JP4742549B2 - Blood purification equipment - Google Patents

Description

  The present invention relates to a blood purification apparatus that assists or substitutes for organ functions of a living body by purifying blood taken out of a body from a blood vessel and, if necessary, supplementing it with useful substances. The internal pressure of the blood circuit and the dialysate circuit can be measured by measuring the strain of the tube constituting the circuit.

  Conventionally, in blood purification therapy, arterial pressure (also called filter inlet pressure) and venous pressure during extracorporeal circulation are measured by connecting a pressure monitor line provided in the air trap chamber of the extracorporeal circulation circuit to each pressure sensor. Is going. In this method, the pressure is measured via air. Therefore, in order to secure an air region, it is necessary to adjust the liquid level in the chamber at the end of priming or during treatment. The liquid level is adjusted by connecting a syringe to the tip of the liquid level adjustment line provided separately in the air trap chamber and pushing or pulling the syringe. This is necessary, and if the operation is wrong, blood may spout and adhere to the filter for protecting the human body or pressure sensor, and there is a high risk of infection.

  Therefore, various blood pressure measuring devices including a pipe and including at least one section for measuring the pressure of blood flowing in the pipe have been proposed. These devices comprise a substantially rigid wall and a hole sealed by an elastically deformable or displaceable closure member, the inner surface of the pipe being in contact with blood and the outer surface being in contact with the outside air, Can be measured by a load sensor. 1. An air compartment is provided between the thin film (or diaphragm) and the load sensor, and the internal pressure of the air compartment, which changes due to the displacement of the thin film, is directly measured; 2. The force applied to the inner surface of the flexible thin film that seals the hole provided in the wall of the compartment is transmitted to the load sensor via the load transmitter and measured. 3. In 2 above, a metal disk is attached to the outer surface of the flexible thin film, and a magnet is attached to the shaft end of the load transmitter to fix the flexible thin film to the load transmitter. The closure member is formed in a single member having a hard wall of the blood pressure measurement section (Patent Document 1).

JP 2002-233570 A, FIG. 1, FIG. 2, FIG. 3, FIG.

  However, the above-mentioned device 1 has a drawback that the air compartment seal may be broken during use, and if the seal is broken, the pressure transmission function is lost. Has the disadvantage that the hole in the wall must be completely sealed with a thin film, so that the mounting of the thin film on the wall of the compartment is relatively complicated and the manufacturing and assembly of the device is laborious. Further, the device 4 has a drawback that it takes time and effort to manufacture and assemble the device because the elastically deformable area is formed to have a substantially corrugated outer diameter. Furthermore, in any of the devices 1 to 4, the inner wall of the pressure measuring unit is formed larger than the inner wall of the liquid circulation circuit, and the shape is also a square cross section. Therefore, when this is applied to the blood circulation circuit, This is a problem because a turbulent flow is generated in the blood flowing into the pressure measuring unit, so that a thrombus may be formed.

  The present invention has been made in view of the above circumstances, and by directly measuring the strain in the blood circuit and the dialysate circuit tube with a strain sensor without providing a pressure measurement unit in the blood circuit, An object of the present invention is to provide a blood purification apparatus capable of measuring pressure.

  The blood purification apparatus of the present invention includes a blood purifier and a blood circuit, a blood pump, a priming liquid supply line, a venous air trap chamber, an on-off valve provided in a venous blood circuit downstream from the venous air trap chamber, dialysis In a blood purification apparatus comprising a fluid circuit, a dialysate pump, and a filtration pump, a strain sensor is provided in each of the arterial blood circuit downstream from the blood pump and the venous blood circuit upstream from the open / close valve. The pressure in the blood circuit can be measured by measuring the strain of the tube of the blood circuit.

Here, a replacement fluid supply line may be provided in the venous blood circuit. A strain sensor equipped with a load sensor and a load transmitter, and the force applied to the inner surface of the circuit tube being transmitted to the load sensor via the load transmitter and measured, can be preferably used. It is. The strain sensor may be accommodated in a housing having a groove capable of accommodating a circuit tube and a load sensor accommodating portion formed at the bottom of the groove, and the housing is provided with a fixing means to the circuit tube. May be. As the fixing means, a lid that can be locked to the housing may be adopted.
Although the present invention has been generally described above, a better understanding can be obtained by reference to certain specific embodiments. These examples are provided herein for illustrative purposes only and are not limiting unless otherwise specified.

According to the present invention, the following effects can be expected. That is, since the pressure in the blood circuit can be measured by directly measuring the strain of the tube of the blood circuit with a strain sensor without providing a pressure measuring unit in the blood circuit, there is no possibility of one thrombus. A blood purification apparatus can be provided. In addition, 2. Since the blood circuit can be made simple and a disposable blood circuit can be manufactured at low cost, the patient's economic burden can be reduced.

A strain sensor is provided in each of the arterial blood circuit downstream from the blood pump and the venous blood circuit upstream from the open / close valve, and the strain in the blood circuit can be measured by measuring strain in the blood circuit tube. To. In addition, a replacement fluid supply line is provided in the venous blood circuit.

First, Example 1 will be described with reference to FIG.
FIG. 1 is a schematic explanatory diagram of a blood purification apparatus according to the first embodiment.
The blood purification apparatus of Example 1 is a blood purification apparatus for performing continuous hemodialysis (CVVHD). As shown in FIG. 1, the blood purification apparatus 1, blood circuit 2 (21, 22), blood pump 3 , A priming fluid supply line 4, a venous air trap chamber 24, an on-off valve V1, a dialysate circuit 5 (51, 52), a dialysate pump 6 and a filtration pump 7. The arterial blood circuit 21 downstream from the blood pump 3 and the venous blood circuit 22 upstream from the open / close valve V1 are provided with strain sensors S1 and S2, respectively. The pressure in the circuit can be measured by measuring the distortion of the circuit.
The blood circuit 2 includes an arterial blood circuit 21 upstream from the blood purifier 1 and a venous blood circuit 22 downstream from the blood purifier 1. A priming fluid supply line 4 is connected to the arterial blood circuit 21 upstream of the blood pump 3 (the priming fluid supply line 4 may be provided downstream of the blood pump 3). A chamber (air trap chamber) 23 for separating the air in the blood is provided in the vicinity of the blood purifier 1. The air trap chamber 23 may be omitted. The strain sensor S <b> 1 is provided downstream of the blood pump 3 and is usually provided downstream of the air trap chamber 23. The venous blood circuit 22 is provided with an air trap chamber 24 adjacent to the blood purifier 1, and a bubble sensor 25 and an open / close valve V 1 are provided in this order downstream of the air trap chamber 24. The strain sensor S2 is provided in the venous blood circuit 22 upstream from the on-off valve V1, and is usually provided upstream from the air trap chamber 24. When the priming liquid supply line 4 is provided upstream of the blood pump 3, when the on-off valve V 2 is opened, the blood pump 3 is driven to drive the blood circulation circuit (arterial blood circuit 21, blood purification) from the priming liquid container 41. The priming solution is supplied to the device 1 and the venous blood circuit 22.
The dialysate circuit 5 includes a dialysate supply circuit 51 upstream from the blood purifier 1 and a drain circuit 52 downstream from the blood purifier 1. A dialysate container 53 is connected to the dialysate supply circuit 51, and the dialysate is supplied from the dialysate container 53 to the blood purifier 1 by driving the dialysate pump 6. In general, the drainage circuit 52 is provided with the pressure gauge P and the filtration pump 7 in this order, and the used dialysate is discharged from the blood purifier 1 by driving the filtration pump 7. Yes. Instead of connecting the drainage circuit 52 to the filtration pump 7, the dialysate supply circuit 51 and the drainage circuit 52 may be connected to an ultrafiltration amount control device (including a filtration pump). As the pressure gauge P, any type can be adopted as long as it is conventionally used in a blood purification apparatus. The location of the pressure gauge P is the drainage circuit 52 side as shown in FIG. However, as long as the dialysate circuit 5 is between the dialysate pump 6 and the filtration pump 7, the dialysate supply circuit 51 side may be used.

As shown in FIGS. 4 to 7, the strain sensor S includes a housing 91 having a groove 911 that can accommodate the circuit tube C, a lid portion 92 that fixes the housing 91 to the circuit tube C, and the housing 91. It consists of a load sensor 93 provided in the groove 911 and a load transmitter 94. The force applied to the inner surface of the tube C of the circuit is transmitted to the load sensor 93 via the load transmitter 94 and measured.
The housing 91 is provided with a groove 911 capable of accommodating the tube C of the circuit and a load sensor accommodating portion 912 for accommodating the load sensor 93. The load sensor 93 is accommodated and fixed in the load sensor accommodating portion 912. Is done. A load transmitter 94 is attached to the load sensor 93. When the circuit tube C is accommodated in the groove 911, the tip of the head 941 of the load transmitter 94 is just in close contact with the tube C of the circuit. The lid portion 92 has a function of protecting the tube C of the circuit from the influence of the ambient temperature, and a concave groove 921 is formed on the inner wall of the lid portion 92 so as to be in close contact with the tube C of the circuit when the lid is closed. Is provided. As means for fixing the housing 91 to the tube C of the circuit, various fixing means other than the lid portion 92, such as a hook having an arm-shaped arm portion, a rubber band, or a groove portion, although not shown, are provided. Various methods such as a structure in which the pressure measuring part can be fitted (the opening of the groove is narrowed so that it can be elastically expanded at the time of fitting) can be adopted.
Although the load sensor 93 is not limited, a strain gauge type is generally used. In the figure, 95 is a lead wire, 913 is a hook for fixing the lid portion 92 to the housing 91, and 922 is an engaging portion with the hook.

Next, Example 2 will be described with reference to FIG.
FIG. 2 is a schematic explanatory diagram of a blood purification apparatus according to the second embodiment.
The blood purification apparatus of Example 2 is provided with the replacement fluid supply line 8 in the venous blood circuit 22 in FIG. 1, and is driven from the replacement fluid container 81 via the venous air trap chamber 24 by driving the replacement fluid pump 82. A replacement fluid is supplied to the blood circuit 22. In this blood purification apparatus, in addition to CVVHD, continuous blood filtration (CVVHF) and continuous blood filtration dialysis (CVVHDF) are also possible.

Next, the use of the blood purification apparatus of Example 2 will be described.
When using the blood purification apparatus, first, prior to treatment, priming of the blood circuit 2 side, the dialysate circuit 5 side, and the replacement fluid supply line 8 is performed. In order to simultaneously prime the whole, the on-off valve V1 of the venous blood circuit 22 and the on-off valve V2 of the priming liquid supply line 4 are opened, and on the blood circuit 2 side, the blood pump 3 is driven and the priming liquid container 41 A priming solution (usually using raw food) is supplied from the priming solution supply line to the blood circuit 2 to prime the arterial blood circuit 21, the blood purifier 1, and the venous blood circuit 22, and washing is performed at the same time. On the dialysate circuit 5 side, the dialysate pump 6 and the filtration pump 7 are driven to supply dialysate from the dialysate container 53 through the dialysate circuit 5 to the blood purifier 1, and the dialysate supply circuit 51, Blood purifier 1 and drainage circuit 52 are primed. For the replacement fluid supply line, the replacement fluid pump 82 is driven to supply the replacement fluid from the replacement fluid container 81 to the venous air trap chamber 24 through the replacement fluid line 8, and the venous blood downstream from the replacement fluid line 8 and the venous air trap chamber 24. The circuit 22 is primed.

After priming of the blood circuit 2 side, dialysate circuit 5 side and replacement fluid supply line 8, the next step is to calibrate the strain sensors S1 and S2 and to determine a curve indicating the relationship between the strain and pressure of the tube C of the circuit. There is a need.
First, when the blood pump 3, the dialysate pump 6 and the filtration pump 7 are stopped and the on-off valve V1 is closed, the pressures P1 and P2 measured by the strain sensors S1 and S2 are as shown in FIG. It can be determined by the heads h1 and h2 between S2 and the pressure gauge P and the pressure P3 measured by the pressure gauge P.
Therefore, the calibration can be mechanically performed by a control device provided in the blood purification device according to the following equations (1) and (2).
P1 = P3-ah1 ... 1
P2 = P3 + ah2 2
(Where a is a constant that converts the drop pressure of the dialysate to the mercury column pressure)
After the calibration of the strain sensors S1 and S2, the dialysate pump 6 and the filtration pump 7 are driven, and the pressure of the pressure gauge P is set to 100 mmHg and 300 mmHg, for example. (Converted into voltage by the sensors S1 and S2). 11 and 12, since the voltage value (strain) and the pressure are in a linear relationship, a straight line indicating the relationship between the strain (voltage) and the pressure with the vertical axis representing the voltage value and the horizontal axis representing the pressure can be obtained. it can. The pressure on the blood side is automatically measured from the strain of the tube of the circuit measured by the strain sensor thereafter by storing this “strain-pressure straight line” in the control device provided in the blood purification device. Can do.
The relationship between the strain measured by the strain sensor and the tube internal pressure is measured by measuring the tube strain (converted to a voltage value by the strain sensor) when the pressure is varied using tubes with different hardness. The value can be obtained by plotting the value on the vertical axis and the pressure on the horizontal axis (FIGS. 11 and 12). Thus, it can be seen that the voltage value (strain) and the pressure are in a linear relationship. However, the hard tube (FIG. 11) has a Shore A hardness of 75, an outer diameter of 5.6 mm, and an inner diameter of 3.4 mm, and the soft tube (FIG. 12) has a Shore A hardness of 73 and an outer diameter of 5. The inner diameter was 1 mm and the inner diameter was 3.0 mm.

Next, CVVHD will be described with reference to FIG.
First, before the treatment, the on-off valves V1 and V2 are opened, and the blood pump 3, the dialysate pump 6, and the filtration pump 7 are driven to perform priming on the blood circuit 2 side and the dialysate circuit 5 side. Further, the blood pump 3, the dialysate pump 6, and the filtration pump 7 are stopped, the on-off valve V1 is closed, and the calibration of the strain sensors S1 and S2 and the curve indicating the relationship between the strain of the tube C of the circuit and the pressure are determined. .
Next, after the blood pump 3, dialysate pump 6 and filtration pump 7 are stopped, the on-off valve V2 is closed and the blood circuit 2 is connected to the blood vessel of the patient, and then the blood pump 3, dialysate pump 6 and filtration pump 7 are restarted. When driven, blood is supplied to the blood purifier 1 through the arterial blood circuit 21, where it is purified (dialyzed) and returned to the patient's blood vessel through the venous blood circuit 22. On the other hand, the dialysate is supplied to the blood purifier 1 through the dialysate supply circuit 51, where the blood is purified, and the used dialysate is discharged through the drainage line 52.
When the calibration of the strain sensors S1 and S2 is necessary during the treatment, the blood pump 3, the dialysate pump 6 and the filtration pump 7 are stopped and the on-off valve V1 is closed as described above. The necessity of calibration of the strain sensors S1, S2 during treatment is determined in the following manner by monitoring the pressures P1, P2 measured by the strain sensors S1, S2.
That is, when the value of (P1-P2) increases, the clogging of the blood purifier occurs, and when the value of (P1-P2) decreases, the leak of the blood purifier membrane occurs. It is. Further, when both the values of P1 and P2 increase, needle clogging occurs. When both of the values of P1 and P2 decrease, needle missing occurs. Therefore, calibration of the strain sensors S1 and S2 is required when changes in P1 and P2 other than those described above occur.

Next, CVVHF will be described with reference to FIG.
First, before the treatment, the on-off valves V1 and V2 of the venous blood circuit 22 are opened, and the blood pump 3, the dialysate pump 6, the filtration pump 7, and the replacement fluid pump 82 are driven, and the blood circuit 2 side and the dialysate are driven. Priming of the replacement fluid supply line 8 is performed on the circuit 5 side. Further, the blood pump 3, the dialysate pump 6, and the filtration pump 7 are stopped, the on-off valve V1 is closed, and the calibration of the strain sensors S1 and S2 and the curve indicating the relationship between the strain of the tube C of the circuit and the pressure are determined. .
Next, the blood pump 3, the dialysate pump 6, the filtration pump 7, and the replacement fluid pump 82 are stopped, the on-off valve V2 is closed, and the blood circuit 2 is connected to the blood vessel of the patient. When 82 is driven again, blood is supplied to the blood purifier 1 through the arterial blood circuit 21, where it is purified (filtered) and returned to the patient's blood vessel through the venous blood circuit 22. Further, the liquid filtered from the blood (filtrate) is discharged through the drainage line 52. On the other hand, the replacement fluid is supplied to the venous air trap chamber 24 through the replacement fluid supply line 8 and is supplied to the blood vessel of the patient through the venous blood circuit 22. The calibration of the strain sensors S1 and S2 during treatment is the same as for CVVHD.

Next, CVVHDF will be described with reference to FIG.
First, before the treatment is performed, the on-off valves V1 and V2 are opened, and the blood pump 3, the dialysate pump 5, the filtration pump 7, and the replacement fluid pump 82 are driven to supply the blood circuit 2 side, the dialysate circuit 5 side, and the replacement fluid supply. Priming of line 8 is performed. Further, the blood pump 3, the dialysate pump 6, and the filtration pump 7 are stopped, the on-off valve V1 is closed, and the calibration of the strain sensors S1 and S2 and the curve indicating the relationship between the strain of the tube C of the circuit and the pressure are determined. .
Next, after closing the on-off valve V2 and connecting the blood circuit 2 to the blood vessel of the patient, when the blood pump 3, the dialysate pump 6 and the filtration pump 7 are driven, the blood passes through the arterial blood circuit 21 and is purified. It is supplied to the vessel 1 where it is purified (diafiltration by filtration) and returned to the patient's blood vessel through the venous blood circuit 22. On the other hand, the dialysate is supplied to the blood purifier 1 through the dialysate supply circuit 51, where the blood is purified, and the used dialysate is discharged through the drainage line 52 together with the filtrate from the blood. Is done. Further, the replacement fluid is supplied to the venous air trap chamber 24 through the replacement fluid supply line 8, and is supplied to the blood vessel of the patient through the venous blood circuit 22. The calibration of the strain sensors S1 and S2 during treatment is the same as for CVVHD.

It is a schematic explanatory drawing which shows Example 1 of the blood purification apparatus of this invention. It is a schematic explanatory drawing which shows Example 2 of the blood purification apparatus of this invention. It is a figure which shows the relationship between the pressure measured with a strain sensor, the drop of a strain sensor and the pressure gauge, and the pressure measured with the pressure gauge. It is a longitudinal cross-sectional view which shows one Example of the distortion sensor of the blood purification apparatus of this invention. It is a front view of the distortion sensor shown in FIG. It is a figure which shows the state which opened the lid | cover of the distortion sensor shown in FIG. FIG. 7 is a side view of FIG. 6. It is explanatory drawing of CVVHD performed using the blood purification apparatus of this invention. It is explanatory drawing of CVVHF performed using the blood purification apparatus of this invention. It is explanatory drawing of CVVHDF performed using the blood purification apparatus of this invention. It is a figure which shows the relationship between the distortion of a distortion sensor in a hard tube, and a pressure. It is a figure which shows the relationship between the distortion of a distortion sensor in a soft tube, and a pressure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Blood purifier 21 Arterial side blood circuit 22 Vein side blood circuit 23 Air trap chamber 24 (Venous side) Air trap chamber 25 Bubble sensor 3 Blood pump 4 Priming liquid supply line 41 Priming liquid container 5 Dialysing liquid circuit 51 Dialysing liquid supply circuit 52 drainage circuit 53 dialysate container 6 dialysate pump 7 filtration pump 8 replacement fluid supply line 81 replacement fluid container 82 replacement fluid pump P pressure gauge S, S1, S2 strain sensor V1, V2 on-off valve 91 housing 911 groove 912 load sensor housing 913 Hook 92 Lid portion 921 Concave groove 922 Engagement portion with hook 93 Load sensor 94 Load transmitter 941 Head 95 Lead wire C Circuit tube

Claims (6)

Blood purifier and blood circuit, blood pump, priming fluid supply line, venous air trap chamber, on-off valve provided in the venous blood circuit downstream from the venous air trap chamber, dialysate circuit, dialysate pump, and In a blood purification apparatus comprising a filtration pump,
A strain sensor provided in an arterial blood circuit downstream from the blood pump and a venous blood circuit upstream from the on-off valve ;
A pressure gauge provided in the dialysate circuit between the dialysate pump and the filtration pump ;
And difference between the pressure gauge and the strain sensor, on the basis of the pressure measured by the pressure gauge, performs calibration of the strain sensors, the correspondence between the distortion and the tube internal pressure of the tube of the blood circuit A control device for measuring the pressure in the blood circuit from the strain measured by the strain sensor based on
A blood purification apparatus comprising:

The blood purification apparatus according to claim 1, wherein a replacement fluid supply line is provided in the venous blood circuit. The strain sensor comprises a load sensor and a load transmitter, and the force applied to the inner surface of the tube of the circuit is transmitted to the load sensor via the load transmitter and measured. 2. The blood purification apparatus according to 2. The blood purification apparatus according to claim 3, wherein the strain sensor is housed in a housing having a groove capable of housing a tube of a circuit and a load sensor housing portion formed at the bottom of the groove. The blood purification apparatus according to claim 4, wherein the housing is provided with means for fixing the circuit tube. Blood purification apparatus of claim 5 wherein the securing means is a lockable lid on said housing.

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