JP7569212B2 - Blood Purification Device - Google Patents

Description

The present invention relates to a blood purification device that detects recirculated blood, which is blood that has been returned to the patient from the venous blood circuit and is then guided back into the arterial blood circuit.

In general, in blood purification therapy, such as hemodialysis, the patient's blood is circulated extracorporeally in a blood circuit, and blood purification is performed by a dialyzer. However, when, for example, an arterial puncture needle and a venous puncture needle are inserted into a patient's shunt (a site where an artery and a vein are connected by a surgical operation) to perform extracorporeal circulation, recirculated blood may occur in which blood that has been purified and returned to the patient's body through the venous puncture needle is introduced back into the blood circuit through the arterial puncture needle without passing through the patient's organs, etc. If such recirculated blood occurs, the purified blood will be further circulated extracorporeally, and the amount of blood that needs to be purified circulating extracorporeally will decrease accordingly, resulting in a problem of reduced blood purification efficiency.

To detect such recirculated blood, as disclosed in Patent Document 1, for example, a blood purification device has been proposed that includes a peak providing unit that can provide a specific peak to the concentration change of blood circulating extracorporeally through a blood circuit, a detection unit that is attached to the blood circuit and detects the specific peak provided by the peak providing unit, and a recirculation detection unit that detects recirculated blood that is blood returned to the patient from the venous blood circuit and then guided back into the arterial blood circuit based on the specific peak detected by the detection unit.

JP 2009-45307 A

However, in the above-mentioned conventional blood purification apparatus, the blood is concentrated solely by removing water to give a specific peak, which causes the following problems.
The amount of water removal required to give a unique peak is not reflected in the integrated water removal value in blood purification treatment, which may cause a water removal error, and therefore there is a problem that the number of times a unique peak can be given is limited. Also, in order to accurately detect recirculated blood by the recirculation detection unit, it is necessary to increase the size of the unique peak given by the peak giving unit, but there is a limit to the giving of a unique peak by water removal.

The present invention was made in consideration of these circumstances, and aims to provide a blood purification device that can suppress water removal errors in blood purification treatment, can provide a large-sized characteristic peak, and can detect recirculating blood with greater accuracy.

The present invention relates to a blood circuit having an arterial blood circuit and a venous blood circuit, and for circulating a patient's blood extracorporeally, a blood purification unit connected to the blood circuit and for purifying the blood flowing through the blood circuit, a dialysate inlet line connected to the blood purification unit and for introducing dialysate into the blood purification unit, a dialysate outlet line connected to the blood purification unit and for discharging dialysate from the blood purification unit, a peak imparting unit capable of imparting a peak specific to the concentration change of blood circulating extracorporeally through the blood circuit, a detection unit attached to the blood circuit and detecting the specific peak imparted by the peak imparting unit, and a peak detected by the detection unit. and a recirculation detection unit that detects recirculated blood, which is blood returned from the venous blood circuit to a patient and is introduced back into the arterial blood circuit based on a characteristic peak obtained by the peak providing unit, wherein the peak providing unit has a concentrated side peak providing unit that provides a characteristic concentrated side peak for concentrating blood circulating extracorporeally in the blood circuit and providing a characteristic dilute side peak for diluting blood circulating extracorporeally in the blood circuit and providing a characteristic dilute side peak, and the recirculation detection unit detects recirculated blood based on a characteristic peak including both the concentrated side peak and the dilute side peak.

According to the present invention, the peak imparting section has a concentrating side peak imparting section which concentrates the blood circulating extracorporeally in the blood circuit to impart a unique concentrated side peak, and a diluting side peak imparting section which dilutes the blood circulating extracorporeally in the blood circuit to impart a unique diluting side peak, and the recirculation detection section detects the recirculating blood based on a unique peak including both the concentrated side peak and the diluting side peak, so that it is possible to suppress water removal errors in blood purification treatment and to impart a large-sized unique peak, thereby enabling more accurate detection of the recirculating blood.

FIG. 1 is a schematic diagram showing a blood purification device according to a first embodiment of the present invention. A graph showing the characteristic peaks detected by the detection unit of the blood purification device. A graph showing characteristic peaks (with symbols added for calculation purposes) detected by the detection unit of the blood purification device. FIG. 1 is a schematic diagram showing a method for detecting recirculated blood in the recirculation detection unit using a characteristic peak detected in the detection unit of the blood purification device. FIG. 1 is a schematic diagram showing a method for detecting recirculated blood in the recirculation detection unit using a characteristic peak detected in the detection unit of the blood purification device. FIG. 1 is a schematic diagram showing a blood purification device according to a second embodiment of the present invention. FIG. 13 is a schematic diagram showing a blood purification device according to a third embodiment of the present invention. FIG. 13 is a schematic diagram showing a blood purification device according to a fourth embodiment of the present invention. Graph showing characteristic peaks detected by a detection unit of a blood purification device according to another embodiment of the present invention. Graph showing characteristic peaks (with symbols added for calculation) detected by the detection unit of the blood purification device according to the second embodiment

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
The blood purification device according to this embodiment purifies the patient's blood while circulating it extracorporeally, and is applied to a hemodialysis device used in hemodialysis treatment. As shown in Fig. 1, the hemodialysis device is mainly composed of a blood circuit 1 connected to a dialyzer 2 as a blood purification unit, and a dialysis device main body 6 that supplies dialysis fluid to the dialyzer 2 while removing water from the dialyzer 2, and also has a peak providing unit (a peak providing unit on the concentration side and a peak providing unit on the dilution side), a detection unit (a first detection unit 5a, a second detection unit 5b), a recirculation detection unit 16, etc.

As shown in the figure, the blood circuit 1 is mainly composed of an arterial blood circuit 1a and a venous blood circuit 1b made of flexible tubes, and a dialyzer 2 is connected between the arterial blood circuit 1a and the venous blood circuit 1b. The arterial blood circuit 1a has an arterial puncture needle a connected to its tip, and a peristaltic blood pump 3, an air trap chamber 4a for removing bubbles, and a first detection unit 5a disposed in the middle. On the other hand, the venous blood circuit 1b has a venous puncture needle b connected to its tip, and a second detection unit 5b and an air trap chamber 4b for removing bubbles are connected in the middle.

When the blood pump 3 is driven with the arterial puncture needle a and the venous puncture needle b inserted into the patient, the patient's blood flows through the arterial blood circuit 1a while being defoamed in the air trap chamber 4a, reaches the dialyzer 2, is purified by the dialyzer 2, and then flows through the venous blood circuit 1b while being defoamed in the air trap chamber 4b, and returns to the patient's body. As a result, the patient's blood is purified by the dialyzer 2 while circulating extracorporeally through the blood circuit 1.

The dialyzer 2 has a blood inlet port 2a, a blood outlet port 2b, a dialysate inlet port 2c, and a dialysate outlet port 2d formed in its housing, of which the base end of the arterial blood circuit 1a is connected to the blood inlet port 2a, and the base end of the venous blood circuit 1b is connected to the blood outlet port 2b. The dialysate inlet port 2c and the dialysate outlet port 2d are
The dialyzer 2 is connected to a dialysate inlet line 7 for introducing dialysate into the dialyzer 2 and a dialysate outlet line 8 for discharging dialysate (wastewater) from the dialyzer 2.

The dialyzer 2 contains multiple hollow fibers, the inside of which serves as a blood flow path, and the space between the outer peripheral surface of the hollow fibers and the inner peripheral surface of the housing serves as a dialysis fluid flow path. The hollow fibers have many tiny holes (pores) that penetrate the outer peripheral surface and the inner peripheral surface to form a hollow fiber membrane, and are configured so that impurities in the blood can pass through the hollow fiber membrane into the dialysis fluid.

The dialysis device main body 6 is composed of a duplex pump C, a bypass line 9 connected to the dialysis fluid discharge line 8, bypassing the drainage side Cb of the duplex pump C, a water removal pump 10 connected to the bypass line 9, a pressure pump 11 that drives the dialysis fluid from the dialyzer 2 to the drainage side Cb of the duplex pump C, a bubble separation chamber 12, an atmospheric release line 13, and a solenoid valve 14.

The duplex pump C is disposed across the dialysis fluid inlet line 7 and the dialysis fluid outlet line 8, and is used to introduce dialysis fluid from the dialysis fluid inlet line 7 to the dialyzer 2 and to discharge the dialysis fluid introduced into the dialyzer 2 from the dialysis fluid outlet line 8. That is, the duplex pump C is a fixed-volume pump with the supply side Ca and the drain side Cb being approximately equal in volume, and the flow path of the dialysis fluid from the supply side Ca to the drain side Cb (specifically, the flow path downstream of the duplex pump C in the dialysis fluid inlet line 7, the flow path upstream of the duplex pump C in the dialysis fluid outlet line 8, and the dialysis fluid flow path of the dialyzer 2) is formed as a closed flow path (a flow path that is kept sealed) when the solenoid valve 14 is closed.

The pressurizing pump 11 is connected between the dialyzer 2 and the duplex pump C in the dialysis fluid discharge line 8, and is used to move the dialysis fluid from the dialyzer 2 to the duplex pump C. It is a non-volume type pump (pressure controlled type) such as a centrifugal type. The water removal pump 10, which will be described later, is also a non-volume type pump (pressure controlled type) such as a centrifugal type, like the pressurizing pump 11.

One end of the dialysis fluid introduction line 7 is connected to the dialysis fluid introduction port 2c of the dialyzer 2, and the other end is connected to a dialysis fluid supplying device (not shown) that prepares dialysis fluid of a predetermined concentration. One end of the dialysis fluid discharge line 8 is connected to the dialysis fluid outlet port 2d of the dialyzer 2, and the other end is connected to a drainage means (not shown). The dialysis fluid supplied from the dialysis fluid supplying device passes through the dialysis fluid introduction line 7 to the dialyzer 2, and then passes through the dialysis fluid discharge line 8 and the bypass line 9 to the drainage means.

The water removal pump 10 is used to remove water from the patient's blood flowing through the dialyzer 2. That is, when the water removal pump 10 is driven, the volume of liquid discharged from the dialysis fluid discharge line 8 becomes greater than the volume of dialysis fluid introduced from the dialysis fluid introduction line 7, because the dual pump C is a fixed volume type, and water is removed from the blood by the greater volume. Note that water may be removed from the patient's blood using means other than the water removal pump 10 (for example, a so-called balancing chamber, etc.).

The bubble separation chamber 12 is a so-called degassing chamber, and is of a predetermined capacity connected between the pressure pump 11 and the duplex pump C in the dialysis fluid discharge line 8, and is configured to capture bubbles in the dialysis fluid. The bypass line 9 described above is extended from this bubble separation chamber 12, and an atmospheric release line 13 is also extended from it. The tip of this atmospheric release line 13 is open to the atmosphere, and a solenoid valve 14 that can open and close the flow path is connected to it.

The solenoid valve 14 can be opened and closed to open or close the atmospheric release line 13. In the open state, the bubble separation chamber 12 is connected to the outside air, and in the closed state, the bubble separation chamber 12 is cut off from the outside air. Then, before or after dialysis treatment, by operating the solenoid valve 14 to open the atmospheric release line 13, the air bubbles trapped in the bubble separation chamber 12 can be released into the atmosphere.

The supply line La is connected to the dialysis fluid introduction line 7 according to this embodiment. The supply line La is a priming line that supplies dialysis fluid as a priming fluid to the blood circuit 1, and its base end is connected to a portion of the dialysis fluid introduction line 7 between the supply side Ca of the duplex pump C and the dialysis fluid introduction port 2c of the dialyzer 2, and its tip is connected to a portion of the arterial blood circuit 1a between the arterial puncture needle a and the blood pump 3.

A peristaltic pump 15 similar to the blood pump 3 is provided in the supply line La, and when the peristaltic pump 15 is driven, the dialysis fluid in the dialysis fluid introduction line 7 is supplied to the arterial blood circuit 1a, enabling priming. In this embodiment, the supply line La is configured as a priming line that supplies dialysis fluid as a priming fluid to the blood circuit 1, but it may also be configured as a replacement fluid line whose tip is connected to the air trap chamber 4a or air trap chamber 4b and supplies dialysis fluid as a replacement fluid to the blood circuit 1.

The blood purification device according to this embodiment has a peak imparting section that can impart a unique peak to the concentration change of blood circulating extracorporeally through the blood circuit 1, and this peak imparting section has a concentrating side peak imparting section that concentrates the blood circulating extracorporeally through the blood circuit 1 to impart a unique concentrating side peak, and a diluting side peak imparting section that dilutes the blood circulating extracorporeally through the blood circuit 1 to impart a unique diluting side peak. In particular, in this embodiment, the diluting side peak imparting section is made up of the supply line La and the peristaltic pump 15, and the concentrating side peak imparting section is made up of the duplex pump C.

The dilution peak imparting section is designed to impart a unique peak (dilution peak) to the blood flowing through the dialyzer 2 by driving the peristaltic pump 15 to introduce dialysis fluid from the dialysis fluid introduction line 7 to the arterial blood circuit 1a. In other words, when the peristaltic pump 15 is driven during dialysis treatment, dialysis fluid can be introduced from the dialysis fluid introduction line 7 to the arterial blood circuit 1a, and the blood circulating extracorporeally through the blood circuit 1 can be diluted in a short time.

This allows blood to be diluted in a short time, and makes it possible to give a peak (dilution side peak) that is specific to the change in blood concentration (hematocrit value). For example, as shown in FIG. 2, the dilution side peak giving unit can give a dilution side peak Q1, which is a specific peak, to the detection value α of the second detection unit 5b, and when recirculating blood is occurring, can give a dilution side peak Q2 corresponding to the dilution side peak Q1 to the detection value β of the first detection unit 5a. In this specification, "specific" refers to a variation pattern that can be distinguished from variations due to other factors such as pump fluctuations or patient movement.

The concentrated peak imparting section imparts a concentrated peak by the dialyzer 2 removing water from the blood (positively filtering the water in the blood) as the dialysis fluid is sent to the blood circuit 1 through the supply line La as described above. That is, in this embodiment, a closed system flow path is formed by the flow path downstream of the duplex pump C in the dialysis fluid introduction line 7, the flow path upstream of the duplex pump C in the dialysis fluid discharge line 8, and the dialyzer 2 (dialysis fluid flow path), and the dilution side peak Q1 is imparted by the dilution side peak imparting section by supplying the dialysis fluid of the closed system flow path to the blood circuit 1 (arterial blood circuit 1a). By continuously operating the duplex pump C, the flow rate balance in the closed system flow path (the flow rate balance between the supply side Ca and the drain side Cb in the duplex pump C) is made equal, and the dialyzer 2 removes water and imparts the concentrated peak P1.

As a result, the action of the duplex pump C, which is a fixed-volume pump with approximately equal volumes of supply side Ca and drain side Cb, allows blood to be naturally dehydrated in the dialyzer 2 as the dialysis fluid is sent to the blood circuit 1 via the supply line La, and a peak (concentrated side peak P1) specific to the change in blood concentration (hematocrit value) can be imparted. For example, as shown in FIG. 2, the concentrated side peak imparting unit can impart a concentrated side peak P1, which is a specific peak, to the detection value α of the second detection unit 5b, and when recirculating blood is occurring, can impart a concentrated side peak P2 corresponding to the concentrated side peak P1 to the detection value β of the first detection unit 5a.

In this embodiment, the dilution side peak Q1 is applied to the blood circulating extracorporeally through the blood circuit by the dilution side peak application unit, so that the concentrated side peak P1 is applied to the blood circulating extracorporeally through the blood circuit 1, and as shown in FIG. 2, the dilution side peak Q1 is applied following (continuously with) the concentrated side peak P1, which is a unique peak, in the detection value α of the second detection unit 5b. As a result, when recirculating blood occurs, as shown in the figure, the concentrated side peak P2 and the dilution side peak Q2 corresponding to the concentrated side peak P1 and the dilution side peak Q1 can be applied in the detection value β of the first detection unit 5a.

The first detector 5a and the second detector 5b are disposed in the arterial blood circuit 1a and the venous blood circuit 1b, respectively, to detect the concentration (specifically, the hematocrit value) of the blood flowing through these flow paths. These first detectors 5a and 5b are composed of a hematocrit sensor, which includes a light-emitting element such as an LED and a light-receiving element such as a photodiode, and detects the hematocrit value, which indicates the concentration of the patient's blood, by irradiating the blood with light from the light-emitting element and receiving the transmitted or reflected light with the light-receiving element.

Specifically, the hematocrit value, which indicates the blood concentration, is calculated based on the electrical signal output from the light-receiving element. That is, each component that makes up blood, such as red blood cells and plasma, has its own unique light absorption characteristics, and this property can be used to electro-optically quantify the red blood cells required to measure the hematocrit value, thereby determining the hematocrit value. More specifically, near-infrared light irradiated from the light-emitting element enters the blood, is affected by absorption and scattering, and is received by the light-receiving element. The light absorption and scattering rate is analyzed from the intensity of the received light, and the hematocrit value is calculated.

The first detector 5a configured as described above is disposed in the arterial blood circuit 1a and detects the hematocrit value of blood collected from the patient through the arterial puncture needle a during dialysis treatment, while the second detector 5b is disposed in the venous blood circuit 1b and detects the hematocrit value of blood that has been purified or dehydrated by the dialyzer 2 and returned to the patient.

As a result, the concentrated peak imparted by opening the solenoid valve 14 is first detected as concentrated peak P1 at the detection value α of the second detection unit 5b, as shown in FIG. 2, and then, when the blood reaches the arterial blood circuit 1a again and is recirculated, the concentrated peak remaining in the recirculated blood can be detected as concentrated peak P2 at the detection value β of the first detection unit 5a.

Furthermore, in this embodiment, the dilution side peak given by driving the peristaltic pump 15 is first detected as dilution side peak Q1 at the detection value α of the second detection unit 5b, as shown in FIG. 2, and then, when the blood reaches the arterial blood circuit 1a again and is recirculated, the dilution side peak remaining in the recirculated blood can be detected as dilution side peak Q2 at the detection value β of the first detection unit 5a.

The recirculation detection unit 16 is composed of, for example, a microcomputer or the like arranged in the dialysis device main body 6, and detects recirculated blood, which is blood returned to the patient from the venous blood circuit 1b and then guided back to the arterial blood circuit 1a based on the characteristic peaks detected by the first detection unit 5a and the second detection unit 5b. In this embodiment, it is configured to detect recirculated blood based on the characteristic peaks including the concentrated side peak and the diluted side peak.

Specifically, as shown in FIG. 3, in the detection value α of the second detection unit 5b, a straight line is drawn between the concentrated peak P1 that first appears at time t1 and the concentrated peak P3 that appears at time t3 after passing the concentrated peak P1 and the dilute peak Q1, and the area S1 is calculated. To calculate the area S1, as shown in FIG. 4, the area S1a (see FIG. 4(a)) of the trapezoid formed by the concentrated peak P1 at time t1 and the concentrated peak P3 at time t3 is calculated, and the area S1b (see FIG. 4(b)) of the waveform by the detection value α including the dilute peak Q1 is calculated. Then, the area S1 shown in FIG. 4(c) can be calculated by subtracting the area S1b from the area S1a.

On the other hand, when blood recirculation is present, as shown in FIG. 3, a straight line is drawn between the concentrated peak P2 that first appears at time t2 in the detection value β of the first detection unit 5a and the concentrated peak P4 that appears at time t4 after passing the concentrated peak P2 and the dilute peak Q2, and the area S2 is calculated. To calculate the area S2, as shown in FIG. 5, the area S2a (see FIG. 5(a)) of the trapezoid formed by the concentrated peak P2 at time t2 and the concentrated peak P4 at time t4 is calculated, and the area S2b (see FIG. 5(b)) of the waveform due to the detection value β including the dilute peak Q2 is calculated. The area S2 shown in FIG. 5(c) can then be calculated by subtracting the area S2b from the area S2a.

In this way, by predicting the time t1 for blood to reach the second detection unit 5b and the time t2 for blood to be recirculated and reach the first detection unit 5a, it is possible to distinguish between cardiopulmonary recirculation (a phenomenon in which purified blood passes only through the heart and lungs and is drawn out of the body without passing through other tissues or organs) and recirculation, which is the subject of measurement. Alternatively, instead of this method, the recirculation detection unit 16 may detect when the hematocrit values detected by the first detection unit 5a and the second detection unit 5b exceed a predetermined value, and the hematocrit values that exceed this value may be compared.

The proportion of recirculated blood (recirculation rate) can be calculated by substituting the area S1 formed by the detection value α of the second detection unit 5b and the area S2 formed by the detection value β of the first detection unit 5a into the following calculation formula (1). This allows medical personnel to recognize not only the presence or absence of blood recirculation, but also the proportion, which can be used as a reference for subsequent treatment (such as reinserting the puncture needle to suppress blood recirculation or re-forming the shunt).
Rrec (%)=S2/S1×100... Arithmetic formula (1)

Next, a second embodiment of the present invention will be described.
The blood purification device according to this embodiment, like the first embodiment, purifies the patient's blood while circulating it extracorporeally, and is applied to a hemodialysis device used in hemodialysis treatment. As shown in Fig. 6, this hemodialysis device is mainly composed of a blood circuit 1 connected to a dialyzer 2 as a blood purification unit, and a dialysis device main body 6 that supplies dialysis fluid to the dialyzer 2 while removing water from the dialyzer 2, and also has a peak providing unit (a concentration-side peak providing unit and a dilution-side peak providing unit), detection units (a first detection unit 5a, a second detection unit 5b), a recirculation detection unit 16, etc.

Here, in the blood purification device according to this embodiment, the concentration side peak imparting section is composed of an air release line 13 and an electromagnetic valve 14, and the dilution side peak imparting section is composed of a water removal pump 10. Note that the same components are given the same reference numerals, and detailed descriptions thereof will be omitted.

The concentrated peak imparting section is designed to impart a unique peak (concentrated peak) to the blood flowing through the dialyzer 2 by operating the solenoid valve 14 to open the atmospheric vent line 13 for a short period of time. That is, when the solenoid valve 14 is operated to open the atmospheric vent line 13, which is closed, during dialysis treatment, the outlet pressure of the pressure pump 11 becomes approximately equal to atmospheric pressure, and a momentary high negative pressure is generated upstream of the pressure pump 11, causing rapid and short-term dehydration (blood concentration) of the blood flowing through the dialyzer 2 (blood flow path).

This allows the blood to be dewatered in a short time with a pressure much greater than the ultrafiltration pressure generated by driving the water removal pump 10, and makes it possible to give a peak (concentrated side peak) specific to the change in blood concentration (hematocrit value). For example, as shown in FIG. 2, the concentrated side peak giving section can give a concentrated side peak P1, which is a specific peak, to the detection value α of the second detection section 5b, and when recirculating blood is occurring, can give a concentrated side peak P2 corresponding to the concentrated side peak P1 to the detection value β of the first detection section 5a.

The dilution side peak imparting section in this embodiment is composed of a water removal pump 10, and as shown in FIG. 6, the water removal pump 10 is driven in reverse to supply the dialysis fluid in the dialysis fluid discharge line 8 to the dialyzer 2, and the dialysis fluid is back-filtered from the dialysis fluid flow path to the blood flow path (filtering water from the blood flowing through the blood flow path in the dialyzer 1 into the dialysis fluid flow path via the hollow fiber membrane), thereby diluting the blood flowing through the dialyzer 2 for a short period of time and imparting a unique peak (dilution side peak Q1).

According to this embodiment, the concentrated peak imparting section imparts concentrated peak P1 to the blood circulating extracorporeally through the blood circuit, and then the dilute peak imparting section performs back filtration to impart dilute peak Q1 to the blood circulating extracorporeally through the blood circuit 1. As a result, as shown in FIG. 2, in the detection value α of the second detection section 5b, the dilute peak Q1 is imparted consecutively to the concentrated peak P1, which is a unique peak. As a result, in the case where recirculated blood is occurring, concentrated peak P2 and dilute peak Q2 corresponding to concentrated peak P1 and dilute peak Q1 can be imparted in the detection value β of the first detection section 5a, as shown in the same figure.

Therefore, according to this embodiment, as in the first embodiment, concentrated side peak P1 and diluted side peak Q1 are given in the detection value α of the second detection unit 5b, and when recirculated blood is present, concentrated side peak P2 and diluted side peak Q2 corresponding to concentrated side peak P1 and diluted side peak Q1 can be given in the detection value β of the first detection unit 5a. Therefore, recirculated blood can be detected by the recirculation detection unit 16 based on the area S1 formed by the detection value α of the second detection unit 5b and the area S2 formed by the detection value β of the first detection unit 5a.

Next, a third embodiment of the present invention will be described.
The blood purification device according to this embodiment, like the first embodiment, purifies the patient's blood while circulating it extracorporeally, and is applied to a hemodialysis device used in hemodialysis treatment. As shown in Fig. 7, this hemodialysis device is mainly composed of a blood circuit 1 connected to a dialyzer 2 as a blood purification unit, and a dialysis device main body 6 that supplies dialysis fluid to the dialyzer 2 while removing water from the dialyzer 2, and also has a peak providing unit (a concentration-side peak providing unit and a dilution-side peak providing unit), detection units (a first detection unit 5a and a second detection unit 5b), a recirculation detection unit 16, etc.

Here, in the blood purification device according to this embodiment, the concentration side peak imparting section is composed of an air release line 13 and an electromagnetic valve 14, and the dilution side peak imparting section is composed of a storage section B and an introduction line Lb. Note that the same components are given the same reference numerals, and detailed descriptions thereof will be omitted.

In this embodiment, the concentrated peak imparting section is composed of an air release line 13 and an electromagnetic valve 14, as in the second embodiment, and the dilute peak imparting section is composed of a storage section B that contains a liquid such as physiological saline solution, and an introduction line Lb that extends from storage section B and is connected to the arterial blood circuit 1a. A predetermined volume of priming liquid (liquid) such as physiological saline solution is contained in storage section B.

Specifically, as shown in FIG. 7, the dilution side peak imparting section according to this embodiment has a storage section B that contains physiological saline solution (or other liquids) and an introduction line Lb that connects storage section B to the blood circuit 1. By supplying the physiological saline solution or the like in storage section B to the blood circuit 1 via the introduction line Lb, the blood flowing through the dialyzer 2 is diluted for a short period of time to impart a unique peak (dilution side peak Q1).

According to this embodiment, the concentrated peak imparting section imparts concentrated peak P1 to the blood circulating extracorporeally through the blood circuit 1, and then the dilute peak imparting section supplies the liquid in the storage section B to impart dilute peak Q1 to the blood circulating extracorporeally through the blood circuit 1. As a result, as shown in FIG. 2, in the detection value α of the second detection section 5b, the dilute peak Q1 is imparted consecutively to the concentrated peak P1, which is a unique peak. As a result, in the case where recirculated blood is occurring, concentrated peak P2 and dilute peak Q2 corresponding to concentrated peak P1 and dilute peak Q1 can be imparted in the detection value β of the first detection section 5a, as shown in the same figure.

Therefore, according to this embodiment, as in the first embodiment, concentrated side peak P1 and diluted side peak Q1 are given in the detection value α of the second detection unit 5b, and when recirculated blood is present, concentrated side peak P2 and diluted side peak Q2 corresponding to concentrated side peak P1 and diluted side peak Q1 can be given in the detection value β of the first detection unit 5a. Therefore, recirculated blood can be detected by the recirculation detection unit 16 based on the area S1 formed by the detection value α of the second detection unit 5b and the area S2 formed by the detection value β of the first detection unit 5a.

Next, a fourth embodiment of the present invention will be described.
The blood purification device according to this embodiment, like the first embodiment, purifies the patient's blood while circulating it extracorporeally, and is applied to a hemodialysis device used in hemodialysis treatment. As shown in Fig. 8, the hemodialysis device is mainly composed of a blood circuit 1 connected to a dialyzer 2 as a blood purification unit, and a dialysis device main body 6 that removes water while supplying dialysis fluid to the dialyzer 2, and also has a peak providing unit (concentration side peak providing unit and dilution side peak providing unit), a detection unit (first detection unit 5a, second detection unit 5b), a recirculation detection unit 16, etc. The same components are denoted by the same reference numerals, and detailed description thereof will be omitted.

In this embodiment, the concentrated side peak imparting section is composed of an air vent line 13 and an electromagnetic valve 14, as in the second and third embodiments, and the dilution side peak imparting section is composed of a bypass line 16 connected to the dialysis fluid introduction line 7 by bypassing the supply side Ca of the duplex pump C, and a supply pump 17 connected to the bypass line 16. Specifically, the dilution side peak imparting section according to this embodiment is composed of the bypass line 16 and the supply pump 17, and as shown in FIG. 8, the supply pump 17 is driven to supply the dialysis fluid in the dialysis fluid introduction line 7 to the dialyzer 2, and the dialysis fluid is back-filtered from the dialysis fluid flow path to the blood flow path, thereby diluting the blood flowing through the dialyzer 2 for a short time to impart a unique peak (dilution side peak).

The concentrated side peak imparting unit imparts a concentrated side peak to the blood circulating extracorporeally through the blood circuit, and then the dilute side peak imparting unit imparts a dilute side peak to the blood circulating extracorporeally through the blood circuit. As shown in FIG. 2, in the detection value α of the second detection unit 5b, the dilute side peak Q1 is imparted consecutively to the concentrated side peak P1, which is a unique peak. As a result, in the case where recirculated blood is occurring, as shown in the figure, in the detection value β of the first detection unit 5a, the concentrated side peak P2 and the dilute side peak Q2 corresponding to the concentrated side peak P1 and the dilute side peak Q1 can be imparted.

Therefore, according to this embodiment, as in the first embodiment, concentrated side peak P1 and diluted side peak Q1 are given in the detection value α of the second detection unit 5b, and when recirculated blood is present, concentrated side peak P2 and diluted side peak Q2 corresponding to concentrated side peak P1 and diluted side peak Q1 can be given in the detection value β of the first detection unit 5a. Therefore, recirculated blood can be detected by the recirculation detection unit 16 based on the area S1 formed by the detection value α of the second detection unit 5b and the area S2 formed by the detection value β of the first detection unit 5a.

According to the first to fourth embodiments of the present invention, the peak imparting unit has a concentrating side peak imparting unit that concentrates the blood circulating extracorporeally in the blood circuit 1 to impart a specific concentrated side peak P1, and a diluting side peak imparting unit that dilutes the blood circulating extracorporeally in the blood circuit 1 to impart a specific diluting side peak Q1, and the recirculation detection unit 16 detects the recirculating blood based on a specific peak including the concentrated side peak P1 and the diluting side peak Q1, so that it is possible to suppress water removal errors in blood purification treatment, and it is possible to impart a large-sized specific peak, improving the signal-to-noise ratio and more accurately detecting the recirculating blood.

In particular, according to the first embodiment of the present invention, a duplex pump C is provided that is disposed across the dialysis fluid inlet line 7 and the dialysis fluid outlet line 8 and introduces and discharges dialysis fluid to and from the dialyzer 2, and a closed system flow path is formed by the flow path downstream of the duplex pump C in the dialysis fluid inlet line 7, the flow path upstream of the duplex pump C in the dialysis fluid outlet line 8, and the dialyzer 2 (dialysis fluid flow path). By supplying the dialysis fluid from the closed system flow path to the blood circuit 1, a concentrated peak P1 and a diluted peak Q1 are imparted, so that the concentrated peak P1 and the diluted peak Q1 can be naturally imparted so that the flow rate balance in the closed system flow path is equal.

According to the first embodiment of the present invention, the supply line La is provided to supply the dialysis fluid in the dialysis fluid introduction line 7 to the blood circuit 1, and the dilution side peak imparting section imparts the dilution side peak Q1 by supplying the dialysis fluid to the blood circuit 1 through the supply line La, and the concentration side peak imparting section imparts the concentration side peak P1 by the dialyzer 2 removing water from the blood as the dialysis fluid is sent to the blood circuit 1 through the supply line La. Therefore, the dialysis fluid in the dialysis fluid introduction line 7 can be reliably and smoothly supplied to the blood circuit 1 by the supply line La. However, since the supply line La is composed of a priming line that supplies the dialysis fluid as a priming fluid to the blood circuit 1, or a replacement fluid line that supplies the dialysis fluid as a replacement fluid to the blood circuit 1, the priming line or the replacement fluid line can be used as the dilution side peak imparting section.

In addition, according to the second and fourth embodiments of the present invention, the concentrated peak imparting section removes water from the blood in the dialyzer 2 to concentrate the blood and impart a concentrated peak P1, and the dilution peak imparting section dilutes the blood by back-filtering the dialysis fluid in the dialysis fluid inlet line 7 or the dialysis fluid outlet line 8 into the blood circuit 1 to impart a dilution peak Q1. This makes it possible to supply dialysis fluid to the blood circulating in the blood circuit 1 and impart a dilution peak without requiring separate flow paths such as a priming line or a replacement fluid line.

Furthermore, according to the third embodiment of the present invention, the concentration side peak imparting section removes water from the blood in the dialyzer 2 to concentrate the blood and impart the concentration side peak P1, and the dilution side peak imparting section dilutes the blood and imparts the dilution side peak Q1 by supplying the liquid in the storage section B connected to the blood circuit 1 to the blood circuit 1, so that the dilution side peak Q1 can be imparted by supplying the liquid in the storage section B to the blood circulating in the blood circuit 1 without requiring backfiltration.

Although the present embodiment has been described above, the present invention is not limited to this. For example, the dilution side peak imparting unit may impart a dilution side peak to the blood circulating extracorporeally through the blood circuit 1, and then the concentration side peak imparting unit may impart a concentration side peak to the blood circulating extracorporeally through the blood circuit 1. As shown in FIG. 9, the concentration side peak P1 may be imparted (continuously) following the dilution side peak Q1, which is a unique peak, in the detection value α of the second detection unit 5b. In this case, the dilution side peak Q1 is detected first in the detection value α, and then the concentration side peak P1 and the dilution side peak Q3 are detected in succession, and when there is recirculating blood, the dilution side peak Q2 corresponding to the dilution side peak Q1 is detected first in the detection value β, and then the concentration side peak P2 and the dilution side peak Q4 corresponding to the concentration side peak P1 and the dilution side peak Q3 are detected.

As a result, like the first to third embodiments, recirculated blood can be detected based on characteristic peaks including concentrated and diluted peaks, and as shown in FIG. 10, the proportion of recirculated blood (recirculation rate) can be calculated by substituting the area S1 formed by the detection value α of the second detection unit 5b and the area S2 formed by the detection value β of the first detection unit 5a into the above-mentioned calculation formula (1).

Furthermore, the concentrated side peak imparting section and the dilute side peak imparting section are not limited to those in the above embodiment, and may be other components that can impart concentrated side peaks and dilute side peaks. In addition, the detection section in this embodiment is made up of a hematocrit sensor, but may be other sensors that are attached to the blood circuit 1 and detect the unique peak imparted by the peak imparting section. In addition, the detection section in this embodiment has a first detection section 5a attached to the arterial blood circuit 1a and a second detection section 5b attached to the venous blood circuit 1b, but may be attached to either the arterial blood circuit 1a or the venous blood circuit 1b.

As long as the purpose is the same as that of the present invention, it can also be applied to products with different external shapes or products with added functions.

1 Blood circuit 1a Arterial blood circuit 1b Venous blood circuit 2 Dialyzer (blood purification section)
3 Blood pump 4a, 4b Air trap chamber 5a First detection section 5b Second detection section 6 Dialysis device body 7 Dialysis fluid inlet line 8 Dialysis fluid outlet line 9 Bypass line 10 Water removal pump 11 Pressurizing pump 12 Air bubble separating chamber 13 Atmospheric release line 14 Solenoid valve 15 Peristaltic pump 16 Recirculation detection section C Duplex pump La Supply line Lb Inlet line

Claims (7)

a blood circuit having an arterial blood circuit and a venous blood circuit, and for circulating the patient's blood extracorporeally;
a blood purification unit connected to the blood circuit and purifying the blood flowing through the blood circuit;
a dialysis fluid introduction line connected to the blood purification unit for introducing a dialysis fluid into the blood purification unit;
a dialysis fluid discharge line connected to the blood purification unit for discharging the dialysis fluid from the blood purification unit;
a peak imparting unit capable of imparting a peak specific to a concentration change of blood circulating extracorporeally through the blood circuit;
A detection unit that is attached to the blood circuit and detects the characteristic peak given by the peak giving unit;
a recirculation detection unit that detects recirculated blood, which is blood returned from the venous blood circuit to the patient and is guided back to the arterial blood circuit based on the characteristic peak detected by the detection unit;
A blood purification apparatus comprising:
The peak providing unit includes a concentrating side peak providing unit that provides a specific concentrated side peak by concentrating the blood circulating extracorporeally in the blood circuit, and a diluting side peak providing unit that dilutes the blood circulating extracorporeally in the blood circuit to provide a specific diluting side peak, and the recirculation detection unit detects recirculated blood based on a specific peak that includes both the concentrated side peak and the diluting side peak. The blood purification device according to claim 1, further comprising a duplex pump arranged across the dialysate inlet line and the dialysate outlet line to introduce and discharge dialysate to the blood purification unit, and a closed system flow path is formed by a flow path downstream of the duplex pump in the dialysate inlet line, a flow path upstream of the duplex pump in the dialysate outlet line, and the blood purification unit, and the concentrated peak and the diluted peak are provided by supplying the dialysate from the closed system flow path to the blood circuit. The blood purification device according to claim 2, further comprising a supply line for supplying the dialysis fluid from the dialysis fluid introduction line to the blood circuit, the dilution side peak providing unit providing the dilution side peak by supplying the dialysis fluid to the blood circuit via the supply line, and the concentration side peak providing unit providing the concentration side peak by removing water from the blood by the blood purification unit as the dialysis fluid is delivered to the blood circuit via the supply line. The blood purification device according to claim 3, wherein the supply line is a priming line that supplies dialysis fluid as a priming fluid to the blood circuit, or a replacement fluid line that supplies dialysis fluid as a replacement fluid to the blood circuit. The blood purification device according to claim 1, wherein the concentrated peak imparting section imparts the concentrated peak by removing water from the blood in the blood purification section, and the dilution peak imparting section supplies the dialysis fluid in the dialysis fluid inlet line or the dialysis fluid outlet line to the blood purification section and back-filters the blood in the blood circuit, thereby diluting the blood and imparting the dilution peak. The blood purification device according to claim 1, wherein the concentrated peak imparting section imparts the concentrated peak by removing water from the blood in the blood purification section, and the dilution peak imparting section imparts the dilution peak by supplying liquid from a storage section connected to the blood circuit to the blood circuit. The blood purification device according to any one of claims 1 to 6, wherein the detection unit is a hematocrit sensor that detects the hematocrit value of blood flowing through the blood circuit.

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