Coronary sinus balloon counterpulsation catheter

Abstract

Provided in the present invention is a coronary sinus balloon counterpulsation catheter, comprising a catheter body and a balloon. The catheter body is provided with a first channel and a second channel that extend through the catheter body along the axial direction thereof. The first channel is eccentric to the catheter body. A cross-section of the second channel comprises a first contour line and a second contour line. The first contour line is at least a part of a first circle. The second contour line is at least a part of a second circle. The first contour line is closer to the first channel than the second contour line, and concave sides of the first contour line and the second contour line both face the first channel. The width of the second channel satisfies a predetermined relationship. The balloon is in sealed connection with a distal outer peripheral surface of the catheter body and is in communication with the second channel. The arrangement mode of the first channel and the second channel enables a filling liquid flowing in the second channel to have a relatively low resistance and a relatively high flow rate. In this way, the coronary sinus balloon counterpulsation catheter can use a liquid such as normal saline instead of a gas as a filling medium, thereby avoiding the occurrence of air embolism caused by balloon rupture and improving the safety of use.

Description

A coronary sinus balloon counterpulsation catheter Technical Field

[0001] This invention belongs to the field of medical device technology, specifically relating to a coronary sinus balloon counterpulsation catheter. Background Technology

[0002] Acute ST-segment elevation myocardial infarction (STEMI) is a rapidly progressing cardiovascular disease with high rates of disability and mortality. Clinically, percutaneous coronary intervention (PCI) to promptly restore epicardial vascular patency is the primary treatment for STEMI. However, even after successful revascularization, up to 30% of STEMI patients experience further enlargement of the ischemic area due to the failure to effectively open previously blocked microchannels, leading to higher mortality and recurrence rates. Therefore, improving microvascular circulation, including addressing issues such as microvascular embolism and microvascular remodeling, is crucial for improving the postoperative quality of life and reducing recurrence and mortality rates in STEMI patients.

[0003] The coronary sinus balloon counterpulsation catheter is placed in the coronary sinus (CS) via a venous access. The counterpulsation device controls the periodic expansion and contraction of the coronary sinus balloon counterpulsation catheter to intermittently block blood flow in the CS, thereby controlling the intermittent increase and decrease of blood pressure in the CS, promoting the backflow of coronary venous blood and its redistribution to the damaged myocardial area. This can improve myocardial perfusion and microcirculatory dysfunction after PCI, reduce the infarct area, and improve cardiac function.

[0004] In existing technologies, most coronary sinus balloon counterpulsation catheters use gas as the balloon inflation medium because gas jets have high velocity and low resistance, enabling rapid inflation and depressurization of the balloon. This allows the balloon's expansion and contraction frequency to match the heart's expansion and contraction frequency. However, if the balloon ruptures, the gas used as the inflation medium enters the bloodstream through the rupture site, forming air bubbles and causing air embolism. Air embolism can lead to serious health problems and even death. In contrast, using saline solution as the balloon inflation medium offers significant safety advantages. Saline solution refers to a 0.9% sodium chloride aqueous solution, which is highly compatible with the human body's physiological environment. Even if the balloon ruptures, the saline solution entering the bloodstream through the rupture site will not cause harm to the body because it is miscible with blood.

[0005] Although saline solution offers significant safety advantages as an filling medium, the physical properties of the liquid result in high resistance and slow flow rate during catheter transport. This leads to longer balloon inflation and depressurization times, reducing the frequency of balloon expansion and contraction, making it difficult to match the balloon's expansion and contraction frequency with the heart's. From a fluid dynamics perspective, the flow velocity in a catheter is closely related to the cross-sectional dimensions of the flow channel. However, in the medical device field, due to the need to accommodate various devices and consider the vessel's internal diameter, the catheter's inner and outer diameters are often limited by the accompanying access devices (such as guidewires and catheter sheaths) and vessel size during catheter design. Increasing the catheter's inner and outer diameters cannot easily increase the flow velocity, thereby hindering the expansion and contraction frequency of the coronary sinus balloon counterpulsation catheter. Therefore, using saline solution as the filling medium for coronary sinus counterpulsation balloons presents certain clinical challenges. Summary of the Invention

[0006] The purpose of this invention is to provide a coronary sinus balloon counterpulsation catheter, which aims to improve the safety of using the coronary sinus balloon counterpulsation catheter by using physiological saline or a liquid with similar properties as the filling medium.

[0007] To achieve the above objectives, the present invention provides a coronary sinus balloon counterpulsation catheter, comprising a catheter body and a balloon. The catheter body has a first cavity and a second cavity extending axially through it and isolated from each other. The first cavity is eccentrically disposed from the catheter body. The cross-section of the second cavity includes a first contour line and a second contour line, wherein the first contour line is at least a portion of a first circle and the second contour line is at least a portion of a second circle. The first contour line is closer to the first cavity than the second contour line, and the concave sides of both the first and second contour lines are arranged toward the first cavity. The balloon is sealed and connected to the distal outer peripheral surface of the catheter body and communicates with the second cavity.

[0008] The width of the second cavity at a specified position in the second circle satisfies the following relationship:

[0009] In the formula, h represents the width of the second cavity at the specified position of the second circle, D represents the diameter of the second circle, d represents the diameter of the first circle, e is the distance between the center of the first circle and the center of the second circle, θ represents the angle formed by the first straight line and the second straight line, the first straight line refers to the straight line passing through the center of the first circle and the center of the second circle, and the second straight line refers to the straight line passing through the specified position and the center of the second circle;

[0010] The width of the second cavity refers to the radial dimension of the second cavity in the first circle.

[0011] Optionally, the cross-section of the first cavity is circular, and the first cavity is coaxial with the first circle; the catheter body is coaxial with the second circle.

[0012] Optionally, the balloon includes a proximal balloon segment and a distal balloon segment that are symmetrically arranged and directly connected. The outer diameter and inner diameter of the proximal balloon segment both increase in the direction from the proximal end to the distal end, and the outer diameter and inner diameter of the distal balloon segment both decrease in the direction from the proximal end to the distal end.

[0013] Optionally, the balloon is configured to be elastic.

[0014] Optionally, the material used to prepare the balloon includes any one of silicone, polyurethane, and polyether block polyamide.

[0015] Optionally, it further includes a liquid aspiration device and a power mechanism. The liquid aspiration device includes a housing and a piston. The housing has an inner cavity and a connection hole communicating with the inner cavity. The liquid aspiration device is connected to the proximal end of the catheter body through the connection hole and communicates with the second cavity. The piston is at least partially disposed in the inner cavity and is also connected to the power mechanism. The power mechanism is used to drive the piston to reciprocate along the axial direction of the connection hole.

[0016] Optionally, the power mechanism includes a motor, a reducer, and a transmission mechanism connected in sequence; the reduction ratio of the reducer is 10:1 to 1:1, and the transmission mechanism is connected to the piston.

[0017] Optionally, the motor is a DC motor; and / or,

[0018] The reducer is a planetary reducer.

[0019] Optionally, the catheter body includes an axially connected proximal segment and a distal segment, the distal segment being configured to bend at least at its proximal end; the balloon is sealed to the outer peripheral surface of the distal segment; the sidewall of the distal segment is further provided with a flow hole communicating with the first cavity, the flow hole being located at the distal end of the balloon.

[0020] Optionally, when the catheter body is bent, the angle formed by the axis of the distal segment and the axis of the proximal segment is less than or equal to 135°; and / or,

[0021] The axial length of the distal pipe section is 15mm to 50mm.

[0022] Optionally, it also includes a pressure monitoring element connected to the proximal end of the catheter body and corresponding to the first cavity and / or the second cavity.

[0023] Compared with the prior art, the coronary sinus balloon counterpulsation catheter of the present invention has the following advantages:

[0024] The aforementioned coronary sinus balloon counterpulsation catheter includes a catheter body and a balloon. The catheter body has a first cavity and a second cavity extending axially through it and isolated from each other. The first cavity is eccentrically disposed from the catheter body. The cross-section of the second cavity includes a first contour line and a second contour line. The first contour line is at least a portion of a first circle, and the second contour line is at least a portion of a second circle. The first contour line is closer to the first cavity than the second contour line, and the concave sides of both the first and second contour lines face the first cavity. The balloon is sealed to the distal outer circumferential surface of the catheter body and communicates with the second cavity. The width of the second cavity at a designated position in the second circle satisfies the following condition: In the formula, h represents the width of the second cavity at the designated position of the second circle, D represents the diameter of the second circle, d represents the diameter of the first circle, e is the distance between the center of the first circle and the center of the second circle, θ represents the angle formed by the first straight line and the second straight line, the first straight line refers to the straight line passing through the center of the first circle and the center of the second circle, the second straight line refers to the straight line between the center of the second circle and the designated position, and the width of the second cavity refers to the radial dimension of the second cavity in the first circle. The second cavity is used for the flow of filling fluid. The arrangement of the first and second cavities results in lower resistance and a faster flow rate of the filling fluid flowing in the second cavity, improving the inflation and aspiration efficiency of the balloon. This allows the balloon aspiration time to be less than or equal to the diastolic duration of the ventricle, enabling the coronary sinus balloon counterpulsation catheter to use a liquid such as saline instead of gas as the filling medium, avoiding air embolism caused by balloon rupture and improving safety. Attached Figure Description

[0025] The accompanying drawings are provided to better understand the invention and are not intended to unduly limit the scope of the invention. Wherein:

[0026] Figure 1 is a schematic diagram of the coronary sinus balloon counterpulsation catheter provided according to an embodiment of the present invention;

[0027] Figure 2 is an AA cross-sectional view of the catheter body of the coronary sinus balloon counterpulsation catheter provided according to an embodiment of the present invention. In the figure, the first circle is coaxial with the first cavity, and the second circle is coaxial with the catheter body.

[0028] Figure 3 is an AA cross-sectional view of the catheter body of the coronary sinus balloon counterpulsation catheter provided according to another embodiment of the present invention. In the figure, the first circle is not coaxial with the first cavity, and the second circle is coaxial with the catheter body.

[0029] Figure 4 is a partially enlarged schematic diagram of the coronary sinus balloon counterpulsation catheter provided according to an embodiment of the present invention;

[0030] Figure 5 is a schematic cross-sectional view of the catheter body of a prior art balloon catheter, the catheter body shown in the figure including a first cavity and a second cavity arranged coaxially.

[0031] [The following are explanations of the reference numerals in the attached drawings]: 10, 100 - catheter body; 11, 101 - first lumen; 12, 102 - second lumen; 12a, 102a - first contour line; 12b, 102b - second contour line; 13, 103 - septum; 104 - flow hole; 110 - proximal segment; 120 - distal segment; 200 - balloon; 210 - proximal balloon segment; 220 - distal balloon segment; 300 - connector; 310 - first connector; 320 - second connector; 330 - third connector; 400 - pressure monitoring element; 500 - suction device; 600 - power mechanism. Detailed Implementation

[0032] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show components related to the present invention and are not drawn according to the actual number, shape, and size of components in the actual implementation. In the actual implementation, the type, quantity, and proportion of each component can be arbitrarily changed, and the component layout may also be more complex.

[0033] Furthermore, while each embodiment described below possesses one or more technical features, this does not imply that users of the present invention must simultaneously implement all technical features in any embodiment, or can only separately implement some or all technical features in different embodiments. In other words, provided it is feasible, those skilled in the art can, based on the disclosure of the present invention and depending on design specifications or implementation requirements, selectively implement some or all technical features in any embodiment, or selectively implement a combination of some or all technical features in multiple embodiments, thereby increasing the flexibility in implementing the present invention.

[0034] As used herein, the singular forms “a,” “an,” and “the” include plural objects, and the plural form “a plurality” includes two or more objects, unless otherwise expressly indicated. As used herein, the term “or” is generally used to include the meaning of “and / or,” unless otherwise expressly indicated, and the terms “installed,” “connected,” and “linked” should be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection. Connections can be mechanical or electrical. Connections can be direct or indirect through an intermediate medium, and can be internal communication between two elements or an interaction between two elements. Relational terms such as “first,” “second,” etc., are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations, nor do they indicate or imply relative importance or implicitly specify the number of indicated technical features. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0035] The terms “proximal” and “distal” used in this article are based on the relative position and orientation of the various components and parts of a medical device. Although they are not restrictive, “proximal” usually refers to the end of the medical device that is closer to the operator during normal use, while “distal” refers to the end that is farther away from the operator.

[0036] For conventional coronary sinus balloon counterpulsation catheters in existing technology, if liquid is used as the filling medium, the high flow resistance and slow flow rate of the liquid result in a longer inflation and deflation rate of the balloon. This makes it difficult to match the aspiration time of conventional coronary sinus balloon counterpulsation catheters with the patient's heart rate, thus failing to achieve the therapeutic effect. The liquid here includes, but is not limited to, normal saline.

[0037] The purpose of this invention is to provide a coronary sinus balloon counterpulsation catheter that can use a liquid such as physiological saline as the filling medium. Through changes in its structural configuration, it shortens the inflation and deflation time of the balloon, allowing the aspiration time of the coronary sinus balloon counterpulsation catheter to match the patient's heart rate. For ease of description, the liquid filling medium will be referred to as the filling fluid below.

[0038] To facilitate understanding of this invention, a brief introduction to the invention process will be given first.

[0039] Figure 5 illustrates a prior art balloon catheter. As shown in Figure 5, this prior art balloon catheter includes a catheter body 10 and a balloon (not shown). The catheter body 10 has a first cavity 11 and a second cavity 12 extending axially through it. The first cavity 11 and the second cavity 12 are coaxially arranged and separated by a partition wall 13. The second cavity 12 surrounds the outer periphery of the first cavity 11. In the cross-section of the catheter body 10, the second cavity 12 includes a first profile line 12a and a second profile line 12b arranged coaxially, both of which are circular. The first cavity 11 is used for inserting a guidewire, and the second cavity 12 is used for the flow of filling medium.

[0040] If the filling fluid is introduced into the second cavity 12 of the prior art balloon catheter, then for the prior art balloon catheter, the filling fluid forms a laminar flow in the second cavity 12, and its unit volume flow rate can be expressed as Q, then the following formula (1) holds:

[0041] In the formula, d represents the diameter of the first contour line 12a; D represents the diameter of the second contour line 12b; h represents the width of the second cavity 12, that is, the radial dimension of the second cavity 12 in the catheter body 10, and its value is... μ represents the viscosity of the filling fluid, which is a constant value for a given filling fluid; L represents the axial length of the catheter body 10; ΔP represents the pressure difference of the filling fluid at both ends of the second cavity 12 along the axis.

[0042] When the balloon is aspirated from its inflated state, the aspiration time is related to the volume of the balloon and the flow rate of the filling fluid by the following formula (2):

[0043] In formula (2), t is the retraction time; V is the volume of the balloon, which is equal to the volume of the filling fluid inside the balloon when the balloon is inflated. Ignoring the wall thickness of the balloon, V is approximately equal to the volume V0 of the balloon in the inflated state.

[0044] Combining formulas (1) and (2), we obtain formula (3):

[0045] As can be seen from formula (3), for the balloon catheter with a coaxial arrangement of a first cavity 11 and a second cavity 12, the aspiration time can be shortened by reducing the volume of the balloon, decreasing the length of the catheter body 10, increasing the inner diameter of the outer tube, decreasing the outer diameter of the inner tube, or increasing the pressure difference of the filling fluid at both ends of the second cavity 12 axially. However, those skilled in the art know that for the design of medical catheters, the inner and outer diameters of the inner and outer tubes, the length of the catheter body, and the pressure difference of the filling fluid at both ends of the second cavity 12 axially all need to be determined according to clinical treatment and usage requirements and cannot be easily changed. That is, for the balloon catheter shown in Figure 5, it is difficult to optimize it so that it can also be used for coronary sinus counterpulsation when using the filling fluid.

[0046] In view of this, the inventors considered changing the arrangement of the first cavity and the second cavity to change the hydrodynamics of the filling fluid flowing in the second cavity, thereby shortening the aspiration time of the balloon catheter.

[0047] Through extensive research, the inventors discovered that when the structure of the balloon catheter body is as shown in Figures 2 and 3, the above-mentioned objective can be achieved by reasonably setting the relevant parameters of the second cavity.

[0048] Specifically, as shown in Figures 2 and 3, the catheter body 100 has a first cavity 101 and a second cavity 102 extending axially through it and separated by a partition wall 103. The first cavity 101 is eccentrically disposed from the catheter body 100. The second cavity 102 includes a first contour line 102a and a second contour line 102b. The first contour line 102a is at least a portion of a first circle, and the second contour line 102b is at least a portion of a second circle. That is, the first contour line 102a is an arc segment, and the circle containing this arc segment is the first circle (as shown in Figure 3), or the first contour line 102a is the entire first circle (as shown in Figure 2); the second contour line 102b is an arc segment, and the circle containing this arc segment is the second circle (as shown in Figure 3), or the second contour line 102b is the entire second circle (as shown in Figure 2). The first contour line 102a is closer to the first cavity 101 than the second contour line 102b. Thus, the first circle corresponds to the first contour line 12a in Figure 5, and the second circle corresponds to the second contour line 12b in Figure 5. The width of the second cavity 102 at the designated position S of the second circle satisfies the following formula (4):

[0049] In the formula, h represents the width of the second cavity 102 at the designated position S of the second circle, D represents the diameter of the second circle, d represents the diameter of the first circle, and e is the distance between the center O1 of the first circle and the center O2 of the second circle. It can be understood that e is less than or equal to θ represents the angle formed by the first straight line l1 and the second straight line l2. The first straight line l1 refers to the straight line passing through the center O1 of the first circle and the center O2 of the second circle, and the second straight line l2 refers to the straight line passing through the center O2 of the second circle and the designated position S. It should be noted that the width of the second cavity 102 refers to the radial dimension of the second cavity 102 in the first circle. Thus, viewed in the cross-section of the catheter body 100, the width of the second cavity 102 at the designated position S in the second circle refers to the portion of the straight line l3 passing through the center O1 of the first circle and the designated position S between the first circle and the second circle. It should be understood that the designated position S is on the second contour line 102b.

[0050] For the catheter body 100, when the filling fluid is introduced into the second cavity 102, the unit volume flow rate Q of the filling fluid in the second cavity 102 conforms to the following formula (5):

[0051] Substituting formula (4) into formula (5) and calculating, we obtain the following formula (6):

[0052] When the catheter body 100 shown in Figures 2 and 3 is applied to a balloon catheter, the aspiration time t of the balloon catheter, obtained by combining formulas (2) and (6), conforms to the following formula (7):

[0053] Comparing formulas (3) and (7), it can be found that when the diameter of the first circle is equal to the diameter of the first contour line 12a, the diameter of the second circle is equal to the diameter of the second contour line 12b, the volume of the balloon 100 is the same, the filling fluid is the same, and the pressure difference of the filling fluid at both ends of the second cavity is the same, the aspiration time of the balloon catheter using the catheter body 100 shown in Figures 2 and 3 is less than the aspiration time of the balloon catheter using the catheter body 10 shown in Figure 5.

[0054] Therefore, the structure of the coronary sinus balloon counterpulsation catheter provided in this embodiment of the invention is shown in Figure 1, including a catheter body 100 and a balloon 200. The cross-section of the catheter body 100 is shown in Figures 2 and 3. Referring to Figures 2 and 3, the catheter body 100 has a first cavity 101 and a second cavity 102. Both the first cavity 101 and the second cavity 102 extend through the axial direction of the catheter body 100 and are separated by a partition wall 103. The first cavity 101 is eccentrically disposed from the catheter body 100. The cross-section of the second cavity 102 includes a first contour line 102a and a second contour line 102b. The first contour line 102a is at least a portion of a first circle, and the second contour line 102b is at least a portion of a second circle. The first contour line 102a is closer to the first cavity 101 than the second contour line 102b, and the concave sides of both the first contour line 102a and the second contour line 102b are arranged facing the first cavity 101. The balloon 200 is sealed to the distal outer peripheral surface of the catheter body 100 and communicates with the second cavity 102 for the flow of filling medium. The width of the second cavity 102 at the designated position S of the second contour line 102b satisfies the aforementioned formula (4). Thus, the aspiration time of the coronary sinus balloon counterpulsation catheter is short, which can be adapted to the patient's cardiac cycle and can achieve a better counterpulsation effect.

[0055] Typically, the first cavity 101 has a circular cross-section, and the second cavity 102 has a crescent-shaped cross-section. In some optional embodiments, the first circle is coaxially arranged with the first cavity 101, and the second circle is coaxially arranged with the catheter body 100 (as shown in Figure 2). In other embodiments, the first circle is not coaxial with the first cavity 101, while the second circle is coaxial with the catheter body 100 (as shown in Figure 3). In still other embodiments, the first circle is coaxial with the first cavity, while the second circle is not coaxial with the catheter body 100. In still some optional embodiments, both the first circle and the second circle are not coaxial with the first cavity 101 and the catheter body 100.

[0056] The effects of the coronary sinus balloon counterpulsation catheter provided by the present invention will be described next through several embodiments.

[0057] In Embodiment 1, the conduit body 100 is composed of an inner tube and an outer tube. Specifically, the outer tube is fitted onto the outer circumferential surface of the inner tube, and the inner surface of the outer tube is bonded to the outer surface of the inner tube with an adhesive. The adhesive has a radial dimension of 0.03 mm (adhesive thickness) on the outer tube, the inner diameter of the outer tube is 1.72 mm, and the outer diameter of the inner tube is 1.25 mm. Thus, in the conduit body 100, the lumen of the inner tube forms the first cavity 101, the space between the inner circumferential surface of the outer tube and the outer circumferential surface of the inner tube forms the second cavity 102, and the wall of the inner tube forms the partition wall 103 separating the first cavity 101 and the second cavity 102. Based on this, the diameter of the first circle is 1.25 mm, the diameter of the second circle is 1.72 mm, and the distance between the center O1 of the first circle and the center O2 of the second circle is 0.21 mm. Furthermore, the length L of the catheter body 100 is 1000 mm. The volume of the balloon 200 is 0.69 mL. The balloon 200 is inflated with physiological saline as the filling fluid, and when the coronary sinus balloon counterpulsation catheter is aspirated, the pressure difference of physiological saline at both ends of the second cavity 102 is 1 atmosphere. The inflated balloon 200 is aspirated, and the aspiration time is calculated to be 0.28 s according to formula (7), while the actual aspiration time is 0.32 s.

[0058] It should be noted that the measured aspiration time of the coronary sinus balloon counterpulsation catheter is longer than the aspiration time calculated according to formula (7) during application because the adhesive layer connecting the inner and outer tubes has a certain area, which occupies part of the space in the second cavity 102, resulting in a reduction in the flow area of ​​the filling fluid. To address this issue, in the actual production of the coronary sinus balloon counterpulsation catheter, the area of ​​the adhesive layer connecting the inner and outer tubes should be controlled to be as small as possible.

[0059] In other embodiments, the catheter body 100 may also be formed by extrusion.

[0060] The dimensional parameters of the coronary sinus balloon counterpulsation catheters provided in Examples 2 to 9, the aspiration time calculated according to formula (7), and the measured aspiration time are shown in Table 1 below. In Examples 2 to 6, the first circle is coaxial with the first cavity 101, and the second circle is coaxial with the catheter body 100. In Examples 7 to 9, the catheter body 100 is formed by extrusion, the first circle is not coaxial with the first cavity 101, and the second circle is coaxial with the catheter body 100. Furthermore, all coronary sinus balloon counterpulsation catheters provided in these examples are filled with saline solution, and during aspiration, the pressure difference between the saline solution at both ends of the second cavity 102 along its axial direction is 1 atmosphere.

[0061] Table 1

[0062] Through the above embodiments, the calculated pullback time according to formula (7) and the measured pullback time can be found that the error between the calculated pullback time and the measured pullback time is no greater than 0.04s, which shows that formula (7) has extremely high reliability.

[0063] Those skilled in the art will understand that the coronary sinus balloon counterpulsation catheter is itself a mechanically assisted circulatory device that improves cardiac function and blood circulation by expanding and contracting the balloon 200 at specific times during the cardiac cycle. Specifically, the balloon 200 inflates during ventricular systole to block the coronary sinus, increasing the pressure within the coronary sinus and forcing more blood to flow backward into the damaged area of ​​the myocardium, thus improving myocardial blood supply. The balloon 200 contracts during ventricular diastole to reduce the pressure within the coronary sinus, allowing blood to flow out of the heart normally, thereby reducing the burden on the heart. Therefore, as long as the contraction time of the balloon 200, i.e., the withdrawal time of the coronary sinus balloon counterpulsation catheter, is less than the duration of ventricular diastole, the effect of reducing the burden on the heart can be achieved, thus having a therapeutic effect.

[0064] With an average adult heart rate of 75 beats per minute, each cardiac cycle averages 0.8 seconds, with an average ventricular systolic period of 0.27 seconds and an average ventricular diastolic period of 0.53 seconds. In the exemplary embodiment described above, the measured aspiration time of the coronary sinus balloon counterpulsation catheter is no greater than 0.52 seconds, which is shorter than the duration of ventricular diastole and can meet the treatment requirements.

[0065] Understandably, in practical applications, doctors adjust various parameters of the coronary sinus balloon counterpulsation catheter according to the heart rate of different patients, so as to adjust the aspiration time of the coronary sinus balloon counterpulsation catheter, so that the aspiration time matches the patient's heart rate as closely as possible, and achieves the best counterpulsation effect.

[0066] It should be noted that, in other embodiments, the catheter body 100 of the coronary sinus balloon counterpulsation catheter can also be formed by extrusion.

[0067] Referring to Figures 1 and 4, the catheter body 100 includes an axially connected proximal segment 110 and a distal segment 120, the distal segment 120 being configured to be flexible at least proximally. Specifically, the distal segment 120 includes an axially connected first sub-segment and a second sub-segment (not labeled in the figures), the first sub-segment being closer to the proximal segment 110 than the second sub-segment, and the first sub-segment being flexible. Thus, the catheter body 100 can be bent at the first sub-segment. This configuration is advantageous because it better accommodates the morphology of the coronary sinus when the distal end of the coronary sinus balloon counterpulsation catheter 10 is inserted into the coronary sinus. The balloon 200 is sealingly connected to the outer peripheral surface of the distal segment 120. Additionally, in some embodiments, the second sub-segment is flexible, while in other embodiments, the second sub-segment is not flexible.

[0068] In this embodiment of the invention, when the catheter body 100 is bent, the angle α formed by the axis of the proximal tube segment 110 and the axis of the distal tube segment 120 is less than or equal to 135°. Furthermore, the axial length L1 of the distal tube segment 120 is 15mm to 50mm.

[0069] When the catheter body 100 is formed by extrusion, the raw materials used for extruding the catheter body 100 include a polymer base material, which includes, but is not limited to, at least one of polyamide (PA), polyether block polyamide (Pebax), polyurethane (TPU), and polyvinyl chloride (PVC). Further, the raw materials may also include inorganic additives, such as reproducible inorganic materials, thus making the catheter body 100 reproducible. Optional reproducible inorganic materials include, but are not limited to, at least one of barium sulfate, bismuth trioxide, bismuth hydroxide, basic bismuth carbonate, and tungsten. Preferably, the amount of inorganic additive added is less than or equal to 40% by mass percentage.

[0070] When the catheter body 100 is formed by combining the inner tube and the outer tube, the connection method between the inner tube and the outer tube is not limited to the aforementioned adhesive bonding, but can also be welding or any other suitable method; or, the inner tube and the outer tube are not directly connected, but only adhere to each other by their own gravity during use. The outer diameter of the inner tube can be 1.5mm to 2mm, and the inner diameter can be 0.45mm to 1.5mm, while the outer diameter of the outer tube can be 2mm to 4mm, and the inner diameter can be 1.5mm to 2mm. Preferably, the outer tube has a multi-layer structure, for example, including an inner layer, a middle layer, and an outer layer arranged from the inside out. The material of the inner layer includes medical polymer materials, such as polytetrafluoroethylene, the material of the middle layer is a metal material, such as medical stainless steel, and the material of the outer layer includes medical polymer materials. In addition, the outer tube body may also be reproducible, for example, by incorporating reproducible inorganic materials such as barium sulfate and bismuth trioxide into the material of the outer layer. In the outer layer, the proportion of reproducible inorganic materials added is less than or equal to 60% by mass percentage.

[0071] Regardless of the method used to form the catheter body 100, it is preferable that the overall hardness of the catheter body 100 is 50A-100D, so that the catheter body 100 has good pushability and controllability.

[0072] Please refer to Figures 1 and 4. The balloon 200 includes a symmetrically arranged and directly connected proximal balloon segment 210 and a distal balloon segment 220. The outer and inner diameters of the proximal balloon segment 210 and the distal balloon segment 220 both increase from the proximal to the distal direction. This allows the balloon 200 to have a minimal volume, thereby shortening the aspiration time.

[0073] The nominal outer diameter C of the balloon 200 when inflated is 4mm to 16mm, and the axial length P is 10mm to 25mm.

[0074] Furthermore, the balloon 200 is made of an elastic material, so that when the balloon 200 is inflated, it stores elastic potential energy. Thus, when the inflation fluid is withdrawn, the balloon 200 releases this elastic potential energy to facilitate the drainage of the inflation fluid, thereby further shortening the withdrawal time. The materials used to manufacture the balloon 200 include, but are not limited to, any one of silicone, polyurethane, and polyether block polyamide.

[0075] Referring back to Figure 1, the coronary sinus balloon counterpulsation catheter 10 further includes a connector 300, which is connected to the proximal end of the catheter body 100 and includes a first connector portion 310, a second connector portion 320, and a third connector portion 330. The first connector portion 310 is connected to the proximal end of the catheter body 100, the second connector portion 320 communicates with the first cavity 101, and the third connector portion 330 communicates with the second cavity 102.

[0076] The second connector 320 serves two purposes: firstly, it allows the guidewire to pass through; secondly, it is correspondingly arranged with a pressure monitoring element 400, such that the pressure monitoring element 400 corresponds to at least one of the first cavity 101 and the second cavity 102. It is understood that when the pressure monitoring element 400 corresponds to the first cavity 101, it can sense the blood pressure in the coronary sinus when blood enters the first cavity 101; when the pressure monitoring element 400 corresponds to the second cavity 102, it can monitor the inflation pressure of the balloon 200 when it is inflated. The specific type and arrangement of the pressure monitoring element 400 are well known to those skilled in the art and will not be elaborated here. It is understood that the coronary sinus balloon counterpulsation catheter 10 may include the pressure monitoring element 400.

[0077] Furthermore, since the distal end of the catheter body 100 is flexible, to ensure that blood still enters the first cavity 101 when the distal end of the catheter body 100 is bent, so that the pressure monitoring element 400 can monitor blood pressure, a flow hole 104 communicating with the first cavity 101 is provided on the wall of the distal tube segment 120 of the catheter body 100 (as shown in Figure 4). In this way, when the distal end of the catheter body 100 is bent, blood enters the first cavity 101 through the flow hole 104. It should be understood that the flow hole 104 should be located on the distal side of the balloon 200.

[0078] The third connector 330 is used to connect to an inflatable fluid source. The inflatable fluid source is an aspiration device 500. The coronary sinus balloon counterpulsation catheter 10 also includes the aspiration device 500 and a power mechanism 600. The aspiration device 500 is used to store the inflatable fluid, and the power mechanism 600 is used to drive the aspiration device to inflate the balloon 200 with the inflatable fluid to inflate the balloon 200, or to aspirate the inflatable fluid from the balloon 200 to depressurize the balloon 200.

[0079] The aspiration device 500 includes a housing and a piston (not shown in the figure). The housing is a hollow structure with an inner cavity, and the housing is also provided with a connection hole communicating with the inner cavity. The aspiration device is connected to the third connector 330 through the connection hole to communicate with the second cavity 102. The piston is at least partially disposed in the inner cavity. The piston is also connected to the power mechanism 600 and can reciprocate linearly along the axial direction of the connection hole under the drive of the power mechanism 600 to move closer to or away from the connection hole. The portion of the inner cavity located on the side of the piston closer to the connection hole is used to store the filling fluid. When the piston moves in the direction closer to the connection hole, the filling fluid is injected into the balloon 200, causing the balloon 200 to inflate; when the piston moves in the direction away from the connection hole, the filling fluid is drawn back into the inner cavity, causing the balloon 200 to depressurize.

[0080] The embodiments of the present invention do not particularly limit the structure of the power mechanism 600. In some embodiments, the power mechanism 600 includes a pneumatically driven cylinder; in other embodiments, the power mechanism 600 includes a hydraulically driven cylinder; and in still other embodiments, the power mechanism 600 includes an electrically driven device.

[0081] In a preferred embodiment, the power mechanism 600 includes an electric drive device, specifically comprising a motor, a reducer, and a transmission mechanism connected in sequence. The reducer has a reduction ratio of 10:1 to 1:1, and the transmission mechanism is a linear motion mechanism connected to the piston. The reduction ratio refers to the ratio of the reducer's input to its output.

[0082] Optionally, the motor is a DC motor, such as a brushless stepper motor, which has the advantages of high speed and low noise, and can operate stably and efficiently. The reducer is a high-precision planetary reducer, which can adapt to the usage requirements under different conditions. The transmission mechanism includes a lead screw and nut pair, such as a ball screw and nut pair. By coordinating the motor, the reducer, and the transmission mechanism, the power mechanism 600 can have the characteristics of low output speed and high output torque, achieving the purpose of accurate filling and retraction of the filling fluid, while also reducing the size and weight of the power mechanism 600.

[0083] In a typical embodiment, the motor is a brushless stepper motor with a rated speed of 5 r / min-60 r / min, a torque of 2 N·m-10 N·m, a step count of 2000-20000 steps, and a drive frequency of 15000 Hz-25000 Hz. The rotational accuracy of the brushless stepper motor is 1.8°. The filling and suction accuracy of the filling fluid by the suction device 500 is 0.5 ml. When the reduction ratio of the reducer is 5:1, through the reduction of the reducer, the output speed of the power mechanism 600 is reduced to 1 r / min-12 r / min, the torque is increased to 10 N·m-50 N·m, the rotational accuracy at the output end reaches 0.36°, and the filling and suction accuracy of the filling fluid by the suction device 500 can reach 0.1 ml.

[0084] Furthermore, the pressure monitoring element 400, the liquid aspiration device 500, and the power mechanism 600 can be integrated into a counterpulsation controller.

[0085] In addition, similar to existing technologies, as shown in Figures 1 and 4, the coronary sinus balloon counterpulsation catheter 10 also includes components such as a contrast ring 710, a marking band 720, and a catheter fixation clip 730. The contrast ring 710 is disposed on the distal outer peripheral surface of the catheter body 100 and located on the distal side of the balloon 200. The marking band 720 is disposed on the outer peripheral surface of the proximal segment 110 of the catheter body 100. The catheter fixation clip 730 is connected to the distal outer surface of the connector 300. The functions of the contrast ring 710, the marking band 720, and the catheter fixation clip 730 are well known to those skilled in the art and will not be described in detail here.

[0086] While the present invention has been disclosed above, it is not limited thereto. Those skilled in the art can make various modifications and variations to the present invention without departing from its spirit and scope. Therefore, if such modifications and variations fall within the scope of the claims and their equivalents, the present invention also intends to include such modifications and variations.

Claims

1. A coronary sinus balloon counterpulsation catheter, characterized by, The catheter body is provided with a first lumen and a second lumen extending through the catheter body in the axial direction and isolated from each other; the first lumen is eccentrically arranged on the catheter body; the cross section of the second lumen comprises a first profile line and a second profile line, the first profile line is at least a part of a first circle, and the second profile line is at least a part of a second circle; the first profile line is closer to the first lumen than the second profile line, and the concave side of the first profile line and the concave side of the second profile line are both arranged towards the first lumen; the balloon is sealingly connected to the outer peripheral surface of the distal end of the catheter body and communicates with the second lumen. The width of the second lumen at a given location of the second circle satisfies the following relationship: In the formula, h represents the width of the second lumen at a specified position of the second circle, D represents the diameter of the second circle, d represents the diameter of the first circle, e is the distance between the center of the first circle and the center of the second circle, and θ represents the included angle formed by a first straight line and a second straight line, the first straight line being a straight line passing through the center of the first circle and the center of the second circle, and the second straight line being a straight line passing through the specified position and the center of the second circle. The width of the second lumen refers to the size of the second lumen in the radial direction of the first circle.

2. The coronary sinus balloon counterpulsation catheter of claim 1, wherein, The cross section of the first lumen is circular, and the first lumen is coaxial with the first circle; the catheter body is coaxial with the second circle.

3. The coronary sinus balloon counterpulsation catheter of claim 1, wherein, The balloon comprises a proximal balloon segment and a distal balloon segment arranged symmetrically and directly connected, the outer diameter and the inner diameter of the proximal balloon segment increase in the direction from the proximal end to the distal end, and the outer diameter and the inner diameter of the distal balloon segment decrease in the direction from the proximal end to the distal end.

4. The coronary sinus balloon counterpulsation catheter of claim 1 or 3, wherein, The balloon is configured to have elasticity.

5. The coronary sinus balloon counterpulsation catheter of claim 4, wherein, The material for preparing the balloon comprises any one of silicone, polyurethane, and polyether block polyamide.

6. The coronary sinus balloon counterpulsation catheter of claim 1, wherein, Further comprising a suction device and a power mechanism, the suction device comprises a housing and a piston, the housing has an inner cavity, and the housing is further provided with a connecting hole communicating with the inner cavity, the suction device is connected with the proximal end of the catheter body through the connecting hole and communicates with the second lumen; the piston is at least partially arranged in the inner cavity, and the piston is further connected with the power mechanism, and the power mechanism is used for driving the piston to reciprocate in the axial direction of the connecting hole.

7. The coronary sinus balloon counterpulsation catheter of claim 6, wherein, The power mechanism comprises a motor, a speed reducer and a transmission mechanism connected in sequence; the speed reduction ratio of the speed reducer is 10:1-1:1, and the transmission mechanism is connected with the piston.

8. The coronary sinus balloon counterpulsation catheter of claim 7, wherein, The motor is a direct current motor; and / or, the speed reducer is a planetary speed reducer.

9. The coronary sinus balloon counterpulsation catheter of claim 1, wherein, The catheter body comprises an axially connected proximal tube segment and a distal tube segment, the distal tube segment is configured to be at least capable of bending at its proximal end; the balloon is sealingly connected to the outer peripheral surface of the distal tube segment; the side wall of the distal tube segment is further provided with a flow-through hole communicating with the first lumen, and the flow-through hole is located at the distal end of the balloon.

10. The coronary sinus balloon counterpulsation catheter of claim 9, wherein, When the catheter body is bent, the included angle formed by the axis of the distal tube segment and the axis of the proximal tube segment is less than or equal to 135°; and / or, The axial length of the distal tube segment is 15-50 mm.

11. The coronary sinus balloon counterpulsation catheter of claim 1, wherein, A pressure monitoring element is also included, connected to the proximal end of the catheter body and arranged in correspondence with the first and / or second lumen.

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