JP2010068927A - Blood purifying apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blood purifying apparatus which correctly detects a change in a blood index caused by an artificial change, by determining whether the transition with time of a blood index value detected by a detection means is stabilized. <P>SOLUTION: The blood purifying apparatus includes: a dialyzer 2 which purifies blood flowing through a blood circuit 1; a change imparting means which imparts the artificial change to the patient's blood extracorporeally circulated by the blood circuit 1; and a first detection means 5a and a second detection means 5b which detect with time the blood index in the patient's blood extracorporeally circulated by the blood circuit 1 and detect the change of the blood index caused by the artificial change imparted by the change imparting means. The blood purifying apparatus includes a determination means 11 which determines whether the transition with time of the blood index value (hematocrit value) detected by the first detection means 5a or the second detection means 5b is stabilized, before the artificial change is imparted by the change imparting means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a blood purification apparatus for purifying a patient's blood while circulating it outside the body.

  In general, in blood purification therapy such as dialysis treatment, a blood circuit composed of a flexible tube is used to circulate a patient's blood extracorporeally. This blood circuit is mainly composed of an arterial blood circuit in which an arterial puncture needle for collecting blood from a patient is attached to the tip, and a venous blood circuit in which a venous puncture needle for returning blood to the patient is attached to the tip. The dialyzer is interposed between the arterial blood circuit and the venous blood circuit to purify blood circulating outside the body.

  In such a dialyzer, a plurality of hollow fibers are arranged inside, and blood passes through the inside of each hollow fiber, and on the outside thereof (between the outer peripheral surface of the hollow fiber and the inner peripheral surface of the housing). It is set as the structure which can flow a dialysate. The hollow fiber has a blood purification membrane with micropores (pores) formed in the wall surface, and waste products of blood passing through the hollow fiber permeate the blood purification membrane and are discharged into the dialysate. At the same time, waste blood is discharged and purified blood returns to the patient's body. In the dialysis machine, a water removal pump for removing water from the patient's blood is disposed, and water removal is performed during dialysis treatment.

  By the way, the dialysis patient forms a vascular access in order to secure a predetermined extracorporeal circulating blood volume. As an example of the vascular access, there is a shunt in which an artery and a vein are connected by a surgical operation. For example, when an arterial puncture needle and a venous puncture needle are punctured around a patient's shunt and its periphery to perform extracorporeal circulation, the blood purified from the venous puncture needle and returned to the patient's body is the patient's organ, etc. In some cases, blood recirculation may occur that is introduced again from the arterial puncture needle without passing through. When such blood recirculation occurs, the purified blood is further circulated extracorporeally, and the amount of extracorporeal blood that needs to be purified decreases accordingly, resulting in a problem that blood purification efficiency decreases. End up.

However, conventionally, a dialysis apparatus has been proposed that can detect blood recirculation by using a dehydration pump that is driven rapidly and only for a short period of time to give a unique peak to changes in the concentration of blood circulating outside the body. (For example, refer to Patent Document 1). According to the dialysis apparatus disclosed in this document, a sensor for detecting blood concentration (a sensor for detecting hemoglobin concentration) is disposed in the arterial blood circuit, and by detecting a specific peak with such a sensor, Blood recirculation during dialysis treatment can be detected.
Special Table 2000-502940

  However, in the conventional blood purification apparatus, a specific peak is given when the detection value (blood index value such as hemoglobin concentration) detected by the sensor (detection means) for detecting the blood concentration is unstable. As a result, it becomes difficult to accurately detect the specific peak, and there is a problem that blood recirculation cannot be detected accurately. That is, if the detected blood index value is unstable, a minute peak will exist in the detected value over time, and the minute peak becomes so-called noise and accurately detects a specific peak. It will not be possible.

  The present invention has been made in view of such circumstances, and a blood index generated due to an artificial change by determining whether or not the time-dependent transition of the blood index value detected by the detection means is stable. An object of the present invention is to provide a blood purification apparatus capable of accurately detecting a change in value.

  According to the first aspect of the present invention, there is provided a blood circuit comprising an arterial blood circuit and a venous blood circuit for circulating the patient's blood extracorporeally, and the blood connected between the arterial blood circuit and the venous blood circuit. Blood purification means for purifying blood flowing through the circuit, change imparting means for imparting an artificial change to the blood of the patient extracorporeally circulating in the blood circuit, and blood index in the blood of the patient extracorporeally circulating in the blood circuit In a blood purification apparatus comprising a detecting means capable of detecting a change in a blood index caused by an artificial change applied by the change applying means, over time. It is characterized in that it comprises a determination means for determining whether or not the transition of the blood index value detected by the detection means is stable before the change is applied.

  According to a second aspect of the present invention, in the blood purification apparatus according to the first aspect, the change applying unit is provided on the condition that the determination unit determines that the time course of the blood index value detected by the detection unit is stable. When the determination means does not determine that the change over time of the blood index value detected by the detection means is stable, it indicates that the blood index value is not stable. It is characterized by notifying.

  According to a third aspect of the present invention, in the blood purification apparatus according to the first or second aspect, the determination means has a predetermined rate of change or amount of change per predetermined time of the blood index value detected by the detection means. When it is determined that the blood index value is within the allowable range, the blood index value is determined to be stable over time.

  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 change imparting means imparts a peculiar peak to a change in blood concentration circulating extracorporeally in the blood circuit. The detection means comprises a sensor for detecting a specific peak provided by the blood concentration means.

  According to the invention of claim 1, since the determination means for determining whether or not the temporal transition of the blood index value detected by the detection means is stable before the artificial change is given by the change giving means, By determining whether or not the temporal transition of the blood index value detected by the detection means is stable, it is possible to accurately detect a change in blood index value caused by an artificial change.

  According to the second aspect of the invention, the artificial change is automatically applied by the change applying means on condition that the determination means determines that the temporal transition of the blood index value detected by the detecting means is stable. Therefore, it is possible to automate the process of applying an artificial change to the blood index, and the blood index value is stable when the determination means does not determine that the temporal change of the blood index value detected by the detection means is stable. Since it is informed that it has not been done, it is possible to prompt the appropriate subsequent treatment by a medical staff such as a doctor.

  According to the invention of claim 3, when the determination means determines that the rate of change or the amount of change per predetermined time of the blood index value detected by the detection means is within a predetermined allowable range, the blood index Since it is determined that the temporal transition of the value is stable, it is possible to determine the stability of the temporal transition of the blood index value with a simple method and with high accuracy.

  According to the invention of claim 4, the change imparting means comprises the blood concentration means capable of imparting a peak peculiar to the change in blood concentration circulated extracorporeally in the blood circuit, and the detection means comprises the blood concentration means. Since the sensor includes a sensor for detecting a given unique peak, it is possible to reliably and accurately detect a parameter related to a patient's vascular access such as detection of blood recirculation.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
The blood purification apparatus according to the present embodiment is for purifying a patient's blood while circulating it extracorporeally, and is applied to a hemodialysis apparatus used in hemodialysis treatment. As shown in FIG. 1, the hemodialysis apparatus mainly includes a blood circuit 1 to which a dialyzer 2 as blood purification means is connected, and a dialyzer body 6 that removes water while supplying dialysate 2 to the dialyzer 2. Has been.

  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 a flexible tube. The arterial blood circuit 1a and the venous blood circuit 1b A dialyzer 2 is connected between them. The arterial blood circuit 1a has an arterial puncture needle a connected to the tip thereof, and an iron-type blood pump 3, a drip chamber 4a for defoaming, and a first detection means 5a disposed in the middle. Yes. On the other hand, a venous puncture needle b is connected to the distal end of the venous blood circuit 1b, and a second detection means 5b and a drip chamber 4b for removing bubbles are connected in the middle. The first detection means 5a and the second detection means 5b constitute the detection means of the present invention.

  When the blood pump 3 is driven with the patient punctured with the artery side puncture needle a and the vein side puncture needle b, the patient's blood passes through the artery side blood circuit 1a while being defoamed in the drip chamber 4a. To the dialyzer 2, blood purification is performed by the dialyzer 2, and defoaming is performed in the drip chamber 4 b to return to the patient's body through the venous blood circuit 1 b. That is, the blood of the patient is purified by the dialyzer 2 while circulating outside the body by the blood circuit 1.

  The dialyzer 2 is formed with a blood introduction port 2a, a blood outlet port 2b, a dialysate inlet port 2c, and a dialysate outlet port 2d in the casing. Among these, the blood inlet port 2a has an arterial blood circuit 1a. The base end of the venous blood circuit 1b is connected to the blood outlet port 2b. The dialysate introduction port 2c and the dialysate lead-out port 2d are connected to a dialysate introduction line 7 and a dialysate discharge line 8 extending from the dialyzer body 6, respectively.

  A plurality of hollow fibers are accommodated in the dialyzer 2, the inside of the hollow fibers is used as a blood flow path, and the flow of dialysate is between the hollow fiber outer peripheral surface and the inner peripheral surface of the housing. It is considered a road. A hollow fiber is formed in the hollow fiber by forming a large number of minute holes (pores) penetrating the outer peripheral surface and the inner peripheral surface, and waste products in blood are dialyzed through the membrane. It is configured to be able to penetrate inside.

  On the other hand, the dialysis machine main body 6 mainly includes a duplex pump P, a bypass line 9 that bypasses the duplex pump P in the dialysate discharge line 8, and a dewatering pump 10 that is connected to the bypass line 9. It is configured. In the present embodiment, the water removal pump 10 applies the change applying means of the present invention (artificial change to the blood of the patient extracorporeally circulated in the blood circuit 1 and the change in the concentration of the blood. Blood concentration means that can give a peculiar peak to the blood pressure). For example, a pressurization pump (not shown) for flowing the dialysate from the dialyzer 2 to the drainage side of the duplex pump P is provided, and the pressurization is performed. The pump may constitute “change imparting means”. The pressurizing pump is a non-volumetric pump (pressure control type) such as a centrifugal type.

  The compound pump P is disposed across the dialysate introduction line 7 and the dialysate discharge line 8 and introduces dialysate from the dialysate introduction line 7 to the dialyzer 2 (blood purification means). The dialysis fluid introduced into the dialysis fluid is discharged from the dialysis fluid discharge line 8. That is, the duplex pump P is composed of a fixed-quantity pump in which the supply side and the drainage side are substantially equal.

  One end of the dialysate introduction line 7 is connected to the dialyzer 2 (dialyte introduction port 2c), and the other end is connected to a dialysate supply device (not shown) for preparing a dialysate having a predetermined concentration. Further, one end of the dialysate discharge line 8 is connected to the dialyzer 2 (dialysate outlet port 2d), and the other end is connected to a drainage means (not shown), and supplied from the dialysate supply device. After the dialysate reaches the dialyzer 2 through the dialysate introduction line 7, it is sent to the drainage means through the dialysate discharge line 8 and the bypass line 9.

  The dewatering pump 10 is for removing water from the blood of the patient flowing through the dialyzer 2. That is, when the dewatering pump 10 is driven, since the dual pump P is of the fixed type, the volume of liquid discharged from the dialysate discharge line 8 is larger than the amount of dialysate introduced from the dialysate introduction line 7. Thus, water is removed from the blood by the large volume. In addition, you may make it remove a water | moisture content from a patient's blood by means other than this water removal pump 10 (for example, what utilizes what is called a balancing chamber etc.).

  Here, the dewatering pump 10 or the pressurizing pump (not shown) in the present embodiment is rapidly driven in a short time, thereby concentrating the blood flowing in the dialyzer 2 rapidly and in a short time, and having a specific peak. Can be granted. That is, the blood flowing through the blood flow path of the dialyzer 2 is concentrated by rapidly filtering the water through the blood purification membrane to the dialysate flow path side in a short time, and it appears as a unique peak. is there.

  The first detection means 5a and the second detection means 5b detect the blood index value in the blood of the patient circulating extracorporeally in the blood circuit 1 over time, and are given by a change giving means composed of a dewatering pump 10 and the like. It is possible to detect changes in blood index values (changes in blood concentration) caused by artificial changes (instantaneous concentration of blood). That is, the first detection means 5a and the second detection means 5b are disposed in the arterial blood circuit 1a and the venous blood circuit 1b, respectively, and blood concentration (specifically, hematocrit value) as a blood index flowing through these circuits. ) Is detected.

  These first detection means 5a and 5b are composed of a hematocrit sensor. The hematocrit sensor includes, for example, a light emitting element such as an LED and a light receiving element such as a photodiode, and irradiates the blood with light from the light emitting element. A hematocrit value indicating the blood concentration of the patient is detected by receiving the transmitted light or the reflected light with a light receiving element.

  Specifically, a hematocrit value indicating the blood concentration is obtained based on the electrical signal output from the light receiving element. That is, each component such as red blood cell and plasma that constitutes blood has a specific light absorption characteristic, and by using this property, red blood cells necessary for measuring a hematocrit value are optically quantified. The hematocrit value can be obtained. More specifically, near infrared rays irradiated from the light emitting element are incident on blood, are affected by absorption and scattering, and are received by the light receiving element. The light absorption / scattering rate is analyzed from the intensity of the received light, and the hematocrit value is calculated.

  Since the first detection means 5a configured as described above is disposed in the arterial blood circuit 1a, it detects the hematocrit value of blood collected from the patient via the arterial puncture needle a during dialysis treatment. Since the second detection means 5b is disposed in the venous blood circuit 1b, the second detection means 5b detects the hematocrit value of the blood purified by the dialyzer 2 and returned to the patient. That is, the specific peak given by the blood concentration means (change imparting means) comprising the dewatering pump 10 etc. is first detected by the second detection means 5b (see FIG. 2), and then the blood is again arterial blood. When the circuit 1a reaches the circuit 1a and recirculation occurs, the first detection means 5a can detect the characteristic peak remaining in the recirculated blood (see FIG. 3).

  Thereby, it is possible to confirm whether or not a specific peak has been given by the second detection means 5b and to detect the presence or absence of recirculated blood by the first detection means 5a. That is, since it can be confirmed whether or not a specific peak has been given, it is related to the patient's vascular access such as blood recirculation more reliably and accurately than in the case where the detection means is provided only in the arterial blood circuit. Parameter detection can be performed.

  Furthermore, as shown in FIG. 4, the first detection means 5a and the second detection means 5b are electrically connected to a determination means 11 constituted by a microcomputer or the like disposed in the dialyzer body 6. The determination means 11 is electrically connected to a calculation means 12 constituted by a microcomputer or the like and a display means 13 constituted by a liquid crystal screen or the like. The determination means 11 is a blood index detected by the first detection means 5a and the second detection means 5b before the artificial change is applied (instantaneous concentration of blood) by the change applying means constituted by the water removal pump 10 or the like. It is determined whether or not the transition of the value (hematocrit value) with time is stable.

  For example, when the second detection means 5b disposed in the venous blood circuit 1b detects the hematocrit value (blood index value) over time as shown in FIG. Determines that the time-dependent transition of the hematocrit value (blood index value) detected by the second detection means 5b is not stable (unstable) by the determination means 11, and between the time α and the time β Determines that the time course of the hematocrit value (blood index value) is stable.

  Thus, on the condition that the time-dependent transition of the hematocrit value (blood index value) detected by the second detection means 5b is stabilized by the determination means 11 (after time β), the water removal pump 10 or the like. Change of blood index value caused by the artificial change given (instantaneous concentration of blood) by giving artificial change (instantaneous concentration of blood) by the configured change giving means ( The second detection means 5b detects the change in hematocrit value.

  Therefore, when the second detection means 5b detects a change in blood index value (change in hematocrit value) caused by an artificial change (instantaneous concentration of blood), the time course of the hematocrit value is changed. It is possible to accurately detect changes in blood index values caused by the artificial change, and to reliably detect parameters related to the patient's vascular access, such as detection of blood recirculation. It can be performed with high accuracy. In addition, although the determination by the determination unit 11 may be performed for the detection value by the first detection unit 5a, in the present embodiment, the determination by the determination unit 11 at least for the detection value by the second detection unit 5b. It is enough if you do.

  The calculating means 12 can compare the hematocrit values (specific peaks) detected by the first detecting means 5a and the second detecting means 5b, and calculate the ratio of recirculated blood in the blood flowing through the arterial blood circuit 1a. It is a thing. Specifically, when there is blood recirculation, the time from when a specific peak is given until the blood reaches the second detection means 5b (time t1 in FIG. 2) and recirculation, the first detection means The time to reach 5a (t3 in FIG. 3) is predicted, and after giving a specific peak, the hematocrit value detected by the second detection means 5b when time t1 has passed and when the time t3 has passed. The computing means 12 compares the hematocrit value detected by the first detecting means 5a.

  Thus, by predicting the time t1 until the blood reaches the second detection means 5b and the time t3 until the blood reaches the first detection means 5a after recirculation, the cardiopulmonary recirculation (the purified blood becomes the heart Or a phenomenon of being pulled out of the body without passing through other tissues or organs) and recirculation to be measured. Instead of such a method, the calculation means 12 recognizes that the hematocrit value detected by the first detection means 5a and the second detection means 5b exceeds a predetermined numerical value, and the hematocrit values exceeding the numerical value are determined. You may make it compare.

  Then, based on the time-hematocrit value graphs as shown in FIGS. 2 and 3, the change in the hematocrit values of the first detection means 5a and the second detection means 5b is obtained, and the time portion to be compared as described above ( The area of the change part) is calculated by a mathematical method such as integration. For example, the area of the change portion (the portion from t1 to t2 in FIG. 2) by the second detection means 5b is Sv, and the area of the change portion (the portion from t3 to t4 in FIG. 3) by the first detection means 5a is Sa. In other words, the ratio of recirculated blood (recirculation rate) Rrec is obtained by the following arithmetic expression.

  Rrec (%) = Sa / Sv × 100

  Here, the time of the change portion by the first detection means 5a (time interval from t3 to t4) is diffused in the process in which blood with a specific peak flows from the second detection means 5b to the first detection means 5a. In view of this, it is set to be larger than the time of the change portion (time interval from t1 to t2) by the second detection means 5b. The obtained ratio of recirculated blood is displayed on the display means 13 disposed in the dialyzer main body 6 so that a medical worker such as a doctor can visually recognize it. When there is no blood recirculation, the above Sa is 0, so the numerical value displayed as the recirculated blood ratio is 0 (%). Thereby, in addition to the presence or absence of blood recirculation, the ratio can be recognized by the medical staff, and subsequent treatments (re-puncture the puncture needle or re-shunt formation to suppress blood recirculation) Etc.).

  Here, in this embodiment, it is determined by the determination means 11 that the time-dependent transition of the blood index value (hematocrit value) detected by the second detection means 5b (the same applies to the first detection means 5a) is stable. On the condition that the artificial change is automatically given by the change giving means composed of the water removal pump 10 or the like, the blood index value (hematocrit value) detected by the second detecting means 5b by the judging means 11 When it is not determined that the change over time is stable, the blood index value is not stable.

  The notification that the blood index value is not stable may be a notification by a separate notification means such as output of sound or sound effect by a speaker, lighting or blinking of a warning light, or notification by the display means 13. It may be displayed. In the case of display and notification by the display means 13, along with the display of the ratio of recirculated blood obtained by the calculation means 12 and the result of determination by the determination means 11, the temporal transition is not stable (it remains unstable) ) It is possible that an error has occurred by displaying a mark that indicates the detected blood index value (hematocrit value) or changing the character color or background color in the display of the ratio of the recirculated blood, etc. It is preferable to make it possible for a health care professional to grasp something.

  Of course, if it is not determined by the determination means 11 that the blood index value (hematocrit value) detected by the second detection means 5b is stable over time, the subsequent operation and control are completely prohibited, and the blood index value (hematocrit value) It may be configured such that the determination by the determination unit 11 is repeatedly performed until the time course of the current becomes stable. Further, when it is determined by the determination means 11 that the blood index value (hematocrit value) detected by the second detection means 5b is stable over time, the artificial change is applied by the change applying means including the water removal pump 10 and the like. Instead of automatically performing the above, it is possible to urge the medical staff to manually apply the artificial change.

Hereinafter, a method for determining whether or not the time course of the blood index value (hematocrit value) in the present embodiment has been stabilized will be described.
In the present embodiment, the determination unit 11 determines that the change rate or change amount per predetermined time of the blood index value (hematocrit value) detected by the second detection unit 5b is within a predetermined allowable range. The blood index value (hematocrit value) is determined to be stable over time. As a specific method, when the hematocrit value is detected over time as shown in FIG. Integrated value) (V1 to Vn in the figure), average value in a certain section (average value of Ht0 to Ht1, Ht1 to Ht2 in the figure), or a linear function slope of a certain section ( In the same figure, those using the slopes of approximate straight lines of Ht0 to Ht1, Ht1 to Ht2,.

In the case where the area using the area (integrated value) (V1 to Vn in the figure) is used as an example, the determination by the determination unit 11 may be performed by the following two methods.
That is, using the area V1 detected first as a reference, the area V1 is compared with the area V2 detected next, for example, (V2−V1) / V1 × 100 (%). A value is obtained, and it is determined whether the increase / decrease value (corresponding to “change rate per predetermined time” in this case) is within a predetermined allowable range. If the result of the determination is an allowable range, the count is incremented by 1 and the area V1 is compared with the area V3 to determine an increase / decrease value. Let Hereinafter, similarly, the comparison based on the area V1 is sequentially performed.

  On the other hand, when the area V1 is compared with the area V2 to be detected next, and the increase / decrease value is outside the predetermined allowable range, the area V2 is compared with the area V3 without counting. It is determined whether the increase / decrease value is within a predetermined allowable range. If it is within the permissible determination, 1 is counted as described above, while if it is out of the permissible range, it is not counted. Note that the count is cleared (ie, becomes “0”) when it falls outside the permissible range.

  In this way, the determination is made sequentially, and the determination means 11 determines that the temporal transition of the blood index value (hematocrit value) is stable on the condition that the count reaches a predetermined number (for example, “3”). Yes. That is, the detection values over time are divided into a plurality of sections, and when the increase / decrease value of the adjacent sections is within the allowable range for a predetermined number of times, the determination means 11 determines that the transition over time is stable.

  Instead of the above method, for example, the area V1 is compared with the area V2 to be detected next to obtain an increase / decrease value, and when the increase / decrease value is within a predetermined allowable range, one count is performed and the next area An increase / decrease value may be obtained by comparing V2 and area V3 (hereinafter, area V3 and area V4...), And whether or not the increase / decrease value is within an allowable range may be sequentially determined and counted. Further, in the above, the increase / decrease value is the rate of change per predetermined time, but it may be configured to determine whether it is within the allowable range using the amount of change per predetermined time.

  According to the above-described embodiment, the temporal transition of the blood index value (hematocrit value) detected by the detection means (first detection means 5a, second detection means 5b) is stable before the artificial change is given by the change assignment means. Since the determination means 11 for determining whether or not the blood index value has been detected is determined in a state in which the so-called noise is removed, it is determined whether or not the temporal transition of the blood index value (hematocrit value) detected by the detection means is stable. It is possible to accurately detect a change in blood index value caused by an artificial change.

  Further, the change applying means uses the condition that the determination means 11 determines that the time course of the blood index value (hematocrit value) detected by the detection means (the first detection means 5a and the second detection means 5b) is stable. Since the artificial change is automatically given, it is possible to automate the process of giving the artificial change to the blood index value (hematocrit value), and the determination means 11 uses the detection means (first detection means 5a, When it is not determined that the blood index value (hematocrit value) detected by the second detection means 5b) is stable over time, the blood index value (hematocrit value) is informed that the blood index value (hematocrit value) is not stable. Encourage further appropriate treatment by workers.

  Further, the determination unit 11 is configured such that the rate of change or amount of change per predetermined time of the blood index value (hematocrit value) detected by the detection unit (the first detection unit 5a and the second detection unit 5b) is within a predetermined allowable range. When it is determined that the blood index value (hematocrit value) is stable over time, it is determined that the blood index value (hematocrit value) is stable over time with a simple method. Can be determined.

  Furthermore, the change imparting means includes a blood concentration means capable of imparting a peculiar peak to a change in blood concentration extracorporeally circulated in the blood circuit 1, and a detection means (first detection means 5a, second detection means 5b). Since it consists of a hematocrit sensor that detects a specific peak given by the blood concentration means, it is possible to reliably and accurately detect parameters relating to the patient's vascular access such as detection of blood recirculation.

  As mentioned above, although this embodiment was described, the present invention is not limited to this, for example, as long as it can detect a change in blood index value caused by a rapid and short-time artificial change, The first detection means and the second detection means may be configured by other than the hematocrit sensor (for example, a sensor for detecting hemoglobin concentration, a sensor for detecting protein concentration, etc.). However, the blood index value that can be detected by the first detection means and the second detection means may be a blood temperature, an in-circuit pressure, or the like in addition to the hemoglobin concentration or the hematocrit value.

  In the above embodiment, the determination means 11 determines the stability of the change in the hematocrit with time, but the determination is based on the rate of change of the circulating blood volume (ΔBV%) obtained from the hematocrit value. Or you may determine by another blood index value. Further, the first detection means and the second detection means may be disposed at any site as long as they are an arterial blood circuit and a venous blood circuit, respectively. Furthermore, the detection means may be arranged in either the arterial blood circuit or the venous blood circuit.

  Further, in the present embodiment, based on the specific peak detected by the detection means, it is possible to detect the recirculated blood in which the blood returned to the patient from the venous blood circuit is led to the arterial blood circuit again and flows. However, other devices such as a shunt capable of measuring the flow rate of a vascular access, measuring the cardiac output, and measuring the actual blood flow may be used. When using vascular access such as shunts for many years, the diameter of the blood vessels changes due to the occurrence of stenosis, thrombus, or aneurysm, making it difficult to secure sufficient extracorporeal circulation necessary for dialysis. Management of dialysis patient's vascular access is important for good dialysis.

  Dialysis patients have auscultated blood flow sounds of vascular access such as shunts with a stethoscope, and measured the flow rate of vascular access using ultrasonic echoes, X-rays, etc., and confirmed that vascular access can be used effectively. Is the actual situation. As one of the techniques, there is a technique for calculating a vascular access flow rate by injecting physiological saline into an extracorporeal circulation blood circuit and obtaining a dilution curve. In this case, since the physiological saline is manually injected, there are disadvantages in that it takes manpower and that a syringe and physiological saline must be prepared separately. According to the present embodiment, this can be solved. For example, in the case where the flow rate of the vascular access can be measured, the following procedure is required.

  First, puncture (reverse puncture) the patient's vascular access so that the arterial puncture needle a of the arterial blood circuit 1a and the venous puncture needle b of the venous blood circuit 1b are opposite to those at the time of treatment. Create a state where the circulation rate is 100%. In this state, when an artificial change is given to the blood of the patient circulating extracorporeally in the blood circuit 1 and a peak peculiar to the change in the blood concentration is given, the first detection means 5a of the arterial blood circuit 1a The second detection means 5b of the venous blood circuit 1b detects blood concentration blocks.

  At this time, if the vascular access flow rate (Qa) = extracorporeal blood flow rate (Qb), the concentration mass detected by the first detection means 5a and the second detection means 5b is its area (as shown in FIGS. 2 and 3). If the horizontal access flow rate (Qa) and the extracorporeal circulation blood flow rate (Qb) are not equal while the horizontal axis is time and the vertical axis is the blood concentration value), the concentrated blood Since it is diluted when it returns to the vascular access (shunt blood vessel or the like), the first concentration means 5a of the arterial blood circuit 1a detects the diluted concentration clot.

  Thus, the area of the blood concentration mass detected by the first detection means 5a of the arterial blood circuit 1a and the area of the blood concentration mass detected by the second detection means 5b of the venous blood circuit 1b are determined. By comparing, it is possible to determine the flow rate of the vascular access. That is, when the area of the blood concentration clot detected by the first detection means 5a is Sa and the area of the blood concentration clot detected by the second detection means 5b is Sv, the relational expression Sv: Sa = Qa + Qb: Qb. Holds. Accordingly, Qa = Qb × (Sv / Sa−1) is derived, and the vascular access flow rate Qa can be obtained.

  Further, in the present embodiment, the detection means (the first detection means 5a and the second detection means 5b) detect the hematocrit value, but detect other blood indicators (parameters related to blood). Also good. Furthermore, the change imparting means for imparting an artificial change to the blood of the patient circulated extracorporeally in the blood circuit 1 may be any form other than the blood concentration means constituted by the water removal pump 10 or the like as in the present embodiment. It may be. In the present embodiment, the dialysis device body 6 is composed of a dialysis monitoring device that does not incorporate a dialysate supply mechanism, but may be applied to a personal dialysis device that incorporates a dialysate supply mechanism. .

If the blood purification apparatus is equipped with a determination means for determining whether or not the temporal change of the blood index value detected by the detection means is stable before the artificial change is applied by the change applying means, the blood is circulated through the extracorporeal circulation. It can also be applied to those used in other treatments for purification (blood filtration therapy, hemofiltration dialysis therapy, etc.) or those with other functions added.

1 is an overall schematic view showing a blood purification apparatus according to an embodiment of the present invention. The graph which shows the change of the hematocrit value detected by the 2nd detection means in the blood purification apparatus The graph which shows the change (when there exists recirculation) of the hematocrit value detected by the 1st detection means in the blood purification apparatus The block diagram which shows the connection relation of the 1st detection means in the blood purification apparatus, 2nd detection means, a determination means, a calculation means, and a display means. The graph which shows the hematocrit value detected with time by the detection means in the blood purification apparatus The graph for demonstrating the method of determining whether the time-dependent transition of the said hematocrit value was stabilized by the determination means by the hematocrit value detected with time by the detection means in the blood purification apparatus

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Blood circuit 1a ... Arterial side blood circuit 1b ... Vein side blood circuit 2 ... Dializer (blood purification means)
3 ... Blood pumps 4a, 4b ... Drip chamber 5a ... First detection means (detection means)
5b ... 2nd detection means (detection means)
DESCRIPTION OF SYMBOLS 6 ... Dialyzer main body 7 ... Dialysate introduction line 8 ... Dialysis system discharge line 9 ... Bypass line 10 ... Dewatering pump 11 ... Judgment means 12 ... Calculation means 13 ... Display means P ... Duplex pump

Claims (4)

A blood circuit comprising an arterial blood circuit and a venous blood circuit for extracorporeal circulation of the patient's blood;
Blood purification means connected between the arterial blood circuit and the venous blood circuit and purifying blood flowing through the blood circuit;
A change imparting means for imparting an artificial change to the blood of the patient circulating extracorporeally in the blood circuit;
Detecting means capable of detecting a blood index in the blood of a patient circulating extracorporeally in the blood circuit with time, and detecting a change in blood index caused by an artificial change given by the change giving means;
In the blood purification apparatus comprising
A blood purification apparatus comprising: a determination unit that determines whether or not a temporal change of a blood index value detected by the detection unit is stable before the artificial change is applied by the change applying unit.   Artificial changes are automatically applied by the change applying means on condition that the determination means determines that the time course of the blood index value detected by the detecting means is stable, and the determination means 2. The blood purification apparatus according to claim 1, wherein when it is not determined that the temporal change of the blood index value detected by the detecting means is stable, the blood purification apparatus notifies that the blood index value is not stable.   The determination means stabilizes the temporal change of the blood index value when it is determined that the rate of change or the amount of change per predetermined time of the blood index value detected by the detection means is within a predetermined allowable range. The blood purification apparatus according to claim 1 or 2, wherein it is determined that the blood purification has been performed.   The change imparting means comprises a blood concentration means capable of imparting a unique peak to a change in blood concentration extracorporeally circulating in the blood circuit, and the detection means comprises a unique peak imparted by the blood concentration means. The blood purification apparatus according to any one of claims 1 to 3, wherein the blood purification apparatus comprises a sensor for detecting a blood pressure.

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