Intubation tube for extracorporeal circulation

Abstract

The invention relates to the technical field of medical equipment, and provides an extracorporeal circulation cannula which comprises a cannula body. A first opening area is arranged at the position, away from the first end by a first distance, of the side wall of the cannula body, and a plurality of first side holes are formed in the first opening area. The first side holes are arranged in the side wall of the cannula body in an array mode. According to the intubation tube for extracorporeal circulation, the first end of the intubation tube body is inserted into the venous blood vessel and communicated with the venous blood vessel, and the second end of the intubation tube body is communicated with the external equipment, so that the intubation tube is matched with the external equipment and the arterial intubation tube to form a circulation loop, and blood is drained out of the body from the body; after being subjected to gas exchange by the membrane type oxygenator, the gas is transfused back into the body through the arterial cannula to temporarily replace the cardiopulmonary function, so that rescue treatment is provided for critical patients; meanwhile, the first side holes which are arranged in an array mode are formed in the position, close to the first end, of the cannula body, the first side holes can effectively improve the flow field near an outlet of the cannula, and the recirculation rate can be reduced easily.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a cannula for extracorporeal circulation. Background Technology

[0002] Arterial and venous cannulas are key components of life support systems such as extracorporeal membrane oxygenation (ECMO), and their core performance indicators include recirculation rate and hemolysis index. Recirculation rate refers to the proportion of oxygenated blood that is not effectively utilized and is directly returned to the ECMO system; a high recirculation rate will significantly reduce the system's oxygenation efficiency. The hemolysis index reflects the degree of mechanical damage to blood cells caused by cannulation.

[0003] Existing intravenous catheters are prone to flow separation, eddy currents, or localized high shear stress zones near their exit points. These unfavorable flow fields may lead to higher recirculation rates and increase the risk of blood injury. Summary of the Invention

[0004] This invention provides a cannula for extracorporeal circulation to solve the problem that in the prior art, the area near the outlet of venous cannulas is prone to flow separation, the formation of eddies or local high shear stress zones. These unfavorable flow fields may lead to a high recirculation rate and increase the risk of blood damage.

[0005] This invention provides a cannula for extracorporeal circulation, comprising: The cannula body has a first end for insertion into a vein to communicate with the vein, and a second end for communication with an external device. A first opening area is provided on the side wall of the cannula body at a first distance from the first end, and a plurality of first side holes are provided in the first opening area; Multiple first side holes are arranged in an array on the side wall of the cannula body.

[0006] According to the extracorporeal circulation cannula of the present invention, a plurality of first side holes are divided into multiple groups, and the multiple groups of first side holes are arranged at intervals along the axial direction of the cannula body. Each group of first side holes includes a plurality of first side holes arranged at intervals along the circumferential direction of the cannula body. Adjacent groups of first side holes are staggered along the axial direction of the cannula body.

[0007] According to the extracorporeal circulation cannula of the present invention, the first side hole is divided into three groups, the three groups of first side holes are arranged at equal intervals along the axial direction of the cannula body, each group of first side holes includes two first side holes, and the two first side holes are arranged opposite each other along the radial direction of the cannula body.

[0008] According to the extracorporeal circulation cannula of the present invention, the first side hole is divided into two groups, and the two groups of first side holes are arranged at intervals along the axial direction of the cannula body; each group of first side holes includes three first side holes, and the three first side holes are arranged at equal intervals along the circumference of the cannula body.

[0009] According to the extracorporeal circulation cannula of the present invention, the distance between two adjacent sets of first side holes along the axial direction of the cannula body is not less than 2 mm and not more than 10 mm.

[0010] According to the extracorporeal circulation cannula of the present invention, the first spacing is not less than 5 mm and not more than 50 mm.

[0011] According to the extracorporeal circulation cannula of the present invention, the cannula body further includes a plurality of second side holes; Multiple second side holes are disposed between the first opening area and the second end of the cannula body; the multiple second side holes are divided into multiple groups, and the multiple groups of second side holes are arranged at intervals along the axial direction of the cannula body, and each group of second side holes includes multiple second side holes arranged at intervals along the circumferential direction of the cannula body.

[0012] According to the extracorporeal circulation cannula of the present invention, the distance between two adjacent sets of second side holes along the axial direction of the cannula body is not less than 25 mm and not more than 50 mm. And / or, The distance between the second side hole and the first side hole closest to the first end of the cannula body is not less than 25mm and not more than 50mm.

[0013] According to the extracorporeal circulation cannula of the present invention, the axial direction of the first side hole is set at an angle to the axial direction of the cannula body; And / or, The axial direction of the second side hole is set at an angle to the axial direction of the cannula body.

[0014] According to the extracorporeal circulation cannula of the present invention, the diameter of the first side hole is not less than 2 mm and not more than 3 mm; and / or; The diameter of the second side hole is not less than 2mm and not more than 3mm.

[0015] According to the extracorporeal circulation cannula of the present invention, by inserting the first end of the cannula body into a vein and communicating with the vein, and by communicating the second end of the cannula body with an external device, a circulation loop is formed in conjunction with the external device and the arterial cannula. Blood is drained from the body to the outside, undergoes gas exchange in a membrane oxygenator, and is then returned to the body through the arterial cannula, temporarily replacing cardiopulmonary function and providing emergency treatment for critically ill patients. At the same time, by setting the first side holes arranged in an array near the first end of the cannula body (within the first opening area of ​​the first end at a first distance from the first spacing), the first side holes can effectively improve the flow field near the cannula outlet, which is beneficial to reducing the recirculation rate. This effectively solves the problem that in the prior art, the area near the outlet of the venous cannula is prone to flow separation, the formation of eddies, or local high shear stress zones. These unfavorable flow fields may lead to a high recirculation rate and increase the risk of blood damage. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is one of the schematic diagrams of the extracorporeal circulation cannula provided in the embodiments of the present invention.

[0018] Figure 2 This is the second schematic diagram of the extracorporeal circulation cannula provided in the embodiments of the present invention.

[0019] Figure 3 This is the third schematic diagram of the extracorporeal circulation cannula provided in the embodiments of the present invention.

[0020] Figure 4 This is the fourth schematic diagram of the extracorporeal circulation cannula provided in the embodiments of the present invention.

[0021] Figure 5 This is the fifth schematic diagram of the extracorporeal circulation cannula provided in the embodiments of the present invention.

[0022] Figure 6 This is the sixth schematic diagram of the extracorporeal circulation cannula provided in the embodiments of the present invention.

[0023] Figure 7 This is the seventh schematic diagram of the extracorporeal circulation cannula provided in the embodiments of the present invention.

[0024] Figure 8 This is the eighth schematic diagram of the extracorporeal circulation cannula provided in the embodiments of the present invention.

[0025] Figure 9This is a schematic diagram of the extracorporeal circulation cannula and cylindrical structure provided in an embodiment of the present invention.

[0026] Figure 10 This is one of the schematic diagrams illustrating the combination of extracorporeal circulation cannula, arterial cannula, superior vena cava, right atrium and inferior vena cava provided in the embodiments of the present invention.

[0027] Figure 11 This is the second schematic diagram of the combination of extracorporeal circulation cannula, arterial cannula, superior vena cava, right atrium and inferior vena cava provided in the embodiments of the present invention.

[0028] Figure label: 1. The cannula body; 11. First end; 12. Second end; 13. First side hole; 14. Second side hole; 2. Cylindrical structure; 3. Superior vena cava; 4. Right atrium; 5. Inferior vena cava. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0030] The following is combined Figures 1-11 The present invention describes an extracorporeal circulation cannula.

[0031] like Figures 1 to 8 As shown, an embodiment of the present invention provides an extracorporeal circulation cannula, comprising: a cannula body 1, a first end 11 of the cannula body 1 for insertion into a vein to communicate with the vein, and a second end 12 of the cannula body 1 for communication with an external device; a first opening area is provided on the side wall of the cannula body 1 at a first distance from the first end 11, and a plurality of first side holes 13 are provided in the first opening area; the plurality of first side holes 13 are arranged in an array on the side wall of the cannula body.

[0032] In this embodiment, the extracorporeal circulation cannula can be used in the ECMO system in conjunction with the arterial cannula and the extracorporeal membrane oxygenator. The extracorporeal circulation cannula drains blood from the body to the outside, and after gas exchange in the membrane oxygenator, it is returned to the body through the arterial cannula, temporarily replacing cardiopulmonary function and providing emergency treatment for critically ill patients.

[0033] Specifically, the first end 11 and the second end 12 of the cannula body 1 are connected to a vein and an external device (membrane oxygenator), respectively, so as to drain blood from the patient's body to the external device.

[0034] Meanwhile, by providing multiple first side holes 13 arranged in an array on the side wall of the cannula body 1, at least a portion of the blood is drained into the cannula body 1 through the first side holes 13 for input into the ECMO device. This drainage method has been confirmed through simulation testing to effectively improve the flow field near the outlet of the extracorporeal circulation cannula, thereby inhibiting recirculation at the extracorporeal circulation cannula.

[0035] According to the extracorporeal circulation cannula of the present invention, by inserting the first end 11 of the cannula body 1 into a vein and communicating with the vein, and by communicating the second end 12 of the cannula body 1 with an external device, a circulation loop is formed in conjunction with the external device and the arterial cannula, so that blood is drained from the body to the outside, gas exchange is performed by a membrane oxygenator, and then blood is returned to the body through the arterial cannula, temporarily replacing cardiopulmonary function and providing emergency treatment for critically ill patients. At the same time, by setting the first side holes 13 arranged in an array near the first end 11 of the cannula body 1 (within the first opening area of ​​the first end 11 at a first distance), the first side holes 13 can effectively improve the flow field near the outlet of the extracorporeal circulation cannula, which is beneficial to reducing the recirculation rate. This effectively solves the problem that in the prior art, the outlet of the venous cannula is prone to flow separation, the formation of eddies or local high shear stress areas. These unfavorable flow fields may lead to a high recirculation rate and increase the risk of blood damage.

[0036] Specifically, in some embodiments, such as Figure 1 As shown, multiple first side holes 13 are divided into multiple groups, and the multiple groups of first side holes 13 are arranged at intervals along the axial direction of the cannula body 1. Each group of first side holes 13 includes multiple first side holes 13 arranged at intervals along the circumferential direction of the cannula body 1. Adjacent groups of first side holes 13 are staggered along the axial direction of the cannula body 1.

[0037] In this embodiment, by dividing the multiple first side holes 13 into multiple groups, each group of first side holes 13 includes multiple first side holes 13 arranged in a ring, and the adjacent two groups of first side holes 13 are staggered along the axial direction of the cannula body 1. That is to say, any two first side holes 13 in two adjacent groups of first side holes 13 will not be located on the same straight line parallel to the axial direction of the cannula body 1. This structure can effectively reduce the recirculation rate of the extracorporeal circulation cannula.

[0038] In some embodiments, such as Figure 1 , Figure 2 and Figure 3 As shown, the first side hole 13 is divided into three groups. The three groups of first side holes 13 are arranged at equal intervals along the axial direction of the cannula body 1. Each group of first side holes 13 includes two first side holes 13, and the two first side holes 13 are arranged opposite each other along the radial direction of the cannula body 1.

[0039] In this embodiment, the cannula body 1 is provided with six first side holes 13, which are divided into three groups. The three groups of first side holes 13 are arranged at equal intervals. Each group of first side holes 13 includes two first side holes 13 arranged radially opposite to each other along the cannula body 1. This design allows blood to flow out more evenly from each first side hole 13, which is beneficial to further improve the flow field at the outlet of the extracorporeal circulation cannula and further reduce the recirculation rate.

[0040] Furthermore, in some embodiments, such as Figure 1 , Figure 2 and Figure 3 As shown, the perpendicular lines from the center point of the two adjacent sets of first side holes 13 to the central axis (X-axis in the figure) of the cannula body 1 are perpendicular to each other.

[0041] In other embodiments, such as Figure 6 and Figure 8 As shown, the first side hole 13 is divided into two groups, and the two groups of first side holes 13 are arranged at intervals along the axial direction of the cannula body 1; each group of first side holes 13 includes three first side holes 13, and the three first side holes 13 are arranged at equal intervals along the circumference of the cannula body 1.

[0042] In this embodiment, the cannula body 1 is provided with six first side holes 13, which are divided into two groups. Each group of first side holes 13 includes three first side holes 13 arranged at equal intervals along the circumference of the cannula body 1 (i.e., the angle between the perpendicular lines from the center of two adjacent first side holes 13 to the central axis of the cannula body 1 is 120°). This design allows blood to flow out more evenly from each of the first side holes 13. This design can further improve the flow field at the outlet of the extracorporeal circulation cannula and further reduce the recirculation rate.

[0043] Optionally, in some embodiments, the distance between two adjacent sets of first side holes 13 along the axial direction of the cannula body 1 is not less than 2 mm and not more than 10 mm. In this embodiment, by limiting the distance between two adjacent sets of first side holes 13 along the axial direction of the cannula body 1, the adjacent first side holes 13 are prevented from being too close or too far apart, so that the flow fields of the blood discharged from the adjacent first side holes 13 can cooperate with each other, thereby reducing the recirculation rate.

[0044] Optionally, in some embodiments, the distance between two adjacent sets of first side holes 13 along the axial direction of the cannula body 1 is 5 mm.

[0045] In some embodiments, the first spacing is not less than 5 mm and not more than 50 mm. The first spacing is typically the distance between the first side hole 13 closest to the first end 11 of the cannula body 1 and the first end 11. By reasonably limiting this spacing, the first side hole 13 can be arranged in the main area where the recirculation phenomenon occurs, which can effectively suppress the occurrence of the recirculation phenomenon.

[0046] In some embodiments, such as Figures 1 to 8 As shown, the cannula body 1 also includes a plurality of second side holes 14; the plurality of second side holes 14 are disposed between the first opening area and the second end 12 of the cannula body 1; the plurality of second side holes 14 are divided into multiple groups, and the multiple groups of second side holes 14 are arranged at intervals along the axial direction of the cannula body 1, and each group of second side holes 14 includes a plurality of second side holes 14 arranged at intervals along the circumferential direction of the cannula body 1.

[0047] It is understood that the first side hole 13 is usually concentrated in the first opening area near the first end 11 of the cannula body 1. In this embodiment, multiple sets of second side holes 14 can be distributed between the first opening area and the second end 12 of the cannula body 1, and are arranged relatively evenly along the circumference and axial direction of the cannula body 1, so as to cooperate with the first side hole 13 to return blood to the venous blood vessel.

[0048] In some embodiments, each group of second side holes 14 includes four second side holes 14, which are arranged at equal intervals along the circumference of the cannula body 1.

[0049] In some embodiments, the distance between two adjacent sets of second side holes 14 along the axial direction of the cannula body 1 is not less than 25 mm and not more than 50 mm.

[0050] Optionally, the distance between a set of second side holes 14 and first side holes 13 closest to the first end 11 of the cannula body 1 is not less than 25 mm and not more than 50 mm.

[0051] In this embodiment, by reasonably limiting the hole spacing between each group of side holes, the recirculation rate of the extracorporeal circulation cannula can be further reduced.

[0052] In some embodiments, the axial direction of the first side hole 13 is angled to the axial direction of the cannula body 1.

[0053] The axial direction of the second side hole 14 is set at an angle to the axial direction of the cannula body 1.

[0054] In this embodiment, by designing the extension direction (i.e., axial direction) of the first side hole 13 and the second side hole 14 to be set at an angle to the cannula body 1, the flow direction of blood in the side hole is changed, so as to improve the flow field at the side hole and thus improve the recirculation rate of the extracorporeal circulation cannula.

[0055] It is understandable that the entire cavity of the first side hole 13 and the second side hole 14 can typically be designed as a cylinder or as a segment of a cylinder; such as Figure 9As shown, in actual modeling, a virtual cylindrical structure 2 can be constructed and inserted into the model of the cannula body 1 at an angle to the axis of the cannula body 1. The overlapping part of the cylindrical structure 2 and the model of the cannula body 1 forms a side hole, and the diameter of the cylindrical structure 2 corresponds to the diameter of the side hole.

[0056] In some embodiments, the diameter of the first side hole 13 is not less than 2 mm and not more than 3 mm; In some embodiments, the diameter of the second side hole 14 is not less than 2 mm and not more than 3 mm.

[0057] In the above embodiments, by limiting the range of the diameters of the two side holes, both types of side holes can improve the flow performance, effectively reduce the recirculation rate, and at the same time avoid the side hole diameters being too large and affecting the structural strength.

[0058] In addition, this application provides the following embodiments and comparative examples to illustrate the technical effects of this application: The structure and arrangement of comparative examples 1-8 can be referenced. Figure 5 For a schematic diagram of the relevant design dimensions, please refer to Figure 1 and Figure 9 .

[0059] Comparative Example 1: The cannula body 1 has a set of first side holes 13 and four sets of second side holes 14 arranged on it. The arrangement of the first side holes 13 and each set of second side holes 14 is the same, each including four side holes arranged at equal intervals along the circumference of the cannula body 1. The first side holes 13 and the second side holes 14 have the same structure, the hole diameter D is 2.5 mm, the hole distance L between two adjacent sets of side holes is 30 mm, the distance S between the first side hole 13 and the first end 11 of the cannula body 1 is 30 mm, and the opening angle θ is 90°.

[0060] Comparative Example 2: Based on Comparative Example 1, the hole spacing L between two adjacent sets of side holes and the distance S between the first side hole 13 and the first end 11 of the cannula body 1 are all adjusted to 35mm, with other settings remaining the same.

[0061] Comparative Example 3: Based on Comparative Example 1, the hole distance L between two adjacent sets of side holes and the distance S between the first side hole 13 and the first end 11 of the cannula body 1 are both adjusted to 40mm. Other settings are the same. Comparative Example 3 can be used as a standard example for comparison and reference with other comparative examples and embodiments.

[0062] Comparative Example 4: Based on Comparative Example 1, the hole spacing L between two adjacent sets of side holes and the distance S between the first side hole 13 and the first end 11 of the cannula body 1 are both adjusted to 45mm, with other settings remaining the same.

[0063] In summary, the simulation results of Comparative Examples 1-4 can reflect the impact of hole spacing changes on indicators such as recirculation rate.

[0064] Comparative Example 5: Based on Comparative Example 3, the opening angle θ of the two adjacent sets of side holes is adjusted to 30°, while other settings remain the same.

[0065] Comparative Example 6: Based on Comparative Example 3, the opening angle θ of the two adjacent sets of side holes is adjusted to 45°, while other settings remain the same.

[0066] In summary, the simulation results of comparative examples 3, 5, and 6 can reflect the impact of changes in the orifice angle on indicators such as the recirculation rate.

[0067] Comparative Example 7: Based on Comparative Example 3, the diameter D of all side holes (first side hole 13 and second side hole 14) is adjusted to 2mm, and other settings remain the same.

[0068] Comparative Example 8: Based on Comparative Example 3, the diameter D of all side holes (first side hole 13 and second side hole 14) is adjusted to 3mm, and other settings remain the same.

[0069] In summary, the simulation results of comparative examples 3, 7, and 8 can reflect the impact of pore size changes on indicators such as recirculation rate.

[0070] Example 1 (e.g.) Figure 1 (as shown) Based on Comparative Example 3, the arrangement of the first side holes 13 is adjusted. Specifically, there are six first side holes 13, which are divided into three groups. The three groups of first side holes 13 are arranged at equal intervals along the axial direction of the cannula body 1. Each group of first side holes 13 includes two first side holes 13, which are arranged opposite each other along the radial direction of the cannula body 1. The perpendicular lines from the center point of two adjacent groups of first side holes 13 to the central axis of the cannula body 1 (X-axis in the figure) are perpendicular to each other. The distance K between two adjacent groups of first side holes 13 along the axial direction of the cannula body 1 is 5 mm. Among them, the distance between the first side hole 13 closest to the first end 11 of the cannula body 1 and the first end 11 (i.e., the first distance S) is 40 mm, and the rest of the arrangement is the same as Comparative Example 3.

[0071] Example 2 (e.g.) Figure 2 (as shown) Based on Example 1, the first spacing S is adjusted to 10mm, and the remaining settings are the same as in Example 1.

[0072] Example 3 (e.g.) Figure 3 (as shown) Based on Embodiment 2, a second set of side holes 14 is added, and the rest of the settings are the same as in Embodiment 1.

[0073] Example 4 (e.g.) Figure 4 (as shown) Based on Comparative Example 3, a second set of side holes 14 is added, and the rest of the settings are the same as Comparative Example 3.

[0074] Example 5 (e.g.) Figure 5 (as shown) Based on Comparative Example 3, the first side hole 13 and the second side hole 14 are adjusted. Specifically, there are three first side holes 13, which are arranged at equal intervals along the circumference of the cannula body 1; there are three second side holes 14 in each group, which are also arranged at equal intervals along the circumference of the cannula body 1; the diameter D of all side holes (first side hole 13 and second side hole 14) is adjusted to 3mm.

[0075] Example 6 (e.g.) Figure 6 (as shown) Based on Embodiment 2, the arrangement of the first side holes 13 is adjusted. Specifically, the six first side holes 13 are divided into two groups. Each group of first side holes 13 includes three first side holes 13 arranged at equal intervals along the circumference of the cannula body 1 (that is, the angle between the perpendicular lines from the center of two adjacent first side holes 13 to the central axis of the cannula body 1 is 120°). The rest of the arrangement is the same as in Embodiment 2.

[0076] Example 7 (e.g.) Figure 7 As shown): Based on Embodiment 6, the arrangement of the first side holes 13 is adjusted. Specifically, there are nine first side holes 13, which are divided into two groups. Each group of first side holes 13 includes three first side holes 13 arranged at equal intervals along the circumference of the cannula body 1 (that is, the angle between the perpendicular lines from the center of two adjacent first side holes 13 to the central axis of the cannula body 1 is 120°). The rest of the arrangement is the same as in Embodiment 6.

[0077] Example 8 (as shown) Figure 8 As shown): Based on Example 8, the spacing K between two adjacent sets of first side holes 13 along the axial direction of the cannula body 1 is adjusted to 10mm, and the rest of the settings are the same as in Example 2.

[0078] Based on the above embodiments and comparative examples, this application constructs a simulation environment for simulating real physiological processes (such as...). Figure 10 and Figure 11 As shown), specifically, the superior vena cava 3, right atrium 4, and inferior vena cava 5 are used for modeling, where: Cardiopulmonary bypass cannulation: Placed in inferior vena cava 5, with the tip 20 mm anterior to the junction of inferior vena cava 5 and right atrium 4.

[0079] Arterial cannulation: Placed in the superior vena cava 3, with the tip 30 mm anterior to the junction of the superior vena cava 3 and the right atrium 4.

[0080] Based on the above simulation environment, this application simulated the blood circulation process in arteriovenous cannulation and the right atrium. The specific simulation results are as follows: Recirculation rate R f : The recirculation rate of extracorporeal circulation cannulas in Comparative Examples 1-8 and Examples 1-8 during the simulation process R f As shown in Table 1 below: Table 1. Recirculation rate of extracorporeal circulation cannulas in Comparative Examples 1-8 and Examples 1-8 during simulation. R f

[0081] The recycling rate of Comparative Examples 1-4 during the simulation process R f It can be seen that as the hole spacing L increases, R f The effect of aperture diameter D shows a gradual upward trend, and a smaller aperture spacing L (e.g., 30 mm) is beneficial for reducing recirculation. Simulation results from Comparative Examples 3 and 5-6 show that the effect of aperture diameter D exhibits a phased change; as the diameter increases from 2.0 mm to 2.5 mm... R f It remained basically stable, but after increasing to 3.0 mm... R f The significant decrease indicates that appropriately increasing the orifice diameter may help improve flow properties; the effect of the orifice angle θ is relatively gradual as the angle increases from 30° to 90°. R f The slight decrease indicates that the angle change has a weak control effect on recirculation.

[0082] In different arrangement methods (Examples 1 to 8), R f The fluctuations are quite significant, reflecting that local structural optimization, such as the number, location, and spacing of the holes, has a significant impact on recirculation. Among them, Examples 2 and 8 have the smallest recirculation coefficients.

[0083] Based on the above analysis, among the various optimization schemes, increasing the orifice diameter to D=3.0 mm (Comparative Example 8) and adopting the arrangement structures of Examples 2 and 8 can significantly reduce the recirculation coefficient, decreasing by 14.21%, 7.75%, and 14.41% respectively compared to the standard example (Comparative Example). However, excessively large orifice diameters may weaken the structural strength of the pipe wall, leading to insufficient local support and increasing the risk of collapse. Therefore, after comprehensively balancing fluid performance and structural reliability, it is recommended to prioritize the arrangement methods of Examples 2 and 8, which can effectively control recirculation while maintaining good pipe rigidity and deformation resistance.

[0084] Hemolysis Index (HI): Table 2 below shows the hemolysis index (HI) of the extracorporeal circulation cannulas used in Comparative Examples 1-8 and Examples 1-8 during the simulation process: Table 2. Hemolysis index (HI) of extracorporeal circulation cannulas used in Comparative Examples 1-8 and Examples 1-8 during the simulation process.

[0085] The results above show that the hemolysis index (HI) increases with increasing orifice spacing (L). When the orifice spacing decreases from 40 mm (baseline) to 30 mm, HI decreases by approximately 1.93%. HI increases with increasing orifice diameter (D). When orifice diameter (D) increases from 2.5 mm to 3.0 mm, HI increases by 4.39%, indicating that increasing orifice diameter (D) increases the risk of hemolysis. HI decreases with increasing orifice angle (θ). Decreasing the angle from 90° to 30° significantly increases HI by 5.57%, indicating that a larger orifice angle (e.g., 90°) is more beneficial for controlling hemolysis.

[0086] The effects of various layout optimization designs on HI differed significantly: Example 2 showed the best effect in effectively reducing HI, decreasing it by 3.31%. Examples 6 and 8 also performed well, reducing HI by 2.95% and 1.52%, respectively.

[0087] Pressure drop ΔP: The pressure drop ΔP of the extracorporeal circulation cannulas used in Comparative Examples 1-8 and Examples 1-8 during the simulation process is shown in Table 3 below: Table 3. Pressure drop ΔP of extracorporeal circulation cannulas in Comparative Examples 1-8 and Examples 1-8 during the simulation process.

[0088] The pressure drop variation reflects the impact of different structures on flow resistance. Data shows that there is an optimal orifice spacing L (L=35mm), which reduces the pressure drop by 5.30% compared to the baseline (L=40mm), while decreasing or increasing the orifice spacing L both lead to an increase in pressure drop. The orifice angle θ has a relatively small impact; within the range of 30° to 90°, the pressure drop fluctuates only within a small range (approximately 1.5%). Notably, increasing the orifice diameter D significantly increases the pressure drop (by 4.04% when D=3.0mm).

[0089] In different arrangement configurations, Examples 2, 6, and 8 all significantly increased the voltage drop (by 5.06%-5.89%). Example 1 showed a 1.62% reduction in voltage drop.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cannula for extracorporeal circulation, characterized in that, include: The cannula body has a first end for insertion into a vein to communicate with the vein, and a second end for communication with an external device. A first opening area is provided on the side wall of the cannula body at a first distance from the first end, and a plurality of first side holes are provided in the first opening area; Multiple first side holes are arranged in an array on the side wall of the cannula body.

2. The extracorporeal circulation cannula according to claim 1, characterized in that, The first side holes are divided into multiple groups, and the multiple groups of first side holes are arranged at intervals along the axial direction of the cannula body. Each group of first side holes includes multiple first side holes arranged at intervals along the circumferential direction of the cannula body. The first side holes of adjacent groups are staggered along the axial direction of the cannula body.

3. The extracorporeal circulation cannula according to claim 2, characterized in that, The first side hole is divided into three groups, and the three groups of first side holes are arranged at equal intervals along the axial direction of the cannula body. Each group of first side holes includes two first side holes, and the two first side holes are arranged opposite each other along the radial direction of the cannula body.

4. The extracorporeal circulation cannula according to claim 2, characterized in that, The first side hole is divided into two groups, and the two groups of first side holes are arranged at intervals along the axial direction of the cannula body; each group of first side holes includes three first side holes, and the three first side holes are arranged at equal intervals along the circumference of the cannula body.

5. The extracorporeal circulation cannula according to any one of claims 1-4, characterized in that, The distance between two adjacent sets of the first side holes along the axial direction of the cannula body shall be no less than 2 mm and no more than 10 mm.

6. The extracorporeal circulation cannula according to any one of claims 1-4, characterized in that, The first spacing is not less than 5mm and not more than 50mm.

7. The extracorporeal circulation cannula according to any one of claims 1-4, characterized in that, The cannula body also includes multiple second side holes; Multiple second side holes are disposed between the first opening area and the second end of the cannula body; the multiple second side holes are divided into multiple groups, and the multiple groups of second side holes are arranged at intervals along the axial direction of the cannula body, and each group of second side holes includes multiple second side holes arranged at intervals along the circumferential direction of the cannula body.

8. The extracorporeal circulation cannula according to claim 7, characterized in that, The distance between two adjacent sets of second side holes along the axial direction of the cannula body shall be no less than 25 mm and no more than 50 mm. And / or, The distance between the second side hole and the first side hole closest to the first end of the cannula body is not less than 25mm and not more than 50mm.

9. The extracorporeal circulation cannula according to claim 7, characterized in that, The axial direction of the first side hole is set at an angle to the axial direction of the cannula body; And / or, The axial direction of the second side hole is set at an angle to the axial direction of the cannula body.

10. The extracorporeal circulation cannula according to claim 7, characterized in that, The diameter of the first side hole is not less than 2mm and not more than 3mm; and / or; The diameter of the second side hole is not less than 2mm and not more than 3mm.

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