JP2013192711A - Closed system extracorporeal circulation circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a closed system extracorporeal circulation circuit capable of suppressing an extracorporeal circulation amount of blood that extracorporeally circulates as much as possible and also reliably catching an air bubble when the air bubble is mixed into the blood that extracorporeally circulates.SOLUTION: A closed system extracorporeal circulation circuit 100 includes: a blood removal line 1; a roller pump 4; a pressure sensor 5 for detecting pressure in the blood removal line 1; an artificial lung 3 being the artificial lung 3 for performing gas exchange with respect to blood that has flowed down through the blood removal line 1, having a first filter and a second filter for catching an air bubble in the blood after the performance of gas exchange, and having a flow passage between the first filter and the second filter; and a recirculation line 9 for connecting the flow passage to a portion of the blood removal line 1 on the upstream side of the roller pump 4, and allowing a part of the blood flowing down through the flow passage toward the second filter to be returned to the blood removal line 1.

Description

  The present invention relates to a closed extracorporeal circuit.

  Conventionally, as an extracorporeal circulation device used in cardiac surgery, a bubble removing device (bubble trap), a centrifugal pump, and an artificial lung are arranged in order from the upstream side of a flow path through which blood circulates, and these are connected to each other by a tube. An extracorporeal circulation device is known (see, for example, Patent Document 1). In the extracorporeal circulation device described in Patent Document 1, the bubble removing device is a device that removes bubbles in blood that has been removed from a patient. The centrifugal pump is a blood pump that circulates blood so that blood is removed from the patient and the removed blood is returned to the patient again. The artificial lung is a device having a hollow fiber membrane layer in which a plurality of hollow fiber membranes that perform gas exchange, that is, oxygenation and decarbonation gas, are laminated on blood removed from a patient.

  In the extracorporeal circulation apparatus having such a configuration, from the viewpoint of minimally invasive treatment, a blood reservoir is omitted in order to suppress the extracorporeal circulation volume (priming volume) of blood circulating in the apparatus. However, if the blood reservoir is simply omitted in order to suppress the amount of extracorporeal blood circulation, bubbles contained in the blood that has been removed cannot be removed. Therefore, the extracorporeal circulation device described in Patent Document 1 uses an air bubble removal device. Provided. Assuming that neither the blood reservoir nor the bubble removing device is omitted, bubbles in the blood flow into the centrifugal pump, and when the bubbles flow in, the centrifugal pump idles and circulates the blood. In addition to failing to do so, it breaks up the bubbles and makes them more difficult to remove.

  Therefore, in the extracorporeal circulation device described in Patent Document 1, an air bubble removing device is installed on the upstream side of the centrifugal pump so that the centrifugal pump can reliably perform the function, and bubbles in the blood are removed by the air bubble removing device. After removal, blood is configured to flow into the centrifugal pump.

  However, in order to further reduce the extracorporeal blood circulation volume and aim for a minimally invasive treatment, it was desirable to eliminate even this bubble removing device.

JP 2007-275473 A

  An object of the present invention is to provide a closed system extracorporeal circulation that can suppress the extracorporeal circulation amount of blood circulating extracorporeally as much as possible, and can reliably capture the bubbles when they are mixed into the extracorporeally circulating blood. It is to provide a circuit.

Such an object is achieved by the present inventions (1) to (9) below.
(1) a blood removal line through which the blood that has been removed flows down;
A roller pump provided in the middle of the blood removal line for transferring blood;
A pressure sensor provided in a portion of the blood removal line upstream of the roller pump, and detecting a pressure in the blood removal line;
A gas exchange part connected to the downstream side of the blood removal line and performing gas exchange with respect to the blood flowing down the blood removal line, and disposed in the downstream side of the gas exchange part, in the blood subjected to the gas exchange A first filter and a second filter that trap air bubbles, wherein the first filter and the second filter are spaced apart from each other along the direction of blood flow, and An artificial lung system that functions as a flow path through which blood passes between the second filter and the second filter;
And a recirculation line that connects the flow path and a portion of the blood removal line upstream of the roller pump and returns a part of the blood passing through the flow path to the blood removal line. Closed system extracorporeal circuit.

  (2) The blood from the recirculation line is a mixture of bubbles that could not be captured by the first filter, and passes through the blood removal line and the first filter again in order at least once. The closed system extracorporeal circuit according to (1), wherein the first filter is configured to capture part or all of the air bubbles mixed in the blood.

  (3) The closed system extracorporeal circuit according to (1) or (2), further including a control unit having a function of controlling the operation of the roller pump based on a detection result of the pressure sensor.

  (4) When the detection result of the pressure sensor falls below a preset lower limit value, the control unit controls to stop the operation of the roller pump or to reduce the rotation speed of the roller pump. The closed extracorporeal circuit according to (3).

  (5) The closed system extracorporeal circuit according to (4), wherein the rotation speed of the roller pump continuously decreases.

  (6) When the control unit stops the operation of the roller pump or decreases the rotation speed of the roller pump, and the detection result of the pressure sensor exceeds a preset upper limit value The closed extracorporeal circuit according to (4) or (5), wherein the roller pump is operated again or the rotation speed of the roller pump is increased.

(7) The first filter has a cylindrical shape and is arranged so that a central axis thereof is parallel to the horizontal direction.
The second filter is arranged on the outer peripheral side of the first filter, vertically below the first filter,
The artificial lung system has a housing that collectively stores the first filter and the second filter, and the housing has a port that is connected to the recirculation line at a vertically upper portion thereof. The closed system extracorporeal circuit according to any one of the above (1) to (6), wherein is formed in a protruding manner.

  (8) The closed system according to any one of (1) to (7), wherein the pressure sensor is disposed in a portion upstream of the portion of the blood removal line to which the recirculation line is connected. Extracorporeal circuit.

  (9) The closed extracorporeal circuit according to any one of (1) to (8), further including a blood supply line that is connected to the downstream side of the oxygenator system and flows down blood from the oxygenator system.

  According to the present invention, when air bubbles are mixed in blood circulating extracorporeally, the blood mixed with the air bubbles can be captured by the first filter of the artificial lung system. If air bubbles cannot be captured by the first filter, the air bubbles can be captured by the second filter of the artificial lung system and returned to the blood removal line via the recirculation line along with the blood. Can be recirculated. In addition, air bubbles can be reliably captured by the first filter during recirculation.

  In addition, according to the present invention, since the air bubbles are reliably captured and removed, the air bubble removing device for removing the air bubbles installed in the conventional extracorporeal circulation device can be omitted. Since the bubble removing device is omitted, the extracorporeal circulation amount of blood circulating extracorporeally can be suppressed as much as possible.

It is the schematic which shows 1st Embodiment of the closed system extracorporeal circuit of this invention. It is a cross-sectional view of the oxygenator provided in the closed extracorporeal circuit shown in FIG. It is a flowchart which shows the control program of the control apparatus with which the closed system extracorporeal circuit shown in FIG. 1 is provided. It is a graph which shows typically the time-dependent change (operation state) of the rotation speed of a roller pump by control of the control apparatus with which the closed system extracorporeal circuit shown in FIG. 1 is provided. It is a flowchart which shows the control program of the control apparatus with which the closed system extracorporeal circuit (2nd Embodiment) of this invention is provided. It is a graph which shows typically the time-dependent change (operation state) of the rotation speed of a roller pump by control of the control apparatus with which the closed system extracorporeal circuit shown in FIG. 5 is provided. It is a flowchart which shows the control program of the control apparatus with which the closed system extracorporeal circuit (3rd Embodiment) of this invention is provided. It is a graph which shows typically the time-dependent change (operation state) of the rotation speed of a roller pump by control of the control apparatus with which the closed system extracorporeal circuit shown in FIG. 7 is provided.

  Hereinafter, a closed system extracorporeal circuit according to the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.

<First Embodiment>
FIG. 1 is a schematic diagram showing a first embodiment of a closed system extracorporeal circuit according to the present invention, FIG. 2 is a cross-sectional view of an artificial lung provided in the closed extracorporeal circuit shown in FIG. 1, and FIG. FIG. 4 is a flow chart showing a control program of the control device provided in the closed system extracorporeal circuit shown in FIG. 4, and FIG. Is a graph schematically showing

  A closed extracorporeal circuit (closed extracorporeal circuit) 100 shown in FIG. 1 includes a blood removal line 1, a blood delivery line 2, a recirculation line 9, and a blood removal line 1 and a blood delivery line 2. An artificial lung (artificial lung system) 3 arranged and connecting these lines, a roller pump 4 provided in the middle of the blood removal line 1, and a portion upstream of the roller pump 4 of the blood removal line 1 The pressure sensor 5 and a control device (control unit) 10 are provided. Hereinafter, the structure of each part is demonstrated.

  In the closed extracorporeal circuit 100, a blood reservoir (reservoir) is omitted in order to suppress the extracorporeal circulation amount (priming volume) of blood circulating in the closed extracorporeal circuit 100. In general, an extracorporeal circuit in which a blood reservoir is omitted may be referred to as a “closed system” extracorporeal circuit, and an extracorporeal circuit having a blood reservoir may be referred to as an “open system” extracorporeal circuit.

  The blood removal line 1 includes a flexible tube 11 connected to a catheter (not shown) placed in a vein (vena cava) of the patient H. The blood removal line 1 is used for blood that has been removed through the catheter (venous blood) to flow down. The blood removal line 1 is connected to the upstream side (blood inflow port 311) of the artificial lung 3 at a portion opposite to the catheter.

  The blood supply line 2 is composed of a flexible tube 21 connected to a catheter (not shown) placed in the artery of the patient H. Then, the blood supply line 2 passes through the blood removal line 1 and the artificial lung 3 in order, and the blood flows down, and the blood can be returned to the patient via the catheter. Further, the blood supply line 2 is connected to the downstream side (blood outflow port 312) of the oxygenator 3 at a portion opposite to the catheter.

  In the middle of the blood removal line 1, a roller pump 4 is disposed. The roller pump 4 is a blood pump that sucks blood into the blood removal line 1 and transfers the blood through the closed extracorporeal circuit 100 to circulate outside the body. The roller pump 4 has a rotor 41 that rotates and squeezes the tube 11 constituting the blood removal line 1 to transfer the blood in the tube 11. In the roller pump 4, the flow rate of blood circulating outside the body also increases and decreases according to the rotational speed of the rotor 41. That is, in the roller pump 4, the flow rate of blood circulating extracorporeally increases as the rotation speed of the rotor 41 increases, and the flow rate of blood circulating extracorporeally decreases as the rotation speed decreases.

  As the blood pump, there is a centrifugal pump, for example, in addition to the roller pump 4. When the blood is sucked from the patient H, the centrifugal pump may finely crush bubbles mixed therein at the same time. On the other hand, in the roller pump 4, it is possible to prevent the mixed bubbles in the blood that may occur in the centrifugal pump from being finely crushed.

  A pressure sensor 5 is arranged in a part of the blood removal line 1 upstream of the roller pump 4. The pressure sensor 5 is a sensor that detects the pressure in the blood removal line 1, that is, the pressure on the upstream side of the artificial lung 3, and for example, a diaphragm gauge can be used. The diaphragm gauge is configured to detect pressure applied to the diaphragm (diaphragm) as deformation of the membrane.

  In addition, as shown in FIG. 1, the pressure sensor 5 is a part of the blood removal line 1 on the upstream side of the roller pump 4, particularly on the upstream side of the connection part 12 to which the recirculation line 9 is connected. It is preferable to be arranged in the part. Thereby, the pressure applied to the venous blood vessel of the patient H can be measured without being influenced by the blood flowing through the recirculation line 9.

  An artificial lung 3 is connected to the downstream side of the blood removal line 1. As shown in FIG. 1, the artificial lung 3 has a cylindrical housing 31. In addition, as shown in FIG. 2, the oxygenator 3 includes a heat exchange part 32, a gas exchange part 33, a first filter member (first filter) 34, and a second filter that are collectively stored in a housing 31. It has a member (second filter) 35 and is arranged in this order from the upstream side along the direction of blood flow (direction of blood flow Q).

  The housing 31 has a blood inflow port 311, a blood outflow port 312, a heat medium inflow port 313, a heat medium outflow port 314, a gas inflow port 315, a gas outflow port 316, and a recirculation port 317. doing.

  As shown in FIG. 1, the blood inflow port 311 is a port to which the tube 11 constituting the blood removal line 1 is connected, and blood from the tube 11 flows into the housing 31. The blood inflow port 311 is formed to project in a tubular shape from the right end portion of the housing 31 in FIG.

  The blood outflow port 312 is a port through which the tube 21 constituting the blood supply line 2 is connected, and the blood in the housing 31 flows out toward the blood supply line 2. The blood outflow port 312 is formed in a tubular shape on the outer peripheral portion of the housing 31 downward in FIG.

  The heat medium inflow port 313 is a port through which a heat medium (for example, water) used for heat exchange with blood flows into the housing 31. The heat medium inflow port 313 is formed to project in a tubular shape from the left end portion of the housing 31 in FIG.

  The heat medium outflow port 314 is a port through which the heat medium used for heat exchange flows out of the housing 31. The heat medium outflow port 314 is formed in a tubular shape at a position different from the heat medium inflow port 313 from the left end of the housing 31 in FIG. 1 toward the left.

  The gas inflow port 315 is a port through which gas (mainly oxygen) used when performing gas exchange for blood flows into the housing 31. The gas inflow port 315 is formed in a tubular shape at a position different from the heat medium inflow port 313 and the heat medium outflow port 314 from the left end of the housing 31 in FIG.

  The gas outflow port 316 is a port through which the gas used for gas exchange flows out of the housing 31. The gas outflow port 316 is formed to project in a tubular shape toward the right at a position different from the blood inflow port 311 at the right end of the housing 31 in FIG.

  The recirculation port 317 is a port through which the tube 91 constituting the recirculation line 9 is connected, and blood in the housing 31 flows out toward the recirculation line 9. The recirculation port 317 is formed in a tubular shape on the outer peripheral portion of the housing 31 upward in FIG.

  The housing 31 is made of, for example, polyolefin such as polyethylene or polypropylene, ester resin (for example, polyester such as polyethylene terephthalate or polybutylene terephthalate), styrene resin (for example, polystyrene, MS resin, MBS resin, ABS resin, BS). Resin, AS resin), polycarbonate or other resin materials, various ceramic materials, metal materials, or the like.

  The heat exchange unit 32 is a part that performs heat exchange (heating or cooling) on blood. As shown in FIG. 2, the overall shape of the heat exchanging portion 32 is cylindrical, and is disposed concentrically with the housing 31. A blood inflow port 311 communicates with the inside of the heat exchange section 32. Then, the blood flowing in from the blood inflow port 311 is directed to the blood outflow port 312 while being in contact with the heat exchange unit 32. Moreover, the heat exchange part 32 is comprised, for example with what is called a bellows type heat exchanger, and a heat medium passes through the said heat exchanger from the heat medium inflow port 313 toward the heat medium outflow port 314. At that time, heat exchange is performed with blood in contact with the heat exchanger. Moreover, the heat exchange part 32 may laminate | stack several hollow fiber membranes similarly to the gas exchange part 33 mentioned later.

  In addition, the heat exchange part 32 can be comprised with resin materials, such as metal materials, such as stainless steel and aluminum, or polyethylene, a polycarbonate, a polyurethane, a polyethylene terephthalate, nylon, a polypropylene, for example.

  As shown in FIG. 2, a gas exchange unit 33 is provided on the downstream side of the heat exchange unit 32, that is, on the outer peripheral side of the heat exchange unit 32. The gas exchange unit 33 flows down the blood removal line 1 and performs gas exchange (oxygenation, decarboxylation gas) on the blood subjected to heat exchange in the heat exchange unit 32. The gas exchange part 33 has a cylindrical shape as a whole and is arranged concentrically with the heat exchange part 32.

  The gas exchange unit 33 is configured by integrating a large number of hollow fiber membranes, and blood can pass between the hollow fiber membranes toward the blood outflow port 312. Each hollow fiber membrane has one end connected to the gas inflow port 315 and the other end connected to the gas outflow port 316. The gas flowing into the gas inflow port 315 passes through each hollow fiber membrane and is discharged from the gas outflow port 316. In that case, gas exchange is performed between the blood which contacts each hollow fiber membrane.

  In addition, as a constituent material of the hollow fiber membrane, for example, a hydrophobic polymer material such as polypropylene, polyethylene, polysulfone, polyacrylonitrile, polytetrafluoroethylene, and polymethylpentene is used. Polyolefin resins are preferred, polypropylene is more preferred, and those having fine pores formed in the wall by a stretching method or a solid-liquid phase separation method are more preferred.

  A first filter member 34 is provided on the downstream side of the gas exchange unit 33, that is, on the outer peripheral side of the gas exchange unit 33, and further on the downstream side of the first filter member 34, the second filter member 35 is provided. Is provided.

  The first filter member 34 is a main filter that captures air bubbles when there are air bubbles in the blood that has undergone gas exchange in the gas exchange section 33. The first filter member 34 is formed of a flat sheet, and the sheet is wound into a cylindrical shape (roll shape) with the sheet in close contact with the outer peripheral portion of the gas exchange unit 33.

  The second filter member 35 is, for example, a case where the rotational speed of the roller pump 4 is excessively large due to some abnormality, and bubbles have passed through the first filter member 34. That is, the first filter member This is an auxiliary filter that captures bubbles when the bubbles that could not be captured at 34 are mixed in the blood. The second filter member 35 is formed of a flat sheet having a strip shape, and is installed in a recess 318 formed in the inner peripheral portion of the housing 31. Note that the area of the second filter member 35 may be smaller than the area of the first filter member 34. Since the second filter member 35 is an auxiliary filter for the first filter member 34 that is the main filter, the air bubble capturing function can be sufficiently exerted even in such a magnitude relationship.

  The bubbles usually do not pass through the first filter member 34, but pass through the first filter member 34 due to some abnormality or depending on the use state (under the usage environment) of the closed extracorporeal circuit 100. In this case, the second filter member 35 is effective in capturing the bubbles. Then, the blood from which bubbles are trapped and removed in this manner flows out from the blood outflow port 312.

  The air bubbles trapped by the first filter member 34 move to the lumen of the hollow fiber membrane due to the pressure difference between the inside and outside of the hollow fiber membrane, and the air bubbles flow out of the gas together with the gas used for gas exchange. It is discharged from the port 316.

  In addition, the air bubbles once captured by the second filter member 35 do not pass through the second filter member 35, but are recirculated together with blood as will be described later, and return to the first filter member 34. When the bubbles pass through the first filter member 34 together with the blood, part or all of the bubbles are captured by the first filter member 34. Bubbles captured by the first filter member 34 are discharged from the gas outflow port 316 as described above. On the other hand, even in the current recirculation, the remaining bubbles that could not be captured by the first filter member 34 are further recirculated. While this recirculation is repeated, any remaining bubbles are eventually captured by the first filter member 34 and discharged from the gas outflow port 316.

  Examples of the form of the first filter member 34 and the second filter member 35 include a mesh-like (net-like) shape, a woven fabric, a non-woven fabric, or a combination thereof. Those having a mesh shape (network shape) are preferable, and screen filters are particularly preferable. Thereby, air bubbles can be reliably captured by both filter members, and blood can pass easily. In addition, when the 1st filter member 34 and the 2nd filter member 35 are what makes mesh shape, respectively, it is preferable that an opening is mutually the same.

  The first filter member 34 and the second filter member 35 are preferably made of the same material. Examples of the constituent material include polyolefins such as polyamide, polyethylene, and polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, nylon, cellulose, polyurethane, and aramid fibers. In particular, it is preferable to use polyethylene terephthalate, polyethylene, or polyurethane as a constituent material of each filter member because it is excellent in antithrombogenicity and hardly clogs.

  In addition, it is preferable that the 1st filter member 34 and the 2nd filter member 35 each have hydrophilic property. That is, it is preferable that each filter member is made of a material having hydrophilicity or is subjected to a hydrophilization treatment (for example, plasma treatment, hydrophilic agent coating, etc.).

  Further, as shown in FIG. 2, the first filter member 34 and the second filter member 35 are separated along the direction of the blood flow Q. Thereby, the space between the first filter member 34 and the second filter member 35 functions as a flow path 36 through which blood passes. The blood that passes through the flow path 36 includes blood that goes to the blood outflow port 312 and blood that goes to the recirculation port 317.

  Further, in the artificial lung 3, the posture shown in FIG. 2, that is, the first filter member 34 is arranged so that the central axis thereof is parallel to the horizontal direction, and the second filter member 35 is the first filter member 34. Is used in such a posture that it is arranged vertically downward. At this time, the recirculation port 317 protrudes from a portion vertically above the artificial lung 3 (housing 31). In the posture shown in FIG. 2, of the blood passing through the flow path 36, the blood that descends and travels toward the blood outflow port 312 becomes blood that is free of air bubbles and rises and travels toward the recirculation port 317. Becomes blood mixed with bubbles. The blood mixed with the bubbles proceeds through the recirculation line 9 toward the blood removal line 1 as it is.

  As shown in FIGS. 1 and 2, the recirculation line 9 includes a flexible tube 91 connected to a recirculation port 317 of the oxygenator 3. The tube 91 communicates with the flow path 36 via the recirculation port 317. Further, the end portion of the tube 91 opposite to the recirculation port 317 is connected (connected) to a portion (connecting portion 12) on the upstream side of the roller pump 4 of the blood removal line 1. By the recirculation line 9 connected to the connection portion 12, the blood passing through the flow path 36 and going to the recirculation port 317 is returned to the blood removal line 1. Then, the blood again flows down the blood removal line 1 from the connection portion 12 and returns to the roller pump 4, that is, recirculates. During recirculation, air bubbles in the blood are removed from the closed extracorporeal circuit 100.

  In addition, it does not specifically limit as a constituent material of the tubes 11, 21, and 91, For example, a soft polyvinyl chloride, ethylene-vinyl acetate copolymer, polybutadiene, a silicon | silicone, a polyurethane, etc., or the material which mainly has these is mentioned. It is done.

  A control device 10 is installed in the closed system extracorporeal circuit 100. The control device 10 is a personal computer with a built-in CPU (Central Processing Unit), for example. The control device 10 has a function of controlling the operations of the roller pump 4 and the pressure sensor 5, and can control the operation of the roller pump 4 based on the detection result of the pressure sensor 5.

  Hereinafter, the control program of the control apparatus 10 of the closed system extracorporeal circuit 100 will be described based on the flowchart of FIG.

  By the way, in the closed system extracorporeal circuit 100, the pressure in the portion between the roller pump 4 and the patient H tends to be the lowest. Depending on the degree of this low pressure, the catheter placed in the vein may stick to the inner wall of the vein and blood may not be sucked, but such a situation can be prevented by the control program of the control device 10.

  The pressure sensor 5 detects the pressure p in the upstream portion of the blood removal line 1 from the oxygenator 3. The operation of the roller pump 4 is controlled based on the pressure p (information) detected (obtained) by the pressure sensor 5.

As shown in FIG. 3, an upper limit value p _max and a lower limit value p _min are set and stored in advance in the control device 10 as threshold values. The lower limit value p _min is a reference pressure for stopping the operation of the roller pump 4 during extracorporeal circulation, and the upper limit value p _max is a reference pressure for operating the stopped roller pump 4 again.

As shown in FIG. 3, when extracorporeal circulation is started, the control device 10 determines whether or not the pressure p detected by the pressure sensor 5 has fallen below the lower limit value p _min (step S200), and the pressure p is lower than the lower limit value. If it is determined that the value is lower than p _min , the operation of the roller pump 4 is stopped, that is, the rotational speed R of the roller pump 4 in the operating state is instantaneously reduced to “0” (step S201, time in FIG. 4). (Refer to the portion of “0” to “t ₁ ”).

Then, by operating the timer built in the control unit 10 (step S202), if it is determined that the predetermined time period has elapsed set by the timer (step S203), the pressure p exceeds the upper limit p _max It is determined whether or not (exceeded) (step S204).

If it is determined in step S204 that the pressure p has exceeded the upper limit value p _max , the roller pump 4 is operated again at the rotational speed R (see step S205, the portion after time “t ₂ ” in FIG. 4). On the other hand, if it is determined in step S204 that the pressure p does not exceed the upper limit value p _max , the roller pump 4 is maintained in a stopped state, and the process returns to step S202. Run sequentially.

  With the control as described above, in the closed extracorporeal circuit 100, even when the catheter placed in the vein sticks to the venous blood vessel wall due to the abnormal negative pressure due to the suction of the roller pump 4, the blood removal failure is likely to occur. The operation of the roller pump 4 can be stopped to prevent the sticking. As a result, in the closed extracorporeal circuit 100, it is possible to prevent the blood removal failure caused by the abnormal negative pressure by the roller pump 4 without using the centrifugal pump. It will have the characteristic that it is hard to crush finely. Due to this feature, in the closed extracorporeal circuit 100, the air bubbles are reliably removed, so that the air bubble removing device for removing the air bubbles installed in the conventional extracorporeal circulation device can be omitted. Since the bubble removing device is omitted, the closed extracorporeal circuit 100 can be reduced in size, and the extracorporeal circulation amount of extracorporeal blood can be suppressed as much as possible, that is, reduced.

Second Embodiment
FIG. 5 is a flowchart showing a control program of a control device provided in the closed system extracorporeal circuit (second embodiment) of the present invention, and FIG. 6 is a roller controlled by the control device provided in the closed system extracorporeal circuit shown in FIG. It is a graph which shows typically a time-dependent change (operation state) of the number of rotations of a pump.

  Hereinafter, the second embodiment of the closed extracorporeal circuit according to the present invention will be described with reference to these drawings. However, the description will focus on the differences from the above-described embodiment, and the description of the same matters will be omitted. .

  This embodiment is the same as the first embodiment except that the control device controls the roller pump, that is, the control program of the control device is different.

As shown in FIG. 5, the upper limit value p _max and the lower limit value p _min are set and stored in the control device 10 as threshold values in advance. The lower limit value p _min is a reference pressure for stopping the operation of the roller pump 4 while decreasing the rotation speed of the roller pump 4 during extracorporeal circulation, and the upper limit value p _max is operated again for the stopped roller pump 4. This is the reference pressure.

As shown in FIG. 5, when extracorporeal circulation is started, the control device 10 determines whether or not the pressure p detected by the pressure sensor 5 is lower than the lower limit value p _min (step S300), and the pressure p is lower than the lower limit value. If it is determined that the value is lower than p _min , the rotational speed R of the roller pump 4 in the operating state is continuously decreased gradually and decreased to “0” (step S301, times “0” to “0” in FIG. 6). see t ₁ ").

Next, a timer built in the control device 10 is activated (step S302), and when it is determined that a predetermined time set by the timer has elapsed (step S303), the pressure p exceeds the upper limit p _max . It is determined whether or not (exceeded) (step S304).

If it is determined in step S304 that the pressure p has exceeded the upper limit value p _max , the rotational speed of the roller pump 4 is continuously increased gradually to the rotational speed R and is operated again (step S305, time in FIG. 6). (Refer to the portion after “t ₂ ”). On the other hand, if it is determined in step S304 that the pressure p does not exceed the upper limit value p _max , the roller pump 4 is maintained in a stopped state, and the process returns to step S302. Run sequentially.

  With the above control, even in this embodiment, even when the catheter placed in the vein sticks to the venous blood vessel wall due to the abnormal negative pressure due to the suction of the roller pump 4, the roller pump 4 Can be stopped to prevent the sticking. As a result, in the closed extracorporeal circuit 100, it is possible to prevent the blood removal failure caused by the abnormal negative pressure by the roller pump 4 without using the centrifugal pump. It will have the characteristic that it is hard to crush finely. This feature ensures that air bubbles are removed.

  In the present embodiment, the rotation speed of the roller pump 4 is continuously reduced until the operation of the roller pump 4 is stopped. As a result, the blood flow gradually decreases, and the burden on the patient H can be reduced. Further, before the roller pump 4 is stopped, it is possible to prevent the catheter from sticking to the blood vessel wall, so that the extracorporeal circulation stop due to the stop of the roller pump 4 can also be avoided.

<Third Embodiment>
FIG. 7 is a flowchart showing a control program of the control device provided in the closed system extracorporeal circuit (third embodiment) of the present invention, and FIG. 8 is a roller controlled by the control device provided in the closed system extracorporeal circuit shown in FIG. It is a graph which shows typically a time-dependent change (operation state) of the number of rotations of a pump.

  Hereinafter, the third embodiment of the closed system extracorporeal circuit according to the present invention will be described with reference to these drawings. However, the description will focus on the differences from the above-described embodiment, and the description of the same matters will be omitted. .

  This embodiment is the same as the first embodiment except that the control device controls the roller pump, that is, the control program of the control device is different.

As shown in FIG. 7, the upper limit value p _max and the lower limit value p _min are set and stored in advance in the control device 10 as threshold values. The lower limit value p _min is a reference pressure for stopping the operation of the roller pump 4 while decreasing the rotation speed of the roller pump 4 during extracorporeal circulation, and the upper limit value p _max is operated again for the stopped roller pump 4. This is the reference pressure.

As shown in FIG. 7, when extracorporeal circulation is started, the control device 10 determines whether or not the pressure p detected by the pressure sensor 5 has fallen below the lower limit value p _min (step S400), and the pressure p is lower than the lower limit value. If it is determined that the value is lower than p _min , the rotational speed R of the roller pump 4 in the operating state is continuously and gradually decreased to the rotational speed R ′ (step S401, time “0” to “t” in FIG. 8). ₁ ”). The rotational speed R ′ is preferably 5 to 80%, more preferably 10 to 50% of the rotational speed R.

Next, a timer built in the control device 10 is activated (step S402), and when it is determined that a predetermined time set by the timer has elapsed (step S403), the pressure p exceeds the upper limit p _max . It is determined whether or not (exceeded) (step S404).

If it is determined in step S404 that the pressure p has exceeded the upper limit value p _max , the rotational speed R ′ of the roller pump 4 is continuously and gradually increased to the rotational speed R (step S405, time “t _{2 in} FIG. 8). "See the part after.) On the other hand, if it is determined in step S404 that the pressure p does not exceed the upper limit p _max , the roller pump 4 maintains a state of rotating at the rotational speed R ′, and the process returns to step S402. Thereafter, the lower steps are sequentially executed.

  With the above control, even in this embodiment, even when the catheter placed in the vein sticks to the venous blood vessel wall due to the abnormal negative pressure due to the suction of the roller pump 4, the roller pump 4 Can be prevented from sticking. As a result, in the closed extracorporeal circuit 100, it is possible to prevent the blood removal failure caused by the abnormal negative pressure by the roller pump 4 without using the centrifugal pump. It will have the characteristic that it is hard to crush finely. This feature ensures that air bubbles are removed.

  The closed system extracorporeal circuit according to the present invention has been described above with reference to the illustrated embodiment.However, the present invention is not limited to this, and each part constituting the closed system extracorporeal circuit exhibits the same function. It can be replaced with any configuration obtained. Moreover, arbitrary components may be added.

  The closed extracorporeal circuit according to the present invention may be a combination of any two or more configurations (features) of the above embodiments.

  Further, a valve mechanism for opening and closing the recirculation line may be provided in the middle of the recirculation line.

  Moreover, although the oxygenator which performs gas exchange has two filter members in each said embodiment, it is not limited to this, For example, you may have one filter member. In this case, an arterial filter is installed on the downstream side of the oxygenator, and as a whole, an oxygenator system including an oxygenator having one filter member and an artery filter can be obtained.

  Further, in each of the embodiments, the pressure sensor is disposed upstream of the blood pump of the blood removal line and upstream of the connection portion to which the recirculation line is connected. However, the present invention is not limited thereto. For example, you may arrange | position in the part upstream from the roller pump of a blood removal line, and a downstream from the connection part of a blood removal line.

100 Closed system extracorporeal circuit (closed system extracorporeal circuit)
DESCRIPTION OF SYMBOLS 1 Blood removal line 11 Tube 12 Connection part 2 Blood supply line 21 Tube 3 Artificial lung (artificial lung system)
31 housing 311 blood inflow port 312 blood outflow port 313 heat medium inflow port 314 heat medium outflow port 315 gas inflow port 316 gas outflow port 317 recirculation port 318 recess 32 heat exchange section 33 gas exchange section 34 first filter member ( (First filter)
35 Second filter member (second filter)
36 Flow path 4 Roller pump 41 Rotor 5 Pressure sensor 9 Recirculation line 91 Tube 10 Control device (control unit)
H patient p pressure p _max upper limit p _min lower limit Q blood flow R, R ′ rotational speed S200 to S205, S300 to S305, S400 to S405 Step t ₁ , t ₂ hours

Claims (9)

A blood removal line through which the blood that has been removed flows down;
A roller pump provided in the middle of the blood removal line for transferring blood;
A pressure sensor provided in a portion of the blood removal line upstream of the roller pump, and detecting a pressure in the blood removal line;
A gas exchange part connected to the downstream side of the blood removal line and performing gas exchange with respect to the blood flowing down the blood removal line, and disposed in the downstream side of the gas exchange part, in the blood subjected to the gas exchange A first filter and a second filter that trap air bubbles, wherein the first filter and the second filter are spaced apart from each other along the direction of blood flow, and An artificial lung system that functions as a flow path through which blood passes between the second filter and the second filter;
And a recirculation line that connects the flow path and a portion of the blood removal line upstream of the roller pump and returns a part of the blood passing through the flow path to the blood removal line. Closed system extracorporeal circuit.   The blood from the recirculation line is a mixture of air bubbles that could not be captured by the first filter, and while passing through the blood removal line and the first filter in order at least once, The closed system extracorporeal circuit according to claim 1, wherein the first filter is configured to capture part or all of bubbles mixed in the blood.   The closed system extracorporeal circuit according to claim 1, further comprising a control unit having a function of controlling the operation of the roller pump based on a detection result of the pressure sensor.   4. The control unit according to claim 3, wherein when the detection result of the pressure sensor falls below a preset lower limit value, the control unit controls to stop the operation of the roller pump or to reduce the rotation speed of the roller pump. The closed system extracorporeal circuit as described.   The closed system extracorporeal circuit according to claim 4, wherein the rotation speed of the roller pump continuously decreases.   When the control unit stops the operation of the roller pump or decreases the rotation speed of the roller pump, and the detection result of the pressure sensor exceeds a preset upper limit value, the roller The closed system extracorporeal circuit according to claim 4 or 5, wherein the pump is operated again or the rotation speed of the roller pump is increased. The first filter has a cylindrical shape and is arranged so that its central axis is parallel to the horizontal direction.
The second filter is arranged on the outer peripheral side of the first filter, vertically below the first filter,
The artificial lung system has a housing that collectively stores the first filter and the second filter, and the housing has a port that is connected to the recirculation line at a vertically upper portion thereof. 7. A closed extracorporeal circuit according to any one of claims 1 to 6, wherein is formed in a protruding manner.   The closed system extracorporeal circuit according to any one of claims 1 to 7, wherein the pressure sensor is arranged in a portion of the blood removal line that is upstream of a portion to which the recirculation line is connected.   The closed extracorporeal circuit according to any one of claims 1 to 8, further comprising a blood supply line that is connected to a downstream side of the oxygenator system and flows down blood from the oxygenator system.

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