Catheter

Abstract

To provide a catheter that can be reduced in diameter, can reduce a load on the heart, and can effectively deliver oxygenated blood to important organs.SOLUTION: A catheter includes: a tubular main body that can be inserted into a blood vessel of a patient; and a first opening that is formed at a position spaced by a predetermined distance from a distal end portion of the main body, is formed so as to be inclined from a distal end side toward a proximal end side of the main body, and is configured to send oxygen-added blood flowing inside the main body into the blood vessel of the patient.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a catheter. [Background technology]

[0002] When a patient experiences a myocardial infarction or other condition that causes a sudden decline in the heart's pumping function, the left ventricle's volume increases excessively, causing the left ventricle to fail to contract. Under such circumstances, the left ventricle is unable to pump enough blood, and an insufficient supply of oxygenated blood to vital organs throughout the body, including the brain, becomes necessary. In such cases, intervention with an extracorporeal circulation device is necessary.

[0003] Currently used percutaneous extracorporeal circulation devices include the intracardiac pump catheter for circulatory support (IMPELLA (registered trademark)) and percutaneous cardiopulmonary support devices (ECMO: extracorporeal membrane oxygenation). Although IMPELLA can reduce cardiac load, it has problems with not being able to oxygenate the patient and being subject to strict facility standards.

[0004] In contrast, ECMO (e.g., Patent Document 1) is widely used because it can oxygenate blood and there are no facility restrictions on device use. However, it has the major problem of increasing cardiac load due to retrograde blood flow from the patient's thigh, and it is also known that vascular complications associated with cannula placement, which requires the placement of a large diameter cannula, are also a major problem.

[0005] First, regarding the issue of increased cardiac load due to retrograde blood flow, ECMO is a device that supplies oxygenated blood to vital organs, particularly the brain, but because blood is sent at a high flow rate in the opposite direction to the blood sent from the heart, it places a strain on the heart, which may delay the recovery of cardiac function.

[0006] Regarding the second issue of vascular complications associated with large-diameter cannulae, the incidence of lower limb ischemia after insertion of an ECMO cannula from the femoral artery is said to be around 10-70%. If lower limb ischemia occurs, it can lead to compartment syndrome or lower limb necrosis, and patients with lower limb ischemia have a significantly worse prognosis.

[0007] According to a meta-analysis of 1,763 adult patients focusing on the outcomes and complications of ECMO, nearly 50% of patients receiving ECMO survive until discharge, even in conditions where death is usually likely, while a significant number of patients (45%) die from complications such as bleeding (33%) and sepsis (22%) associated with long-term ECMO placement (see, for example, Non-Patent Document 1).

[0008] In recent years, a method called "ECPELLA" has been developed that combines Impella with ECMO, which allows oxygenated blood to be supplied to the brain while reducing cardiac load. However, since this method still uses Impella, there is a problem in that strict facility standards must be met.

[0009] Therefore, a cannula capable of antegrade blood transfer is known as a blood transfer cannula used in extracorporeal circulation of blood using a heart-lung machine (see Patent Document 2). This cannula consists of an outer tube and an inner tube, and blood passes through an annular return flow path formed between the inner tube and the outer tube, whose tip is closed, and is released in the antegrade direction from the blood release hole in the outer tube into the aorta.

[0010] However, the cannula of Patent Document 2 has an inward-facing protruding edge on the edge of each blood discharge hole as a mechanism for guiding the blood discharge direction in the antegrade direction. However, the inward-facing protruding edge only guides blood inside the outer tube, and is not capable of guiding blood discharged from the outer tube. Therefore, there is a problem that the antegrade guidance is insufficient. Furthermore, the cannula of Patent Document 1 has a problem that it is difficult to reduce the diameter of the cannula due to its structure, because the outer tube is arranged to cover the inner tube. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Patent No. 7293355 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-23970 [Non-Patent Document 1] Alberto Zangrillo et al., "A meta-analysis of complications and mortality of extracorporeal membrane oxygenation", Crit Care Resusc. 2013 Sep;15(3):172-8. Summary of the Invention [Problem to be solved by the invention]

[0012] In view of this situation, the present invention aims to provide a blood transfer catheter for ECMO that can effectively deliver oxygenated blood to vital organs while reducing the diameter of the catheter and reducing the load on the heart. [Means for solving the problem]

[0013] The invention to achieve the above object is a catheter comprising: a tubular main body portion that can be inserted into a patient's blood vessel; and a first opening formed at a position a predetermined distance from the distal end of the main body portion so as to be inclined from the distal end side to the proximal end side of the main body portion, for delivering oxygenated blood flowing inside the main body portion into the patient's blood vessel. Other features of the invention will become clear from the description and drawings that will be described later. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a catheter that can be made thinner, reduce the load on the heart, and effectively deliver oxygenated blood to important organs. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic diagram illustrating an extracorporeal circulation device 1 according to an embodiment. [Figure 2] 3A and 3B are diagrams illustrating details of the blood feed catheter 13 of the embodiment. [Figure 3] FIG. 10 is a diagram illustrating a section 135 according to an embodiment. [Figure 4] FIG. 10 is a diagram illustrating a section 135 according to an embodiment. [Figure 5] FIG. 10 is a diagram illustrating a section 135 according to an embodiment. [Figure 6] FIG. 10 is a diagram illustrating a section 135 according to an embodiment. [Figure 7] FIG. 2 is a diagram illustrating blood feeding through a blood feeding side catheter 13. [Figure 8] 3A and 3B are diagrams illustrating the details of the blood feed catheter 23 of the embodiment. [Figure 9] FIG. 2 is a diagram illustrating a section 235 according to an embodiment. [Figure 10] FIG. 2 is a diagram illustrating a section 235 according to an embodiment. [Figure 11] FIG. 2 is a diagram illustrating a section 235 according to an embodiment. [Figure 12] 10 is a diagram illustrating blood feeding through a blood feeding side catheter 23. FIG. [Figure 13]FIG. 10 is a diagram illustrating a section 335 of a modified example. [Figure 14] FIG. 10 is a diagram illustrating a section 435 of a modified example. [Figure 15] FIG. 10 is a diagram illustrating a section 435 of a modified example. [Figure 16] FIG. 10 is a diagram illustrating a section 435 of a modified example. [Figure 17] FIG. 10 is a diagram illustrating a section 435 of a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0016] ==First Embodiment== 1 is a schematic diagram illustrating an extracorporeal circulation apparatus 1 according to this embodiment. The extracorporeal circulation apparatus 1 is an apparatus that performs auxiliary circulation.

[0017] The "auxiliary circulation operation" refers to the operation of circulating blood and exchanging gas with blood being performed by the extracorporeal circulation device 1 when the heart of the patient P cannot function sufficiently or when the lungs cannot perform sufficient gas exchange. In other words, the extracorporeal circulation device 1 is a device that acts as a substitute for the heart and lungs.

[0018] The extracorporeal circulation device 1 is applied when the heart of a patient P is not functioning normally, or when the heart of a patient P is functioning normally but the lungs are not functioning normally. The extracorporeal circulation device 1 is used, for example, when performing cardiac surgery on the patient P or for subsequent treatment in an ICU.

[0019] The extracorporeal circulation device 1 first operates a centrifugal pump 13 (described in detail later) of the extracorporeal circulation device 1 to withdraw blood from the patient's veins. Then, the extracorporeal circulation device 1 adds oxygen to the blood by performing gas exchange in the blood using an artificial lung 17 (described in detail later). Then, the extracorporeal circulation device 1 returns the oxygenated blood to the patient's arteries or veins.

[0020] The extracorporeal circulation device 1 has a cardiac function measurement system 10, a blood removal side catheter 11, a blood removal tube 12, a blood supply side catheter 13, a blood supply tube 14, a drive motor 15, a centrifugal pump 16, an oxygenator 17, and a flow rate measurement unit 18.

[0021] [Blood removal catheter 11] The blood removal side catheter 11 is inserted from the femoral vein of the patient P. The tip of the blood removal side catheter 11 is placed in the right atrium. The blood removal side catheter 11 is connected to a blood removal tube 12 and is connected to a centrifugal pump 16 via the blood removal tube 12.

[0022] [Blood removal tube 12] The blood removal tube 12 is a conduit that connects the blood removal catheter 11 and the centrifugal pump 16 , and guides the blood removed from the patient P via the blood removal catheter 11 to the centrifugal pump 16 .

[0023] The blood removal tube 12 is made of a highly transparent, elastically deformable, flexible synthetic resin such as vinyl chloride resin or silicone rubber.

[0024] [Blood inlet catheter 13] The blood sending side catheter 13 is inserted from the femoral artery of the patient P. The blood sending side catheter 13 is connected to a blood sending tube 14, and is also connected to an oxygenator 17 via the blood sending tube 14. The blood sending side catheter 13 sends the blood that has passed through the oxygenator 17 to the blood vessels of the patient P via the blood sending tube 14. The detailed configuration of the blood sending side catheter 13 will be described later. The blood sending side catheter 13 corresponds to the "catheter" according to the present invention.

[0025] [Blood Transfusion Tube 14] The blood transfer tube 14 is a conduit that connects the oxygenator 17 and the blood transfer catheter 13, and guides the blood that has passed through the oxygenator 17 to the patient P. As the blood transfer tube 14, a conduit similar to that of the blood removal tube 12 is used.

[0026] 1, the direction of blood flow through the blood removal tube 12 and the blood transfer tube 14 is indicated by arrows. Blood taken out from the patient P via the blood removal catheter 11 flows in the order of the blood removal tube 14, centrifugal pump 16, and oxygenator 17. The blood to which oxygen has been added in the oxygenator 17 flows in the order of the blood transfer tube 14 and blood transfer catheter 13, and is then returned to the patient P.

[0027] In the following description, in the above-described route along which blood flows in the extracorporeal circulation apparatus 1, the side of the blood removal catheter 11 is referred to as "upstream" and the side of the blood transfer catheter 13 is referred to as "downstream."

[0028] [Cardiac Function Measurement System 10] The cardiac function measurement system 10 is a computer that controls the extracorporeal circulation apparatus 1. The cardiac function measurement system 10 generates a control signal for controlling the operation of the drive motor 15 based on a signal related to the rotation speed of the centrifugal pump 16, a signal related to the blood flow rate from the flow rate measurement unit 18, and the like, and transmits the control signal to the drive motor 15.

[0029] [Drive motor 15] The drive motor 15 controls the driving of the centrifugal pump 16 based on a command from the cardiac function measurement system 10 .

[0030] [Centrifugal Pump 16] The centrifugal pump 16 is provided downstream of the blood removal side catheter 11 and is driven by the driving force transmitted from the drive motor 15. The centrifugal pump 16 extracts blood from the patient P via the blood removal side catheter 11 and the blood removal tube 12, sends the blood to the oxygenator 17, and then returns the blood to the patient P via the blood transfer tube 14 and the blood transfer side catheter 13. The centrifugal pump 16 transmits a signal related to the rotation speed of the centrifugal pump 16 to the cardiac function measurement system 10.

[0031] [Artificial lung 17] The oxygenator 17 is provided downstream of the centrifugal pump 16. Specifically, the oxygenator 17 is disposed between the centrifugal pump 16 and the blood feed tube 14. The oxygenator 17 performs gas exchange (oxygen addition and / or carbon dioxide removal) on the blood. Oxygen gas (O2 gas) is supplied to the oxygenator 17 from an oxygen supply tube 19.

[0032] [Flow rate measurement section 18] The flow rate measuring unit 18 is provided in the blood transfer tube 14. The flow rate measuring unit 18 measures the flow rate of blood being returned to the patient P, and transmits a signal related to the blood flow rate to the cardiac function measuring system 10.

[0033] The flow rate measuring unit 18 is, for example, a flow rate sensor, and measures the flow rate of blood pumped out from the centrifugal pump 16. The flow rate measuring unit 18 transmits a signal related to the flow rate of blood flowing through the blood transfer tube 14 to the cardiac function measuring system 10.

[0034] <Details of the blood supply catheter 13> 2 is a diagram illustrating the details of the blood feed side catheter 13 of this embodiment. The blood feed side catheter 13 includes a main body 131 and a blood feed port 132.

[0035] [Main body 131] The main body 131 is a tubular member that can be inserted into a patient's blood vessel. As shown in FIG. 2, directions D1 and D2 are defined. Direction D1 is parallel to the axis X1 of the main body 131 and is the direction from the distal end 131a to the proximal end 131b of the main body 131. Direction D2 is the opposite direction to direction D1. In other words, direction D2 is the direction from the proximal end 131b to the distal end 131a of the main body 131.

[0036] The main body 131 of this embodiment has two tubes 134 and one joint 135 .

[0037] The tube 134 is a tubular member that can be inserted into the patient's blood vessels. Blood that has been oxygenated by the oxygenator 17 (FIG. 1) is supplied to the inside of the tube 134 via the blood feed port 132.

[0038] The joint 135 is a tubular member for connecting two tubes 134. The joint 135 is provided at a position a predetermined distance from the tip end 131a of the main body 131. The axis X1 of the main body 131 is the same as the axis of the joint 135. Therefore, hereinafter, the axis X1 of the main body 131 may be simply referred to as the "axis X1." The configuration of the joint 135 will be described in detail below.

[0039] 3 to 6 are diagrams illustrating the joint 135 of this embodiment. Fig. 3 is a perspective view of the joint 135, Fig. 4 is a cross-sectional view of the joint 135, Fig. 5 is a side view of the joint 135, and Fig. 6 is a cross-sectional view of the joint 135 (details will be described later).

[0040] 3 to 6, a three-dimensional Cartesian coordinate system consisting of an X-axis, a Y-axis, and a Z-axis is defined in these figures. In Figures 3 to 6, node 135 is disposed in the three-dimensional Cartesian coordinate system so that axis X1 is parallel to the X-axis and the direction D1 is the positive direction of the X-axis.

[0041] In the following description, the surface of the segment 135 facing the lumen will be referred to as the "inner surface 135a" and the outer surface will be referred to as the "outer surface 135b."

[0042] 3, the two tubes 134 connected to the joint 135 are indicated by dashed lines. The joint 135 is provided with connection portions 135c on the distal end 131a side and the proximal end 131b side, and an opening 135d.

[0043] The connecting portions 135c on the distal end 131a side and the proximal end 131b side are inserted into the inner lumens of the tubes 134 and bonded to the inner surfaces of the tubes 134. In this way, the two tubes 134 are connected via the joints 135.

[0044] The opening 135d (corresponding to the "first opening") is provided to send oxygenated blood flowing inside the main body 131 into the patient P's blood vessels.

[0045] Although details will be described later, the opening 135d is formed so as to send out oxygenated blood in the same direction (forward direction) as the flow of blood sent out from the heart of the patient P when the main body 131 is inserted into the blood vessel of the patient P. Therefore, the opening 135d may be referred to as the "forward direction opening 135d."

[0046] In this embodiment, a plurality of forward openings 135d are provided in the joint 135. The forward openings 135d are formed at predetermined intervals in the length direction of the main body 131.

[0047] Furthermore, in this embodiment, the forward opening 135d is formed to have four-fold rotational symmetry with respect to the axis X1 (FIG. 6).

[0048] The forward opening 135d is not limited to having four-fold rotational symmetry with respect to the axis X1, but may be formed to have n-fold rotational symmetry (n is an integer greater than 2).

[0049] The forward opening 135d will be described in detail using Figures 4 to 6. Figure 4 is a cross-sectional view of the node 135 taken along a plane passing through the axis X1 and parallel to the X and Z axes. Figure 5 is a side view of the node 135 as viewed from the Y-axis direction. Figure 6 is a cross-sectional view of the node 135 taken along the YZ plane passing through A1-A2 shown in Figures 4 and 5.

[0050] 4, forward opening 135d is formed so as to incline from tip end 131a toward base end 131b of main body 131. In other words, angle θ (FIG. 4) between the positive direction of the X axis (i.e., direction D1) and the direction in which forward opening 135d penetrates from inner surface 135a to outer surface 135b is an acute angle.

[0051] With this configuration, when oxygenated blood is pumped from the forward opening 135d into the blood vessels of the patient P, it is pumped in the direction of the base end 131b.

[0052] That is, in the vicinity of the forward opening 135d, the component of the X-axis direction of the flow of oxygenated blood is positive.

[0053] Moreover, one forward opening 135d is formed so that the opening edge on the outer surface 135b side is located closer to the base end 131b than the opening edge on the inner surface 135a side. This will be explained in detail with reference to FIG.

[0054] 4, point P1 is an end portion of one forward opening 135d on the opening edge on the outer surface 135b side, closer to the tip end 131a, and point P2 is an end portion of one forward opening on the opening edge on the inner surface 135a side, closer to the base end 131b.

[0055] In this embodiment, the forward opening 135d is formed so that point P1 is located closer to the base end 131b than point P2.

[0056] With this configuration, oxygenated blood is more easily sent in the direction toward the base end 131b when it is sent from the forward opening 135d into the blood vessels of the patient P. Note that the opening 135d is formed so that the angle θ approaches 0 degrees as the width of the forward opening 135d increases or the thickness of the section 135 (the distance between the inner surface 135a and the inner surface 135b) increases.

[0057] [Blood Infusion Port 132] The blood feed port 132 is provided at the base end 131b of the main body 131. The blood feed port 132 is a member for supplying the main body 131 with oxygenated blood.

[0058] The blood feed side catheter 13 of this embodiment has been described above, but the blood feed side catheter 13 may further include a guidewire port. The guidewire port is a member for inserting a guidewire into the main body portion 131. The guidewire is a long member that is inserted into the lumen of the main body portion 131 to guide the main body portion 131 to a desired position in the blood vessel of the patient P.

[0059] <Blood feeding through the blood feeding catheter 13> 7 is a diagram illustrating blood transfer using the blood transfer side catheter 13. As shown in this figure, the main body 131 of the blood transfer side catheter 13 is inserted into the blood vessel of the patient P so that the tip 131a is positioned on the heart side.

[0060] That is, the main body 131 is inserted into the blood vessel so that the direction D1 from the distal end 131a to the proximal end 131b coincides with the direction of blood flow pumped out from the patient P's heart.

[0061] In the following description, the direction of blood flow pumped out from the patient's heart may be referred to as the "forward direction," and the direction opposite to the forward direction may be referred to as the "reverse direction."

[0062] 7, arrows shown in blood vessels indicate the flow of blood. Here, the "flow of blood" includes the flow of blood pumped from the heart of patient P and the flow of oxygenated blood pumped from the blood supply catheter 13.

[0063] As shown in FIG. 7, blood sent from the forward opening 135d formed in the section 135 into the blood vessel of the patient P flows in the forward direction.

[0064] Therefore, according to the blood sending catheter 13 of this embodiment, the oxygenated blood does not go against the flow of blood sent out from the heart of the patient P, so the burden on the heart of the patient P can be reduced.

[0065] ==Second Embodiment== The blood feed side catheter can have various configurations other than those described in the first embodiment. In this embodiment, the configuration of the blood feed side catheter 23 will be described. Below, the blood feed side catheter 23 will be described, focusing on the parts that are different from the first embodiment, and a description of the common parts will be omitted. The blood feed side catheter 23 corresponds to the "catheter" according to the present invention.

[0066] 8 is a diagram illustrating the details of the blood feed side catheter 23 of this embodiment. The blood feed side catheter 23 includes a main body 231 and a blood feed port 132. The blood feed port 132 is the same as in the first embodiment.

[0067] [Main body 231] The main body 231 is a tubular member that can be inserted into the blood vessel of the patient P. As shown in Fig. 8, the direction D1 and the direction D2 are defined in the same manner as in the first embodiment (Fig. 2).

[0068] The main body 231 of this embodiment has three tubes 234 and two joints 135, 235. Of the two joints, joint 135 is the same as in the first embodiment. In this embodiment, joint 135 is arranged on the base end 131b side (FIG. 8). On the other hand, joint 235 is arranged on the tip end side. The configuration of joint 235 will be described in detail below.

[0069] 9 to 11 are diagrams illustrating the joint 235 of this embodiment. Fig. 9 is a cross-sectional view of the joint 235, Fig. 10 is a side view of the joint 235, and Fig. 11 is a cross-sectional view of the joint 235 (details will be described later). In Figs. 9 to 11, the same three-dimensional Cartesian coordinate system as in the first embodiment (Figs. 3 to 6) is defined.

[0070] The node 235 differs from the node 135 of the first embodiment in that it is provided with an opening 235d that is different from the forward opening 135d.

[0071] Opening 235d (corresponding to the "second opening"), like forward opening 135d, is provided to send oxygenated blood flowing inside main body 231 into the blood vessels of patient P.

[0072] Although the details will be described later, when the main body 231 is inserted into the blood vessels of the patient P, the opening 235d sends out oxygenated blood in a direction opposite to the flow of blood sent out from the heart of the patient P. Therefore, the opening 235d may be referred to as the "reverse direction opening 235d."

[0073] In this embodiment, a plurality of openings 235d in the reverse direction are provided in the joint 235. The openings 235d in the reverse direction are formed at predetermined intervals in the length direction of the main body 231.

[0074] Furthermore, in this embodiment, the opening 235d in the opposite direction is formed to have four-fold rotational symmetry with respect to the axis X2 of the main body 231.

[0075] The opening 235d in the opposite direction is not limited to being four-fold rotationally symmetric with respect to the axis X2 of the main body 231, but may be formed to be n-fold rotationally symmetric (n is an integer greater than 2).

[0076] The opening 235d in the opposite direction will be described in detail using Figures 9 to 11. Figure 9 is a cross-sectional view of the node 235 taken along a plane that passes through the axis X2 of the main body 231 and is parallel to the X and Z axes. Figure 10 is a side view of the node 235 as viewed from the Y axis direction. Figure 11 is a cross-sectional view of the node 235 taken along a YZ plane that is perpendicular to the X axis and passes through A1-A2 shown in Figures 9 and 10.

[0077] 9, the reverse opening 235d is formed so as to incline from the base end 231b side toward the tip end 231a side of the main body 231. In other words, the angle θ (FIG. 9) between the positive direction of the X axis (i.e., direction D1) and the direction in which the reverse opening 235d penetrates from the inner surface 235a to the outer surface 235b is an obtuse angle.

[0078] With this configuration, when oxygenated blood is sent from the opening 235d in the reverse direction into the blood vessels of the patient P, it is sent in the direction of the tip portion 231a.

[0079] That is, in the vicinity of the opening 235d in the reverse direction, the component of the flow direction of oxygenated blood in the X-axis direction is negative.

[0080] Moreover, one opening 235d in the opposite direction is formed so that the opening edge on the outer surface 135b side is positioned closer to the tip end 231a than the opening edge on the inner surface 235a side. This will be explained in detail with reference to FIG.

[0081] 9, point P1 is an end portion on the base end portion 231b side of the opening edge on the inner surface 235a side of one opening 235d in the opposite direction. Furthermore, point P2 is defined as an end portion on the tip end portion 231a side of the opening edge on the outer surface 235b side of the one opening 235d in the opposite direction.

[0082] In this embodiment, the opening 235d in the opposite direction is formed so that point P2 is located closer to the tip end 231a than point P1.

[0083] With this configuration, when oxygenated blood is sent into the blood vessels of the patient P from the opening 235d in the reverse direction, it is more likely to be sent in the direction toward the tip portion 231a.

[0084] In this embodiment, the forward opening 135d and the reverse opening 235d are formed so that the total area of ​​the forward opening 135d is larger than the total area of ​​the reverse opening 235d, so that the flow rate of oxygenated blood in the forward direction is larger than the flow rate in the reverse direction when it is pumped out from the main body 231.

[0085] In this embodiment, the area of ​​the forward opening 135d is the area of ​​the region surrounded by the opening edge on the outer surface 135b side of the forward opening 135d. The same applies to the area of ​​the backward opening 235d.

[0086] <Blood feeding through the blood feeding catheter 23> 12 is a diagram illustrating blood feeding using the blood feed side catheter 23. As in the first embodiment, the main body 231 of the blood feed side catheter 23 is inserted into the blood vessel of the patient P so that the tip portion 231a is positioned on the heart side of the patient P.

[0087] As shown in Figure 12, oxygenated blood is pumped in the forward direction from the forward opening 135d formed in the node 135. On the other hand, oxygenated blood is pumped in the backward direction from the backward opening 235d formed in the node 235.

[0088] As a result, the flow of blood pumped out from the heart of patient P collides with the flow of blood pumped in the opposite direction from node 235. Here, the oxygen concentration in the blood pumped out from the heart of patient P is lower than the oxygen concentration in the blood pumped in the opposite direction from node 235. When such a collision of blood flows occurs, blood with different oxygen concentrations mixes with each other, and the uniformity of the oxygen concentration in the blood increases.

[0089] == Variation 1 == The shape of the opening in the node is not limited to the example of the embodiment.

[0090] Fig. 13 is a diagram illustrating joint 335 of this modified example, showing a cross section similar to that of Fig. 4. Forward opening 335d according to this modified example is formed so that the opening edge on the inner surface 335a side (see the wavy circle in Fig. 13) is rounded.

[0091] With this configuration, when oxygenated blood is pumped into the blood vessels of the patient P, the white blood cells in the blood are less likely to be destroyed.

[0092] The opening edge on the outer surface 335b side shown in Fig. 13 may also be rounded. Furthermore, the opening 235d on the opposite side of the joint 235 shown in the second embodiment may also have a rounded opening edge, similar to this modification.

[0093] ==Variation 2== In the main body 231 of the second embodiment, only the forward opening 135d is formed in the joint 135, and only the backward opening 235d is formed in the joint 235.

[0094] However, the present invention is not limited to this, and at least one of the forward opening 135d and the reverse opening 235d may be formed in the node.

[0095] 14 to 17 are diagrams illustrating the joint 435 of this modified example. FIG. 14 is a cross-sectional view of the joint 435 taken along a plane passing through the axis X4 and parallel to the X-axis and Z-axis. FIG. 15 is a cross-sectional view of the joint 435 taken along a plane passing through the axis X4 and parallel to the X-axis and Y-axis. FIG. 16 is a side view of the joint 435 as viewed from the Y-axis direction. FIG. 17 shows a cross-sectional view similar to FIG. 6.

[0096] This modification is different from the first embodiment in that the joint 435 is formed with not only the forward opening 135d but also the reverse opening 235d.

[0097] In the present embodiment, the joint 435 is formed with a plurality of forward openings 135d and a plurality of reverse openings 235d.

[0098] In the cross-sectional view of Figure 14, two forward openings 135d are shown, and in the cross-sectional view of Figure 15, which is taken along a different plane from that of Figure 14, two reverse openings 235d are shown.

[0099] Two forward openings 135d and one reverse opening 235d are shown in the side view of Figure 16. Two forward openings 135d and two reverse openings 235d are shown in the cross-sectional view of Figure 17.

[0100] The forward openings 135d and the reverse openings 235d are formed so that the forward openings 135d and the reverse openings 235d are alternately arranged in the rotation direction of the main body 431 about the axis X4.

[0101] In this modification, the forward opening 135d and the reverse opening 235d are formed so as to have two-fold rotational symmetry with respect to the axis X4 of the joint 435, respectively.

[0102] When a forward opening 135d and a reverse opening 235d are formed at one node as in this modified example, the forward opening 135d and the reverse opening 235d may be formed so that the flow rate of blood discharged from the forward opening 135d is greater than the flow rate of blood discharged from the reverse opening 235d as the node approaches the base end.

[0103] Specifically, the forward opening 135d and the reverse opening 235d may be formed so that the total area of ​​the forward opening 135d is larger than the total area of ​​the reverse opening 235d as the node approaches the base end.

[0104] ==Summary== The blood delivery catheter 13 of the first embodiment described above comprises a tubular main body 131 that can be inserted into the blood vessels of a patient P, and a forward opening 135d that is formed at a position a predetermined distance from the tip 131a of the main body 131 so as to be inclined from the tip 131a side to the base end 131b side of the main body 131, and that is used to deliver oxygenated blood flowing inside the main body 131 into the blood vessels of the patient P.

[0105] With this configuration, the main body 131 can be made hollow, and therefore the diameter of the blood feed catheter 13 can be reduced.

[0106] Furthermore, with this configuration, when oxygenated blood is sent to the blood vessels of the patient P, it can be sent in the same direction (forward direction) as the flow of blood sent out from the heart of the patient P. Therefore, since it does not go against the flow of blood sent out from the heart of the patient P, it is possible to effectively deliver oxygenated blood to important organs while reducing the diameter and reducing the load on the heart.

[0107] In the blood feed side catheter 13, the forward opening 135d is formed so that an end P1 on the tip end 131a side of the opening edge on the outer surface side of the main body 131 is located closer to the base end 131b than an end P2 on the base end 131b side of the opening edge on the inner surface side of the main body 131. With this configuration, oxygenated blood can be more easily sent in the forward direction when being sent to the blood vessels of the patient P.

[0108] In the blood feed catheter 33 of the first modification, the forward opening 335d is formed so that the opening edge on the inner surface side is rounded. With this configuration, when oxygenated blood is sent to the blood vessels of the patient P, white blood cells in the blood are less likely to be destroyed.

[0109] The blood feed side catheter 23 of the second embodiment further includes a reverse opening 235d formed at a position a predetermined distance from the distal end 231a of the main body 231 so as to be inclined from the base end 231b side of the main body 231 toward the distal end 231a, for feeding oxygenated blood into a blood vessel. With this configuration, the flow of blood fed from the heart of the patient P collides with the flow of blood fed from the reverse opening 235d, thereby increasing the uniformity of the oxygen concentration in the blood.

[0110] In the blood feed side catheter 23 of the second embodiment, a plurality of forward openings 135d and a plurality of reverse openings 235d are formed in the main body 231. With this configuration, it becomes easier to adjust the flow rate of the blood being fed into the blood vessels of the patient P while maintaining the flow direction of the blood in a desired direction.

[0111] In the blood feed side catheter 23 of the second embodiment, the forward opening 135d and the reverse opening 235d are formed so that the total area of ​​the forward opening 135d is larger than that of the reverse opening 235d. With this configuration, the flow rate of blood fed in the forward direction is greater than the flow rate of blood fed in the reverse direction, thereby reducing the burden on the heart of the patient P.

[0112] In the blood feed side catheter 23 of the second embodiment, the forward opening 135d and the reverse opening 235d are formed at a predetermined interval in the longitudinal direction of the main body. With this configuration, the flow rate of the blood being fed into the blood vessel of the patient P can be easily adjusted while maintaining the desired direction of the blood being fed.

[0113] In the blood feed side catheter 23 of the second embodiment, the forward opening 135d and the reverse opening 235d are each formed to have n-fold rotational symmetry (n is an integer greater than 2) about the axis of the main body. With this configuration, it becomes easier to adjust the flow rate of the blood being fed while maintaining the strength of the joint 235.

[0114] In the blood feed side catheter 23 of the second modification, the forward openings 135d and the reverse openings 235d are formed so that the forward openings 135d and the reverse openings 235d are alternately arranged in the rotational direction about the axis X4 of the main body 431. With this configuration, the oxygen concentration in the blood can be made more uniform, while reducing the burden on the heart of the patient P.

[0115] The main body 131 of the first embodiment has a plurality of tubes 134 and a joint 135 that connects two of the plurality of tubes 134, and at least one of a forward opening 135d and a reverse opening 235d is formed in the joint 135. With this configuration, it is not necessary to form the forward opening 135d or the reverse opening 235d in the tube 134, which makes it easy to mold the forward opening 135d and the reverse opening 235d.

[0116] In the blood feed side catheter 23 of the second embodiment, the number of tubes 234 is three or more, and the forward openings 135d and the reverse openings 235d are formed so that the total area of ​​the forward openings 135d is larger than the total area of ​​the reverse openings 235d toward the base end 231b. With this configuration, the flow rate of blood fed in the forward direction is greater than the flow rate of blood fed in the reverse direction, thereby reducing the burden on the patient's heart.

[0117] [1] a tubular main body portion that can be inserted into a patient's blood vessel; a first opening formed at a position a predetermined distance from the distal end of the main body portion so as to be inclined from the distal end side to the proximal end side of the main body portion, for sending oxygenated blood flowing inside the main body portion into the patient's blood vessels; catheter.

[0118] [2] The first opening is an end portion of the opening edge on the outer surface side of the main body portion on the tip end side is formed to be located closer to the base end side than an end portion of the opening edge on the inner surface side of the main body portion on the base end side; [1] The catheter described in [1].

[0119] [3] The first opening is The opening edge on the inner surface side is formed to be rounded. [1] or [2].

[0120] [4] The blood vessel further includes a second opening formed at a position a predetermined distance from the distal end of the main body portion, the second opening being inclined from the base end side of the main body portion toward the distal end side, for delivering the oxygenated blood into the blood vessel. The catheter according to any one of [1] to [3].

[0121] [5] The first opening and the second opening are each formed in a plurality of parts in the main body. [4] The catheter described in [4].

[0122] [6] The first and second openings are formed so that the total area of ​​the first opening is larger than that of the second opening. [4] or [5].

[0123] [7] The first and second openings are formed at predetermined intervals in the longitudinal direction of the main body. The catheter according to any one of [4] to [6].

[0124] [8] The first and second openings are each formed to have n-fold rotational symmetry (n is an integer greater than 2) with respect to the axis of the main body. The catheter according to any one of [4] to [7].

[0125] [9] The first and second openings are formed so as to be alternately arranged in a rotational direction relative to the axis of the main body. The catheter according to any one of [4] to [8].

[0126]

[10] The main body portion is A plurality of tubes; a node connecting two tubes of the plurality of tubes; At least one of the first and second openings is formed in the node. The catheter according to any one of [4] to [9].

[0127]

[11] The number of the tubes is 3 or more, The first and second openings are The nodes are formed so that the total area of ​​the first openings is larger than the total area of ​​the second openings toward the base end side.

[10] The catheter described in

[10] .

[0128] The above-described embodiments are presented as examples and do not limit the scope of the invention. The above configurations can be implemented in appropriate combinations, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. The above-described embodiments and their modifications are included in the scope and spirit of the invention, as well as in the inventions described in the claims and their equivalents.

[0129] For example, in the above embodiment, a plurality of forward openings 135d are formed in the main body 131, but it is sufficient to form at least one opening. The same applies to the reverse opening 235d.

[0130] Furthermore, the angle θ (FIG. 4) between the direction D1 and the direction in which the forward opening 135d penetrates from the inner surface 135a to the outer surface 135b is sufficient as long as it is at least an acute angle. Furthermore, the angle θ (FIG. 4) between the direction D1 and the direction in which the forward opening 135d penetrates from the inner surface 135a to the outer surface 135b is sufficient as long as it is at least an acute angle. [Explanation of symbols]

[0131] Extracorporeal circulation device 1 Cardiac function measurement system 10 Drainage catheter 11 Blood removal tube 12 Blood inlet catheter 13,23 Main body 131 Blood inlet port 132 Tube 134,234 Section 135,235,335,435 Blood transfusion tube 14 Drive motor 15 Centrifugal pumps 16 artificial lung 17 Flow measurement part 18

Claims

1. a tubular main body portion that can be inserted into a patient's blood vessel; a first opening formed at a position a predetermined distance from the distal end of the main body portion so as to be inclined from the distal end side to the proximal end side of the main body portion, for sending oxygenated blood flowing inside the main body portion into the patient's blood vessels; catheter.

2. The first opening is an end portion of the opening edge on the outer surface side of the main body portion on the tip end side is formed to be located closer to the base end side than an end portion of the opening edge on the inner surface side of the main body portion on the base end side; The catheter of claim 1 .

3. The first opening is The opening edge on the inner surface side is formed to be rounded. The catheter of claim 1 .

4. a second opening formed at a position a predetermined distance from the distal end of the main body portion and inclined from the base end side to the distal end side of the main body portion, for sending the oxygenated blood into the blood vessel; The catheter of claim 1 .

5. The first opening and the second opening are each formed in a plurality of parts in the main body. The catheter of claim 4.

6. The first and second openings are formed so that the total area of ​​the first opening is larger than that of the second opening. The catheter of claim 5.

7. The first and second openings are formed at predetermined intervals in the longitudinal direction of the main body. The catheter of claim 5.

8. the first and second openings are each formed to have n-fold rotational symmetry (n is an integer greater than 2) with respect to the axis of the main body; The catheter of claim 5.

9. the first and second openings are formed so as to be alternately arranged in a rotational direction relative to the axis of the main body; The catheter of claim 8.

10. The main body portion is A plurality of tubes; a node connecting two tubes among the plurality of tubes; At least one of the first and second openings is formed in the node. The catheter according to any one of claims 4 to 9.

11. the number of tubes is three or more; The first and second openings are The nodes are formed so that the total area of ​​the first openings is larger than the total area of ​​the second openings toward the base end side. The catheter of claim 10.

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