JP2010213941A - Blood circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blood circuit having a function of removing air bubbles and foreign matter from a blood circuit, while preventing the impossibility of liquid passage in a filter caused by the generation of a thrombus. <P>SOLUTION: The blood circuit 1 for cleaning blood in a connected state to a human body includes: an air chamber 30 for capturing the air bubbles in the blood circuit 1; and a foreign matter removal filter 100 arranged on the downstream side of the air chamber 30 and having the filter 103 for filtering the foreign matter. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a blood circuit for purifying blood.

  Conventionally, for example, in order to purify the blood of a patient with renal insufficiency, continuous slow hemofiltration (CHF) or continuous hemodiafiltration (CHDF) has been performed. The treatment used is being performed.

  CHF is blood purified by injecting blood taken from a patient into a blood purifier provided with a semipermeable membrane for filtration (hereinafter referred to as “filtration membrane”) and filtering the blood using a filtration membrane. Is returned to the patient, and waste products (for example, electrolyte substances such as urea and sodium chloride) and the solvent (water) in the blood obtained by filtration are discarded. At the same time, in order to compensate for the decrease in the solvent in the patient's blood, a method of continuously and slowly replenishing the patient's blood with a predetermined replenisher (hereinafter referred to as “replacement”). In CHF, waste products and solvents in blood to be discarded are referred to as filtrate (hereinafter referred to as “filtrate”).

  On the other hand, CHDF is a method for improving small molecule removal ability in CHF, and is a method of performing dialysis treatment in addition to CHF. That is, CHDF uses a blood purifier provided with a dialysis membrane together with a filtration membrane, supplies dialysis fluid to the blood purifier, and passes waste products still contained in blood purified by filtration through the dialysis membrane. The waste product is removed from the blood by moving it into the dialysate. Then, the blood purified by filtration and dialysis is returned to the patient and the replacement fluid is replenished to the patient's blood continuously and slowly. In CHDF, waste products and solvents in blood obtained by filtration and used dialysate are referred to as filtrate.

  By the way, when the purified blood is returned to the patient and the replacement fluid is replenished to the patient's blood, the blood and the replacement fluid are prevented from flowing into the patient's body. It is necessary to remove bubbles and foreign matter. For this reason, conventionally, in the CHDF, a drip chamber that mixes blood and a replacement fluid and captures bubbles and foreign substances from the mixed solution has been proposed (for example, see Patent Document 1).

  This drip chamber will be described with reference to FIG. FIG. 1 is a view showing a configuration of a conventional drip chamber. The drip chamber 90 is a gas-liquid separator that removes bubbles and foreign substances contained in the liquid flowing into the interior and flows out the liquid from which the bubbles and foreign substances have been removed. As shown in the figure, the drip chamber 90 includes an inlet portion 91, a main body 92, a filter 93 and an outlet portion 94.

  The inlet portion 91 includes two inlets, an inlet through which purified blood flows and an inlet through which supplemental fluid to be refilled flows. That is, the blood and the replacement fluid flow from the inlet portion 91 and are mixed.

  The main body 92 collects the air bubbles in the mixed liquid by collecting the air bubbles in the mixed liquid mixture on the inlet portion 91 side of the main body 92 by utilizing the property that the air bubbles rise in the liquid. And the foreign material in a liquid mixture is filtered with the mesh-shaped filter 93. FIG. Then, the mixed liquid from which bubbles and foreign matters are removed flows out from the outlet portion 94.

  In this way, the bubbles and foreign substances are removed from the blood circuit so that the bubbles and foreign substances in the blood circuit do not flow into the patient's body.

JP 2002-159571 A

  However, in a blood circuit equipped with a conventional drip chamber, there is a problem that a large amount of thrombus is generated, and the thrombus clogs the filter of the drip chamber, so that liquid cannot pass through.

  Here, the thrombus is caused by the retention of blood. If the internal volume of the drip chamber is large, the internal fluid tends to stay. That is, if the length of the drip chamber is long and the inner diameter is large, retention is likely to occur. However, conventional drip chambers must be lengthened to collect air bubbles. In addition, the conventional drip chamber must have a large inner diameter in order to filter out foreign substances.

  For this reason, the conventional drip chamber is in an environment in which stagnation is likely to occur in the internal fluid and thrombi are likely to occur. In addition, in the conventional drip chamber, a mesh-like filter is attached to remove foreign matter. However, when a thrombus generated in the chamber adheres to this filter, the thrombus tends to grow with the attachment site as a root. . Therefore, once a thrombus is generated, a large amount of thrombus is generated, and the thrombus is clogged in the filter of the drip chamber, so that there is a possibility that liquid cannot be passed. If the drip chamber is unable to pass liquid, it is necessary to replace each component incorporated in the circuit, such as a blood circuit or a blood purifier, and thus treatment by hemodialysis is interrupted for a long time.

  Therefore, the present invention has been made in view of such problems, and blood having a function capable of removing bubbles and foreign substances from the blood circuit while preventing infiltration of the filter due to thrombus generation. An object is to provide a circuit.

  In order to achieve the above object, a blood circuit according to the present invention is a blood circuit for purifying blood in a state connected to a human body, the air chamber collecting air bubbles in the blood circuit, and the air chamber And a foreign substance removal filter that includes a filter that filters foreign substances.

  According to this, the air chamber and the foreign matter removing filter are separated and provided separately. In this way, by separating the two functions of air bubble collection and foreign matter filtration, the length and inner diameter of the air chamber and the foreign matter removal filter can be made the minimum length and inner diameter as necessary. That is, the fluid in the air chamber and the foreign matter removal filter is unlikely to stay, so that thrombus is unlikely to occur. For this reason, bubbles and foreign substances can be removed from the blood circuit while preventing the filter from passing through due to thrombus.

  Preferably, the length of the foreign matter removal filter in the fluid flow direction is shorter than the length of the air chamber in the fluid flow direction. The length of the foreign matter removal filter in the fluid flow direction is 45 to 65 millimeters. Further, the filter is a mesh filter, and the area of the outer surface of the filter is 1000 to 1300 square millimeters.

  According to this, the length of the foreign matter removal filter is shorter than the length of the air chamber, and is preferably 45 to 65 mm. That is, the length of the foreign matter removal filter can be shortened as compared with the conventional drip chamber length of 100 to 160 mm. Therefore, stagnation is unlikely to occur because the fluid in the foreign matter removal filter is unlikely to stay. For this reason, bubbles and foreign substances can be removed from the blood circuit while preventing the filter from passing through due to thrombus.

  Preferably, a tube for connecting the air chamber and the foreign matter removing filter is provided, and the inner diameter of the air chamber is 1.5 to 2.5 times the inner diameter of the tube. More preferably, the inner diameter of the air chamber is 8 to 12 millimeters.

  According to this, it is preferable that the inner diameter of the air chamber is 1.5 to 2.5 times (8 to 12 mm) the inner diameter of the tube (for example, 5 mm). That is, the inner diameter of the air chamber can be made smaller than 3 to 4 times (16 to 20 mm) the inner diameter of the tube, which is the inner diameter of the conventional drip chamber. Accordingly, stagnation is unlikely to occur because the fluid in the air chamber is unlikely to stay. For this reason, bubbles and foreign substances can be removed from the blood circuit while preventing the filter from passing through due to thrombus.

  Preferably, a plurality of the foreign substance removal filters are provided, and the blood circuit further controls the flow of fluid so that the fluid flows to any one of the plurality of foreign substance removal filters. A switching unit for switching is provided.

  According to this, a plurality of foreign matter removal filters are provided in parallel, and the foreign matter removal filter can be switched. Therefore, even when the foreign matter removal filter is clogged with a thrombus or the like, it can be switched to another foreign matter removal filter. For this reason, bubbles and foreign substances can be removed from the blood circuit while preventing the filter from passing through due to thrombus.

  In addition, preferably, a pressure detection unit that detects a differential pressure before and after the foreign matter removal filter and a switch to the switching unit when the differential pressure detected by the pressure detection unit exceeds a predetermined value. And a control unit that outputs an instruction, and the switching unit switches the flow of the fluid so that the fluid flows from the foreign matter removal filter through which the fluid flows to another foreign matter removal filter in accordance with the switching instruction.

  According to this, when the differential pressure before and after the foreign matter removal filter becomes high, the foreign matter removal filter is switched. Therefore, even when the foreign matter removal filter is clogged with a thrombus or the like, it is switched to another foreign matter removal filter. For this reason, bubbles and foreign substances can be removed from the blood circuit while preventing the filter from passing through due to thrombus.

  In addition, preferably, a connection portion for connecting to a human body is further provided on the downstream side of the foreign matter removal filter, and the foreign matter removal filter is disposed in the vicinity of the connection portion.

  According to this, the foreign substance removal filter is disposed in the vicinity of the connection portion for connecting to the patient. Therefore, since the foreign substance removal filter is installed at a place where the foreign substance removal filter can be easily exchanged, it is not necessary to exchange the entire blood circuit when the foreign substance removal filter is exchanged, and the hemodialysis treatment can be continued. In addition, since the foreign matter is filtered immediately before the blood is returned to the patient, the inflow of the foreign matter to the patient can be prevented.

  According to the present invention, in a blood circuit for purifying blood, it is possible to remove bubbles and foreign substances from the blood circuit while preventing infiltration of the filter due to thrombus generation.

It is a figure which shows the structure of the blood circuit in embodiment of this invention. It is a figure which shows the structure of a foreign material removal part. It is a figure which shows the structure of an air chamber. It is a figure which shows the structure of a foreign material removal filter. It is a figure which shows the structure of the filter with which a foreign material removal filter is provided. It is a figure which shows the structure of the filter with which a foreign material removal filter is provided. It is a flowchart which shows an example of the operation | movement which a switching part switches a foreign material removal filter. It is a figure which shows the evaluation apparatus for evaluating the ease of the production | generation of a thrombus. It is a figure which shows the evaluation result by an evaluation apparatus. It is a figure which shows the evaluation result by an evaluation apparatus. It is a figure which shows the evaluation result by an evaluation apparatus. It is a figure which shows the other structure of a foreign material removal part. It is a figure which shows the structure of the conventional drip chamber.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated with reference to drawings.

  FIG. 1 is a diagram showing a configuration of a blood circuit 1 in the embodiment of the present invention.

  The blood circuit 1 is a circuit that purifies blood while connected to a human body (patient). As shown in the figure, the blood circuit 1 includes a liquid supply pack 10, a blood purifier 20, an air chamber 30, a foreign substance removal unit 40, a first connection unit 50, a second connection unit 60, a filtrate pack 70, and a tube 80. It has.

  The liquid supply pack 10 is a container in which liquid supply is stored. Here, “liquid supply” is a general term for “replacement fluid” and “dialysis fluid”. “Replacement fluid” refers to a chemical solution that replenishes lost water or electrolytes by injecting blood circuit 1. The “dialysis solution” refers to a chemical solution that exchanges substances with blood in the blood purifier 20. That is, here, it is assumed that “replacement fluid” and “dialysis fluid” are the same fluid. In addition, for the “liquid supply”, an isotonic solution adjusted so that the body fluid, the osmotic pressure and the electrolyte are generally equal is used.

  The blood purifier 20 is an instrument that purifies blood. Specifically, the blood purifier 20 has a cylindrical shape, and blood flows from a blood inlet provided in the upper part of the cylinder, and blood flows from a blood return port provided in the lower part of the cylinder. Blood is returned. In addition, the dialysate flows from the dialysate inlet provided at the lower side of the cylinder and the dialysate after purifying the blood from the dialysate outlet provided at the upper side of the cylinder, that is, the filtrate Discharged.

  The air chamber 30 collects air bubbles in the blood circuit 1 so that the air bubbles in the blood circuit 1 do not flow into the patient's body. Specifically, the air chamber 30 mixes the blood returned from the blood purifier 20 and the replacement fluid replenished from the liquid supply pack 10. The air chamber 30 collects bubbles contained in the mixed liquid by utilizing the property that the bubbles rise in the liquid.

  The foreign substance removing unit 40 is a part that removes foreign substances in the blood circuit 1 and is disposed on the downstream side of the air chamber 30. Specifically, the foreign matter removing unit 40 removes the foreign matter by filtering the foreign matter in the fluid discharged from the air chamber 30 with a filter. Details of the foreign matter removing unit 40 will be described later.

  The first connection part 50 is a part for connecting to the human body, which is arranged on the downstream side of the foreign substance removal part 40. Specifically, the first connection unit 50 is an instrument that is provided near the fluid outlet of the foreign substance removal unit 40 and returns blood to the patient's body. The 1st connection part 50 is a catheter inserted in a patient's blood vessel, for example. The purified blood is returned to the patient through this catheter. The first connection portion 50 corresponds to a “connection portion” described in the claims.

  The 2nd connection part 60 is a site | part for connecting with the human body arrange | positioned in the upstream of the blood purifier 20. FIG. Specifically, the 2nd connection part 60 is an instrument for taking out the blood from a patient. The 2nd connection part 60 is a catheter inserted in a patient's blood vessel, for example. The patient's blood is taken into the blood circuit 1 through this catheter and sent to the blood purifier 20.

  The filtrate pack 70 is a container in which filtrate that is dialysate after blood purification in the blood purifier 20 is stored. Here, the filtrate refers to a dialysate after purifying the blood, including waste products and excess water filtered from the blood.

  The tube 80 is a tube that connects each part in the blood circuit 1 and carries fluid such as blood and replacement fluid that flows in the blood circuit 1. For example, the tube 80 connects the air chamber 30 and the foreign matter removing unit 40 and carries the fluid at the outlet of the air chamber 30 to the foreign matter removing unit 40. Specifically, the tube 80 is a tube having an inner diameter of 5 mm.

  Next, the configuration of the foreign matter removing unit 40 will be described in detail.

  FIG. 2 is a diagram illustrating the configuration of the foreign matter removing unit 40.

  As shown in the figure, the foreign matter removing unit 40 includes a foreign matter removing filter 100, a switching unit 200, a pressure detecting unit 300, and a control unit 400. In the drawing, for convenience of explanation, a tube 80 that connects the air chamber 30 and the foreign matter removing unit 40 is shown in a short form.

  The foreign matter removal filter 100 is a part for removing foreign matter that is disposed in the vicinity of the first connection portion 50 on the downstream side of the air chamber 30. A plurality of foreign matter removal filters 100 are provided. Here, three foreign matter removal filters 100 are provided. Details of the foreign matter removal filter 100 will be described later.

  The switching unit 200 is a part that switches the flow of fluid so that the fluid flows to any one of the plurality of foreign matter removal filters 100. Specifically, the switching unit 200 is provided on the upstream side of the foreign matter removal filter 100, and by switching the flow path at the outlet of the switching unit 200, the fluid flows so that any one of the foreign matter removal filters 100 flows. It is a valve that switches the flow.

  For example, when each of the three foreign matter removal filters 100 is a foreign matter removal filter A, a foreign matter removal filter B, and a foreign matter removal filter C, the switching unit 200 changes the foreign matter removal filter A to the foreign matter removal filter B or the foreign matter removal filter. The fluid flow is switched so that the fluid flows through C. Similarly, the switching unit 200 allows the fluid to flow from the foreign matter removal filter B to the foreign matter removal filter A or the foreign matter removal filter C, or from the foreign matter removal filter C to the foreign matter removal filter A or the foreign matter removal filter B. Switches the fluid flow.

  The pressure detection unit 300 is a device that detects a differential pressure before and after the foreign matter removal filter 100. Specifically, in this embodiment, the pressure detection unit 300 detects the difference between the pressure at the inlet of the switching unit 200 and the pressure at the outlet of the foreign matter removal filter 100. In the present embodiment, the one pressure detection portion is illustrated in the vicinity of the upstream side of the foreign matter removal filter 100, but is not particularly limited as long as it is provided on the upstream side of the foreign matter removal filter 100. However, the present embodiment in which the one pressure detection part is provided in the vicinity of the upstream side of the foreign substance removal filter 100 (the one pressure detection part) is provided in the foreign substance removal filter (due to thrombus formation or the like) rather than the one pressure detection part in the other part. It is possible to quickly detect the blockage, detect the differential pressure, and cope with it.

  The control unit 400 performs control for switching the foreign matter removal filter 100. Specifically, the control unit 400 outputs a switching instruction to the switching unit 200 when the differential pressure detected by the pressure detection unit 300 exceeds a predetermined value. That is, the control unit 400 controls the foreign matter removal filter 100 to be switched when the differential pressure before and after the foreign matter removal filter 100 exceeds a predetermined value due to the foreign matter removal filter 100 being clogged with foreign matter. I do.

  Then, according to the switching instruction output by the control unit 400, the switching unit 200 switches the flow of fluid so that the fluid flows from the foreign matter removal filter 100 in which the fluid is flowing to the other foreign matter removal filter 100.

  Next, the configuration of the air chamber 30 will be described in detail.

  FIG. 3 is a diagram showing the configuration of the air chamber 30.

  As shown in the figure, the air chamber 30 includes a chamber inlet portion 31, a chamber body 32, and a chamber outlet portion 33.

  The chamber inlet 31 includes two inlets, an inlet through which blood purified by the blood purifier 20 flows and an inlet through which a replacement fluid replenished from the supply liquid pack 10 flows. That is, the blood and the replacement fluid flow from the chamber inlet 31 and are mixed.

  The chamber main body 32 collects the bubbles in the mixed liquid by collecting the bubbles in the mixed liquid mixture on the chamber inlet portion 31 side by utilizing the property that the bubbles rise in the liquid. To do.

  Here, the length of the chamber main body 32 in the fluid flow direction (length a1 shown in the figure) is equal to the length of the main body of the conventional drip chamber. Specifically, the length a1 of the chamber body 32 is 100 to 160 mm.

  Further, the inner diameter of the chamber main body 32 (inner diameter b1 shown in the figure) is smaller than the inner diameter of the main body of the conventional drip chamber. Specifically, the inner diameter b1 of the chamber main body 32 is smaller than the inner diameter of the foreign matter removing filter 100, and preferably the inner diameter b1 of the chamber main body 32 is 1.5 of the inner diameter of the tube 80 (the inner diameter c shown in the figure). ~ 2.5 times. Specifically, the inner diameter b1 of the chamber body 32 is 8 to 12 mm. In addition, the internal diameter of the main body of the conventional drip chamber is 16 to 20 mm (3 to 4 times the internal diameter c of the tube 80).

  If the length a1 and the inner diameter b1 are such dimensions, the air chamber 30 can effectively collect bubbles in the mixed liquid. Specifically, the air chamber 30 can collect bubbles of 6.4 cc or more, which is equivalent to the conventional drip chamber.

  Then, the mixed liquid from which bubbles are removed by the chamber body 32 flows out from the chamber outlet 33. In this way, the bubbles are removed from the blood circuit 1 so that the bubbles in the blood circuit 1 do not flow into the patient's body.

  Next, the configuration of the foreign matter removal filter 100 will be described in detail.

  FIG. 4 is a diagram illustrating a configuration of the foreign matter removal filter 100.

  As shown in the figure, the foreign matter removal filter 100 includes a removal filter inlet portion 101, a removal filter body 102, a filter 103, and a removal filter outlet portion 104.

  The removal filter inlet portion 101 is an inlet through which fluid from the air chamber 30 flows.

  The removal filter body 102 is a part that removes foreign matter in the blood circuit 1 by filtering foreign matter in the fluid. The removal filter main body 102 includes a filter 103 that filters foreign substances in the blood circuit 1. Details of the filter 103 will be described later.

  Here, the length of the removal filter main body 102 in the fluid flow direction (the length a2 shown in the figure) is shorter than the length of the main body of the conventional drip chamber. Specifically, the length a2 of the removal filter body 102 is shorter than the length of the air chamber 30 in the fluid flow direction, and preferably the length a2 of the removal filter body 102 is 45 to 65 mm. In addition, the length of the main body of the conventional drip chamber is 100 to 160 mm.

  Further, the inner diameter of the removal filter main body 102 (the inner diameter b2 shown in the figure) is equal to the inner diameter of the main body of the conventional drip chamber. Specifically, the inner diameter b2 of the removal filter body 102 is 15 to 25 mm (3 to 5 times the inner diameter c of the tube 80).

  If the length a2 and the inner diameter b2 are such dimensions, the foreign matter removal filter 100 can effectively filter foreign matter in the fluid. Specifically, the foreign matter removal filter 100 can filter foreign matter equivalent to the conventional drip chamber.

  Then, the fluid from which the foreign matter has been removed by the foreign matter removal filter 100 flows out from the removal filter outlet portion 104. In this way, the foreign matter is removed from the blood circuit 1 so that the foreign matter in the blood circuit 1 does not flow into the patient's body.

  Next, the structure of the filter 103 will be described in detail.

  5A and 5B are diagrams illustrating the structure of the filter 103 included in the foreign matter removal filter 100. FIG. Specifically, FIG. 5A is a plan view showing the appearance of the filter 103, and FIG. 5B is a cross-sectional view showing a cross section of the filter 103.

  As shown in these figures, the filter 103 is a mesh (mesh) filter.

  The area of the outer surface of the filter 103 is preferably 500 to 2000 square millimeters, and more preferably 1000 to 1300 square millimeters. This is equivalent to the filter area of a conventional drip chamber.

  The mesh size of the filter 103 is preferably 0.2 to 0.3 mm. This is equivalent to the mesh size of a conventional drip chamber filter.

  Next, an example of an operation in which the switching unit 200 switches the foreign matter removal filter 100 under the control of the control unit 400 will be described.

  FIG. 6 is a flowchart illustrating an example of an operation in which the switching unit 200 switches the foreign matter removal filter 100.

  As shown in the figure, first, by performing artificial dialysis, the foreign substance removal filter 100 removes foreign substances contained in the fluid in the blood circuit 1 (S102).

  And the pressure detection part 300 detects the differential pressure before and behind the foreign material removal filter 100 (S104). Since foreign matters are accumulated in the foreign matter removal filter 100, the differential pressure detected by the pressure detection unit 300 gradually increases.

  And the control part 400 judges whether the differential pressure | voltage detected by the pressure detection part 300 is more than predetermined value (S106).

  When it is determined that the differential pressure is equal to or greater than the predetermined value (YES in S106), the control unit 400 outputs a switching instruction to the switching unit 200 (S108).

  Then, the switching unit 200 switches the flow of the fluid so that the fluid flows from the foreign matter removal filter 100 in which the fluid is flowing to the other foreign matter removal filter 100 in accordance with the switching instruction output by the control unit 400 (S110).

  Further, when the control unit 400 determines that the differential pressure is not greater than or equal to a predetermined value (NO in S106), the control unit 400 ends the process without outputting a switching instruction to the switching unit 200.

  Next, the effect of the blood circuit 1 having such a configuration will be described in detail.

  First, the evaluation of the ease of thrombus formation will be described.

  FIG. 7 is a diagram showing an evaluation apparatus 500 for evaluating the easiness of thrombus formation.

  As shown in the figure, the evaluation apparatus 500 includes a blood container 501, a raw food container 502, a three-way stopcock 503, a test filter 504, a transmittance measuring device 505, a waste liquid container 506, and pumps P1 and P2.

  Cow blood is stored in the blood container 501. Further, the saline container 502 stores physiological saline. That is, bovine blood and physiological saline are test liquids for testing. Then, the test liquid is sent to the test filter 504 by the pumps P1 and P2. The three-way stopcock 503 is used for switching the test solution.

  The test filter 504 includes a mesh filter. Then, the test solution is filled up to 2/3 of the test filter 504, and discharged from the outlet at the lower part of the test filter 504 to the waste liquid container 506. When the test solution is discharged from the test filter 504, the transmittance of the discharged test solution is measured by the transmittance measuring device 505.

  In the evaluation apparatus 500 described above, from the transmittance measured by the transmittance measuring device 505, the replacement status in which the physiological saline is replaced with bovine blood is converted into data, thereby calculating the replacement time for the replacement. it can.

  If the replacement time is long, it can be determined that a long time of residence has occurred in the test filter 504. Conversely, if the replacement time is short, it can be determined that the residence time in the test filter 504 is short. If the residence time is long, thrombus is likely to occur, and if the residence time is short, thrombus is difficult to occur. That is, in the test filter 504 with a short replacement time, thrombus is unlikely to occur.

  8A, 8B, and 9 are diagrams showing evaluation results by the evaluation apparatus 500. FIG. Specifically, FIG. 8A is a graph showing the relationship between the area of the filter in the test filter 504 and the replacement time. FIG. 8B is a graph showing the relationship between the filter mesh size in the test filter 504 and the replacement time. Further, FIG. 9 is a graph showing the relationship between the tube length, which is the length of the test filter 504, and the replacement time.

  As shown in FIG. 8A, even if the area of the filter in the test filter 504 increases or decreases, the replacement time increases or decreases slightly. That is, the slope of the graph shown in FIG. For this reason, the area of the filter in the test filter 504 does not greatly affect the replacement time.

  Further, as shown in FIG. 8B, even if the mesh size of the filter in the test filter 504 is increased or decreased, the change in the replacement time is slight. That is, the slope of the graph shown in FIG. For this reason, the mesh size of the filter in the test filter 504 does not greatly affect the replacement time.

  Here, as shown in FIG. 9, when the tube length of the test filter 504 increases or decreases, the replacement time also greatly increases or decreases. That is, the slope of the graph shown in FIG. For this reason, a correlation is recognized between the tube length of the test filter 504 and the replacement time, and the tube length of the test filter 504 greatly affects the replacement time. Specifically, the longer the tube length of the test filter 504, the longer the replacement time.

  From the above results, when the tube length of the test filter 504 is long, the replacement time becomes long. That is, when the tube length of the test filter 504 is long, the residence time becomes long, and blood clots are easily generated. Therefore, the use of the foreign substance removal filter 100 having a short length makes it difficult for thrombus to occur.

  Here, the blood circuit 1 according to the present invention includes the air chamber 30 and the foreign matter removing filter 100 separately and separately provided. In this way, by separating the two functions of air bubble collection and foreign matter filtration, the length and the inner diameter of the air chamber 30 and the foreign matter removal filter 100 can be made the minimum length and the inner diameter.

  And the length of the foreign material removal filter 100 is shorter than the length of the air chamber 30, and 45-65 mm is preferable. That is, the length of the foreign matter removal filter 100 can be shortened as compared with 100 to 160 mm which is the length of the conventional drip chamber. Accordingly, stagnation is unlikely to occur because the fluid in the foreign matter removal filter 100 is unlikely to stay. For this reason, foreign matter can be removed from the blood circuit 1 while preventing the filter 103 from passing through due to thrombus.

  Further, as described above, the thrombus grows greatly by adhering to the filter 103. For this reason, in the air chamber 30 that does not include a filter to which thrombi easily adhere, thrombus is unlikely to occur. However, if stagnation occurs in the air chamber 30, there is a possibility that a thrombus may occur.

  Here, the inner diameter of the air chamber 30 is preferably smaller than the inner diameter of the foreign matter removal filter 100 and is 1.5 to 2.5 times the inner diameter of the tube. That is, the inner diameter of the air chamber 30 can be made smaller than 3 to 4 times the inner diameter of the tube, which is the inner diameter of the conventional drip chamber. Accordingly, stagnation is unlikely to occur because the fluid in the air chamber 30 is unlikely to stay. For this reason, bubbles can be removed from the blood circuit 1 while preventing the filter 103 from passing through due to the occurrence of thrombus.

  Further, a plurality of foreign matter removal filters 100 are provided, and the foreign matter removal filter 100 can be switched. Therefore, even when the foreign matter removal filter 100 is clogged with a thrombus or the like, it can be switched to another foreign matter removal filter 100.

  Moreover, when the differential pressure before and after the foreign matter removal filter 100 becomes high, the foreign matter removal filter 100 is switched. Therefore, even when the foreign matter removal filter 100 is clogged with a thrombus or the like, it is switched to another foreign matter removal filter 100.

  Moreover, the foreign substance removal filter 100 is arrange | positioned in the vicinity of the 1st connection part 50 for connecting with a patient. Therefore, since the foreign substance removal filter 100 is installed at a place where the foreign substance removal filter 100 is replaceable and easy to replace, it is not necessary to replace the entire blood circuit 1 when the foreign substance removal filter 100 is replaced, and hemodialysis treatment can be continued. . In addition, since the foreign matter is filtered immediately before the blood is returned to the patient, the inflow of the foreign matter to the patient can be prevented.

  As described above, according to the blood circuit 1 according to the present invention, it is possible to remove bubbles and foreign substances from the blood circuit while preventing the filter from passing through due to the occurrence of thrombus.

  As mentioned above, although the blood circuit which concerns on this invention was demonstrated using the said embodiment, this invention is not limited to this.

  That is, the embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  For example, in the above embodiment, the foreign matter removing unit 40 includes the three foreign matter removing filters 100, and the switching unit 200 switches the three foreign matter removing filters 100. However, the number of foreign matter removal filters 100 is not limited to three, and may be one or four or more. In this case, the switching unit 200 switches the flow of fluid so that the fluid flows to one foreign matter removal filter 100 among all the foreign matter removal filters 100.

  Further, in the above embodiment, the switching unit 200 switches the flow of fluid so that the fluid flows through any one of the plurality of foreign matter removal filters 100. However, the switching unit 200 may switch the flow of fluid so that the fluid flows through any two or more foreign matter removal filters 100 of the plurality of foreign matter removal filters 100.

  Moreover, in the said embodiment, the switching part 200 was provided in the upstream of the foreign material removal filter 100, and decided to switch the foreign material removal filter 100 through which the fluid flows by switching the flow path of the exit of the switching part 200. However, as shown in FIG. 10, the switching unit 200 is provided on the downstream side of the foreign matter removal filter 100, and the foreign matter removal filter 100 through which fluid flows is switched by switching the flow path at the entrance of the switching unit 200. Good. Here, this figure is a diagram showing another configuration of the foreign matter removing unit 40. The switching unit 200 may be provided on both the upstream side and the downstream side of the foreign matter removal filter 100, and the foreign matter removal filter 100 through which the fluid flows may be switched.

  In the above embodiment, the pressure detection unit 300 detects the difference between the pressure at the inlet of the switching unit 200 and the pressure at the outlet of the foreign matter removal filter 100. However, the pressure detection unit 300 may detect the pressure at any position as long as it can detect the differential pressure before and after the foreign matter removal filter 100.

  The blood circuit according to the present invention removes bubbles and foreign substances from the blood circuit, for example, in order to purify the blood of the patient with renal insufficiency while preventing infiltration of the filter due to thrombus generation. This is useful as a blood circuit having a function that can be removed.

DESCRIPTION OF SYMBOLS 1 Blood circuit 10 Supply pack 20 Blood purifier 30 Air chamber 31 Chamber inlet part 32 Chamber main body 33 Chamber outlet part 40 Foreign material removal part 50 1st connection part 60 2nd connection part 70 Filtrate pack 80 Tube 90 Drip chamber 100 Foreign substance Removal filter 101 Removal filter inlet section 102 Removal filter body 103 Filter 104 Removal filter outlet section 200 Switching section 300 Pressure detection section 400 Control section 500 Evaluation device 501 Blood container 502 Saline container 503 Three-way stopcock 504 Test filter 505 Permeability meter 506 Waste container

Claims (9)

A blood circuit that purifies blood while connected to the human body,
An air chamber for collecting bubbles in the blood circuit;
A blood circuit comprising: a foreign matter removal filter provided on a downstream side of the air chamber and provided with a filter for filtering foreign matter. The blood circuit according to claim 1, wherein a length of the foreign matter removal filter in a fluid flow direction is shorter than a length of the air chamber in a fluid flow direction. The blood circuit according to claim 2, wherein a length of the foreign matter removing filter in a fluid flow direction is 45 to 65 millimeters. The blood circuit according to any one of claims 1 to 3, wherein the filter is a mesh filter, and an area of an outer surface of the filter is 1000 to 1300 square millimeters. further,
A tube for connecting the air chamber and the foreign matter removing filter;
The blood circuit according to claim 1, wherein an inner diameter of the air chamber is 1.5 to 2.5 times an inner diameter of the tube. The blood circuit according to claim 5, wherein an inner diameter of the air chamber is 8 to 12 millimeters. A plurality of the foreign matter removal filters are provided,
The blood circuit further includes
The blood circuit according to any one of claims 1 to 6, further comprising a switching unit that switches a fluid flow so that the fluid flows to any one of the plurality of foreign matter removal filters. further,
A pressure detector for detecting a differential pressure before and after the foreign matter removal filter;
A control unit that outputs a switching instruction to the switching unit when the differential pressure detected by the pressure detection unit exceeds a predetermined value;
The blood circuit according to claim 7, wherein the switching unit switches the flow of the fluid so that the fluid flows from the foreign matter removal filter in which the fluid is flowing to another foreign matter removal filter in accordance with the switching instruction. further,
On the downstream side of the foreign matter removal filter, provided with a connection portion for connecting to the human body,
The blood circuit according to claim 1, wherein the foreign matter removal filter is disposed in the vicinity of the connection portion.

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