JP2022131709A - Blood purification device - Google Patents

Abstract

To provide a blood purification device capable of coping with a change in a detection value of a first detection part smoothly.SOLUTION: A blood purification device for purifying a patient's blood by circulating the blood extracorporeally through a dialyzer 3 and a blood circuit includes: a blood pump 4 for sending blood in the blood circuit; a piping part having a dialysis fluid introduction line L1 for introducing dialysis fluid to the dialyzer 3 and a drainage discharge line L2 for discharging drainage from the dialyzer 3; a first detection part disposed at a predetermined detection position in the blood circuit for detecting a flow rate or a pressure of the fluid; a second detection part for detecting a flow rate or a pressure either of the fluid on a downstream side of the detection position in the blood circuit or of the dialysis fluid in the piping part; and a determination part 23 for determining propriety of the detection value of the first detection part on the basis of a change in the pressure detected by the second detection part when the detection value of the first detection part reaches a predetermined threshold.SELECTED DRAWING: Figure 1

Description

The present invention relates to a blood purification apparatus for purifying a patient's blood and administering blood purification treatment.

A general blood circuit used during hemodialysis treatment is mainly composed of an arterial blood circuit having an arterial puncture needle attached to its tip and a venous blood circuit having a venous puncture needle attached to its tip. A blood purifier such as a dialyzer can be connected to each proximal end of the arterial blood circuit and the venous blood circuit. The arterial blood circuit is provided with a squeezing-type blood pump, and by driving the blood pump while both the arterial and venous puncture needles are piercing the patient, the blood from the arterial puncture needle As blood is collected, the blood is made to flow in the arterial blood circuit and is led to the dialyzer, and the blood purified by the dialyzer is made to flow in the venous blood circuit and into the patient's body through the venous puncture needle. It is configured to be returned for dialysis treatment.

Conventionally, as disclosed in Japanese Patent Laid-Open No. 2002-100001, a tube to be squeezed which is compressed in the radial direction and squeezed in the longitudinal direction by the squeezing portion of the blood pump is used so that the liquid (blood, etc.) inside can flow. , Blood equipped with a detection unit capable of detecting the depressurization of the arterial blood circuit (the pressure between the tip of the arterial blood circuit and the tube to be ironed) by detecting radial displacement of the tube to be ironed. Purification devices have been proposed.

JP 2014-83092 A

However, in the above-described conventional detection unit, since the radial displacement of the tube to be ironed made of a flexible tube is detected, as the blood purification treatment progresses, the reaction force (due to elasticity) of the flexible tube at the detection position There is a possibility of erroneous detection due to a decrease in the generated repulsive force). However, it is difficult to visually determine whether the detection value of the detection unit is appropriate or whether it is an erroneous detection due to a decrease in the reaction force of the flexible tube. It was difficult to carry out smoothly.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a blood purification apparatus capable of smoothly responding to a change in the detection value of the detection unit.

A blood purification apparatus according to one embodiment of the present invention is a blood purification apparatus for extracorporeally circulating a patient's blood through a blood purifier and a blood circuit to purify the blood, wherein the blood is sent through the blood circuit. A piping unit having a pump, a dialysate introduction line for introducing dialysate into the blood purifier, and a drainage discharge line for discharging drainage from the blood purifier, and arranged at a predetermined detection position in the blood circuit. a first detection unit for detecting the flow rate or pressure of the liquid; and a second detection unit for detecting the flow rate or pressure of either the liquid downstream from the detection position in the blood circuit or the dialysate in the piping section. and when the detected value of the first detection unit reaches a predetermined threshold value, the adequacy of the detection value of the first detection unit is determined based on the change in flow rate or pressure detected by the second detection unit. and a determination unit for

According to the present invention, when the detected value of the first detection unit changes by exceeding the predetermined threshold value, the change in pressure detected by the second detection unit is compared with the change in the pressure detected by the first detection unit. Since the suitability is determined, it is possible to smoothly respond to a change in the detection value of the first detection unit.

Schematic diagram showing a blood purification device according to an embodiment of the present invention. A perspective view showing a blood pump in which a detection unit (first detection unit) of the blood purification apparatus is arranged. Plan view showing the same blood pump Schematic cross-sectional view showing a first detection unit provided in the same blood pump Schematic diagram showing the initial calibration state of the same blood purification device Graph showing the relationship between the flow rate ratio and voltage of the same detection device (experimental results obtained in advance) Graph showing the calibration curve obtained in the initial calibration with the same detector Schematic diagram showing the drive of the blood pump at the time of initial calibration in the detection device Schematic diagram showing a state during blood purification treatment in the same blood purification apparatus Graph showing changes in set blood flow rate and estimated blood flow rate (detection value of the first detection unit) when blood removal failure occurs in the same blood purification apparatus Graph when the detection value of the second detection unit also decreases when the detection value of the first detection unit decreases in the same blood purification apparatus. Graph when the detection value of the second detection unit does not decrease when the detection value of the first detection unit decreases in the same blood purification apparatus Graph showing the calibration curve obtained in the initial calibration and the corrected calibration curve in the same blood purification device Graph showing the difference due to the presence or absence of correction of the calibration curve in the same blood purification device Flowchart for explaining control content of the same blood purification apparatus Graph showing the venous pressure, dialysate pressure and estimated blood flow (when the judgment unit judges that it is not appropriate) detected in the same blood purification device Graph showing the venous pressure, dialysate pressure and estimated blood flow (when the judging unit judges it to be appropriate) detected in the same blood purification device FIG. 4 is a perspective view showing a blood pump applied to a blood purification apparatus according to another embodiment of the present invention; Schematic cross-sectional view showing a first detection unit provided in the same blood pump

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
The blood purification apparatus according to the present embodiment purifies the patient's blood by extracorporeally circulating it through a blood purifier and a blood circuit to perform blood purification treatment (for example, hemodialysis treatment). It comprises a blood circuit having an arterial blood circuit 1 and a venous blood circuit 2, and a dialyzer 3 as a blood purifier.

The arterial blood circuit 1 constitutes a liquid flow path composed of a flexible tube through which a predetermined liquid can flow, and an arterial puncture needle (not shown) can be attached to the distal end thereof via a connector a. In addition, an artery side air trap chamber 5 for defoaming is connected in the middle. One end of a dialysate supply line L3 is connected to the arterial blood circuit 1 via a T-tube c, and the other end of the dialysate supply line L3 is connected to a dialysate introduction line via a sampling port 19. connected to L1. The dialysate supply line L3 can be arbitrarily opened and closed by an electromagnetic valve V9, and is configured to supply the dialysate in the dialysate introduction line L1 into the blood circuit.

A tube to be ironed 1 a is connected in the middle of the arterial blood circuit 1 (between the T-tube c and the arterial air trap chamber 5 ). is possible. The tube 1a to be squeezed is radially compressed by the rollers 10 of the blood pump 4, which will be described in detail later, and is squeezed longitudinally so that the liquid inside can flow in the direction of rotation of the rotor 9. It consists of a flexible tube that is softer and has a larger diameter than the other flexible tubes that make up the blood circuit 1 . A solenoid valve V1 is arranged on the distal end side of the arterial blood circuit 1 so that the flow path can be opened and closed at an arbitrary timing.

Furthermore, a pressure monitor line extending to an inlet pressure sensor 8 is provided on the air layer side (upper portion) of the artery side air trap chamber 5 . The inlet pressure sensor 8 can detect the inlet pressure of the dialyzer 3 in the arterial blood circuit 1 by measuring the pressure on the air layer side of the arterial air trap chamber 5 .

The venous blood circuit 2 constitutes a liquid flow path composed of a flexible tube through which a predetermined liquid can flow, and a venous puncture needle (not shown) can be attached to the tip thereof via a connector b. In addition, a venous air trap chamber 6 for defoaming is connected in the middle. However, the flexible tube forming the venous blood circuit 2 is substantially the same in material and size as the flexible tube forming the arterial blood circuit 1 . A solenoid valve V2 is arranged on the distal end side of the venous blood circuit 2 so that the flow path can be opened and closed at an arbitrary timing.

On the air layer side (upper portion) of the venous air trap chamber 6, an overflow line L4 is extended to allow the air or gas in the venous air trap chamber 6 to be discharged to the outside. is provided with an electromagnetic valve V3 capable of opening and closing the flow path at arbitrary timing. Furthermore, a pressure monitor line extending to a venous pressure sensor 7 is provided on the air layer side (upper portion) of the venous air trap chamber 6 . The venous pressure sensor 7 is designed to detect the fluid pressure in the venous blood circuit 2 (venous pressure measured during blood purification treatment) by measuring the pressure on the air layer side of the venous air trap chamber 6. It has become.

A dialyzer 3 is connected between the arterial blood circuit 1 and the venous blood circuit 2. After puncturing the patient with the arterial and venous puncture needles, the blood pump 4 is driven forward. (in the direction of the arrow of the blood pump 4 in FIG. 9), the patient's blood is extracorporeally circulated during the blood purification treatment through the liquid flow path constituted by the arterial blood circuit 1, the venous blood circuit 2, and the dialyzer 3. It is designed to allow

On the other hand, before the blood purification treatment, as shown in FIG. The side blood circuit 1 and the venous blood circuit 2 (including the blood flow path in the dialyzer 3) can form a closed circuit on the side of the blood circuit. By supplying the dialysate into the closed circuit through the dialysate supply line L3, the blood circuits (the arterial blood circuit 1 and the venous blood circuit 2) are filled with the dialysate to perform the priming operation. It is possible. In the process of the priming operation, the dialysate is allowed to overflow from the overflow line L4 to wash the inside of the closed circuit on the blood circuit side.

The dialyzer 3 contains a plurality of hollow fibers having micropores formed therein and is provided with a blood inlet port 3a, a blood outlet port 3b, and a dialysate inlet port. 3c and a dialysate outlet port 3d are formed, of which the proximal end of the arterial blood circuit 1 is connected to the blood inlet port 3a, and the proximal end of the venous blood circuit 2 is connected to the blood outlet port 3b. there is The dialysate introduction port 3c and the dialysate outlet port 3d are connected to a dialysate introduction line L1 and a drainage discharge line L2, respectively, which extend from the dialyzer main body.

The patient's blood introduced into the dialyzer 3 passes through the inside of the hollow fiber membrane and is discharged from the blood outlet port 3b, while the dialysate introduced from the dialysate inlet port 3c flows out of the hollow fiber membrane. and is discharged from the dialysate outlet port 3d. As a result, waste products and the like in the blood passing through the blood flow path can be permeated to the dialysate side and cleaned, and the clean blood can be returned to the patient's body via the venous blood circuit 2. can.

The dialysis apparatus main body includes a piping section having a dialysate introduction line L1 and a drainage discharge line L2, and a dual pump 21, bypass lines L5 to L8 (these are also included as piping sections of the present invention), and an electromagnetic valve V4. ~V8. Among these, the dual pump 21 is disposed across the dialysate introduction line L1 and the waste fluid discharge line L2, and introduces the dialysate adjusted to a predetermined concentration into the dialyzer 3 and the waste fluid after dialysis from the dialyzer 3. is discharged.

A solenoid valve V4 is connected in the middle of the dialysate introduction line L1 (between the sampling port 19 in the dialysate introduction line L1 and the dialyzer 3), and in the middle of the drainage discharge line L2 (in the drainage discharge line L2). A solenoid valve V5 is connected between the connecting portion with the bypass line L6 and the dialyzer 3). Filtration filters 23 and 24 are connected between the double pump 21 and the electromagnetic valve V4 in the dialysate introduction line L1.

The filtration filters 23 and 24 are for filtering and purifying the dialysate flowing through the dialysate introduction line L1, and the dialysate is led to the filtration filters 23 and 24 by bypassing the drainage discharge line L2. Bypass lines L5 and L6 are respectively connected for this purpose. Electromagnetic valves V6 and V7 are connected to the bypass lines L5 and L6, respectively.

On the other hand, between the connecting portion of the drainage discharge line L2 with the bypass line L5 and the connecting portion with the bypass line L6, there is a dialysate pressure that can measure the hydraulic pressure of the dialysate (waste fluid discharged from the dialyzer 3). A sensor 20 is provided. The dialysate pressure sensor 20 is capable of measuring the pressure (fluid pressure) of the dialysate (drainage) discharged from the dialyzer 3 and flowing through the drainage discharge line L2 during dialysis treatment (during blood purification treatment). .

Furthermore, bypass lines L7 and L8 that bypass the dual pump 21 are connected to the drainage line L2, respectively. A water removal pump 22 is provided for removing water, and a bypass line L8 is provided with an electromagnetic valve V8 capable of opening and closing the flow path. Although not shown, the liquid pressure on the drainage side of the dual pump 21 is located upstream of the dual pump 21 in the liquid drainage line L2 (between the connection with the bypass line L7 and the dual pump 21). A pump is provided for adjustment.

By the way, the blood pump 4 according to the present embodiment is composed of a squeezing type pump, and as shown in FIGS. A pair of upper and lower guide pins 11, an upstream gripping portion 12, a downstream gripping portion 13, and a load sensor 18 as a first detection portion. In the figure, the cover covering the upper portion of the stator G in the blood pump 4 is omitted.

The stator G is formed with a mounting recess Ga to which a tube to be ironed 1a (a portion to be ironed) is mounted, and is configured so that the tube to be ironed 1a is mounted along an inner peripheral wall surface forming the mounting recess Ga. there is A rotor 9 that can be rotated by a motor is arranged substantially in the center of the mounting recess Ga. A pair of rollers 10 and a guide pin 11 are arranged on the side surface of the rotor 9 (the surface facing the inner peripheral wall surface of the mounting recess Ga).

The roller 10 is rotatable around a rotation axis M formed on the outer edge side of the rotor 9, and rotates the rotor 9 while radially compressing the tube to be ironed 1a attached to the attachment recess Ga. By squeezing in the longitudinal direction (blood flow direction) along with this, the blood can flow in the arterial blood circuit 1 and can be sent. That is, when the tube 1a to be ironed is attached in the mounting recess Ga and the rotor 9 is driven to rotate, the tube 1a to be ironed is compressed between the roller 10 and the inner peripheral wall surface of the mounting recess Ga, and the rotor 9 is rotated. As it is driven to rotate, it can be squeezed in its rotational direction (longitudinal direction). The squeezing action causes the blood in the arterial blood circuit 1 to flow in the direction of rotation of the rotor 9, so that extracorporeal circulation in the blood circuit 1 is possible.

As shown in FIG. 2, the guide pins 11 are composed of a pair of upper and lower pin-like members projecting from the upper end side and the lower end side of the rotor 9 toward the inner peripheral wall surface of the mounting recess Ga. The tube to be ironed 1 a is held between the pair of guide pins 11 . That is, when the rotor 9 is driven, the pair of upper and lower guide pins 11 hold the tube 1a to be ironed at a regular position, and the upper guide pin 11 prevents the tube 1a to be ironed from being separated upward from the mounting recess Ga. -ing

The upstream gripping portion 12 is for gripping the upstream side of the tube to be ironed 1a attached to the mounting recess Ga of the stator 8 of the blood pump 4 (the portion to which the distal end side of the arterial blood circuit 1 is connected). 2 to 4, it has a gripping piece 14 that can press and grip the tube 1a to be ironed in the radial direction, and a torsion spring 15 that biases the gripping piece 14 toward the tube 1a to be ironed.

As shown in FIG. 4, the gripping piece 14 is made up of a part that can swing about a swinging axis La, and is biased relatively strongly in the gripping direction by a torsion spring 15, so that the tube to be ironed 1a is pushed. It can be fixed by pressing the upstream part and holding it tightly. As shown in the figure, the torsion spring 15 is attached to the swing shaft La to urge the gripping piece 14, and also to the fixed portion of the stator G (in this embodiment, the load sensor 18 attached to the stator G). ) and a pressing end 15b for pressing the gripping piece 14. As shown in FIG. Note that, instead of the torsion spring 15, another urging portion that urges the gripping piece 14 may be used.

The downstream gripping portion 13 is for gripping the downstream side (the portion to which the proximal end side of the arterial blood circuit 1 is connected) of the tube to be ironed 1a attached to the mounting recess Ga of the stator 8 of the blood pump 4. It has a gripping piece 16 that can press and grip the tube 1a to be ironed in the radial direction, and a torsion spring 17 that biases the gripping piece 16 toward the tube 1a to be ironed.

Like the gripping piece 14 of the upstream gripping part 12, the gripping piece 16 is made of a component that can swing around the swing axis Lb, and is biased relatively strongly in the gripping direction by a torsion spring 17. Fixing is made possible by pressing the downstream portion of the tube to be ironed 1a and holding it tightly. Similar to the torsion spring 15 of the upstream side gripping portion 12, the torsion spring 17 is attached to the swing shaft Lb to urge the gripping piece 16 and press the gripping piece 16 against the fixed end positioned at the fixed portion of the stator G. and a pressing end.

However, the blood pump 4 according to this embodiment is provided with a load sensor 18 that constitutes a first detection section. The load sensor 18 detects the load that changes according to the displacement in the radial direction at a predetermined position (this position is referred to as a predetermined detection position) on the upstream side of the portion of the tube 1a to be ironed that is ironed by the rollers 10. is. The first detection unit of the present embodiment includes a load sensor 18 provided in the blood pump 4, and detects a predetermined load upstream of the portion of the tube 1a to be ironed that is ironed by the rollers 10. The radial displacement at the position is detected, and the radial displacement at a predetermined detection position of the flexible tube constituting the arterial blood circuit 1 connected to the upstream side of the tube 1a to be ironed is detected. (eg, a pillow, etc.).

The load sensor 18 according to the present embodiment is capable of detecting radial displacement of the portion of the tube 1a to be ironed gripped by the upstream gripping portion 12, and the load applied to the fixed end 15a side of the torsion spring 15 is detected. is detected, and the radial displacement of the tube 1a to be ironed is detected based on the detected load. This load sensor 18 is capable of generating an electrical signal corresponding to the applied load.

That is, since the arterial puncture needle is attached to the tip of the arterial blood circuit during dialysis treatment, when blood is collected from the patient and flowed in the arterial blood circuit 1 (blood pump in FIG. 9) 4 ), a negative pressure is generated between the tip of the arterial blood circuit 1 and the blood pump 4 . When such a negative pressure is generated, the hydraulic pressure in the tube to be ironed 1a is reduced, and the portion of the tube to be ironed 1a gripped by the upstream gripping portion 12 is displaced in the radial direction (the diameter becomes smaller). The load detected by the sensor 18 will decrease. By detecting the decrease in the load, it is possible to detect that the arterial blood circuit 1 has a negative pressure. In this way, at the detection position on the upstream side in the liquid feeding direction of the blood circuit (the direction from the tip of the arterial blood circuit 1 to the tip of the venous blood circuit 2) from the part to be squeezed by the roller 10 (squeezing part), The load sensor 18 detects the load applied by the gripping piece 14 that swings according to the radial displacement of the ironing tube 1a (the portion to be ironed).

The load sensor 18 according to the present embodiment is electrically connected to the calculator 25 by extending wiring or the like. The calculation unit 25 constitutes the first detection unit of the present invention together with the load sensor 18, and based on the radial displacement of the tube 1a to be ironed detected by the load sensor 18, the arterial blood circuit 1 It is configured to be able to calculate pressure and flow rate.

That is, when the output voltage corresponding to the radial displacement of the tube 1a to be ironed is detected by the load sensor 18, the output signal is transmitted to the calculation unit 25, and the calculation unit 25 detects the voltage of the arterial blood circuit 1. The pressure at the detection position (in this embodiment, between the tip of the arterial blood circuit 1 and the site where the load sensor 18 is arranged) (withdrawal blood pressure during blood purification treatment) and the flow rate ratio (actual flow rate with respect to the set flow rate) ratio) is calculated. The flow rate ratio and blood pressure withdrawn calculated by the calculator 25 are configured to be displayed on a monitor (not shown) or the like as an estimated blood flow rate or an estimated blood withdrawal amount.

Further, in this embodiment, a controller 26 and a calibration curve generator 27 for calibrating the load sensor 18 and the calculator 25 are provided. The control unit 26 sets a predetermined specific flow rate or pressure at a predetermined detection position (a position on the upstream side of the portion of the tube 1a to be ironed that is ironed by the rollers 10). 5, the rotor 9 of the blood pump 4 is rotated by a predetermined angle while the electromagnetic valves V1 and V9 are closed to close the upstream side of the detection position. (flow ratio) or pressure. The calculator 25, the controller 26, and the calibration curve generator 27 are composed of, for example, a microcomputer installed in the main body of the dialysis machine.

That is, the control unit 26 controls the liquid transfer so that the flow rate or pressure at the detection position in the blood circuit becomes a specific value within the control range. Such specific values include arbitrary points between the upper limit value and the lower limit value of the control range, and may be two or more instead of one. In addition, the calibration curve creation unit 27 acquires the detection value by the load sensor 18 in a state where the control unit 26 controls the flow rate or pressure at the detection position in the liquid flow path to be a specific value, and includes the detection value. By using at least two values, a calibration curve D for calibrating the load sensor 18 and the calculator 25 is created.

Specifically, at the time of calibration, as shown in FIG. 5, the control unit 26 closes the solenoid valves V1 and V9 so that the upstream side of the detection position is closed, and as shown in FIG. By rotating the rotor 9 at the initial position P0 of the pump 4 by a predetermined angle K1 to bring the rotor 9 to the position P1 as shown in FIG. Specifically, the first step of setting the flow ratio F1) or the pressure shown in FIG. 6 is executed.

After executing the first step, the control unit 26 maintains the closed state of the solenoid valves V1 and V9 to maintain the closed state on the upstream side of the detection position, and further rotates the rotor 9 of the blood pump 4 by a predetermined angle K2. by rotating the rotor 9 to position P2 as shown in FIG. 2nd step is executed. In this way, by intermittently rotating the rotor 9 of the blood pump 4 and passing through the first step and the second step, the detection value D1 at the flow rate ratio F1 and the detection value D2 at the flow rate ratio F2 differ from each other. Based on this, the calibration curve D (see FIG. 7) can be obtained in the calibration curve creation unit 27. FIG.

However, according to the results of experiments conducted in advance, the relationship between the flow rate ratio of the liquid flowing through the detection position (ratio of the actual flow rate to the set flow rate) and the output voltage of the load sensor 18 tends as shown in the graph of FIG. , and has two inflection points (inflection point A1 on the lower limit side and inflection point A2 on the upper limit side) between the lower limit and the upper limit. In the present embodiment, the range avoids the inflection points (A1, A2) in the predetermined range between the upper limit and the lower limit detectable by the load sensor 18 (the range that does not straddle the inflection points). , the calibration curve D (Fig. 7) is obtained.

When the calculation unit 25 calculates the flow rate ratio, the upper limit value detectable by the load sensor 18 is the value at which the flow rate ratio at the detection position is 1 (the set flow rate and the actual flow rate are equal). The lower limit value that can be detected means the value at which the flow rate ratio at the detection position is 0 (the actual flow rate is 0 with respect to the set flow rate). Further, when the calculation unit 25 calculates the pressure (withdrawal of blood pressure), the upper limit detectable by the load sensor 18 is the value when the flow rate ratio at the detection position is 1 (the set flow rate and the actual flow rate are equal). Pressure (fluid pressure), and the lower limit detectable by the load sensor 18 is the pressure (fluid pressure) when the flow rate ratio at the detection position is a value of 0 (the actual flow rate is 0 with respect to the set flow rate). . The upper limit value is not limited to 1 and the lower limit value is 0. For example, the upper limit value (actual flow rate exceeding the set flow rate) may be 1 or more.

The calibration curve creation unit 27 acquires the detection value by the load sensor 18 when the detection position is set to a specific flow rate or pressure by the control unit 26, and based on the relationship between the specific flow rate or pressure and the acquired detection value A calibration curve for calibration of the load sensor 18 and the calculation unit 25 is created and acquired. In the present embodiment, the upper limit (flow rate ratio 1) and the lower limit (flow rate ratio 0) (the range between the flow ratio F1 obtained in the first step performed by the control unit 26 and the flow ratio F2 obtained in the second step). is supposed to be obtained.

Specifically, as shown in FIG. 7, the calibration curve creation unit 27 has a specific flow rate ratio F1 or F2 set between a flow rate ratio 0 (lower limit) and a flow rate ratio 1 (upper limit) or pressure , the detection value (D1) obtained by the load sensor 18 when the specific flow rate (flow rate ratio F1) or pressure is set in the first step, and the specific flow rate (flow rate ratio F2) or pressure is set in the second step The detected value (D2) obtained by the load sensor 18 at that time is connected with a straight line, and this straight line is obtained as a calibration curve D.

Here, in the present embodiment, when the detection value (estimated blood flow or estimated withdrawal blood pressure) of the first detection unit (load sensor 18 and calculation unit 25) reaches a predetermined threshold value, the second detection unit detects A determination unit 28 is provided for determining whether the detection value of the first detection unit is appropriate based on the change in flow rate or pressure. Similar to the control unit 26 and the calibration curve acquisition unit 27, the judgment unit 28 is composed of a microcomputer or the like installed in the dialysis apparatus main body, for example. The second detection unit includes an inlet pressure sensor 8 arranged in the arterial blood circuit 1 to detect the inlet pressure of the dialyzer 3, a venous pressure sensor 7 arranged in the venous blood circuit 2 to detect the venous pressure, and a dialysate pressure sensor 20 for detecting the hydraulic pressure of the dialysate (waste) in the drain discharge line L2 or a combination of two or more.

Note that there is a certain correlation or causal relationship between the detection value of the first detection unit and the detection value of the second detection unit. In the case of a configuration arranged downstream of the blood pump 4 as in the case of FIG. Also, when the second detection unit, like the dialysate pressure sensor 20, is arranged in a piping unit connected to the blood circuit via the dialyzer 3 or the dialysate supply line L3, the venous pressure sensor The flow rate or pressure can change according to the flow rate or pressure of the blood pump 4, although the degree of influence is different compared to 7 and the inlet pressure sensor 8. FIG. Focusing on the fact that there is a correlation or causal relationship between the detection values of the first detection unit and the second detection unit, the determination unit 28 determines that the detection value of the first detection unit is a predetermined threshold value. is reached, the adequacy of the detection value of the first detection unit is determined based on the change in the flow rate or pressure detected by the second detection unit.

Specifically, when the pressure detected by the second detection unit changes as the detection value of the first detection unit reaches a predetermined threshold value, the determination unit 28 detects the detection value of the first detection unit. When it is determined that the value is appropriate and the pressure detected by the second detection unit does not change as the detection value of the first detection unit reaches the predetermined threshold value, the detection of the first detection unit It is judged that the value is not appropriate.

For example, as shown in FIG. 10, when the estimated blood flow Q2 calculated by the calculation unit 25 based on the output voltage of the load sensor 18 decreases by 20% with respect to the set blood flow Q1, the determination unit 28 Considering the venous pressure detected by the venous pressure sensor 7 as the detection unit of 2, as shown in FIG. 11, when the venous pressure W1 is lower than the reference value W0, the first detection unit When it is determined that the value is appropriate and, as shown in FIG. 12, the venous pressure W1 has not decreased with respect to the reference value W0 (maintains a value greater than the reference value W0), the first detection is performed. It is judged that the detection value of the part is not appropriate.

Note that the reference value W0 is a value obtained by adding or subtracting a predetermined value to the venous pressure after the venous pressure has stabilized (for example, after 1 minute) after the operation of the blood pump 4 is started or the flow rate is changed, for example. . In addition, (1) the blood flow estimated by the first detection unit 18 can be used during the blood purification treatment process, and (2) the decision unit 28 can It can be set so that determinations such as those described above are made. The reference value W0 may not be a value obtained by subtracting the venous pressure after the passage of time for the venous pressure to stabilize after the flow rate is changed. You may judge whether the detection value of the detection part is appropriate. The venous pressure detected in the past is desirably the venous pressure detected in the past within the scope of the blood purification treatment being performed, and does not include the venous pressure detected in the previous blood purification treatment. . More desirably, the venous pressure detected relatively immediately before (several minutes to several tens of minutes before) within the range of blood purification treatment being performed is preferable.

Further, in the present embodiment, when the determination unit 28 determines that the detection value of the first detection unit is appropriate, an alarm based on the detection value of the first detection unit is issued, and the determination unit 28 A notification unit 29 is provided for notifying that the detection value of the first detection unit is not appropriate or suggesting that the detection value of the first detection unit is not appropriate when the detection value of the first detection unit is determined to be inappropriate. The notification unit 29 has a speaker, a monitor, etc., and is configured to be able to output voice, effect sound, etc. from the speaker and to display warnings on the monitor.

Furthermore, in the present embodiment, as described above, before the blood is extracorporeally circulated in the blood circuit and the blood purification treatment is performed, the first detection unit is initially calibrated to obtain the calibration curve D, and the determination When the unit 28 determines that the detection value of the first detection unit is not appropriate, the calibration curve D obtained by the initial calibration is corrected to obtain the calibration curve E after correction.

Specifically, when the determination unit 28 determines that the detection value of the first detection unit is not appropriate, the driving speed of the blood pump 4 is reduced to, for example, 40 (mL/m or so), or the blood pump 4 is driven. is stopped, and the output voltage detected by the load sensor 18 at that time is defined as the span voltage (Ds1). Then, as shown in FIG. 13, the correction value E1 of D1 at the flow ratio F1 and the flow ratio A correction value E2 for D2 in F2 is determined, and a calibration curve E is obtained by correcting the calibration curve D based on these correction values E1 and E2.

Note that, for example, the predetermined arithmetic expression is based on the difference or ratio between the span voltage (Ds0) obtained at the initial calibration and the span voltage (Ds1) obtained at the time of correction, the detected value (D1, D2) may be calculated to obtain the correction values (E1, E2), or values obtained by experiments conducted in advance may be used as parameters. Further, the arithmetic expression for correcting the calibration curve D or its parameters may be changed according to the material or diameter of the blood circuit used. As described above, according to the present embodiment, the calibration curve D is corrected based on the detection value of the load sensor 18 when the driving amount of the blood pump 4 is reduced or stopped to obtain an appropriate calibration curve E. can be done.

However, as shown in FIG. 14, when the determination unit 28 determines that the detection value of the first detection unit is not appropriate and the calibration curve D at the time of initial calibration is used, the blood pump flow rate changes at the set flow rate. However, a flow rate (Na) lower than the blood pump set flow rate is detected, whereas the determination unit 28 determines that the detection value of the first detection unit is not appropriate, and the calibration curve after correction When E is used, a flow rate (Nb) approximately equal to the blood pump set flow rate can be detected if the blood pump set flow rate is maintained. In addition, the symbol Nc in the figure indicates the detection value of the load sensor 18 .

Next, the contents of control of the blood purification apparatus according to this embodiment will be described based on the flowchart of FIG.
Prior to the start of dialysis treatment (blood purification treatment), first, the liquid replacement step S1 is performed to fill the inside of the piping in the dialysis machine body with the dialysate, and to perform self-diagnosis such as leakage diagnosis and testing of the piping. After that, the process proceeds to the dialysis preparation step S2, in which dialysis conditions are set, the tube 1a to be ironed in the arterial blood circuit 1 is attached to the blood pump 4, and priming of the blood circuit and the replacement fluid circuit (filling operation of the replacement fluid) is performed. . In parallel with the dialysis preparation step S2, priming (gas purge) of the dialysate flow path side of the dialyzer 3 is also performed.

After completing the dialysis preparation step S2, the process proceeds to the calibration step S3. In the calibration step S3, the state shown in FIG. 5 is established, and the value detected by the load sensor 18 is acquired when the detection position is set to a specific flow rate (flow rate ratio) or pressure by the control unit 26 as described above. A calibration curve D for calibration (initial calibration) of the load sensor 18 and the calculation unit 25 is created and acquired by the calibration curve creation unit 27 based on the relationship between the specific flow rate or pressure and the acquired detection value. Calibration is performed by

Thereafter, as shown in FIG. 9, the patient is punctured with the arterial puncture needle a and the venous puncture needle b, and the blood pump 4 is driven to rotate the roller 10 to start blood removal (blood removal start). S4), the patient's blood is extracorporeally circulated through the arterial blood circuit 1 and the venous blood circuit 2. As a result, the blood in the extracorporeal circulation process is purified by the dialyzer 3, and dialysis treatment (blood purification treatment) is performed.

After the start of blood removal, the load sensor 18 calibrated in the calibration step (S3) and the calculation unit 25 calculate the flow rate ratio or blood pressure removal (S5), and the flow rate ratio or blood pressure removal is displayed on a monitor or the like. will be monitored. Thereafter, in S6, a value obtained by subtracting a predetermined value from the venous pressure after the venous pressure has stabilized (for example, after 1 minute) is set as a reference point.

A reference point is set in S6, and the process proceeds to S7, in which it is determined whether or not the flow rate ratio or the withdrawal blood pressure calculated in S5 exceeds a preset set value. , the process proceeds to S8 to determine whether or not the venous pressure is equal to or lower than the reference point set in S6. It should be noted that if the value does not decrease beyond the set value in S7, S8 to S11 are not performed and the treatment is continued. When it is determined in S8 that the venous pressure is not equal to or lower than the reference point, the determination unit 28 determines that the detection value of the first detection unit is not appropriate, and proceeds to S9, where the notification unit 29 gives a predetermined notification (first (notification that the detection value of the detection unit is not appropriate or a suggestion thereof).

After that, a correction process is performed in S11 to correct the calibration curve D obtained in the initial calibration to obtain a corrected calibration curve E, and in the subsequent dialysis treatment, the corrected calibration curve E is used. will be Further, when it is determined in S8 that the venous pressure is equal to or lower than the reference point, the determination unit 28 determines that the detection value of the first detection unit is appropriate, and the process proceeds to S10, where the notification unit 29 gives a predetermined notification. (Alert notification based on the detection value of the first detection unit) is performed. It should be noted that when the notification in S10 is performed, the treatment is continued after the cause of the notification is removed (for example, the crookedness of the blood circuit is eliminated). After the cause of the notification is removed, the venous pressure reference point may be reset.

Then, after the correction processing of S11 or the notification of S10 is performed, the process proceeds to S12, it is determined whether or not the dialysis treatment has ended, and if it is determined that the dialysis treatment has not ended, the process returns to S5, Monitoring of the flow rate or withdrawal blood pressure using the corrected calibration curve E continues. On the other hand, when it is determined in S12 that the dialysis treatment has ended, the blood returning step S13 (the step of returning the blood in the blood circuit to the patient's body) is followed by the draining step S14 of draining the dialyzer 3. , the series of controls ends. Through the series of steps described above, in dialysis treatment (blood purification treatment), the flow ratio or blood pressure withdrawal can be detected in real time during dialysis treatment, and the flow ratio or blood removal state can be monitored.

Next, experimental results of the blood purification apparatus according to this embodiment will be described based on the graphs of FIGS. 16 and 17. FIG.
While setting the drive speed (liquid feeding amount) R1 of the blood pump 4 constant, the estimated blood flow R2 calculated by the load sensor 18 and the calculation unit 25, the venous pressure R3, and the dialysate pressure R4 were monitored. When the estimated blood flow R calculated by the sensor 18 and the calculation unit 25 is not appropriate, as shown in FIG. 16, the estimated blood flow R2 and the output voltage of the load sensor 18 decrease, while the venous pressure R3 and dialysate pressure R4 does not decrease and remains constant.

When the estimated blood flow R calculated by the load sensor 18 and the calculation unit 25 is appropriate, the venous pressure R3 increases as the estimated blood flow R2 and the output voltage of the load sensor 18 decrease, as shown in FIG. and the dialysate pressure R4 changes (decreases). Therefore, as the detection values (estimated blood flow and estimated withdrawal blood pressure) of the first detection unit (load sensor 18 and calculation unit 25) change beyond a predetermined threshold value, the second detection unit (in this experiment In this case, when the pressure detected by the venous pressure sensor 7 and the dialysate pressure sensor 20) changes, it can be determined that the detection value of the first detection unit is appropriate, and the detection value of the first detection unit When the pressure detected by the second detection unit does not change as the threshold of is exceeded, it can be determined that the detection value of the first detection unit is not appropriate.

Even when the inlet pressure sensor 8 is used as the second detection unit, the tendency similar to that of the venous pressure sensor 7 and the dialysate pressure sensor 20 is exhibited. When the pressure detected by the inlet pressure sensor 8 as the second detection unit changes as the detected value (estimated blood flow or estimated withdrawal blood pressure) changes beyond a predetermined threshold, the first detection If it can be determined that the detection value of the first detection unit is appropriate, and the pressure detected by the inlet pressure sensor 8 does not change as the detection value of the first detection unit changes by exceeding the predetermined threshold value, the first can be determined that the detection value of the detection unit is not appropriate.

According to this embodiment, when the detected value of the first detection unit changes by exceeding the predetermined threshold value, the change in pressure detected by the second detection unit is compared with the change in the pressure detected by the first detection unit. Therefore, it is possible to determine whether or not erroneous detection has occurred due to a decrease in the reaction force (repulsive force generated by elasticity) of the flexible tube at the detection position as the blood purification treatment progresses. When the detection value of the detection unit of (1) is changed, the response can be smoothly performed.

The blood pump 4 is a squeezing type pump that compresses the squeezing portion (tube 1a to be squeezed) of the blood circuit by squeezing portions (rollers 10) in the radial direction while squeezing it in the longitudinal direction. Since the detection unit detects a radial displacement at a detection position on the upstream side (the distal end side of the arterial blood circuit 1) from the part that is squeezed by the squeezing unit, the actual blood flow is insufficient with respect to the set blood flow, and the blood pressure is reduced. Shortage can be estimated with high accuracy.

Further, the blood circuit includes an arterial blood circuit 1 for removing blood from a patient and a venous blood circuit 2 for returning blood to the patient. An inlet pressure sensor 8 provided to detect the inlet pressure of the dialyzer 3, a venous pressure sensor 7 provided in the venous blood circuit 2 to detect the venous pressure, or a dialysate fluid pressure in the drainage discharge line L2. Since the dialysate pressure sensor 20 is composed of the dialysate pressure sensor 20, a sensor necessary for blood purification treatment can be diverted and used as the second detection unit.

Furthermore, when the pressure detected by the second detection unit changes as the detection value of the first detection unit changes by exceeding a predetermined threshold value, the determination unit 28 determines whether the pressure detected by the first detection unit When it is determined that the detected value is appropriate and the pressure detected by the second detector does not change as the detected value of the first detector changes beyond a predetermined threshold value, the first Since it is determined that the detection value of the detection unit is not appropriate, it is possible to accurately and quickly determine whether the detection value of the first detection unit is appropriate.

In addition, when the determination unit 28 determines that the detection value of the first detection unit is appropriate, an alarm is issued based on the detection value of the first detection unit, and the determination unit 28 performs the first detection. If the detection value of the first detection unit is determined to be inappropriate, the notification unit 29 is provided to notify that the detection value of the first detection unit is not appropriate or its suggestion. and suggestion can be reported, and a response can be made more quickly when the detection value of the first detection unit changes.

In addition, before the blood is extracorporeally circulated in the blood circuit to perform blood purification treatment, the first detection unit is initially calibrated to obtain a calibration curve D, and the detection value of the first detection unit is determined by the determination unit 28. If it is determined to be inappropriate, the calibration curve D obtained in the initial calibration is corrected, so detection by the first detection unit after the calibration curve D has been corrected can be performed with high accuracy. In particular, since the calibration curve D is corrected based on the detection value of the first detection unit when the driving amount of the blood pump 4 is reduced or stopped, excessive negative pressure is not generated in the blood circuit during blood purification treatment. You can avoid getting lost.

The blood pump 4 is provided with gripping portions (upstream gripping portion 12 and downstream gripping portion 13) for gripping the tube 1a to be ironed attached to the blood pump 4, and as a first detection portion, Since the load sensor 18 can detect the radial displacement of the portion gripped by the upstream gripping portion 12, the tube to be ironed 1a is attached to the blood pump 4 and gripped by the upstream gripping portion 12. As a result, the tube to be ironed 1a is attached to the detection device, and the work burden on medical personnel and the like can be reduced.

Further, the upstream gripping portion 12 has a gripping piece 14 that can press and grip the tube 1a to be ironed in the radial direction, and a torsion spring 15 that biases the gripping piece 14 toward the tube 1a to be ironed, A load sensor 18 as a first detection unit detects the load applied to the fixed end 15a side of the torsion spring 15, and detects radial displacement of the tube 1a to be ironed based on the detected load. Therefore, the torsion spring 15 in the blood pump 4 can have both the function of generating a gripping force on the tube 1a to be ironed and the function of detecting the pressure in the arterial blood circuit 1. FIG.

Although the present embodiment has been described above, the present invention is not limited to these, and for example, the blood pump 4 shown in FIGS. 18 and 19 may be used. As shown in the figure, the blood pump 4 includes a stator 8, a rotor 9 rotatable within the stator 8, rollers 10 formed on the rotor 9, a pair of upper and lower guide pins 11, and an upstream It is mainly composed of a side grip portion 12, a downstream grip portion 13, and a pressure transducer 30 as a first detection portion.

The upstream gripping portion 12 is for gripping the upstream side of the tube to be ironed 1a attached to the mounting recess Ga of the stator 8 of the blood pump 4 (the portion to which the distal end side of the arterial blood circuit 1 is connected). As shown in FIG. 19, it has gripping pieces 14 that can press and grip the tube 1a to be ironed in the radial direction, and a torsion spring 15 that biases the gripping pieces 14 toward the tube 1a to be ironed.

The pressure transducer 30 constituting the first detection section is capable of detecting the radial displacement of the portion of the tube to be ironed 1a gripped by the upstream side gripping section 12. is disposed at a portion facing the gripping piece 14 with the gripping piece 14 therebetween, detects the pressure applied to the side surface of the tube to be ironed 1a pressed by the gripping piece 14, and detects the pressure applied to the tube to be ironed 1a based on the detected pressure It is intended to detect radial displacement of 1a.

That is, when blood is collected from a patient and made to flow through the arterial blood circuit 1, if a negative pressure is generated between the tip of the arterial blood circuit 1 and the blood pump 4, the fluid pressure in the tube 1a to be ironed will increase. decreases, and the portion of the tube to be ironed 1a gripped by the upstream gripping portion 12 tends to be displaced in the radial direction (deforms flat and the diameter on the short axis side tends to decrease), so the pressure transducer 30 will decrease the pressure detected by By detecting such a pressure drop, it is possible to detect that the arterial blood circuit 1 has a negative pressure.

The pressure transducer 30 according to the present embodiment is electrically connected to the calculator 25 by extending wiring or the like, as in the previous embodiment. The calculation unit 25 constitutes a first detection unit together with the calculation unit 25, and is composed of, for example, a microcomputer or the like arranged in the dialysis apparatus main body. It is configured to be able to calculate the pressure and flow ratio of the arterial blood circuit 1 (liquid flow path) based on the displacement.

The pressure transducer 30 and the calculator 25 are configured to be calibrated by the calibration curve D acquired by the calibration curve generator 27 . Note that instead of the load sensor 18 and the pressure transducer 30 attached to the blood pump 4, sensors of other forms may be used, and sensors attached to a position separate from the blood pump 4 may be used.

Further, the second detection unit is not limited to the venous pressure sensor 7, the inlet pressure sensor 8, and the dialysate pressure sensor 20, and the detection value changes according to the change in the detection value of the first detection unit. Other pressure sensors may be used. It is sufficient that the second detection section detects the flow rate or pressure of either the liquid downstream of the detection position in the blood circuit or the dialysate in the piping section. Furthermore, it can be applied to other types of blood circuits (including blood purifiers of other types in place of the dialyzer 3) and dialysis apparatus main bodies (including those of a chamber type in place of the dual pump 21). can.

As long as it has the same meaning as the present invention, it can be applied to a device having a different external shape or a device to which other functions are added.

1 Arterial blood circuit (liquid flow path)
1a Tube to be ironed (part to be ironed)
2 Venous blood circuit 3 Dialyzer (blood purifier)
4 blood pump 5 arterial side air trap chamber 6 venous side air trap chamber 7 venous pressure sensor 8 inlet pressure sensor 9 rotor 10 roller (squeezing part)
11 guide pin 12 upstream gripping portion 13 downstream gripping portion 14 gripping piece 15 torsion spring 16 gripping piece 17 torsion spring 18 load sensor (first detection portion)
19 Sampling port 20 Dialysate pressure sensor 21 Duplex pump 22 Water removal pump 23 Filtration filter 24 Filtration filter 25 Calculation unit (first detection unit)
26 control unit 27 calibration curve acquisition unit 28 determination unit 29 notification unit 30 pressure transducer L1 dialysate introduction line (piping unit)
L2 drainage line (piping part)
L3 Dialysate supply line L4 Overflow line L5-L8 Bypass line G Stator Ga Mounting recess V1-V9 Solenoid valve D Calibration curve (at initial calibration)
E calibration curve (after correction)

Claims (8)

A blood purification device for extracorporeally circulating a patient's blood through a blood purifier and a blood circuit to purify the blood,
a blood pump for sending blood in the blood circuit;
a piping section having a dialysate introduction line for introducing dialysate into the blood purifier and a drainage discharge line for discharging drainage from the blood purifier;
a first detection unit disposed at a predetermined detection position in the blood circuit and detecting the flow rate or pressure of the liquid;
a second detection unit that detects the flow rate or pressure of either the fluid downstream of the detection position in the blood circuit or the dialysate in the piping unit;
A judgment unit for judging whether the detection value of the first detection unit is appropriate based on a change in flow rate or pressure detected by the second detection unit when the detection value of the first detection unit reaches a predetermined threshold value. When,
A blood purification device comprising: The blood pump is a squeezing type pump that radially compresses the squeezing portion of the blood circuit by the squeezing portion while squeezing it in the longitudinal direction to feed the liquid,
A grasping piece configured to be able to swing about a predetermined axis and grasping the portion to be ironed at one end thereof is provided, and the first detecting portion has a load sensor that receives a load from the other end of the grasping piece. and the load sensor senses a load applied by the gripping piece swinging according to the radial displacement of the portion to be worked-out at the detection position upstream in the liquid feeding direction of the blood circuit from the portion to be worked-out by the squeezing portion. 2. The blood purification device according to claim 1, wherein is detected. The blood circuit includes an arterial blood circuit for withdrawing blood from a patient and a venous blood circuit for returning blood to the patient, and the second detector is disposed in the arterial blood circuit. an inlet pressure sensor that detects the inlet pressure of the blood purifier, a venous pressure sensor that is arranged in the venous blood circuit and detects the venous pressure, or a dialyzer that detects the fluid pressure of the dialysate in the drainage discharge line 3. A blood purification apparatus according to claim 1, comprising a fluid pressure sensor. When the pressure detected by the second detection unit changes as the detection value of the first detection unit reaches a predetermined threshold value, the judgment unit determines that the detection value of the first detection unit is appropriate. and when the pressure detected by the second detection unit does not change as the detection value of the first detection unit reaches a predetermined threshold value, the detection value of the first detection unit 4. The blood purification apparatus according to any one of claims 1 to 3, wherein the blood purifying apparatus is determined to be inappropriate. When the determination unit determines that the detection value of the first detection unit is appropriate, an alarm is issued based on the detection value of the first detection unit, and the determination unit determines the detection value of the first detection unit. 5. The blood purification according to any one of claims 1 to 4, further comprising a notification unit that notifies that the detection value of the first detection unit is not appropriate or suggests that the detection value of the first detection unit is not appropriate. Device. The blood purification apparatus according to any one of claims 1 to 5, wherein the detection value of the first detection unit is corrected when the determination unit determines that the detection value of the first detection unit is inappropriate. Before blood purification treatment is performed by extracorporeally circulating blood in the blood circuit, the first detection unit is initially calibrated to obtain a calibration curve, and the determination unit determines whether the detection value of the first detection unit is 7. The blood purification apparatus according to claim 6, wherein, when it is determined that the value is not appropriate, the detection value of the first detection unit is corrected by correcting the calibration curve obtained by the initial calibration. 8. The blood purification apparatus according to claim 7, wherein the calibration curve is corrected based on the detection value of the first detection section when the driving amount of the blood pump is reduced or stopped.

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