JP5276909B2 - Blood purification equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blood purification apparatus capable of easily and accurately detecting the completion of the blood removal. <P>SOLUTION: This blood purification apparatus is provided with: a computing means 9 that simultaneously introduces patient's blood from both of the tip of an artery-side blood circuit 1 and the tip of a vein-side blood circuit 2 to a dialyzer to replace it with priming liquid with the blood circuit and a blood pathway of the dialyzer 3 filled with priming liquid in a priming liquid filling process, performs the blood removal process for filtering the replaced liquid through a blood purification membrane of the dialyzer to the dialysis solution pathway side, and finds an ultrafiltration rate or a transmembrane pressure difference of the blood purification membrane in the dialyzer 3 with time in the blood removal process; and a monitoring means 10 that monitors a change rate of the transmembrane pressure difference or the ultrafiltration rate found with time by the computing means 9, detects that the change rate of the transmembrane pressure difference or the ultrafiltration rate becomes larger than a prescribed value and detects the completion of the blood removal process. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a blood purification apparatus for purifying a patient's blood while circulating it extracorporeally, such as dialysis treatment using a dialyzer.

  Generally, at the time of dialysis treatment, a blood circuit for circulating the collected patient's blood extracorporeally and returning it to the body is used. Such a blood circuit is, for example, a dialyzer (blood purification means) having a hollow fiber membrane. It is mainly composed of an arterial blood circuit and a venous blood circuit that can be connected to each other. An arterial puncture needle and a venous puncture needle are attached to the tips of the arterial blood circuit and the venous blood circuit, respectively, and are punctured by the patient to perform extracorporeal circulation of blood in dialysis treatment.

  Among these, the arterial blood circuit is provided with a squeezed blood pump, and by driving the blood pump, blood is sent from the patient's body to the dialyzer side, while the arterial blood circuit and the venous blood are supplied. An arterial drip chamber and a venous drip chamber are connected to the circuit so that blood is returned to the patient's body after defoaming.

  In addition, a priming solution supply line (saline solution line) for supplying physiological saline at the time of priming or blood return is provided upstream of the blood pump in the arterial blood circuit (that is, the arterial puncture needle side). It is connected via a T-shaped tube or the like, so that prior to dialysis treatment, priming can be performed by flowing and filling physiological saline (priming solution) into the blood circuit and components such as the drip chamber connected to the blood circuit. It is configured.

  However, the arterial puncture needle attached to the tip of the arterial blood circuit and the venous puncture needle attached to the tip of the venous blood circuit are punctured into the patient, and the blood circuit of the blood circuit and dialyzer are primed by priming. In the state filled with the priming liquid, the patient's blood is guided from both the arterial puncture needle and the vein puncture needle to the dialyzer at the same time to replace the priming liquid, and the substituted liquid is passed through the blood purification membrane of the dialyzer. Filtration to the dialysate flow path side is performed. Thereby, blood removal can be performed without introducing the priming solution into the patient's body.

In the conventional blood purification apparatus, at the time of blood removal as described above, for example, an ultrafiltration pump or the like is driven to filter the liquid in the blood channel to the dialysate channel side through the blood purification membrane. The priming volume (volume of the filled priming solution) of the dialyzer blood channel and blood circuit is stored in advance, and it is determined that the ultrafiltration pump or the like has been driven by the priming volume. It was known that the blood was finished (see, for example, Patent Document 1).
JP 2000-325470 A

  However, in the above-described conventional blood purification apparatus, the blood flow path of the dialyzer and the priming volume of the blood circuit are stored in advance, and the ultrafiltration pump or the like is driven by the priming volume, thereby removing the blood flow. Since he knew that the blood had ended, he had the following problems.

  That is, the type of dialyzer used and the components to be connected to the blood circuit differ depending on the characteristics of the patient and so on, so the blood flow path of the dialyzer and the priming volume of the blood circuit differ from patient to patient. . Thus, since the priming volumes are different, it is difficult to determine the end of the blood removal based on the priming volume.

  The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a blood purification apparatus capable of easily and accurately detecting the end of blood removal.

  The invention according to claim 1 is composed of an arterial blood circuit and a venous blood circuit, a blood circuit capable of extracorporeally circulating a patient's blood from the tip of the arterial blood circuit to the tip of the venous blood circuit, and the blood A blood flow path that is interposed between the arterial blood circuit and the venous blood circuit of the circuit to purify blood flowing through the blood circuit, and through which a patient's blood flows through a blood purification film for purifying the blood; Blood purification means having a dialysate flow path through which the dialysate flows, a blood pump disposed in the arterial blood circuit, and dialysate introduction connected to the dialysate flow path inlet and outlet of the blood purification means In a blood purification apparatus comprising a line and a dialysate discharge line, the priming liquid is supplied into the blood flow path of the blood circuit and the blood purification means in priming before treatment, and the blood circuit and A priming liquid filling step for filling in the liquid flow path, and in the state where the blood flow path of the blood circuit and the blood purification means is filled with the priming liquid in the priming liquid filling step, The patient's blood is guided from both of the distal ends of the venous side blood circuit to the blood purification means at the same time to replace the priming liquid, and the substituted liquid is transferred to the dialysate flow path side through the blood purification membrane of the blood purification means. A blood removal step for filtering, and a treatment step for purifying the patient's blood while circulating externally from the tip of the arterial blood circuit to the tip of the venous blood circuit via the blood purification means after the blood removal step. Calculation means for obtaining the ultrafiltration rate or transmembrane pressure difference of the blood purification membrane in the blood purification means over time in the course of the blood removal step; While monitoring the obtained transmembrane pressure difference or the rate of change of the ultrafiltration rate, detecting that the transmembrane pressure difference or the rate of change of the ultrafiltration rate is greater than a specified value, the blood removal step And monitoring means for detecting completion.

According to a second aspect of the present invention, in the blood purification apparatus according to the first aspect, a priming liquid side hydraulic pressure measuring means for measuring a hydraulic pressure in any part of the blood circuit, and the dialysate introduction line or dialysate discharge A dialysate-side fluid pressure measuring means for measuring the fluid pressure at any part of the line, and the calculating means includes a fluid pressure measured by the priming fluid-side fluid pressure measuring means and a dialysate-side fluid pressure. The transmembrane pressure difference or the ultrafiltration rate is obtained based on the hydraulic pressure measured by the measuring means.

  According to a third aspect of the present invention, in the blood purification apparatus according to the first or second aspect, an ultrafiltration pump is provided in the middle of the dialysate discharge line, and the blood removal step includes the ultrafiltration pump. Is driven at a constant speed so that the dialysate flow path side of the blood purification means has a negative pressure with respect to the blood flow path, and the blood pump is driven at a speed slower than the ultrafiltration pump. It is characterized by.

  According to a fourth aspect of the present invention, in the blood purification apparatus according to any one of the first to third aspects, the rate of change in the transmembrane pressure difference or the ultrafiltration rate is greater than a specified value in the monitoring means. When this is detected, the treatment process is automatically started.

  According to the invention of claim 1, while monitoring the transmembrane pressure difference or the rate of change of the ultrafiltration rate obtained over time, the transmembrane pressure difference or the rate of change of the ultrafiltration rate is greater than the specified value. Since it is configured to detect that the blood removal process has ended, it is possible to easily and accurately detect the end of blood removal.

According to the second aspect of the present invention, the computing means is a transmembrane pressure difference or a limit based on the fluid pressure measured by the priming fluid side fluid pressure measuring device and the fluid pressure measured by the dialysis fluid side fluid pressure measuring device. Since a filtration rate is calculated | required, the ultrafiltration rate in an ultrafiltration rate measurement process can be calculated | required using the existing method (existing calculation method etc.).

  According to the invention of claim 3, in the blood removal step, the ultrafiltration pump is driven at a constant speed so that the dialysate flow path side of the blood purification means is negative with respect to the blood flow path, and the blood pump is Since blood is removed by driving at a slower speed than the ultrafiltration pump, the patient's blood is more surely guided from both the tip of the arterial blood circuit and the tip of the venous blood circuit simultaneously to the blood purification means. Can be replaced with the priming solution.

  According to the invention of claim 4, when the monitoring means detects that the transmembrane pressure difference or the rate of change of the ultrafiltration rate is greater than the specified value, the treatment process is automatically started. To the treatment process can be automated.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
The blood purification apparatus according to this embodiment includes a dialysis apparatus for performing dialysis treatment. As shown in FIG. 1, a blood circuit including an arterial blood circuit 1 and a venous blood circuit 2, and an arterial blood circuit 1. And a dialyzer 3 (blood purifying means) interposed between the venous blood circuit 2 and purifying blood flowing in the blood circuit, a squeezed blood pump 4 disposed in the arterial blood circuit 1, and a venous side A venous drip chamber 5 disposed in the middle of the blood circuit 2, a storage means 7 that stores physiological saline as a priming liquid, and a priming fluid supply line that connects the storage means 7 and the arterial blood circuit 1. Lc, the 1st sensor P1 (priming fluid side fluid pressure measuring means), the 2nd sensor P2 (dialysate side fluid pressure measuring means), the calculating means 9, and the monitoring means 10 are mainly comprised.

  An arterial puncture needle a is connected to the distal end of the arterial blood circuit 1 via a connector c, while a venous puncture needle b is connected to the distal end of the arterial blood circuit 2 via a connector d. In addition, the venous drip chamber 5 is connected on the way. Then, when the blood pump 4 is driven with the patient punctured with the arterial puncture needle a and the venous puncture needle b, the patient's blood passes through the arterial blood circuit 1 and reaches the dialyzer 3, Blood purification is performed by the dialyzer 3, and air bubbles are removed in the venous drip chamber 5, and then returned to the patient's body through the venous blood circuit 2. That is, the blood of the patient is purified by the dialyzer 3 while circulating externally from the tip of the arterial blood circuit 1 to the tip of the venous blood circuit 2 of the blood circuit.

  The dialyzer 3 includes a blood inlet 3a (blood inlet port), a blood outlet 3b (blood outlet port), a dialysate inlet 3c (dialysate inlet port), and a dialysate outlet 3d (dialysate). A blood outlet port 3a is connected to the arterial blood circuit 1, and the blood outlet port 3b is connected to the venous blood circuit 2. The dialysate inlet 3c and dialysate outlet 3d are respectively connected to a dialysate inlet line La and a dialysate outlet line Lb extending from the dialyzer body.

  A plurality of hollow fibers (not shown) are accommodated in the dialyzer 3, and these hollow fibers constitute a blood purification membrane for purifying blood. Thus, the dialyzer 3 is formed with a blood flow path through which the patient's blood flows and a dialysate flow path through which the dialysate flows through the blood purification membrane. The hollow fiber constituting the blood purification membrane is formed with a large number of minute holes (pores) penetrating the outer peripheral surface and the inner peripheral surface to form a hollow fiber membrane, and blood is passed through the membrane. It is configured so that wastes and the like therein can permeate into the dialysate.

  The compound pump 6 (reciprocating pump) is disposed across the dialysate introduction line La and the dialysate discharge line Lb in the dialyzer body, and the dialyzer body includes a patient flowing through the dialyzer 3. A water removal pump 8 is provided for removing water from the blood. The water removal pump 8 is formed in the middle of the water removal line Ld formed so as to bypass the double pump 6 in the dialysate discharge line Lb. By driving the water removal pump 8, the duplex pump 6 is of a fixed type (the amount of dialysate to be introduced and the amount of dialysate to be discharged is substantially equal), so the amount of dialysate introduced from the dialysate introduction line La As a result, the volume of the liquid discharged from the dialysate discharge line Lb increases, and water is removed (dehydrated) from the blood by the larger volume.

Further, the dewatering pump 8 is configured to function as an ultrafiltration pump disposed in the middle of the dialysate discharge line Lb, and is driven during the blood removal process described later and filled in the priming liquid filling process. Normal physiological saline (priming solution) is filtered through the blood purification membrane from the blood channel to the dialysate channel (filtration from the blood channel side to the dialysate channel side) and passed through the dialysate discharge line Lb. However, it is configured to be discharged to the outside.

  Furthermore, one end of the dialysate introduction line La is connected to the dialyzer 3 (dialyte introduction port 3c), and the other end is connected to a dialysate supply device (not shown) for preparing a predetermined concentration of dialysate. In addition, one end of the dialysate discharge line Lb is connected to the dialyzer 3 (dialysate outlet 3d) and the other end is connected to a drainage means (not shown), which is supplied from the dialysate supply device. After the dialysate reaches the dialyzer 3 through the dialysate introduction line La, it is sent to the drainage means through the dialysate discharge line Lb.

  The storage means 7 (so-called “saline bag”) is made of a flexible transparent container and can store a predetermined volume of physiological saline (priming solution). It is attached to the tip of a pole (not shown). The priming fluid supply line Lc is connected to a portion (connecting portion P) between the arterial puncture needle a and the blood pump 4 in the arterial blood circuit 1, and the physiological saline (priming fluid) in the housing means 7 is used as blood. It can be supplied in the circuit. The priming liquid supply line Lc is formed with an electromagnetic valve V1 that can arbitrarily open and close the flow path.

  The first sensor P1 (priming liquid side hydraulic pressure measuring means) is for measuring the hydraulic pressure in the venous drip chamber 5 disposed in the middle of the venous blood circuit 2, for example, the venous drip chamber 5 The pressure (pressure and fluid pressure) in the venous blood circuit 2 can be measured by measuring the pressure in the venous drip chamber 5. . With this first sensor P1, the pressure (fluid pressure) of blood flowing in the venous blood circuit 2 at the time of treatment can be measured.

The second sensor P2 (dialysate side fluid pressure measuring means) is arranged in the middle of the dialysate discharge line Lb to measure the fluid pressure, and is formed at the tip of a tube extending from the dialysate discharge line Lb, for example. The fluid pressure at the site can be measured. With this second sensor P2, the pressure of the dialysate flowing through the dialysate discharge line Lb at the time of treatment can be measured. The first sensor P1 and the second sensor P2 are electrically connected to, for example, a calculation unit 9 disposed in the dialysis machine body, and the calculation unit 9 and the monitoring unit 10 are electrically connected. .

  As shown in FIG. 2, the dialysis apparatus (blood purification apparatus) as described above connects connectors c and d to form a closed circuit as shown in FIG. 2, and also uses a priming fluid supply line Lc to connect the blood circuit (artery). A priming solution filling step is performed in which physiological saline (priming solution) is supplied into the side blood circuit 1 and the venous side blood circuit 2) and filled in the blood circuit. However, by filling the blood circuit with physiological saline (priming liquid) as described above in the priming liquid filling step, the physiological saline (priming) is also applied to the blood flow path (flow path in the hollow fiber membrane) in the dialyzer 3. Liquid).

  After the priming solution filling process as described above, as shown in FIG. 3, the connectors c and d are disconnected, and the arterial puncture needle a and the venous puncture needle b are attached to the connectors c and d, respectively. By driving the blood pump 4 and the dewatering pump 8 as the ultrafiltration pump while puncturing the patient's shunt with the needle a and the venous puncture needle b, physiological saline (priming solution) and blood are sequentially replaced. A blood removal step will be performed.

  In this blood removal step, the water removal pump 8 as the ultrafiltration pump is driven at a constant speed so that the dialysate flow path side of the dialyzer 3 is negative with respect to the blood flow path, and the blood pump 4 is removed. The blood pump 8 (ultrafiltration pump) is driven at a speed slower than that of the water pump 8 so that blood can be removed from both the distal end of the arterial blood circuit 1 and the distal end of the venous blood circuit 2 simultaneously. The patient's blood is led to replace the priming solution that has been filled.

  That is, in the blood removal process, the blood circuit and the blood flow path of the dialyzer 3 are filled with physiological saline (priming liquid) in the priming liquid filling process, and the tip (arterial puncture needle a) ) And the distal end of the venous blood circuit 2 (venous puncture needle b) are simultaneously guided to the dialyzer 3 to replace the blood of the patient with the physiological saline (priming solution), and the replaced liquid is the blood of the dialyzer 3. It is filtered to the dialysate flow path side through the purification membrane.

  When the physiological saline (priming solution) is completely replaced with the patient's blood, the blood removal process is completed, and the tip of the arterial blood circuit 1 (arterial puncture needle a) is passed through the dialyzer 3 (blood channel). Dialysis treatment such as purification by the blood purification membrane of the dialyzer 3 and water removal by driving the water removal pump 8 while the patient's blood is circulated extracorporeally to the tip of the vein side blood circuit 2 (vein side puncture needle b) ( Treatment process).

  Here, the dialysis apparatus (blood purification apparatus) according to the present embodiment includes a calculation unit 9 electrically connected to the first sensor P1 and the second sensor P2, and a monitor electrically connected to the calculation unit 9. Means 10. The calculating means 9 is a liquid pressure measured by the first sensor P1 (priming liquid side hydraulic pressure measuring means) and a liquid measured by the second sensor P2 (dialysate side hydraulic pressure measuring means) during the blood removal process. This is to obtain the ultrafiltration rate (UFR) or transmembrane pressure difference (TMP) of the blood purification membrane in the dialyzer 3 based on the pressure over time (real time).

  Specifically, the ultrafiltration rate (UFR) and the transmembrane pressure difference (TMP) are expressed by the following relational expression (excluding the ultrafiltration rate (UFR) = water removal rate / transmembrane pressure difference (TMP)). Since the water velocity is equal to the flow rate driven by the dewatering pump 8, the ultrafiltration rate (UFR) is lower when the transmembrane pressure difference (TMP) is higher and the transmembrane pressure difference is lower. If (TMP) is low, the ultrafiltration rate (UFR) tends to be high.

The head differential pressure (α) generated by the head difference between the part where the hydraulic pressure is measured by the first sensor P1 and the part where the hydraulic pressure is measured by the second sensor P2 is obtained, and the first sensor P1 is obtained. The sub- membrane pressure difference is obtained by subtracting the head differential pressure α from the value obtained by subtracting the measured value (PBout) by the second sensor P2 and the measured value (PDout) by the second sensor P2 ((PBout−PDout) −α). It is preferable to obtain (TMP) or obtain an ultrafiltration rate (UFR) from the transmembrane pressure difference (TMP).

In order to obtain the head differential pressure (α), the blood flow path of the dialyzer 3 is filled with physiological saline (priming liquid) and the dialysate flow path of the dialyzer 3 is filled with dialysate in the priming liquid filling step. In this state, it is preferable to determine the transmembrane pressure difference (TMP) of the blood purification membrane of the dialyzer 3 or the ultrafiltration rate (UFR) therefrom.

  The monitoring means 10 monitors the transmembrane pressure difference or ultrafiltration rate change rate obtained by the calculation means 9 over time (for example, the amount of change per unit time), and the transmembrane pressure difference or the ultrafiltration rate. This is to detect that the rate of change of the filtration rate has become larger than the specified value, and to detect that the blood removal step has ended. That is, the blood purification membrane of the dialyzer 3 is composed of a semipermeable membrane that allows a substance smaller than a certain size to pass but not a large substance, so that the blood flow path of the dialyzer 3 as the blood removal process proceeds. If the side is replaced with blood from a physiological saline (priming solution made of an aqueous electrolyte solution or the like), blood cells and plasma components in the blood cannot pass through the blood purification membrane and inhibit water membrane permeation (filtration). .

  Thus, when the blood removal step is completed and the blood flow path side of the dialyzer 3 is replaced with blood, the transmembrane pressure difference is compared with the blood flow path side filled with physiological saline (priming solution). (TMP) increases rapidly, and the ultrafiltration rate (UFR) derived therefrom decreases rapidly. When the monitoring means 10 detects this abrupt change (the change amount per unit time has become larger than the specified value), it is possible to detect that the blood removal process has been completed.

Hereinafter, the operation of the dialysis apparatus according to the present embodiment will be described.
First, as shown in FIG. 2, the proximal ends of the arterial blood circuit 1 and the venous blood circuit 2 are connected to the blood inlet 3a and blood outlet 3b of the dialyzer 3, respectively, and the dialysate inlet 3c and dialysis The dialysate introduction line La and the dialysate discharge line Lb are connected to the liquid outlet port 3d, respectively, and the connector c and the connector d are connected to communicate with each other.

  On the other hand, the tip of the priming fluid supply line Lc is connected to the connecting portion P of the arterial blood circuit 1, and the solenoid valve V1 in the middle is opened. Thereby, the physiological saline (priming solution) in the storage means 7 passes through the priming solution supply line Lc due to its own weight and reaches the blood circuit (including in the venous drip chamber 5) and the blood flow path of the dialyzer 3. It will be satisfied (priming liquid filling step). At this time, the blood pump 4 is in a stopped state.

  In the state where the physiological circuit (priming solution) is filled in the blood circuit (including in the venous drip chamber 5) and the blood flow path of the dialyzer 3 as described above, the dual pump 6 is driven to start the dialysate introduction line La. The dialysate is supplied to the dialysate flow path in the dialyzer 3 and discharged from the dialysate discharge line Lb (a so-called gas purge step is performed). Then, after the duplex pump 6 is stopped and the pressure on the dialysate flow path side and the blood flow path side in the dialyzer 3 is stabilized (after a certain period of time when the pressure is stabilized), the first sensor P1 and the second sensor P2 respectively Measure fluid pressure.

  At this time, the compound pump 6 and the blood pump 4 are stopped, and the distal end of the arterial blood circuit 1 and the distal end of the venous blood circuit 2 are connected. It is supposed to constitute. Even if the distal end of the arterial blood circuit 1 and the distal end of the venous blood circuit 2 are not connected and open, it is sufficient if the pressure balance between them is balanced.

  Thus, the calculation means 9 obtains the head differential pressure (α) from the measured value (PBout) of the first sensor P1 and the measured value (PDout) of the second sensor P2 using a predetermined calculation formula. That is, if the arithmetic expression of α = PBout−PDout is executed by the arithmetic means 9, the first sensor P1 (priming fluid side fluid pressure measuring means) measures the fluid pressure and the second sensor P2 (dialysis fluid side fluid). It is possible to obtain the head differential pressure (α) generated by the head difference (height difference) from the portion where the pressure measuring means) measures the hydraulic pressure.

  Thereafter, as shown in FIG. 3, the connectors c and d are disconnected, and the arterial puncture needle a and the venous puncture needle b are attached to the connectors c and d, respectively. The patient is punctured with b and proceeds to the blood removal process. In such a blood removal step, the water removal pump 8 as an ultrafiltration pump is driven to cause the dialysate to flow in the water removal line Ld at a constant speed v (ultrafiltration speed), and the blood pump 4 is driven. However, the blood pump 4 is driven at a slower speed than the dewatering pump 8 as the ultrafiltration pump.

Thus, in the state where the blood circuit and the blood flow path of the dialyzer 3 are filled with physiological saline (priming solution) in the priming solution filling step, the tip of the artery side blood circuit 1 (arterial puncture needle a) and vein both with Ru was replaced with physiological saline (priming liquid) led to the patient's blood at the same time the dialyzer 3 from the tip side blood circuit (venous needle), the dialyzer 3 by the actuation by the ultrafiltration pump 8 When the dialysate channel side is set to a negative pressure, the physiological saline (priming solution) on the blood channel side is positively filtered through the blood purification membrane to the dialysate channel side at a constant speed v (dialysate flow from the blood channel side). Filtered in the roadside direction).

Thereby, since the physiological saline (priming solution) can be filtered between the blood channel and the dialysate channel via the blood purification membrane of the dialyzer 3, the first sensor P1 and the second sensor P2 respectively. And the transmembrane pressure difference (TMP) is calculated by the calculation means 9 using a predetermined calculation formula from these measurement values (measurement value PBout of the first sensor P1 and measurement value PDout of the second sensor P2). Can be sought. The predetermined arithmetic expression is “TMP = PBout−PDout−α”.

That is, as in the present embodiment, the water removal pump 8 as an ultrafiltration pump is driven at a constant speed so that the dialysate flow path side of the dialyzer 3 is negative with respect to the blood flow path, and the blood pump 4 is removed. By removing blood by driving at a slower speed than the water pump 8 (ultrafiltration pump), the transmembrane pressure is based on the fluid pressure measured by the first sensor P1 and the fluid pressure measured by the second sensor P2. The difference (TMP) is obtained over time (in real time). And the calculating means 9 calculates | requires the ultrafiltration rate (UFR) of the blood purification membrane in the dialyzer 3 using a predetermined | prescribed arithmetic expression based on this calculated | required transmembrane pressure difference (TMP) with time. The predetermined arithmetic expression is “raw food UFR = v ÷ TMP”.

The transmembrane pressure difference (TMP) or ultrafiltration rate (UFR) obtained over time is monitored by the monitoring means 10. That is, the monitoring means 10 monitors the change rate (change amount per unit time) of the transmembrane pressure difference (TMP) or the ultrafiltration rate (UFR) obtained over time by the calculation means 9, and Detecting that the rate of change in transmembrane pressure difference (TMP) or ultrafiltration rate (UFR) is greater than a specified value (preliminarily obtained by experiment etc.) and detecting that the blood removal process is completed. It is.

As described above, when the monitoring means 10 detects that the change rate of the transmembrane pressure difference (TMP) or the ultrafiltration rate (UFR) is larger than the specified value and detects that the blood removal process is completed, Thus, dialysis treatment (treatment process) is started. Thereby, automation from a blood removal process to a treatment process can be achieved. When the monitoring means 10 detects that the change rate of the transmembrane pressure difference (TMP) or the ultrafiltration rate (UFR) is larger than the specified value, it does not automatically shift to the treatment process, for example, a screen or the like. It may be configured to notify the fact that the blood removal process has been completed by displaying such information or by outputting by voice or the like.

  According to the blood purification apparatus according to the embodiment, the change rate of the transmembrane pressure difference (TMP) or the ultrafiltration rate (UFR) obtained with time is monitored, and the transmembrane pressure difference (TMP) or Since it is configured to detect that the rate of change of the ultrafiltration rate (UFR) has become larger than the specified value and to detect that the blood removal process has been completed, the end of blood removal can be detected easily and accurately. be able to. The calculation means 9 does not calculate the ultrafiltration rate (UFR) but only the transmembrane pressure difference (TMP), and the monitoring means 10 monitors the rate of change of the transmembrane pressure difference (TMP). It may be detected that the blood removal step is completed.

The arithmetic unit 9, the film based on the hydraulic pressure measured by the first sensor P1 hydraulic and second sensor P2 (dialysate side liquid pressure measuring means) measured by the (priming fluid side pressure measuring means) Since the inter-pressure difference (TMP) or the ultrafiltration rate (UFR) is obtained, the ultrafiltration rate can be obtained in the computing means 9 using an existing method (existing computing method or the like).

  Further, in the blood removal step, the water removal pump 8 as an ultrafiltration pump is driven at a constant speed so that the dialysate flow path side of the dialyzer 3 is negative with respect to the blood flow path, and the blood pump 4 is Since blood is removed by being driven at a slower speed than the external filtration pump, the tips of the arterial blood circuit 1 (arterial puncture needle a) and the venous blood circuit 2 (venous puncture needle b) are more reliably connected. The patient's blood can be led from both sides to the dialyzer 3 and replaced with the priming solution.

Next, examples of the present invention will be described.
Using a type IV dialyzer with a membrane area of 1.5 m ² and priming with physiological saline, attach a puncture needle to the tip of the arterial blood circuit and the venous blood circuit, and connect it to the bovine blood (1 L) tank. Automatic blood removal was confirmed. The hematocrit (Ht) of bovine blood was 28%, 41% and 45%.

  The time course of transmembrane pressure difference (TMP) accompanying blood removal was as shown in the graph of FIG. In all cases (all hematocrit was 28, 41, 45%), blood removal was completed macroscopically when the transmembrane pressure difference (TMP) increased (indicated by a two-dot chain line in the graph). . Here, since UFR = V / TMP (V is the ultrafiltration rate), the method of detecting the completion of blood removal using the transmembrane pressure difference (TMP) is shown in FIG. 6 (increasing the transmembrane pressure difference (TMP)). This will be described with reference to “Blood removal completed”.

  The ultrafiltration is started at the ultrafiltration speed V, the time and the value of TMP are continuously monitored, and the relationship between the time and TMP is linearly approximated at regular intervals. Such a linear approximation formula is expressed as Y = aX + b, but it changes sequentially as Y = cX + d, Y = eX + f,. At this time, a, c, and e are inclinations of the approximate line, and indicate how rapidly the transmembrane pressure difference (TMP) is increasing.

  Approximate linear slope ratios c / a and e / a shown in Y = cX + d and Y = eX + f are calculated based on the stage (Y = aX + b) in which blood removal is performed by ultrafiltration of physiological saline (priming solution). When the prescribed value is reached (at the time indicated by the two-dot chain line in the figure), it is determined that the blood removal is completed. As another method, the Y-intercept of the linear approximation formula is b> d> f as shown in FIG. 6 (rising of TMP and completion of blood removal). It is also possible to determine that blood removal has been completed when the size of the Y-intercept reaches a predetermined value based on the Y-intercept b of the linear approximation formula established in the initial stage. In addition, since the rising curve of TMP differs depending on the hematocrit, the completion of blood removal can be more reliably determined by inputting individual hematocrit values for each patient in advance.

  As yet another method, the correlation coefficient R is calculated from the linear approximation formula Y = aX + b. If the linear approximation formula is extended from the start of blood removal to the present time, the correlation coefficient R decreases from the time when TMP starts to rise. If the R decrease range is stored as a specified value, it is possible to determine the completion of blood removal when the specified value is reached. The correlation coefficient may be R × R (R squared). In this way, it is possible to determine the completion of blood removal using the approximate expression or the correlation coefficient for the approximate expression.

  Although the present embodiment has been described above, the present invention is not limited to these embodiments. For example, the priming liquid side hydraulic pressure measuring means including the first sensor P1 is a liquid for the priming liquid in any part of the blood circuit. As long as the pressure is measured, it may be disposed at another position, or the dialysate side fluid pressure measuring means comprising the second sensor P2 is the dialysate introduction line La or the dialysate discharge line Lb. As long as the fluid pressure of the dialysis fluid at any one of the above sites is measured, it may be disposed at another position.

  Further, the head difference between the part where the first sensor P1 (priming fluid side fluid pressure measuring means) measures the fluid pressure and the part where the second sensor P2 (dialysate side fluid pressure measuring means) measures the fluid pressure ( When the head differential pressure generated by the height difference is extremely small, it may be determined that the error due to the head differential pressure is small and the head differential pressure is not obtained.

  In this embodiment, the water removal pump 4 functions as an ultrafiltration pump. However, a separate ultrafiltration pump may be provided in the middle of the dialysate discharge line Lb. Although applied to a dialysis device used during dialysis treatment, other devices that can purify the patient's blood while circulating it extracorporeally (for example, blood filtration dialysis method, blood filtration method, blood purification device used in AFBF, It may be applied to a plasma adsorption device or the like.

  In the course of the blood removal step, calculation means for obtaining the ultrafiltration rate or transmembrane pressure difference of the blood purification membrane in the blood purification means over time, and the transmembrane pressure difference or limit obtained over time by the calculation means Monitoring means for monitoring the rate of change of the outer filtration rate, detecting that the transmembrane pressure difference or the rate of change of the ultrafiltration rate is greater than a specified value, and detecting that the blood removal step has been completed. As long as the blood purification apparatus is provided, it can be applied to other forms and uses.

The schematic diagram which shows the dialysis apparatus (blood purification apparatus) which concerns on embodiment of this invention. Schematic showing the state during the priming solution filling process in the dialysis machine Schematic showing the state during the blood removal process in the dialysis machine Schematic diagram showing the state of the dialysis machine during the treatment process The graph which shows the time-dependent change of TMP in an Example. The graph which shows the relationship between the raise of TMP and the completion of blood removal in an Example

Explanation of symbols

1 Arterial blood circuit 2 Venous blood circuit 3 Dialyzer (blood purification means)
4 Blood pump 5 Drip chamber on the venous side 6 Duplex pump 7 Storage means 8 Dewatering pump
9 Calculation means 10 Monitoring means P1 1st sensor (priming liquid side hydraulic pressure measurement means)
P2 Second sensor (dialysate side fluid pressure measuring means)
La Dialysate introduction line Lb Dialysate discharge line Lc Priming solution supply line Ld Dewatering line

Claims (4)

A blood circuit comprising an arterial blood circuit and a venous blood circuit, and capable of extracorporeally circulating the patient's blood from the distal end of the arterial blood circuit to the distal end of the venous blood circuit;
A blood flow that is interposed between the arterial blood circuit and the venous blood circuit of the blood circuit to purify the blood flowing through the blood circuit and to which the patient's blood flows through a blood purification film for purifying the blood Blood purification means in which a dialysis fluid flow path through which the passage and dialysis fluid flow is formed;
A blood pump disposed in the arterial blood circuit;
A dialysate introduction line and a dialysate discharge line connected to the dialysate flow path inlet and outlet of the blood purification means;
In the blood purification apparatus comprising
A priming solution filling step of supplying a priming solution into the blood circuit and the blood flow path of the blood purification means and filling the blood circuit and the blood flow channel in priming before treatment;
In the priming fluid filling step, the blood circuit and the blood purification means are filled with priming fluid, and the blood is simultaneously applied from both the distal end of the arterial blood circuit and the distal end of the venous blood circuit. A blood removal step of guiding the patient's blood to the purification means and replacing it with the priming liquid, and filtering the substituted liquid to the dialysate flow path side through the blood purification membrane of the blood purification means;
After the blood removal step, a treatment step of purifying the patient's blood while circulating externally from the tip of the arterial blood circuit to the tip of the venous blood circuit via the blood purification means;
Is done,
In the course of the blood removal step, calculation means for obtaining the ultrafiltration rate of the blood purification membrane or the transmembrane pressure difference over time in the blood purification means;
While monitoring the transmembrane pressure difference or ultrafiltration rate change rate obtained over time by the computing means, the transmembrane pressure difference or ultrafiltration rate change rate is greater than the specified value. Monitoring means for detecting and detecting that the blood removal step is completed;
A blood purification apparatus comprising: Priming fluid side fluid pressure measuring means for measuring fluid pressure in any part of the blood circuit;
Dialysate side fluid pressure measuring means for measuring fluid pressure at any part of the dialysate introduction line or dialysate discharge line;
And the calculating means includes the transmembrane pressure difference or ultrafiltration based on the fluid pressure measured by the priming fluid side fluid pressure measuring device and the fluid pressure measured by the dialysis fluid side fluid pressure measuring device. 2. The blood purification apparatus according to claim 1, wherein the rate is obtained.   In the middle of the dialysate discharge line, an ultrafiltration pump is provided. In the blood removal step, the ultrafiltration pump is driven at a constant speed so that the dialysate channel side of the blood purification means is connected to the blood channel. The blood purification apparatus according to claim 1 or 2, wherein the blood purification apparatus performs negative blood removal by driving the blood pump at a slower speed than the ultrafiltration pump.   The treatment process is automatically started when the monitoring means detects that the transmembrane pressure difference or the rate of change of the ultrafiltration rate is greater than a specified value. The blood purification apparatus as described in any one.

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