JP2005348950A - Blood removal pressure measuring system and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blood removal pressure measuring system and a method capable of quickly and precisely measuring a blood removing pressure of the primary side of a blood pump using a pressure detecting value from an existing pressure detector without changing an existing blood circuit and without adding a pressure detector to a blood dialyzer. <P>SOLUTION: The system is the blood removal pressure measuring system in a blood extracorporeal circulation device having the blood circuit for circulating the blood between the inside of the body of a patient and the same using a blood pump and has a pressure detecting means detecting the pressure in the blood circuit in the downstream of the blood pump, and a blood removal pressure calculating means calculating a blood removal pressure from the amplitude of the fluctuation of the detected pressure by the pressure detecting means and a set flow rate of the blood pump. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a blood pressure reduction measurement system and method, and in particular, in blood extracorporeal circulation devices such as hemodialysis devices and blood purification devices, blood pressure removal can be obtained quickly and accurately using substantially existing equipment. The present invention relates to a measurement system and method.

  BACKGROUND ART An extracorporeal blood circulation device having a blood circuit that circulates blood between a patient's body using a blood pump, in particular, a hemodialysis device and a blood purification device are widely known. For example, in hemodialysis, blood is collected from the arterial side of a patient and purified after being dialyzed by an external hemodialysis apparatus is returned to the vein side. Such hemodialysis apparatuses are widely put into practical use, and typical ones described in Patent Document 1, Patent Document 2, and the like are known.

  In a hemodialysis machine, a hemodialysis element including a dialysis membrane is used as a hemodialysis element for performing hemodialysis. From the blood sent from the patient's artery side, the hemodialysis element is connected to the blood circuit side. Urine components and the like are removed through the dialysis membrane between the dialysis fluid circuit and the dialysate circuit, and excess water is removed to return the dialyzed blood to the venous side of the patient. A blood pump composed of a tube pump provided on the upstream side of the hemodialysis element in the blood circuit is usually used for sending and circulating blood between the patient's body. This tube pump is configured to push the blood in the tube by rotating the two rollers so that the tube is squeezed against the tube curved in an arc shape. Can be set.

  When hemodialysis is performed, blood is removed from the shunt by a blood pump. At this time, since the shunt puncture portion becomes resistance, the blood pressure removal on the primary side of the blood pump is usually negative pressure. When the negative pressure value of the blood pressure removal becomes excessive, the burden on the patient increases, and excessive blood pressure removal may indicate a puncture error. Therefore, it is desired that the blood pressure reduction measurement is performed as quickly and accurately as possible in order to reduce the burden on the patient.

  Conventionally, in order to measure and detect the blood pressure drop on the primary side of the blood pump during hemodialysis, a pillow that expands and contracts according to the internal pressure is provided in the blood circuit for hemodialysis, and this pillow is used to monitor the negative pressure. There are a monitoring method and a special blood dialysis blood circuit configuration in which a dedicated circuit portion for blood pressure reduction is provided on the primary side of the blood pump, and a pressure detector is added thereto to measure blood pressure reduction.

  In the blood pressure monitoring using the pillow, a pillow is provided between the artery side puncture portion and the blood pump inlet side, and the swelling of the pillow is monitored. When the blood flow is good, it shows a sufficient bulge, and when it is insufficient, the circuit has a negative pressure, so the pillow bulge disappears. By setting this pillow on the sensor of the negative pressure monitoring unit, the blood flow state is monitored. However, with this method, although it is possible to roughly monitor, it is difficult to accurately relate the degree of expansion and contraction of the pillow and the blood pressure, so it is necessary to measure the blood pressure primary blood pressure accurately during hemodialysis. I can't.

In addition, when using the special hemodialysis blood circuit described above, a blood pressure monitor is added to the existing hemodialysis blood circuit, or a pressure detector is additionally installed in the hemodialysis machine. In many cases, it is impossible to perform measurement using an existing hemodialysis apparatus that does not originally have such a part.
Japanese Patent Publication No.56-82 Japanese Examined Patent Publication No. 61-25382

  An object of the present invention is to use a pressure detection value from an existing pressure detector without changing the existing blood circuit and without adding a pressure detector to the hemodialysis apparatus in view of the above situation. Thus, it is an object of the present invention to provide a blood pressure reduction measurement system and method capable of measuring blood pressure primary blood pressure reduction quickly and accurately.

  In order to solve the above problems, a blood pressure reduction measurement system according to the present invention is a blood pressure reduction measurement system in an extracorporeal blood circulation device having a blood circuit that circulates blood between a patient's body using a blood pump. A pressure detecting means for detecting a pressure in the blood circuit after the blood pump, a blood pressure removing pressure calculating means based on the amplitude of fluctuation of the detected pressure by the pressure detecting means and a set flow rate of the blood pump. And a calculating means.

  In the blood pressure removal measurement system, the blood pressure removal calculating means includes means for calculating blood pressure removal based on a characteristic curve representing a relationship between the amplitude and blood pressure obtained in advance for each set flow rate of the blood pump. Can be configured.

  As the blood pump, a tube pump provided with a tube and a roller can be used. Such a tube pump is usually provided with two rollers, and causes two fluctuations of pressure by one rotation of the rotor and generates an amplitude corresponding to the fluctuation.

  The blood pressure-reducing measurement system according to the present invention can be applied to any type of blood extracorporeal circulation device as long as it has a blood circuit that circulates blood between the patient's body using the blood pump as described above. Is also applicable. Typically, as an extracorporeal blood circulation apparatus, a hemodialysis apparatus that performs hemodialysis between the blood circuit and the dialysate circuit can be cited. The present invention can also be applied to a blood purification apparatus that merely purifies the blood in the blood circuit without performing dialysis.

  The blood pressure removal measuring method according to the present invention is a blood pressure removal measuring method in a blood extracorporeal circulation device having a blood circuit for circulating blood between a patient's body using a blood pump, and the blood pressure subsequent to the blood pump The method comprises detecting a pressure in the blood circuit and calculating a blood pressure removal based on an amplitude of fluctuation of the detected pressure and a set flow rate of the blood pump.

  In this blood pressure removal measuring method, for each set flow rate of the blood pump, a characteristic curve representing the relationship between the amplitude and blood pressure removal is obtained in advance, and the blood pressure removal can be calculated based on the characteristic curve.

  In addition, the blood pump is composed of a tube pump having a tube and a roller, and can be configured to detect pressure fluctuations accompanying rotation of the roller in pressure detection.

  In this method of measuring blood pressure reduction according to the present invention, when the blood extracorporeal circulation device is a hemodialysis device that performs hemodialysis between a blood circuit and a dialysate circuit, the blood extracorporeal circulation device is disposed in the blood circuit. The present invention can be applied to any blood purification device that purifies blood.

  Such a blood pressure reduction measuring system and method according to the present invention have been completed based on the following technical idea. That is, in an extracorporeal blood circulation apparatus having a blood pump and having a pressure detection unit on the artery side and / or vein side (for example, before and after the blood control element (dialyzer) in the hemodialysis apparatus) The pressure detected by the detection unit causes an amplitude of two pressure fluctuations per rotation in a two-rotor (two-roller) blood pump. Corresponding amplitudes are also generated on the venous side. The magnitude of this amplitude varies depending on the speed of the blood pump (set flow rate) and the pressure on the primary side of the blood pump (that is, blood pressure removal). The higher the speed of the blood pump, the smaller the width of the fluctuation phase and the larger the amplitude. The lower the blood pump primary pressure that is negative pressure, the lower the pressure detected by the arterial pressure detector, and the larger the amplitude. As an absolute value of the amplitude, the higher the speed of the blood pump and the lower the pressure on the primary side of the blood pump, the larger the amplitude. As described above, the detected pressure in the arterial side pressure detection unit depends on the blood pump speed (that is, the set flow rate of the blood pump) and the blood pump primary side pressure (that is, blood pressure removal), and the maximum value and the minimum value thereof. The amplitude, which is the difference between the two, also changes depending on the set flow rate of the blood pump and the blood pressure reduction. Therefore, if the magnitude of the amplitude of the change in the detected pressure at a set flow rate of a certain blood pump can be grasped, the blood pump primary pressure (blood pressure removal) at that time can be measured. The present invention has been completed based on such a technical idea, and as is clear from the results of individual examination, it is possible to measure blood pressure removal quickly and accurately by actually calculating based on this technical idea. It has been confirmed.

As an actual method for measuring blood pressure reduction, for example,
(1) Obtained from blood pump speed (blood pump set flow rate) and arterial pressure amplitude.
(2) Initial correction is performed at 0 mmHg, and then obtained from the change value of the arterial pressure amplitude.
There are methods.

  According to the system and method for measuring blood pressure reduction according to the present invention, blood pressure reduction can be achieved only by measuring the amplitude of arterial pressure using an existing mechanical configuration, although the circuit configuration is extremely simple. Measurement can be performed easily and quickly with sufficient accuracy in practice.

  For example, when hemodialysis is performed, blood is removed from the shunt by a blood pump. At this time, excessive blood pressure on the primary side of the blood pump indicates a heavy burden on the patient and a puncture error. . The blood pressure reduction measurement according to the present invention is extremely effective in reducing the burden on such patients.

  Hereinafter, preferred embodiments of the present invention will be described with respect to hemodialysis apparatuses with reference to the drawings. As described above, the present invention can be applied to an extracorporeal blood circulation apparatus such as a blood purification apparatus in addition to a hemodialysis apparatus.

  FIG. 1 shows a blood pressure removal measuring system according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a hemodialysis apparatus as a blood extracorporeal circulation apparatus, and has a blood circuit 4 that circulates blood between a patient 3 and a body using a blood pump 2. Blood is collected from the shunt artery side 5 and returned to the patient 3 through the shunt vein side 6. The blood is sent to the blood circuit 4 by a blood pump 2 comprising a tube pump having a tube and a roller (for example, 2 rollers), but the primary side of the blood pump 2 is generally at a negative pressure due to the resistance of the shunt artery side 5. Become. In the present invention, the pressure on the primary side of the blood pump 2 is referred to as blood removal pressure.

  The blood discharged from the blood pump 2 is sent to the blood flow path 9 side of the hemodialysis element (dialyzer) 8 through the sealed drip device 7. The hemodialysis element 8 is defined by the dialysis membrane 10 on the blood channel 9 side and the dialysate channel 11 side. A dialysate liquid supply path 13 and a dialysate drainage path 14 of the dialysate circuit 12 are connected to the dialysate flow path 11 side of the hemodialysis element 8, and blood circulated through the dialysis membrane 10. Dialysis is performed on the blood to purify blood and remove water as needed. The dialyzed blood is returned from the blood flow path 9 of the hemodialysis element 8 to the venous side of the patient 3 via the sealed drip device 15.

  As means for detecting the pressure in the blood circuit 4 after the blood pump 2, in this embodiment, a pressure sensor 16 is provided in the drip device 7 portion, and the pressure on the inlet side of the hemodialysis element 8 is detected. It is like that. In the present invention, this pressure is called arterial pressure. Then, the amplitude of fluctuation of the detected pressure by the pressure sensor 16 is calculated by the blood pressure removal calculating means 18 incorporated in the control device 17. The calculated amplitude of fluctuation of the arterial pressure is used for calculating blood pressure reduction described later. In this embodiment, the fluctuation of the arterial pressure is generated twice by one rotation by the rotation of the blood pump 2, more precisely by the rotation of the two rollers, and each has an amplitude. Since the fluctuation corresponding to the fluctuation of the arterial pressure can be detected even on the vein side after passing through the hemodialysis element 8, the amplitude detected by the pressure sensor 19 on the vein side provided in the drip device 15 is used to be described later. It is also possible to calculate blood pressure removal.

  Based on the signal from the control device 17, the speed of the blood pump 2 is set and the flow rate of the blood pump 2 is set. Based on the set flow rate of the blood pump 2 and the amplitude of fluctuation of the detected pressure by the pressure sensor 16, the blood pressure removal means 18 calculates the blood pressure removal pressure which is the primary pressure of the blood pump 2.

  As described above, in the present embodiment, the blood pressure removal is calculated by the blood pressure removal calculating means 18 from the amplitude of the fluctuation of the detected pressure by the pressure sensor 16. This calculation is basically performed for each setting of the blood pump 2. Performed for each flow rate. Therefore, if a characteristic curve representing the relationship between the amplitude and the blood pressure reduction is obtained in advance for each set flow rate of the blood pump 2 by a test, the blood pressure removal at that time can be quickly and easily performed by the blood pressure removal calculating means 18. Will be calculated. Further, when the set flow rate of the blood pump 2 is in an intermediate region between the set flow rates in the test performed in advance, correction is performed based on both characteristic curves of the set flow rate actually tested on both sides (for example, the correction coefficient) ), It is possible to easily calculate a characteristic curve at the set flow rate in the intermediate region, and based on the characteristic curve, the blood pressure is calculated from the amplitude of the fluctuation of the detected pressure. Can be calculated.

  In order to obtain a characteristic curve representing the relationship between the amplitude of the fluctuation in the detected pressure and the blood pressure removal, the following test was performed. The apparatus used for the test is shown in FIG.

  In FIG. 2, 21 indicates a hemodialysis apparatus (TR-7000S, manufactured by Toray Medical Co., Ltd.). The hemodialysis apparatus 21 includes a blood pump 22 including a tube pump (flow rate control range in the test: 50). -400 mL / min) and a pressure sensor and a display unit (arterial pressure sensor and display unit 24) before and after dialyzer 23 (BS-1.6UL, manufactured by Toray Medical Co., Ltd.) in the blood flow path A venous pressure sensor and display unit 25) is provided.

  A test liquid (xanthan gum (XG) solution (equivalent to hematocrit value [Ht] 20%, 30%, 40%)) having a viscosity equivalent to that of blood is stored in the test liquid storage tank 26 in each test, and blood pump The pressure on the primary side of the blood pump 22, that is, the blood pressure drop, was measured with the pressure gauge 28 for each set flow rate of the blood pump 22 while changing the flow path resistance with the flow rate adjustment valve 27. At the same time, the pressure detected by the arterial pressure sensor 24 is recorded by a recorder 29 so that the amplitude of fluctuation of the detected pressure at that time can be calculated. The dialysate was supplied to the dialysate circuit 31 side of the dialyzer 23 relative to the blood circuit 30 side (dialyte temperature: 36 ° C., dialysate flow rate: 500 mL / min). The return blood pressure from the dialyzer 23 is measured by the pressure gauge 32, and adjusted by the relief valve 33 to 150 mmHg whenever the set flow rate of the blood pump 22 is changed, and the return side (venous side) test liquid is the test liquid storage tank 26. Recovered. In the flow configured as described above, the set flow rate of the blood pump 22 is set to 50, 100, 150, 200, 250, 300, 350, and 400 mL / min, respectively, and the blood pressure reduction and the arterial pressure amplitude at each set flow rate are set. Sought a relationship with. For the arterial pressure amplitude, the maximum and minimum values of arterial pressure voltage fluctuation indicated on the recorder 29 are read and replaced with the arterial pressure, and the maximum and minimum values of the arterial pressure at the blood pump set flow rate at that time The difference (amplitude) was calculated. The results are shown in FIGS.

3 to 10, for each Ht value (20%, 30%, 40%), the data obtained above is approximated by a polynomial in the form of y = ax ² + bx + c to obtain a characteristic line. Is represented by R ² .

  As apparent from FIGS. 3 to 10, it was confirmed that the relationship between the arterial pressure amplitude and the blood pressure reduction can be expressed by a specific characteristic curve with a sufficiently high correlation at each blood pump set flow rate. Therefore, the blood pressure removal can be calculated based on the blood pump set flow rate and the arterial pressure amplitude at that time. 3 to 10, the characteristic curve is obtained for each Ht value. However, depending on the blood pump set flow rate, these characteristic curves can be represented by one characteristic curve. Even if represented by two characteristic curves, sufficient accuracy can be obtained regardless of changes in the Ht value.

  In addition, when the blood pump set flow rate at that time is between the blood pump set flow rates obtained by the above-described test (for example, the blood pump set flow rate at that time is 120 mL / min and the characteristic curve is obtained by the test. When the blood pump set flow rate is 100 mL / min and 150 mL / min), the characteristic curve at the blood pump set flow rate at that time is calculated using the correction coefficient etc. from both characteristic curves obtained in the test. Based on the calculated characteristic curve, the blood pressure removal can be calculated from the arterial pressure amplitude at that time.

  As described above, according to the present invention, it is possible to calculate blood pressure removal quickly, accurately, and easily based on the amplitude of fluctuation of the detected pressure in the blood circuit after the blood pump and the set flow rate of the blood pump. The present invention can be easily applied to existing devices without newly adding a pressure gauge.

  In the above embodiment and the test apparatus, the blood pressure is calculated from the arterial pressure amplitude before the dialyzer, but even the venous pressure after the dialyzer causes pressure fluctuation due to the blood pump rotation, and the amplitude can be calculated. By calculating the relationship between the amplitude and the blood pressure reduction for each blood pump set flow rate, the blood pressure reduction calculation similar to the above can be performed.

  The blood pressure reduction measuring system and method according to the present invention can be applied to an extracorporeal blood circulation apparatus such as a blood purification apparatus that merely purifies blood in addition to a hemodialysis apparatus.

1 is a schematic configuration diagram of a blood pressure reduction measuring system according to an embodiment of the present invention. It is a schematic block diagram of the test apparatus for calculating | requiring the characteristic curve of an arterial pressure amplitude and a blood pressure reduction. It is a characteristic view which shows the test result in the test apparatus of FIG. It is a characteristic view which shows another test result in the test apparatus of FIG. It is a characteristic view which shows another test result in the test apparatus of FIG. It is a characteristic view which shows another test result in the test apparatus of FIG. It is a characteristic view which shows another test result in the test apparatus of FIG. It is a characteristic view which shows another test result in the test apparatus of FIG. It is a characteristic view which shows another test result in the test apparatus of FIG. It is a characteristic view which shows another test result in the test apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hemodialysis apparatus as extracorporeal blood circulation apparatus 2 Blood pump 3 Patient 4 Blood circuit 5 Shunt artery side 6 Shunt vein side 7, 15 Sealed drip apparatus 8 Hemodialysis element (dialyzer)
DESCRIPTION OF SYMBOLS 9 Blood flow path of hemodialysis element 10 Dialysis membrane 11 Dialysate flow path 12 Dialysate circuit 13 Dialysate liquid supply path 14 Dialysate drainage path 16 Arterial side pressure sensor 17 Control device 18 Detension blood pressure calculation means 19 Pressure sensor 21 Hemodialysis apparatus 22 Blood pump 23 Dialyzer 24 Arterial pressure sensor and display unit 25 Venous pressure sensor and display unit 26 Test liquid storage tank 27 Flow rate adjustment valve 28 Pressure gauge for blood pressure reduction 29 Recorder 30 Blood circuit 31 Dialysate circuit 32 Pressure gauge for return blood pressure 33 Relief valve

Claims (10)

  A blood pressure extracorporeal circulator having a blood circuit that circulates blood between a patient's body using a blood pump, and a pressure detection system that detects a pressure in the blood circuit after the blood pump. And a blood pressure removal calculating means for calculating blood pressure removal based on the amplitude of fluctuation of the detected pressure by the pressure detection means and the set flow rate of the blood pump.   The blood pressure removal measurement according to claim 1, wherein the blood pressure removal calculating means comprises means for calculating blood pressure removal based on a characteristic curve representing a relationship between the amplitude and blood pressure obtained in advance for each set flow rate of the blood pump. system.   3. The blood pressure reduction measuring system according to claim 1 or 2, wherein the blood pump is a tube pump having a tube and a roller.   The blood pressure-reducing measurement system according to any one of claims 1 to 3, wherein the extracorporeal blood circulation device comprises a hemodialysis device that performs hemodialysis between the blood circuit and a dialysate circuit.   The blood pressure removal measurement system according to any one of claims 1 to 3, wherein the extracorporeal blood circulation device comprises a blood purification device that purifies blood in the blood circuit.   In a blood extracorporeal circulation apparatus having a blood circuit that circulates blood between a patient's body using a blood pump, a method for measuring blood pressure reduction, the pressure in the blood circuit after the blood pump is detected, A method for measuring blood pressure reduction, characterized in that blood pressure reduction is calculated on the basis of the amplitude of fluctuation in detected pressure and the set flow rate of the blood pump.   The blood pressure removal measuring method according to claim 6, wherein a characteristic curve representing a relationship between the amplitude and blood pressure removal is obtained in advance for each set flow rate of the blood pump, and the blood pressure removal is calculated based on the characteristic curve.   The blood pressure measurement method according to claim 6 or 7, wherein the blood pump comprises a tube pump having a tube and a roller, and in pressure detection, fluctuations in pressure accompanying rotation of the roller are detected.   The blood pressure removal measuring method according to any one of claims 6 to 8, wherein the extracorporeal blood circulation device is a hemodialysis device that performs hemodialysis between the blood circuit and a dialysate circuit.   The blood pressure removal measuring method according to any one of claims 6 to 8, wherein the extracorporeal blood circulation device is a blood purification device that purifies blood in the blood circuit.

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