforms according to a pressure difference between the air chamber and the liquid chamber, and a pressure measurement that is detachably connected to the air chamber through the air inlet / outlet. In the extracorporeal circulation system, the pressure measurement unit calibration method performed when the connection between the pressure measurement means and the air chamber is disconnected, the extracorporeal circulation system is configured by the extracorporeal circulation circuit. A first opening / closing means capable of closing and opening both sides of the pressure measuring unit, and a branch branched from the extracorporeal circuit in a section which can be closed by the first opening / closing means, and a liquid storage part connected to the terminal tube And a second opening / closing means capable of closing and opening the branch pipe, and after the connection between the pressure measuring means and the air chamber is disconnected, the first opening / closing means A step of closing both sides of the pressure measuring unit of the extracorporeal circuit, and then opening the branch pipe by the second opening / closing means, and applying a pressure due to a liquid level difference of the liquid in the liquid reservoir to the liquid chamber Adjusting the pressure in the liquid chamber, then reconnecting the pressure measuring means to the air chamber, and then opening both sides of the pressure measuring section of the extracorporeal circuit by the first opening / closing means. And a step of closing the branch conduit by the second opening / closing means.
(2) The pressure measuring unit calibration method according to (1), wherein the liquid storing unit stores a liquid supplied into the extracorporeal circuit.
(3) In the initial connection between the pressure measuring means and the air chamber, which is performed before the start of pressure measurement, the second opening / closing means opens the branch pipe, and the liquid level in the liquid storage section The pressure measurement unit according to (1) or (2), wherein the pressure in the liquid chamber is adjusted by applying a pressure due to the difference, and then the pressure measuring means and the air chamber are connected. Calibration method.
(4) In the section of the extracorporeal circuit that can be closed by the first opening / closing means, a plurality of the pressure measuring units are connected, and between the plurality of pressure measuring units of the extracorporeal circuit. And a third opening / closing means capable of closing and opening the extracorporeal circuit, wherein the liquid reservoir is in a state where the pressure measuring parts of the extracorporeal circuit are opened by the third opening / closing means. The pressure measurement unit calibration according to any one of (1) to (3), wherein the pressure in each liquid chamber is adjusted by applying a pressure due to a difference in water level of the liquid to the liquid in the liquid chambers of the plurality of pressure measurement units. Method.
In addition, when “the connection between the pressure measuring means and the air chamber is disconnected”, not only when the connection between the pressure measuring means and the air chamber is intentionally disconnected, but also when the connection is unintentionally disconnected. Is also included. The connection between the pressure measuring means and the air chamber includes not only a direct connection but also an indirect connection.

  According to the present invention, when the connection between the air chamber of the pressure measuring unit and the pressure measuring means is disconnected and then reconnected, the pressure in the extracorporeal circuit is stably measured, and the body fluid in the extracorporeal circuit or Risk of infection due to leakage of chemicals can be eliminated.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram showing an outline of a configuration of an extracorporeal circulation system 1 in which a pressure measuring unit calibration method according to the present embodiment is implemented.

  As shown in FIG. 1, the extracorporeal circulation system 1 includes an extracorporeal circulation circuit 2 through which a liquid such as blood flows. The extracorporeal circuit 2 has, for example, a circuit that sends blood taken from the patient to the blood purifier 3 and returns it to the patient. For example, the first opening / closing means 10, the pressure sensor 11, the first opening / closing means 12, the tube pump 13, and the pressure sensor 14 are arranged in this order from the blood collection section side to the blood collection section side of the extracorporeal circuit 2 from the blood purifier 3. Is provided. Further, a drip chamber 15 for performing blood deaeration and measuring pressure and an opening / closing means 16 are provided in this order from the blood collection unit side on the blood return side of the extracorporeal circuit 2 relative to the blood purifier 3. ing.

  Further, a branch pipe 20 is branched in a section that can be closed by the first opening / closing means 10, 12 of the extracorporeal circuit 2. A second opening / closing means 21 is connected to the branch pipeline 20. A liquid storage part 22 in which liquid is stored is connected to the end of the branch pipe 20. This liquid storage part 22 is installed in the position higher than the liquid chamber of the pressure measurement part A of the pressure sensor 11 mentioned later, for example. In the liquid reservoir 22, for example, a liquid such as physiological saline supplied into the extracorporeal circuit 2 after the extracorporeal circulation processing is stored.

  The first opening / closing means 10, 12, the opening / closing means 16 and the second opening / closing means 21 are capable of closing and opening the conduit, for example, using forceps, a manual clamp, a valve or the like.

  For example, as shown in FIG. 2, the pressure sensor 11 includes an air chamber 31 in which an air inlet / outlet 30 is formed, a liquid inlet 32 connected to the extracorporeal circuit 2, and a liquid chamber 34 in which a liquid outlet 33 is formed, A pressure measuring unit A including a container 36 that includes an air chamber 31 and a liquid chamber 34 and includes a flexible diaphragm 35 that deforms according to a pressure difference between the air chamber 31 and the liquid chamber 34, and an air inlet / outlet 30. And a pressure measuring means 37 detachably connected to the air chamber 31. The air inlet / outlet port 30 of the air chamber 31 and the pressure measuring means 37 are connected by a communication part 38, and are detachable by a connection means 39 provided in the communication part 38.

  The flexible diaphragm 35 is made of, for example, a soft material having biocompatibility. For example, polyvinyl chloride, silicone resin, styrene thermoplastic elastomer, styrene thermoplastic elastomer compound, or the like is used as the material of the flexible diaphragm 35.

  For the pressure measuring means 37, for example, a pressure measuring unit or a Bourdon tube is used to measure the pressure. As the connection means 39, for example, a luer connector system, a coupler system, a sleeve-like tube insertion system, or the like is used.

  Next, in the above extracorporeal circulation system 1, a calibration method of the pressure measuring unit A performed when the connection between the air chamber 31 and the pressure measuring unit 37 by the connecting unit 39 is disconnected will be described. When the connection between the air chamber 31 and the pressure measuring means 37 is disconnected, the case where the air chamber 31 and the pressure measuring means 37 are disconnected is included. For example, it may be intentionally removed after a leak check with air before the start of extracorporeal circulation processing or a priming process for cleaning the inside of the circuit, or it may be removed due to an accident during extracorporeal circulation processing.

  First, before the pressure measurement by the pressure sensor 11 is started in the extracorporeal circulation system 1, the initial connection between the air chamber 31 of the pressure measurement unit A and the pressure measurement unit 37 is performed. The initial position of the flexible diaphragm 35 is determined by the initial pressure in the liquid chamber 34 and the air chamber 31 at this time. The initial pressure in the air chamber 31 is atmospheric pressure because the air inlet / outlet port 50 is open to the atmosphere.

  The initial pressure of the liquid chamber 34 may be atmospheric pressure or may not be atmospheric pressure. When the initial pressure of the liquid chamber 34 is not atmospheric pressure, for example, when the initial pressure is a positive pressure, the initial position of the flexible diaphragm 35 is the air chamber 31, and the measurement range of the negative pressure can be increased. Conversely, when the initial pressure is a negative pressure, the initial position of the flexible diaphragm 35 is located in the liquid chamber 34, and the positive pressure measurement range can be increased. The initial pressure in the liquid chamber 34 must be appropriately selected depending on the pressure measurement range, but is preferably −200 mmHg (−26 kPa) to 200 mmHg (26 kPa), more preferably −100 mmHg (−13 kPa) to 100 mmHg. (13 kPa), and most preferably -50 mmHg (-6 kPa) to 50 mmHg (6 kPa). The initial pressure in the liquid chamber 24 may be adjusted by flowing liquid or air into the liquid chamber 34 using, for example, the tube pump 13. Further, when the initial pressure is atmospheric pressure, the pressure measurement unit A and the pressure measurement unit 37 may be connected without positively adjusting the pressure of the liquid chamber 24.

  In addition, the following effects are obtained by bending the flexible diaphragm 35 in advance toward the air chamber 31 side. When the pressure sensor 11 on the upstream side of the tube pump 13 is mainly used at a negative pressure as in the present embodiment, the air gradually enters the air chamber 31 from the connection means 39 by continuous use for a long time. Since it enters, the position of the flexible diaphragm 35 moves to the liquid chamber 34 side. As a result, the flexible diaphragm 35 is finally greatly bent toward the liquid chamber 34 and its movement is suppressed, so that the accuracy of pressure measurement is reduced. Therefore, by previously bending the flexible diaphragm 35 toward the air chamber 31, the pressure measuring unit A can be used continuously for a long time.

  The position of the flexible diaphragm 35 is set by setting the installation height of the liquid reservoir 22 and the water level of the liquid reservoir 22.

  After the pressure measuring means 37 and the air chamber 31 are initially connected by the connecting means 39, the priming process and the extracorporeal circulation process for the patient are started in the extracorporeal circulation system 1, and the liquid circulation is performed in the extracorporeal circulation circuit 2. Accordingly, pressure measurement by the pressure sensor 11 is appropriately performed. At this time, the branch line 20 is closed by the second opening / closing means 21, and the extracorporeal circuit 2 is opened by the first opening / closing means 10, 12. In the extracorporeal circulation processing, for example, blood collected from a patient is supplied to the blood purifier 3 through the extracorporeal circulation circuit 2, and after a predetermined component is separated or adsorbed, the blood is returned to the patient.

For example, when the connection between the pressure measuring means 37 and the air chamber 31 is disconnected by the connecting means 39 during the extracorporeal circulation processing, first, the pressure measuring unit A of the extracorporeal circulation circuit 2 by the first opening / closing means 10 and 12. Both sides of the are blocked. Next, the branch pipe 20 is opened by the second opening / closing means 21, and the pressure P ₀ due to the liquid level difference of the liquid in the liquid reservoir 22 is applied to the liquid chamber 34, and the inside of the liquid chamber 34 is adjusted to the pressure P _0. The In this state, the pressure measuring means 37 and the air chamber 31 are reconnected by the connecting means 39. Thereafter, both sides of the pressure measuring unit A of the extracorporeal circuit 2 are opened by the first opening / closing means 10, 12, and the branch line 20 is closed by the second opening / closing means 21. Here, the pressure P ₀ may be any pressure that moves the flexible diaphragm 35 to a position where pressure measurement is possible in the target pressure measurement range. The allowable range of the pressure P ₀ may be set as appropriate depending on the target pressure measurement range, but is preferably within the initial pressure of the liquid chamber 34 ± 50 mHg (± 6 kPa), and more preferably the initial pressure ± 20 mmHg (± 2. 6 kPa), more preferably an initial pressure of ± 5 mmHg (± 0.6 kPa), and most preferably an initial pressure. In the case where the negative pressure is mainly measured as described above, if the pressure higher than the initial pressure is set as the pressure P ₀ , it is possible to perform the pressure measurement for a longer time. If the pressure is excessively high, the flexible diaphragm 35 sticks to the air chamber 31 and measurement on the positive pressure side becomes impossible. However, there is no particular problem when used mainly for measurement of negative pressure. For example, there is no problem even in a state of initial pressure +300 mmHg (40 kPa).

According to the above embodiment, before the pressure measuring means 37 and the air chamber 31 are reconnected by the connecting means 39, the pressure P ₀ due to the liquid level difference in the liquid reservoir 22 is applied to the liquid chamber 34. Since the pressure in the liquid chamber 34 is adjusted, the flexible diaphragm 35 can be adjusted to an appropriate position. As a result, the pressure in the extracorporeal circuit 2 using the pressure measurement unit A can be stably measured even after reconnection. Further, since a syringe is not used as in the prior art, it is possible to eliminate the risk of infection or the like due to leakage of bodily fluids or drug solutions in the extracorporeal circuit 2.

The liquid reservoir 22 stores a liquid such as physiological saline supplied into the extracorporeal circuit 2 and is necessary for emergency infusion when the blood pressure of the patient during extracorporeal circulation is lowered. Since this is an existing liquid reservoir required for blood collection after circulation processing and washing in the circuit, it is not necessary to provide a new device for adjusting the pressure in the liquid chamber 34. In addition, since the water level in the liquid reservoir 22 does not change during or before the extracorporeal circulation process, the pressure P ₀ applied to the liquid chamber 34 at the time of reconnection becomes constant, and the flexible diaphragm 35 The adjustment position becomes constant. Thereby, the position of the flexible diaphragm 35 can be adjusted more accurately. Even when the liquid in the liquid reservoir 22 is used during the extracorporeal circulation treatment, the pressure P ₀ is less fluctuated if the water level is not fluctuated greatly, and the flexible diaphragm 35 can be adjusted to an appropriate position. .

In the above embodiment, when the initial pressure of the liquid chamber 34 is set when the air chamber 31 of the pressure measuring unit A and the pressure measuring means 37 are initially connected, the second opening / closing means 21 branches. The pipe 20 is opened, the pressure P ₀ due to the liquid level difference in the liquid reservoir 22 is applied to the liquid in the liquid chamber 34 to adjust the pressure in the liquid chamber 34, and then the pressure measuring means 37 and the air chamber 31 are connected. You may do it. By doing so, it is possible to easily adjust the pressure in the liquid chamber 34 at the time of initial setting before the start of pressure measurement. Also, since the pressure P ₀ is adjusted from the start to the end of the pressure measurement using the pressure P ₀ due to the difference in the liquid level of the liquid in the same liquid reservoir 22, the adjustment of the liquid chamber 34 is performed from the start to the end of the pressure measurement. The pressure can be kept constant.

The above embodiment is the calibration of the pressure measurement unit A when the pressure measurement unit 37 and the air chamber 31 are disconnected by the pressure sensor 11, but the pressure measurement unit A has the same configuration. If there is, the pressure measurement unit A of the pressure sensor 14 may perform the same calibration. In such a case, for example, as shown in FIG. 3, the tube pump 13 has a movable housing 40 that can put the extracorporeal circuit 2 into a closed state and an open state. Thereby, the tube pump 13 becomes the third opening / closing means. Further, the opening / closing means 16 on the downstream side of the two pressure sensors 11 and 14 is defined as a first opening / closing means. For example, when the connection between the pressure measuring means 37 of the pressure sensors 11 and 14 and the air chamber 31 is disconnected, the extracorporeal circuit 2 is closed by the two first opening and closing means 10 and 16, and the tube pump 13 The extracorporeal circuit 2 between the pressure sensor 11 and the pressure sensor 14 is opened by the housing 40 and the first opening / closing means 12. Thereafter, the branch pipe 20 is opened by the second opening / closing means 21, and the pressure P ₀ due to the liquid level difference of the liquid in the liquid storage unit 22 is applied to the liquid chamber 34 of each pressure measuring unit A, and the pressure in each liquid chamber 34 is changed. Adjusted. Thereby, the flexible diaphragm 35 in each container 36 is adjusted to an appropriate position. In this state, the pressure adjusting means 37 of the pressure sensors 11 and 14 and the air chamber 31 are connected by the connecting means 39. By doing so, the calibration of the two pressure measuring units A can be performed using the pressure P ₀ due to the liquid level difference of the liquid in the liquid storage unit 22.

  Further, when calibrating the pressure measuring unit A of the pressure sensor 14, for example, a first opening / closing unit is separately provided on both sides of the pressure measuring unit A of the pressure sensor 14 of the extracorporeal circuit 2, and the first opening / closing unit Another branch conduit that leads to the liquid reservoir 22 may be separately provided in the blockable section. In this case, the pressure of the liquid chamber 34 can be adjusted to a desired pressure for each of the pressure sensors 11 and 14. For example, when used mainly at positive pressure, such as the pressure sensor 14 located on the downstream side of the tube pump 13, the air in the air chamber 31 is gradually released by the connecting means 39 by continuous use for a long time. Since the position of the flexible diaphragm 35 moves to the air chamber 31 side, the pressure of the liquid chamber 34 may be adjusted in advance so that the flexible diaphragm 35 bends to the liquid chamber 34 side. By doing so, the pressure measuring unit A of the pressure sensor 14 can be continuously used for a longer time.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes or modifications can be made within the scope of the ideas described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

  For example, in the above embodiment, the liquid storage unit 22 is installed such that the water level in the liquid storage unit 22 is higher than the water level in the liquid chamber 34 of the pressure measurement unit A (position of the flexible diaphragm 35). However, the liquid reservoir 22 may be installed so that the water level in the liquid reservoir 22 is lower than the water level in the liquid chamber 34 according to the adjustment pressure of the liquid chamber 34. In addition, when the connection between the pressure measuring unit 37 and the pressure measuring unit A is disconnected, the flexible diaphragm 35 may bend and the water level in the liquid chamber 34 may be lowered or raised. The liquid reservoir 22 may be set so that the water level 22 is the same as the position of the flexible diaphragm 35 when flat. Further, for example, the present invention can be applied to an extracorporeal circulation system and an extracorporeal circulation circuit having configurations other than those described above. In addition, the liquid flowing into the extracorporeal circuit having the pressure measuring unit may be any body fluid or drug solution. Examples of the body fluid include blood, plasma, lymph fluid, tissue fluid, urine and the like. Examples of the drug solution include Examples include physiological saline, anticoagulant, fresh frozen plasma, dialysate, albumin solution, filtration artificial kidney replacement fluid, and the like. Examples of extracorporeal circulation treatment include hemofiltration, hemodialysis, hemodialysis, continuous hemodialysis, continuous hemofiltration, continuous hemofiltration, plasma exchange, plasma adsorption, The treatment includes extracorporeal circulation therapy such as heavy filtration plasma exchange therapy, blood adsorption therapy, blood cell component removal therapy, ascites filtration concentration reinfusion therapy, and percutaneous cardiopulmonary adjuvant therapy.

  The present invention can stably measure the pressure in the extracorporeal circuit when the connection between the air chamber of the pressure measuring unit and the pressure measuring means is disconnected and then reconnected, and the body fluid or chemical solution in the extracorporeal circuit can be measured. This is useful when calibrating a pressure measurement unit without risk of infection due to leakage.

It is explanatory drawing which shows the outline of a structure of the extracorporeal circulation system in this Embodiment. It is explanatory drawing which shows the outline of a structure of the pressure sensor in this Embodiment. It is explanatory drawing which shows the other structure of the extracorporeal circuit in this Embodiment. It is a schematic diagram which shows the structure of the conventional pressure measurement part. It is a schematic diagram of the extracorporeal circuit for demonstrating the calibration of the conventional pressure measurement part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Extracorporeal circulation system 2 Extracorporeal circulation circuit 3 Blood purifier 10 First opening / closing means 11 Pressure sensor 12 First opening / closing means 13 Tube pump 16 Opening / closing means (first opening / closing means)
20 branch pipe 21 second opening / closing means 22 liquid reservoir 30 air inlet / outlet 31 air chamber 32 liquid inlet 33 liquid outlet 34 liquid chamber 35 flexible diaphragm 36 container 37 pressure measuring means 39 connecting means A pressure measuring section

Claims (4)

An extracorporeal circuit,
An air chamber in which an air inlet / outlet is formed, a liquid inlet connected to the extracorporeal circuit, a liquid chamber in which a liquid outlet is formed, the air chamber and the liquid chamber are partitioned, and the air chamber and the liquid A pressure measuring unit comprising a container provided with a flexible diaphragm that deforms in accordance with a pressure difference in the room;
Pressure measuring means detachably connected to the air chamber through the air inlet and outlet;
In the extracorporeal circulation system, the pressure measuring unit calibration method performed when the connection between the pressure measuring means and the air chamber is disconnected,
The extracorporeal circulation system branches from an extracorporeal circuit in a section that can be closed and opened by the first opening and closing means, and a first opening and closing means capable of closing and opening both sides of the pressure measuring unit of the extracorporeal circulation circuit, The liquid storage section further includes a branch pipe connected to the end, and a second opening / closing means capable of closing and opening the branch pipe,
A step of closing both sides of the pressure measuring unit of the extracorporeal circuit by the first opening / closing means after the connection between the pressure measuring means and the air chamber is disconnected;
Then, the step of opening the branch pipe by the second opening and closing means, and adjusting the pressure in the liquid chamber by applying a pressure due to the liquid level difference of the liquid in the liquid storage portion to the liquid chamber;
And then reconnecting the pressure measuring means and the air chamber;
And then opening both sides of the pressure measuring unit of the extracorporeal circuit with the first opening and closing means and closing the branch pipe with the second opening and closing means. Calibration method for the measurement unit.   The pressure measuring unit calibration method according to claim 1, wherein a liquid supplied into the extracorporeal circuit is stored in the liquid storing unit.   At the time of initial connection between the pressure measuring means and the air chamber, which is performed before the start of pressure measurement, the branch conduit is opened by the second opening / closing means, and the liquid level difference of the liquid in the liquid reservoir is caused. The pressure measuring unit calibration method according to claim 1 or 2, wherein pressure is applied to the liquid chamber to adjust the pressure in the liquid chamber, and then the pressure measuring means and the air chamber are connected. . A plurality of the pressure measurement units are connected to a section of the extracorporeal circuit that can be closed by the first opening / closing means, and the extracorporeal circuit is connected between the plurality of pressure measurement units of the extracorporeal circuit. A third opening / closing means capable of closing and opening the circulation circuit is provided;
In a state where the pressure measuring units of the extracorporeal circuit are opened by the third opening / closing means, a pressure due to a liquid level difference of the liquid in the liquid reservoir is applied to the liquid chambers of the plurality of pressure measuring units, The pressure measurement unit calibration method according to claim 1, wherein the pressure is adjusted.

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