JP2019063248A - Blood circuit and extracorporeal circulation apparatus comprising the blood circuit - Google Patents

Abstract

To provide: a blood circuit that in the case of measuring a flow rate of the blood circuit using an ultrasonic sensor, allows for more accurate measurement than measurement of a flow rate using a tube having a small diameter; and an extracorporeal circulation apparatus comprising the blood circuit.SOLUTION: A blood circuit 110 used for an extracorporeal circulation apparatus comprises: a pump segment part 1110; an artery side line 111 composed of a first artery side line and a second artery side line; and connection members which includes, on one end side, a large diameter part 115L to which the pump segment can be connected and on the other end side, a small diameter part 115S to which the artery side line can be connected. Either one of a first connection member and a second connection member is a measurement connection member 115M having a constant diameter part 115C between the large diameter part 115L and the small diameter part 115S. Wave transmission/reception devices 141A, 141B of an ultrasonic flow meter 140A are attached to the constant diameter part 115C.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a blood circuit used for an extracorporeal circulation device for circulating a patient's blood from the outside of the body, and an extracorporeal circulation device including the blood circuit.

Blood purification devices used for treatment such as hemodialysis, plasma exchange, adsorption therapy, and extracorporeal circulation devices such as artificial heart-lung machines generally deliver a blood circuit for flowing blood, a blood purification device such as a dialyzer, and blood. A blood pump is provided to circulate the patient's blood outside the body.
In the extracorporeal circulatory system, it is necessary to monitor the flow rate of blood flowing through the blood circuit in order to detect poor blood removal from the patient, blockage of the blood circuit due to thrombus, and the like. Therefore, ultrasonic sensors are used to monitor the flow rate of blood (see Patent Documents 1 and 2).

  A tube having a diameter of about 3.3 mm to 6.5 mm is used as a main tube that mainly constitutes a blood circuit in blood purification, in order to make the amount of blood to be extracorporeally circulated appropriately.

JP 2008-023269 A Japanese Patent Application Laid-Open No. 2003-169893

  Here, when the flow rate is calculated based on the propagation time of the ultrasonic wave, the accuracy can be increased by increasing the propagation distance of the ultrasonic wave, but in the case of a tube with a small diameter, the propagation distance of the ultrasonic wave It is difficult to lengthen.

  Therefore, the present invention, when measuring the flow rate of the blood circuit with an ultrasonic sensor, comprises a blood circuit capable of measurement with higher accuracy than when measuring the flow rate using a thin-diameter tube, and the blood circuit. An object of the present invention is to provide an extracorporeal circulation device.

  The present invention comprises a blood purifier for purifying blood, a blood pump comprising a tube pump for flowing the liquid in the tube by squeezing the tube, and a transducer for transmitting and receiving ultrasonic waves, A blood circuit connected to the blood purifier for circulating blood, the blood pump being disposed and having a predetermined diameter. An arterial line composed of a pump segment composed of a tube, a tube having a diameter smaller than the predetermined diameter, and a large diameter part to which the pump segment can be connected at one end side A connecting member in which a small diameter portion to which the arterial line can be connected is disposed, and the arterial line has one end connected to the patient's artery and the other end connected to the first connecting member A first arterial line connected to one end of the pump segment and one end are connected to the other end of the pump segment by the second connecting member, and the other end is connected to the blood purifier A second arterial line, and any one of the first connection member and the second connection member is disposed between the large diameter portion and the small diameter portion and has a diameter A measuring connection member including a constant diameter portion having a predetermined length in a fluid flow direction and having a diameter larger than the diameter of the artery side line and smaller than the predetermined diameter. The present invention relates to a blood circuit in which the transducer is attached to the constant diameter portion.

  The diameter of the constant diameter portion is preferably substantially the same as the predetermined diameter of the pump segment portion.

  Further, the large diameter portion of the connection member for measurement is a first large diameter portion disposed at one end side and capable of connecting the pump segment portion having a first diameter, the first large diameter portion and the constant diameter portion And a second large diameter portion capable of connecting the pump segment portion having a second diameter smaller than the first diameter.

  Preferably, the diameter of the constant diameter portion is substantially the same as the second diameter.

  The present invention also relates to a blood pump comprising a device body, a blood purifier for purifying blood, and a tube pump for flowing the liquid in the tube by squeezing the tube, and a transducer for transmitting and receiving ultrasonic waves. The present invention relates to an extracorporeal circulatory apparatus including an ultrasonic flow meter for measuring blood flow rate, and the blood circuit.

  Further, the ultrasonic flow meter further includes a mounting portion having a pair of sensor flat portions disposed opposite to each other so as to sandwich the constant diameter portion, and the pair of transducers includes the pair of sensor flat surfaces. It is preferable to arrange in the part.

  The blood pressure pump further includes a pressing member disposed on the one end side of the pump segment portion and pressing the pump segment portion so that the pump segment portion is not detached from the blood pump, and the first connection member is for measuring It is a connecting member, It is preferable that the said mounting part is fixed and arrange | positioned in the vicinity of the said pressing member.

  Moreover, it is preferable that the pair of the transducers be disposed at a predetermined distance in the flow direction of the liquid in the constant diameter portion, and transmit and receive ultrasonic signals obliquely to the flow direction of the liquid.

  According to the present invention, in the case of measuring the flow rate of the blood circuit by the ultrasonic sensor, the blood circuit capable of measurement with higher accuracy than in the case of measuring the flow rate using a thin diameter tube, and the blood circuit An extracorporeal circulation device can be provided.

The schematic block diagram of the hemodialysis apparatus in 1st Embodiment of this invention is shown. It is a block diagram of a hemodialysis apparatus in a 1st embodiment, and an explanatory view of a connection member for measurement. It is a figure which shows the concrete structure of the artery side line of the blood circuit in 1st Embodiment. The enlarged view of the pump segment part in FIG. 3A is shown. The schematic block diagram of the hemodialysis apparatus in 2nd Embodiment of this invention is shown. It is a block diagram of a hemodialysis apparatus in a 2nd embodiment, and an explanatory view of a connection member for measurement. FIG. 6 is an XX cross-sectional view of the mounting portion in FIG. 5;

  BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the blood circuit, the ultrasonic flowmeter, and the extracorporeal circulation device including the same according to the present invention will be described below with reference to the drawings. In the present invention, as an example of an extracorporeal circulatory apparatus, a hemodialysis apparatus that purifies the blood of a patient with renal failure, removes excess water in the blood, and replenishes the blood as necessary Do.

  In addition, the hemodialysis apparatus of the present embodiment automatically and continuously performs each process such as the priming process, the blood removal process, the dialysis process, and the blood return process by controlling the flow of the dialysate in the blood circuit. It is an automatic hemodialysis apparatus.

  Further, in the description of the tube and the like in the present specification, "having a predetermined diameter" means having a predetermined inner diameter and an outer diameter. Also, "the diameter is the same" means that the inner diameter and the outer diameter are the same.

First Embodiment
The entire configuration of the hemodialysis apparatus 100A according to the first embodiment will be described with reference to FIGS. FIG. 1 is a view showing a schematic configuration of a hemodialysis apparatus 100A in the first embodiment of the present invention, and FIG. 2 is a block diagram showing the hemodialysis apparatus 100A and an attachment portion of an ultrasonic flowmeter in a blood circuit. It is explanatory drawing, FIG. 3A is a figure which shows the concrete structure of the artery side line of a blood circuit, FIG. 3B shows the enlarged view of the pump segment part in FIG. 3A.

  As shown in FIGS. 1 and 2, the hemodialysis apparatus 100A includes a blood circuit 110 for flowing blood, a blood pump 111a, a blood purifier 120, a dialysate circuit 130, and an ultrasonic flowmeter 140A. And a control device 150.

  The blood circuit 110 is a connecting member 115 that connects the pump segment 1110, the arterial line 111, the venous line 112, the drug line 113, the drainage line 114, the pump segment 1110, and the arterial line 111. And. Each of the pump segment 1110, the artery side line 111, the vein side line 112, the drug line 113, and the drainage line 114 is a flexible tube (for example, having an outer diameter of 6.5 mm) having a flexibility allowing liquid to flow therethrough. And the inner diameter is 4.7 mm).

The pump segment portion 1110 is a tube constituting a portion of the blood circuit 110 where the blood pump 111a is disposed, has a diameter larger than that of the artery side line 111 described later, and has flexibility. 3B). As the pump segment portion 1110, for example, one having an outer diameter of 10 mm and an inner diameter of 6.5 mm is used.
The blood pump 111a is constituted by a tube pump for delivering a liquid such as blood or priming fluid inside by squeezing the pump segment portion 1110 with a roller.

The arterial line 111 is configured to include a first arterial line 1111 and a second arterial line 1112 as shown in FIG. 3A.
In the first artery side line 1111, the artery side connection portion 111 c is disposed on one end side, and the other end side is connected to the pump segment portion 1110. A needle to be punctured in a blood vessel of a patient is connected to the artery side connection portion 111c. In the first arterial line 1111, an arterial air bubble detector 111b for detecting air bubbles is disposed.
One end of the second arterial line 1112 is connected to the pump segment 1110, and the other end is connected to a blood inlet 122a of the blood purifier 120 described later.

One end of the vein line 112 is connected to a blood outlet 122 b of the blood purifier 120 which will be described later. In the vein side line 112, a drip chamber 112a, a vein side air bubble detector 112b, a vein side clamp 112c, and a vein side connection portion 112d are disposed.
The drip chamber 112 a stores a certain amount of blood in order to remove air bubbles, coagulated blood and the like mixed in the vein side line 112.
The vein-side air bubble detector 112 b is disposed downstream of the drip chamber 112 a and detects the presence or absence of air bubbles in the tube.
The vein-side clamp 112c is disposed downstream of the vein-side air bubble detector 112b. The vein-side clamp 112 c is controlled according to the detection result of the air bubble by the vein-side air bubble detector 112 b and opens and closes the flow path of the vein side line 112.
The vein side connection part 112d is arrange | positioned at the other end side of the vein side line. A needle to be punctured in a blood vessel of a patient is connected to the vein side connection portion 112 d.

  The drug line 113 supplies drugs necessary for hemodialysis to the arterial line 111. One end side of the medicine line 113 is connected to the medicine feeding device 113 a that delivers the medicine, and the other end side is connected to the arterial line 111. Further, the drug line 113 is provided with clamp means (not shown), and the flow path is closed by the clamp means except when injecting the drug.

  The drainage line 114 is connected to the drip chamber 112a. A drainage line clamp 114 a is disposed in the drainage line 114. The drainage line 114 is a line for draining the priming solution in the priming step.

The connection member 115 is a member for connecting the pump segment portion 1110 and the artery side line 111, and is made of a soft resin member. In the present embodiment, the connection member 115 is made of polyvinyl chloride.
The connecting member 115 is, as shown in FIG. 2, a large diameter portion 115L disposed on one end side to which the pump segment portion 1110 can be connected, and a small diameter portion 115S disposed on the other end side to which the arterial line 111 can be connected. Have.
In the present embodiment, the connection member 115 for connecting the pump segment portion 1110 and the first arterial line 1111 is the first connection member 1151, and the connection for connecting the pump segment portion 1110 and the second arterial line 1112. The member 115 is a second connection member 1152.
In addition, a measurement connection member 115M used for measuring the flow rate is used for any one of the first connection member 1151 and the second connection member 1152, and the measurement connection member 115M includes The transducers 141A and 141B included in the sonic flowmeter 140A are attached. In the present embodiment, the measurement connection member 115M is used as the second connection member 1152.

As shown in FIG. 2, the connection member 115M for measurement includes a large diameter portion 115L disposed at one end side and a small diameter portion 115S disposed at the other end side, and further, the large diameter portion 115L and the small diameter portion 115S. And a constant diameter portion 115C having a constant diameter and a predetermined length in the fluid flow direction.
The diameter of the constant diameter portion 115C is set to be larger than the diameter of the tube constituting the artery side line 111 and smaller than the diameter of the pump segment portion 1110. Thereby, the flow of the liquid (blood) in the measurement connection member 115M can be smoothed. In the present embodiment, the diameter (inner diameter) of the constant diameter portion 115C is substantially equal to the predetermined diameter (inner diameter) of the pump segment 1110 in order to increase the propagation distance of ultrasonic waves between the transducers 141A and 141B described later. It is assumed to be the same.

  The blood purifier 120 includes a cylindrical container body 121, and a dialysis membrane (not shown) housed inside the container body 121. The inside of the container body 121 is divided into a blood side flow passage and a dialysate side flow passage by a dialysis membrane (both not shown). The container body 121 is formed with a blood inlet 122 a and a blood outlet 122 b communicating with the blood circuit 110, and a dialysate inlet 123 a and a dialysate outlet 123 b communicating with the dialysate circuit 130. In the present embodiment, a dialyzer is used as the blood purifier 120.

  According to the blood circuit 110 and the blood purifier 120 described above, the blood taken from the artery of the subject (dialysis patient) flows through the arterial line 111 by the blood pump 111 a and the blood side channel of the blood purifier 120 Introduced to The blood introduced into the blood purifier 120 is purified by the dialysate flowing through the dialysate circuit 130 described later via the dialysis membrane. The blood purified in the blood purifier 120 flows through the vein side line 112 and is returned to the vein of the subject.

  In the present embodiment, the dialysate circuit 130 is constituted by a so-called closed volume control type dialysate circuit 130. The dialysate circuit 130 includes the dialysate chamber 131, the dialysate supply line 132a, the dialysate introduction line 133a, the dialysate outlet line 133b, the dialysate drainage line 132b, the bypass line L1, and the water removal / And a reverse filtration pump P1.

  The dialysate chamber 131 is constituted by a hard container capable of containing a fixed volume (for example, 300 ml to 500 ml) of dialysate, and the inside of this container is a soft liquid diaphragm (diaphragm) and the liquid storage 1311a and the drainage storage It is divided into sections 1311 b.

  The dialysate supply line 132 a is connected to the dialysate supply device (not shown) at its proximal end and to the dialysate chamber 131 at its distal end. The dialysate supply line 132 a supplies the dialysate to the fluid storage 1311 a of the dialysate chamber 131.

  The dialysate introduction line 133a connects the dialysate chamber 131 and the dialysate inlet 123a of the blood purifier 120, and the dialysate contained in the fluid storage portion 1311a of the dialysate chamber 131 is dialyzed with the blood purifier 120. Introduce to the liquid side channel.

  The dialysate outlet line 133 b connects the dialysate outlet 123 b of the blood purifier 120 and the dialysate chamber 131, and the dialysate discharged from the blood purifier 120 is extracted to the drainage storage portion 1311 b of the dialysate chamber 131. Do.

  A proximal end side of the dialysate drainage line 132b is connected to the dialysate chamber 131, and the dialysate drainage line 132b drains the drainage of the dialysate stored in the drainage storage portion 1311b.

  The bypass line L1 connects the dialysate outlet line 133b and the dialysate drain line 132b.

  The water removal / reverse filtration pump P1 is provided in the middle of the bypass line L1. The dewatering / reverse filtration pump P1 is controlled by a control device 150 described later, and the dialysate in the bypass line L1 is caused to flow to the dialysate drainage line 132b side (dehydration direction) and the dialysate outlet line 133b side. The pump is driven by a pump that can be fed in a direction (reverse filtration direction) in which the fluid is circulated.

According to the above-described dialysate circuit 130, the inside of the hard container constituting the dialysate chamber 131 is partitioned by a soft diaphragm, so that the amount of dialysate discharged from the dialysate chamber 131 The amount of supply of dialysate to the portion 1311a) and the amount of drainage collected in the dialysate chamber 131 (the drainage containing portion 1311b) can be made equal.
Thereby, in a state where the water removal / reverse filtration pump P1 is stopped, the flow rate of the dialysate introduced into the blood purifier 120 and the amount of the dialysate (drainage) derived from the blood purifier 120 are the same. You can

  When the water removal / reverse filtration pump P1 is driven to feed in the reverse filtration direction, part of the drainage discharged from the dialysate chamber 131 is bypass line L1 and dialysate outlet line 133b. It is again collected in the dialysate chamber 131 through. Therefore, the amount of dialysate discharged from the blood purifier 120 is the amount of dialysis that flows through the bypass line L1 from the amount collected in the dialysate chamber 131 (that is, the amount of dialysate flowing through the dialysate introduction line 133a). It is the amount obtained by subtracting the amount of liquid. As a result, the amount of dialysate derived from the blood purifier 120 flows through the dialysate introduction line 133a by the amount of dialysate (drainage) collected again in the dialysate chamber 131 through the bypass line L1. Less than the flow rate of the dialysate. That is, when the water removal / reverse filtration pump P1 is driven to feed in the reverse filtration direction, a predetermined amount of dialysate is injected (reverse filtration) in the blood circuit 110 in the blood purifier 120.

  On the other hand, when the dewatering / reverse filtration pump P1 is driven to feed in the dewatering direction, the amount of dialysate flowing through the dialysate outlet line 133b is the dialysate recovered in the dialysate chamber 131. (Ie, the amount of dialysate flowing through the dialysate introduction line 133a) plus the amount of dialysate flowing through the bypass line L1. As a result, the amount of dialysate flowing through the dialysate outlet line 133b is equal to the amount of dialysate (drainage) discharged to the dialysate outlet line 132b through the bypass line L1. It will be more than the amount of dialysate flowing through. That is, when the water removal / reverse filtration pump P1 is driven to send liquid in the water removal direction, the blood purifier 120 removes water from the blood by a predetermined amount.

  As shown in FIG. 2, the ultrasonic flowmeter 140A includes a pair of transducers 141A and 141B, and a flow rate measuring unit 142, both of which are connected by a wire. The pair of transducers 141A and 141B are attached to the measurement connection member 115M. Since the measurement connection member 115M is disposed at either end of the pump segment 1110 as the first connection member 1151 or the second connection member 1152, the influence of water removal by the blood purifier 120 or the drug line Measurement of the flow rate in the blood circuit 110 is possible without being affected by the injection of the drug solution from 113.

The transducers 141A and 141B each include a piezoelectric element 1411 and a piezoelectric element cover 1412, and can transmit and receive ultrasonic signals.
As shown in FIG. 2, the pair of transducers 141A and 141B are disposed at a predetermined distance in the flow direction of the liquid flowing through the measurement connection member 115M, and the transmission / reception wavefront 1413 contacts the measurement connection member 115M. It is attached diagonally oppositely. Further, the pair of transducers 141A and 141B transmit and receive ultrasonic signals obliquely to the flow direction of the liquid (blood).
Electrodes (not shown) are attached to both sides of the piezoelectric element 1411 to convert the input electric signal into mechanical vibration, and convert the transmitted mechanical vibration into electric signal and output it. Can. The piezoelectric element 1411 is embedded in a piezoelectric element cover 1412 formed of a resin such as hard polyvinyl chloride, modified polyphenylene ether, polycarbonate, or acrylic. As a material of the piezoelectric element, piezoelectric ceramics such as lead zirconate titanate, piezoelectric thin films such as zinc oxide, piezoelectric polymer films such as vinylidene fluoride, and the like are applicable. In the present embodiment, lead zirconate titanate is used as the material of the piezoelectric element, and silver and platinum are used as the electrode.

  The flow rate measurement unit 142 includes a transmission unit 1421, a reception unit 1422, a transmission / reception switching unit 1423, and a flow rate calculation unit 1424, and is disposed in the control device 150 described later. The flow rate measuring unit 142 can measure the flow rate of the liquid based on the ultrasonic signals transmitted and received by the pair of transducers 141A and 141B.

The transmitting unit 1421 is connected to the piezoelectric element 1411 of the transmitter-receiver 141A or 141B via the transmission / reception switching unit 1423 to transmit an ultrasonic signal.
The receiving unit 1422 is connected to the piezoelectric element 1411 of the transmitter / receiver 10A or 10B via the transmission / reception switching unit 1423 to receive an ultrasonic signal and amplify the received ultrasonic signal.
The transmission / reception switching unit 1423 switches one of the transducers 141A and 141B to the transmitting unit 1421 and the other to the receiving unit 1422. Accordingly, the transmission / reception switching unit 1423 transmits the ultrasonic signal from the transmitter / receiver 141A and transmits the ultrasonic signal from the transmitter / receiver 141B and transmits the ultrasonic signal from the transmitter / receiver 141B to the transmitter / receiver 141A. It is possible to measure the propagation time when receiving at.
The flow rate calculating unit 1424 calculates the flow rate of the liquid flowing through the blood circuit 110 based on the propagation time of the ultrasonic signal between the transducers 141A and 141B. The method of calculating the flow rate will be described in detail later.

  The control device 150 is configured by an information processing device (computer), and includes a pump operation unit 151, a clamp operation unit 152, and a flow rate measurement unit 142.

  The pump operation unit 151 controls the operation of various pumps disposed in the blood circuit 110 and the dialysate circuit 130.

  The clamp operation unit 152 controls the operation of various clamps disposed in the blood circuit 110 and the dialysate circuit 130 in accordance with the operation of various pumps and the detection result of air bubbles by the air bubble detector.

The control device 150 described above controls and operates the operation of the hemodialysis apparatus 100A by executing the control program of each process described below.
Each step is a priming step which is a preparatory step of cleaning and cleaning the blood circuit 110 and the blood purifier 120, a blood removal step of filling the patient's blood into the blood circuit 110 after puncturing and extracorporeal circulation, and a blood removal step. Subsequently, a dialysis process for dialyzing and purifying blood, a blood return process for returning the blood in the blood circuit 110, and the like are performed.

  In the present embodiment, the control device 150, the water removal / reverse filtration pump P1, the chemical dosing device 113a, the ultrasonic flowmeter 140A, and the blood pump 111a are integrated in a predetermined arrangement, and the console (device main body) 160 is Configured.

  Next, a specific flow rate calculation method in the flow rate calculation unit 1424 will be described. There are various methods of calculating the flow rate using ultrasonic waves, such as the Doppler method and the propagation time difference method, but in the present embodiment, the flow rate Q is calculated as follows using the propagation time reciprocal difference method as an example Do. The transducers 141A and 141B transmit and receive ultrasonic signals obliquely to the flow direction of the liquid. Specifically, the ultrasonic signals are alternately arranged so as to face the outside of the measurement connection member 115M such that the angle between the direction in which the ultrasonic signal is transmitted and received and the flow direction of the liquid is a predetermined angle θ. Transmit and receive, and measure the time required for the propagation of the ultrasonic signal (see FIG. 2).

The time for ultrasonic waves to propagate from transducer 141A to 141B T _AB , the time for ultrasonic waves to propagate from transducer 141 B to 141 A T _BA , the distance for ultrasonic waves to propagate L, the speed of sound C, a tube for measurement Let V be the flow velocity of the liquid in 110 s.
When the actual flow rate is zero, ie, the flow rate V is zero, with the liquid filled in the measurement tube 110s, T _AB and T _BA are equal,
T _AB = T _BA = L / C (a)
It becomes.

As shown in FIG. 2, when the liquid flows from the transducer 141A to the transducer 141B at the flow velocity V,
T _AB = L / (C + V cos θ) (b)
And
T _BA = L / (C−V cos θ) (c)
It becomes. From the relationship between the equations (b) and (c), taking the difference of the reciprocals of the propagation times T _AB and T _BA ,
1 / T _AB −1 / T _BA = (2 V cos θ) / L (d)
It becomes. When the flow velocity V is obtained from the equation (d),
V = L / (2 cos θ) × (1 / T _AB −1 / T _BA ) (e)
It becomes. According to the equation (e), the flow velocity V can be calculated by measuring the propagation time of the ultrasonic wave.

  According to the hemodialysis apparatus 100A provided with the blood circuit 110 and the ultrasonic flowmeter 140A of the first embodiment described above, the following effects can be obtained.

  (1) A measurement connection which connects the pump segment 1110 and the artery side line 111 and the ultrasonic flowmeter 140A can be attached while the blood circuit 110 is constituted by a tube having a predetermined diameter. The measuring connection member 115M includes a large diameter portion 115L to which the pump segment portion 1110 can be connected, a small diameter portion 115S to which the arterial line 111 can be connected, and the large diameter portions 115L. And a small diameter portion 115S, and includes a constant diameter portion 115C having a diameter larger than that of the arterial line. As a result, since the transducers 141A and 141B are attached to the fixed diameter portion 115C, the propagation distance of ultrasonic waves can be made longer than in the case where the transducers 141A and 141B are attached to the arterial line 111. . Therefore, it is possible to measure the flow rate with higher accuracy. Further, since the diameter of the constant diameter portion 115C is larger than the diameter of the arterial line 111 and smaller than the diameter of the pump segment portion 1110, the diameter of the liquid (blood) in the measurement connection member 115M is The flow can be smoothed, and the formation of thrombus, the retention of air bubbles, and the like can be suppressed.

  (2) The diameter of the constant diameter portion 115C is substantially the same as the predetermined diameter of the pump segment portion 1110. Thus, the same ultrasonic wave propagation distance as in the case where the transducers 141A and 141B are attached to the pump segment portion 1110 can be obtained, and the flow rate can be measured with high accuracy.

  (3) A pair of transducers 141A and 141B are disposed at a predetermined distance in the flow direction of blood in the measurement connection member 115M, and transmit and receive ultrasonic signals obliquely to the flow direction of blood did. Thereby, the flow rate can be calculated using the propagation time inverse difference method.

Second Embodiment
Next, a second embodiment of the present invention will be described. The present embodiment is the same as the configuration of the first embodiment except that the configurations of the pump segment portion, the blood pump, the connection member for measurement, and the ultrasonic flowmeter are different, so the same reference numerals are given and described. I omit it. Further, in the present embodiment, a connection member and a measurement connection member which can connect pump segment portions having two different diameters will be described.

  The entire configuration of the hemodialysis apparatus 100B according to the second embodiment will be described with reference to FIGS. FIG. 4 is a view showing a schematic configuration of a hemodialysis apparatus 100B according to a second embodiment of the present invention, and FIG. 5 is a block diagram showing the hemodialysis apparatus 100B and an attachment portion of an ultrasonic flowmeter in a blood circuit. FIG. 6 is an explanatory view, and FIG. 6 is a cross-sectional view taken along line XX in FIG.

  As shown in FIGS. 4 and 5, the hemodialysis apparatus 100B includes a blood circuit 110 for flowing blood, a blood pump 111a ', a blood purifier 120, a dialysate circuit 130, and a water removal / back filtration pump. P1, ultrasonic flowmeter 140 B, and controller 150. In the present embodiment, the measurement connection member 115 M ′ is used as the first connection member 1151.

  The measurement connection member 115 M ′ of the second embodiment is configured to be able to correspond to the pump segment portions 1110 of two types of diameter (diameter). For example, the measurement connection member 115M ′ of the second embodiment has a pump segment 1110L having a first diameter R1 (for example, an outer diameter 12 mm, an inner diameter 8 mm) shown in FIG. 5 and a second diameter thinner than the first diameter. (For example, the outer diameter is 10 mm, the inner diameter is 6.5 mm) of the pump segment portion (not shown).

In the measurement connection member 115M ′ of the second embodiment, as shown in FIG. 5, the large diameter portion 115L includes a first large diameter portion 115L1 and a second large diameter portion 115L2. Further, although not shown, the large diameter portion of the connecting member 115 'also has a first large diameter portion and a second large diameter portion.
The first large diameter portion 115L1 is connectable to the pump segment portion 1110L having the first diameter R1, and the second large diameter portion 115L2 is connected to the pump segment portion (not shown) having the second diameter R2 It is possible.

  The diameter of the constant diameter portion 115C is larger than the diameter of the tube constituting the artery side line 111, and by setting the diameter equal to or less than the diameter of the pump segment portion 1110L, the liquid (blood in the measurement connection member 115M ' Flow can be smoothed. In the present embodiment, the diameter of the constant diameter portion 115C is substantially the same as the second diameter R2. As a result, the flow velocity of the liquid in the constant diameter portion 115C becomes faster while the propagation distance of the ultrasonic wave becomes shorter than when the diameter of the constant diameter portion 115C is made substantially the same as the first diameter R1. In the present embodiment, the improvement of the accuracy due to the increase of the flow velocity becomes larger than the decrease of the accuracy due to the increase of the propagation distance of the ultrasonic wave.

  The blood pump 111a 'is constituted by a tube pump for delivering a liquid such as internal blood or a priming solution by squeezing the pump segment portion 1110L (or a pump segment portion with a second diameter R2 not shown) with a roller. In the present embodiment, the blood pump 111a ′ is a pump segment so that the pump segment 1110 does not come off at one end of the pump segment 1110 on the upstream side (the side connected to the first arterial line 1111). It further comprises a pressing member 116 for pressing 1110.

  The ultrasonic flowmeter 140B includes a pair of transducers 141A and 141B, a flow rate measuring unit 142, and a mounting unit 143, and the pair of transducers 141A and 141B and the flow rate measuring unit 142 are connected by wiring Be done.

  As shown in FIGS. 5 and 6, the mounting portion 143 is formed in a block shape in which a groove having a width that can be held in a state in which the constant diameter portion 115C is held is formed. The pair of side surfaces constituting the groove of the mounting portion 143 is disposed in parallel, and constitutes a pair of sensor flat portions 1431A and 1431B disposed to face each other.

  The pair of sensor flat portions 1431A and 1431B are disposed so as to face the measurement connection member 115M 'so as to be held by the constant diameter portion 115C. The width between the pair of sensor flat portions 1431A and 1431B is set smaller than the outer diameter of the constant diameter portion 115C. As a result, as shown in FIG. 6, the measurement connection member 115M 'is in close contact with the pair of sensor flat portions 1431A and 1431B at the constant diameter portion 115C. In addition, in the transducers 141A and 141B, the mounting portion is substantially at the center in the vertical direction of the pair of sensor flat portions 1431A and 1431B so that the transmission / reception wave surface 1413 is flush with the pair of sensor flat portions 1431A and 1431B. Each is fixedly arranged at 143. In addition, the mounting portion 143 is disposed in the vicinity of the pressing member 116.

As described above, according to the mounting portion 143 described above, the diameter-constant portion 115C and the pair of sensor flat portions 1431A and 1431B are in close contact with each other simply by mounting the measurement connection member 115M ′ included in the blood circuit 110 to the mounting portion 143. It is fixed in the state. Further, since the transducers 141A and 141B are fixedly disposed in the mounting portion 143, the distance between the transducers 141A and 141B can be maintained constant, and the measurement accuracy of the flow rate can be improved. Also, the mounting portion 143 is disposed in the vicinity of the pressing member 116. Therefore, when the pump segment portion 1110L is attached to the blood pump 111a ′ in a state where the measurement connection member 115M ′ (first connection member) is connected to the pump segment portion 1110L, the position of the pump segment portion 1110 by the pressing member 116 Therefore, the measurement connection member 115 M ′ can be easily attached to the attachment portion 143.
In the present embodiment, the mounting portion 143 is fixedly disposed near the upstream side of the blood pump 111a ′ (see FIG. 4).

  According to the hemodialysis apparatus 100B including the blood circuit 110 and the ultrasonic flowmeter 140B of the second embodiment described above, the following effects can be obtained in addition to the effects (1) to (3) described above.

  (4) The first large diameter portion 115L1 to which the large diameter portion 115L of the measurement connection member 115M 'can be connected and the pump segment portion 1110L having the first diameter R1, the first large diameter portion 115L1 and the constant diameter portion 115C And a second large diameter portion 115L2 to which a pump segment portion having a second diameter R2 smaller than the first diameter R1 can be connected. Thereby, even if the diameter of the pump segment portion 1110 is any of the first diameter R1 and the second diameter R2, the pump segment portion 1110 can be connected to the large diameter portion 115L.

  (5) The diameter of the constant diameter portion 115C is approximately equal to the second diameter R2. Thereby, the balance between the propagation distance of ultrasonic waves and the flow velocity can be optimized, and the accuracy of flow rate measurement can be improved.

  (6) The ultrasonic flowmeter 140B is disposed on the mounting portion 143 including the pair of sensor flat portions 1431A and 1431B disposed opposite to each other with the diameter constant portion 115C interposed therebetween, and the pair of sensor flat portions 1431A and 1431B And transmitters / receivers 141A and 141B. As a result, only by mounting the measurement connection member 115M ′ included in the blood circuit 110 to the mounting portion 143, the fixed diameter portion 115C and the sensor flat portions 1431A and 1431B are fixed in close contact with each other. Further, since the transducers 141A and 141B are fixedly disposed in the mounting portion 143, the distance between the transducers 141A and 141B can be maintained constant, and the measurement accuracy of the flow rate can be improved.

  (7) The blood circuit 110 includes the pressing member 116 for pressing the pump segment 1110 so that the pump segment 1110 is not detached from the blood pump 111a ′, and the mounting portion 143 is disposed in the vicinity of the pressing member 116 . Thus, when the pump segment portion 1110 is attached to the blood pump 111 a ′ in a state where the measurement connection member 115 M ′ (first connection member) is connected to the pump segment portion 1110, the pump segment portion 1110 is formed by the pressing member 116. Therefore, the measurement connection member 115 M ′ can be easily attached to the mounting portion 143.

The preferred embodiments and modifications of the blood circuit, ultrasonic flow meter, and hemodialysis apparatus including these according to the present invention have been described above, but the present invention is limited to the above-described embodiments and modifications. Rather, they can be modified accordingly.
For example, in each embodiment, although an example in which a pair of ultrasonic transducers are disposed to face each other is shown, the present invention is not limited thereto. Only one transducer may be disposed, or two transducers may be disposed on the same side to transmit and receive reflected ultrasonic waves.

  Moreover, in each embodiment and modification, although the example by a propagation time inverse difference method was shown as a calculation method of flow volume, it does not restrict to this. The flow rate may be calculated by a well-known calculation method such as the Doppler method or the propagation time difference method.

100A, 100B hemodialysis apparatus 110 blood circuit 111 artery side line 1110, 1110L pump segment 1111 first artery side line 1112 second artery side line 111a blood pump 112 vein side line 113 drug line 114 drainage line 115 connecting member 115L Large diameter portion 115S Small diameter portion 115M, 115M 'Measurement connection member 115C Constant diameter portion 1151 First connection member 1152 Second connection member 116 Pressing member 120 Blood purifier 130 Dialysate circuit P1 Water removal / reverse filtration pump L1 Bypass line 140A, 140B Ultrasonic flowmeter 141A, 141B Transducer 1413 Transmitting / receiving wavefront 142 Flow rate measuring unit 143 Mounting unit 1431A, 1431B Sensor flat unit 150 Control device 151 Pump operation unit 152 Clamping motion Part

Claims (8)

It has a blood purifier that purifies blood, a blood pump that consists of a tube pump that causes fluid in the tube to flow by squeezing a tube, and a transmitter-receiver that transmits and receives ultrasonic waves, and measures the flow rate of blood. A blood circuit for use in an extracorporeal circulatory system comprising an acoustic flow meter, connected to the blood purifier, and circulating the blood,
A pump segment portion in which the blood pump is disposed and which is constituted by a tube having a predetermined diameter;
An arterial line comprising a tube having a diameter smaller than the predetermined diameter;
A connecting member having a large diameter portion to which the pump segment portion can be connected at one end and a small diameter portion to which the arterial line can be connected at the other end;
The arterial line is
A first arterial line connected at one end to the patient's artery and at the other end to one end of the pump segment by the first connection member;
And a second arterial line connected at one end to the other end of the pump segment by the second connection member and connected at the other end to the blood purifier.
One of the first connection member and the second connection member is disposed between the large diameter portion and the small diameter portion, has a constant diameter, and has a predetermined length in the flow direction of the liquid. It is a connection member for measurement provided with the diameter fixed part which has a diameter larger than the diameter which the above-mentioned artery side line has, and the size of the above-mentioned predetermined diameter, and in the diameter fixed part, Blood circuit to be attached.   The blood circuit according to claim 1, wherein a diameter of the constant diameter portion is substantially the same as the predetermined diameter of the pump segment portion.   The large diameter portion of the connection member for measurement is a first large diameter portion disposed at one end side and capable of connecting the pump segment portion having a first diameter, the first large diameter portion, and the constant diameter portion 3. The blood circuit according to claim 1, further comprising: a second large diameter portion that can be connected between the pump segment portions having a second diameter smaller than the first diameter.   The blood circuit according to claim 3, wherein a diameter of the constant diameter portion is substantially the same as the second diameter. A blood purifier for purifying blood,
A blood pump comprising a tube pump that causes fluid in the tube to flow by filling the tube;
An ultrasonic flowmeter having a transducer for transmitting and receiving ultrasonic waves and measuring the flow rate of blood;
The blood circuit according to any one of claims 1 to 4.
Extracorporeal circulation device comprising: The ultrasonic flow meter is
It further comprises a mounting portion having a pair of sensor flat portions disposed opposite to each other so as to sandwich the constant diameter portion,
The extracorporeal circulatory system according to claim 5, wherein the pair of transducers is disposed on the pair of sensor flat portions. The blood pump further includes a pressing member disposed at the one end of the pump segment and pressing the pump segment so that the pump segment is not detached from the blood pump.
The first connection member is the measurement connection member,
The blood circuit according to claim 6, wherein the mounting portion is fixedly disposed in the vicinity of the pressing member.   The pair of the transducers are disposed at a predetermined distance in the flow direction of the liquid in the constant diameter portion, and transmit and receive ultrasonic signals obliquely with respect to the flow direction of the liquid. Extracorporeal circulation device.

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