Interventional delivery system for a collapsible blood pump

Abstract

The application aims to provide an intervention delivery system of a foldable blood pump capable of measuring arterial blood pressure and guiding precision and small trauma, comprising an extracorporeal sheath tube, an intracorporeal sheath tube and a dilator. A pressure sensor is arranged on the extracorporeal part of the intracorporeal sheath tube, and arterial blood is measured by measuring the pressure of the flushing liquid between the intracorporeal sheath tube and the catheter, thus solving a big problem of arranging the pressure sensor on the foldable blood pump; the pressure sensor located outside avoids forming a flow dead angle on the foldable blood pump, reduces thrombosis, and has low requirements for the selection of the sensor and low cost. The intracorporeal sheath tube extends into the left ventricle, the foldable blood pump is directly delivered into the left ventricle for release, and the cooperation of the intracorporeal sheath tube and the dilator ensures that the intracorporeal sheath tube does not enter other blood vessel passages during the intervention into the left ventricle from the blood vessel, thereby reducing the damage to the blood vessel and the valve; and the guide cone surface of the intracorporeal sheath tube improves the guiding precision and simplifies the operation steps.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and more specifically to an interventional delivery system with a foldable blood pump. Background Technology

[0002] A percutaneous transluminal (PTT) blood pump is a device inserted into the desired location within the heart of a heart failure patient to assist the heart's pumping action. It comes in two types: those with an internal, non-foldable pump head and those with an external, foldable pump head. The foldable pump head, with its folded, small size, is inserted into the heart during the interventional procedure and then expands upon reaching the heart. This allows for minimal trauma, high flow rate, low speed, and low hemolysis, making it a future development trend. Correspondingly, how to insert a foldable blood pump into the heart remains a challenge within the industry. Summary of the Invention

[0003] The purpose of this invention is to provide an interventional delivery system with a foldable blood pump that can measure arterial blood pressure with precise guidance and minimal invasiveness.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: an interventional delivery system with a foldable blood pump, the foldable blood pump including a pump head assembly and a catheter, and the interventional delivery system including:

[0005] An external retractable sheath is fitted over the pump head assembly and has a first channel. The length of the first channel at least covers the foldable housing and pigtail tube section in the pump head assembly.

[0006] The internal sheath is configured to be inserted into the patient’s vascular system through a puncture site. It has a second channel, the proximal end of which can be connected to the distal end of the external sheath, allowing the foldable blood pump in the folded state to enter the second channel from the first channel. A pressure sensor is installed on it to measure arterial blood pressure.

[0007] The dilator is slidably positioned within the second channel of the intravascular sheath and can be fixed to the intravascular sheath by a locking structure. In conjunction with the guidewire, it guides the intravascular sheath to move through the vascular system and reach the left ventricle.

[0008] Furthermore, the in vivo constriction sheath includes a constriction sleeve and a sheath seat located at the proximal end of the constriction sleeve. A hemostatic valve is provided inside the sheath seat, and an irrigation tube is connected to the side wall of the sheath seat. The irrigation tube communicates with the chamber distal to the hemostatic valve, and an irrigation connector is provided at the end of the irrigation tube. The pressure sensor is located inside the irrigation connector, and the pressure sensor reflects the arterial blood pressure by measuring the pressure of the irrigation fluid.

[0009] The flushing connector integrates a fluid chamber, as well as a fluid inlet and a fluid outlet connecting the fluid chamber. A pressure sensing probe of a pressure sensor is integrated on the wall of the fluid chamber.

[0010] The inner wall of the sheath seat distal to the hemostatic valve is provided with a guide cone surface. The inclination angle of the guide cone surface matches the inclination angle of the guide section provided at the distal end of the external retractable sheath. The inner diameter of the proximal end of the guide cone surface is larger than the outer diameter of the guide section, and the inner diameter of the distal end of the guide cone surface is smaller than the inner diameter of the guide section. The distal end of the guide cone surface is smoothly connected to the inner wall of the retractable sheath.

[0011] Furthermore, the angle between the guide cone surface and the axis is 10° to 60°.

[0012] Furthermore, a locking structure is provided on the sheath seat on the distal side of the hemostatic valve, which forms an axial and circumferential limiting fit with the proximal end of the dilator.

[0013] Furthermore, the locking structure is a threaded structure, including an internal thread on the inner wall of the sheath seat near the hemostatic valve, and an external thread on the proximal end of the dilator that cooperates with the internal thread to form the locking structure.

[0014] Furthermore, the length of the internal constricting sheath is 90cm to 120cm, the length of the dilator is 95cm to 125cm, and the distal conical segment of the dilator protrudes beyond the distal end of the internal constricting sheath.

[0015] Furthermore, the inner diameter of the external retraction sheath is larger than that of the retraction sleeve, and the length of the external retraction sheath is equal to the sum of the length of the foldable shell in the retracted state and the length of the pig tail tube in the extended state.

[0016] Furthermore, the externally retractable sheath is a tearable sheath.

[0017] The above solution has at least the following beneficial effects:

[0018] 1. A pressure sensor is installed on the external part of the internal bundle sheath. Arterial blood is measured by measuring the pressure of the flushing fluid between the internal bundle sheath and the catheter, which solves a major problem in installing a pressure sensor on a foldable blood pump.

[0019] 2. The external pressure sensor avoids the formation of dead zones in the foldable blood pump, reducing thrombus formation, while also having lower requirements for sensor selection and lower cost.

[0020] 3. The internal bundle sheath extends into the left ventricle, and the foldable blood pump delivers blood directly to the left ventricle within the internal bundle sheath, without causing damage to blood vessels and valves.

[0021] 4. Through the cooperation of the internal bundle sheath and the dilator, the internal bundle sheath will not enter other blood vessels during the process of intervening in the left ventricle from the blood vessel, thus reducing damage to blood vessels and valves.

[0022] 5. The foldable blood pump is first pre-folded in the external folding sheath. After the external folding sheath is connected to the internal folding sheath, it is guided by the guide cone surface in the internal folding sheath and further folded to the designed size. The pre-folding operation is simple.

[0023] 6. The guide cone surface of the internal retractable sheath simultaneously performs the triple functions of guidance, limiting, and dimensional compression, improving guidance accuracy and simplifying operation steps. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the interventional delivery system;

[0025] Figure 2 This is a cross-sectional view of the in-body convergence cannula;

[0026] Figure 3 This is a schematic diagram showing the connection between the internal convergence sheath and the external convergence sleeve.

[0027] Figure 4 for Figure 3 Enlarged diagram of the middle section;

[0028] Figure 5 This is a connection diagram for the pressure sensor;

[0029] Figure 6 This is a schematic diagram of guidewire intervention in the left ventricle.

[0030] Figure 7 A schematic diagram of a sheath with a dilator inserted into the left ventricle;

[0031] Figure 8 This is a schematic diagram after the dilator and guidewire have been removed.

[0032] Figure 9 This is a schematic diagram showing the connection between the external and internal convergence sheaths.

[0033] Figure 10 This is a schematic diagram showing the foldable shell being released into the left ventricle.

[0034] Figure 11 This is a schematic diagram of the retraction of the sheath within the body back into the descending aorta. Detailed Implementation

[0035] To facilitate understanding, let's first define the orientation: "proximal" or "proximal" refers to the side closer to the operator / doctor, while "distal" or "distal" refers to the side farther from the operator / doctor, i.e., the side closer to the heart. Below, we'll combine these definitions... Figures 1-11 The present invention will be described in further detail below.

[0036] An interventional delivery system with a foldable blood pump, the foldable blood pump A including a pump head assembly and a catheter, such as Figure 1As shown, the intervention delivery system includes:

[0037] The external sheath 10 is fitted over the pump head assembly and has a first channel. The length of the first channel at least covers the foldable shell and the pig tail tube segment in the pump head assembly. In its naturally expanded state, the foldable shell of the foldable blood pump A is the largest diameter part. Inside the foldable shell is a foldable impeller. The proximal side of the foldable shell is a thin film that forms the blood outflow channel, and the distal side is a pig tail tube with a very small diameter. Therefore, the external sheath 10 must at least fold the foldable shell inside to reduce the size of the foldable blood pump A, making it easier to push it into the second channel inside the internal sheath 20.

[0038] The internal folding sheath 20 is configured to be inserted into the patient's vascular system through a puncture site. It has a second channel, the proximal end of which can connect with the distal end of the external folding sheath 10, allowing the folded foldable blood pump A to enter the second channel from the first channel. The internal folding sheath 20 minimizes the size of the foldable blood pump A, with an outer diameter of only 8-10 Fr and a diameter of only 9-10 Fr. Therefore, its prolonged presence in the blood vessel will not affect blood flow. No additional sheath-like components are needed at the puncture site; the maximum size the puncture site can pass through is the size of the internal folding sheath 20, resulting in minimal trauma. The internal folding sheath 20 is inserted into the left ventricle through the puncture site. The foldable blood pump A is pushed into the left ventricle within the lumen of the internal folding sheath 20, where it expands and releases, reducing damage to the vascular system and valves.

[0039] Meanwhile, it is equipped with a pressure sensor 26 to measure arterial blood pressure. During operation, there is a flushing fluid between the internal sheath 20 and the catheter of the foldable blood pump A. The purpose of setting the flushing fluid is to prevent blood from entering the gap between the internal sheath 20 and the catheter during the pumping process and forming a thrombus. Moreover, the flushing fluid can transmit blood pressure. Therefore, by setting a pressure sensor on the internal sheath 20, blood pressure can be measured indirectly, which solves the problem that the structure of the foldable blood pump cannot be equipped with a pressure sensor and thus cannot measure blood.

[0040] The dilator 30 is slidably positioned within the second channel of the internal contraction sheath 20 and can be fixed to the internal contraction sheath 20 via a locking structure. In conjunction with the guidewire, it guides the internal contraction sheath 20 through the vascular system and into the left ventricle. When the internal contraction sheath 20 is inserted along the guidewire alone, the distal opening can easily enter other vascular pathways when passing the aortic arch, and the opening may also damage the vessel wall and valves. Therefore, the internal contraction sheath 20 is used in conjunction with the dilator 30. Because the dilator 30 has a conical segment at its distal end, which protrudes beyond the distal end of the internal contraction sheath 20, it can precisely guide the internal contraction sheath 20 into the left ventricle, preventing it from entering other vascular pathways and reducing damage to vessels and valves.

[0041] As a preferred embodiment of the present invention, see [reference]. Figures 2-4 As shown, the in vivo retractable sheath 20 includes a retractable sleeve 21 and a sheath seat 22 located proximal to the retractable sleeve 21. The sheath seat 22 is the external portion, while most of the retractable sleeve 21 is internal, with a small section adjacent to the sheath seat 22 also external. In other words, the smaller-diameter retractable sleeve 21 is in direct contact with the puncture site. A hemostatic valve 23 is installed within the sheath seat 22, and an irrigation tube 24 is connected to the side wall of the sheath seat 22. The irrigation tube 24 communicates with the chamber distal to the hemostatic valve 23, ensuring that irrigation fluid can enter the gap between the retractable sleeve 21 and the catheter. Simultaneously, the hemostatic valve 23 effectively prevents leakage of the irrigation fluid. An irrigation connector 25 is provided at the end of the irrigation tube 24, and a pressure sensor 26 is installed within the irrigation connector 25. The pressure sensor 26 measures the pressure of the irrigation fluid to reflect the arterial blood pressure. The flushing solution here can be, but is not limited to, physiological saline or a mixture of glucose and heparin. The flushing solution comes into contact with the blood in the artery, and based on the principle of fluid pressure transmission, the pressure of the flushing solution can synchronously reflect the blood pressure within the artery. Furthermore, the pressure sensor 26 is located externally, rather than integrated into the foldable blood pump. Due to the unique structure of the foldable blood pump, there is no suitable location to integrate the pressure sensor. This overcomes the aforementioned difficulties; integrating the pressure sensor into the foldable blood pump could create dead zones in the flow, potentially leading to thrombosis. The externally located pressure sensor 26 reduces the requirements for sensor selection, thereby lowering sensor costs.

[0042] There are many ways to set up the pressure sensor 26. Here is a preferred embodiment, such as... Figure 5 As shown, the flushing connector 25 integrates a fluid chamber, as well as a fluid inlet and a fluid outlet connecting the fluid chamber. The pressure sensing probe of the pressure sensor 26 is integrated on the wall of the fluid chamber. Since the flushing fluid in the fluid chamber is in direct contact with the arterial blood, the pressure sensing probe senses the pressure of the flushing fluid in the fluid chamber, which is the pressure of the arterial blood.

[0043] The inner wall of the sheath seat 22 on the distal side of the hemostatic valve 23 is provided with a guide cone surface 221. The inclination angle of the guide cone surface 221 matches the inclination angle of the guide section 11 provided at the distal end of the external retractable sheath 10. The inner diameter of the proximal end of the guide cone surface 221 is larger than the outer diameter of the guide section 11, and the inner diameter of the distal end of the guide cone surface 221 is smaller than the inner diameter of the guide section 11. The distal end of the guide cone surface 221 is smoothly connected to the inner wall of the retractable sheath 21. The setting of the guide cone 221 has at least the following beneficial effects: (1) Guiding - the tilt angle of the guide cone 221 matches the tilt angle of the guide segment 11, thus guiding the direction of travel of the external retractable sheath 10; (2) Limiting - through the reasonable design of the inner diameter, when the guide segment 11 can no longer be pushed, it means that the guide segment 11 has passed through the hemostatic valve 23 and reached the designated position; (3) Size compression - the inner diameter of the distal end of the guide cone 221 is smaller than the inner diameter of the guide segment 11 and the guide The distal end of the conical surface 221 smoothly connects to the inner wall of the retractable sheath 21. This means the guiding conical surface 221 can further reduce the retracted size of the foldable blood pump A, thereby reducing the size of the retractable sheath 21 and minimizing damage to the puncture site. Furthermore, the retracting of the foldable blood pump A by the external retractable sheath 10 is a pre-retracted process, not requiring folding to its minimum size. Therefore, the insertion of the foldable blood pump A into the external retractable sheath 10 can be achieved without the need for specialized folding and gripping tools or machines. In summary, the guiding conical surface 221 simultaneously performs the triple functions of guidance, limitation, and size compression, improving guidance accuracy and simplifying the operation.

[0044] Extensive experiments have shown that the angle between the guiding cone 221 and the axis is 10° to 60°. Within this angle range, the dimensions of the sheath seat 22 and the retractable sleeve 21 match well, and the guidance of the external retractable sheath 10 is also better.

[0045] To prevent axial movement or circumferential rotation between the internal constriction sheath 20 and the dilator 30 during intervention, a locking structure is provided on the sheath seat 22 distal to the hemostatic valve 23. The locking structure and the proximal end of the dilator 30 form an axial and circumferential limiting fit, which can ensure the positional stability of the two during intervention.

[0046] Specifically, the locking structure is a threaded structure, including an internal thread on the inner wall of the sheath seat 22 near the hemostatic valve 23, and an external thread near the end of the expander 30 that engages with the internal thread to form the locking structure. Of course, the locking structure can also be a snap-fit ​​structure, an elastic pawl, or a magnetic adsorption structure. The figure shows one of these, namely a threaded locking structure. A suitable locking structure can be selected according to different scenario requirements.

[0047] The length of the internal constriction sheath 20 is 90cm to 120cm, which can pass through the aorta from the puncture site to the left ventricle. The length of the dilator 30 is 95cm to 125cm. The distal conical segment of the dilator 30 protrudes beyond the distal end of the internal constriction sheath 20. Due to the limited space in the left ventricle, the part of the dilator 30 protruding beyond the distal end of the internal constriction sheath 20 cannot protrude too much while ensuring effective guidance. Therefore, when the internal constriction sheath 20 and the dilator 30 are locked in position, only the distal conical segment protrudes to ensure that the distal end of the internal constriction sheath 20 can be guided to the left ventricle.

[0048] The inner diameter of the external sheath 10 is larger than that of the sheath 21. The foldable blood pump A is not folded to its minimum size inside the external sheath 10, but is folded to its minimum size inside the sheath 21. Preferably, the length of the external sheath 10 is equal to the sum of the length of the foldable shell in its folded state and the length of the pigtail tube in its straightened state. This reduces the time it takes for the foldable blood pump A to enter the external sheath 10 and also reduces friction on the foldable blood pump A. Of course, the length of the external sheath 10 can also cover the sum of the lengths of the pigtail tube, the foldable shell, and the membrane, as long as the purpose of folding and intervention of the foldable blood pump is achieved.

[0049] The external retraction sheath 10 is a tearable sheath, which can be easily and quickly torn open and removed after the foldable blood pump A is inserted into the left ventricle.

[0050] The interventional method for foldable blood pump A is as follows:

[0051] 1. Tuck the foldable housing of the foldable blood pump A into the external folding sheath 10 for later use;

[0052] 2. Under image-guided guidance, the guidewire is inserted into the aorta through the puncture site, crosses the aortic arch, and enters the left ventricle. Figure 6 As shown;

[0053] 3. Take the internal contraction sheath 20 with dilator 30, lock the two in place using the locking mechanism, and pass the guidewire through the channel in the middle of the dilator. Under the guidance of the guide, the internal contraction sheath 20 with dilator 30 enters the aorta through the puncture site, crosses the aortic arch, and enters the left ventricle. Figure 7 As shown;

[0054] 4. Unlock the locking structure and remove the guidewire and dilator 30 from the body, as follows: Figure 8 As shown;

[0055] 5. First, pass the pigtail tube of the foldable blood pump A through the hemostasis valve 23 of the internal constriction sheath 20, then pass the guide section 11 of the external constriction sheath 10 through the hemostasis valve 23. Stop pushing the external constriction sheath 10 when it can no longer be pushed. Figure 9 As shown;

[0056] 6. Push the foldable blood pump A from the first channel into the second channel until the foldable shell part comes out of the body's retractable sheath 20 and expands in the left ventricle;

[0057] 7. Tear open and remove the external retraction sheath 10, as follows: Figure 10 As shown;

[0058] 8. Withdraw the internal retraction sheath 20 to its distal position at the descending aorta, such as... Figure 11 As shown, the interventional procedure for the foldable blood pump A was completed.

[0059] The working process of the foldable blood pump A is as follows:

[0060] An external motor drives the impeller of the foldable blood pump to rotate, pumping blood from the left ventricle into the aorta. To prevent blood from entering the gap between the constriction cannula 21 and the catheter, flushing fluid is injected into the gap at regular intervals to prevent thrombus formation. Pressure sensor 26 collects the pressure of the flushing fluid. Since the flushing fluid is in direct contact with arterial blood, the pressure of the flushing fluid is the pressure of the arterial blood, thereby monitoring the arterial blood pressure.

[0061] The withdrawal process of the foldable blood pump A is as follows:

[0062] 1. The impeller of the foldable blood pump is stopped from rotating by an external motor;

[0063] 2. Pull the catheter outward, and the pump head assembly enters the aorta from the left ventricle. Continue to pull the catheter outward, and the pump head assembly enters the retractable sheath 21 and is folded and compressed until it is withdrawn from the proximal end of the retractable sheath 20 in the body.

[0064] 3. Withdraw the internal retractor sheath 20 from the body through the incision.

[0065] Of course, those skilled in the art will recognize that the present invention is not limited to the details of the exemplary embodiments described above, but also includes the same or similar structures that can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0066] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An interventional delivery system with a foldable blood pump, the foldable blood pump (A) comprising a pump head assembly and a catheter, characterized in that, The interventional delivery system includes: An externally retractable sheath (10) is fitted over the pump head assembly and has a first channel. The length of the first channel covers at least the foldable housing and pig tail tube segment in the pump head assembly. The foldable housing portion of the foldable blood pump (A) is retracted into the externally retractable sheath (10). The internal folding sheath (20) is configured to be inserted into the patient's vascular system through a puncture port. It has a second channel, the proximal end of which can be connected to the distal end of the external folding sheath (10). After the pigtail tube of the foldable blood pump (A) is passed through the hemostasis valve (23) of the internal folding sheath (20), the guide section (11) of the external folding sheath (10) is passed through the hemostasis valve (23). When the external folding sheath (10) can no longer be pushed, it stops. The foldable blood pump (A) in the folded state enters the second channel from the first channel. A pressure sensor (26) is installed on it to measure arterial blood pressure. The dilator (30) is slidably disposed in the second channel of the in vivo constriction sheath (20) and works with the guidewire (40) to guide the movement of the in vivo constriction sheath (20) in the vascular system and to the left ventricle; The internal sheath (20) includes a sheath (21) and a sheath seat (22) located at the proximal end of the sheath (21). A hemostatic valve (23) is provided inside the sheath seat (22). A flushing tube (24) is connected to the side wall of the sheath seat (22). The flushing tube (24) is connected to the chamber distal to the hemostatic valve (23). A flushing connector (25) is provided at the end of the flushing tube (24). A pressure sensor (26) is located inside the flushing connector (25). The pressure sensor (26) measures the pressure of the flushing fluid to reflect the arterial blood pressure. The flushing connector (25) integrates a fluid cavity, as well as a fluid inlet and a fluid outlet that connect the fluid cavity. The pressure sensing probe of the pressure sensor (26) is integrated on the cavity wall of the fluid cavity. The inner diameter of the external retraction sheath (10) is larger than the inner diameter of the retraction sleeve (21).

2. The interventional delivery system with a foldable blood pump according to claim 1, characterized in that: The inner wall of the sheath seat (22) on the distal side of the hemostatic valve (23) is provided with a guide cone surface (221). The tilt angle of the guide cone surface (221) matches the tilt angle of the guide section (11) provided at the distal end of the external retractable sheath (10). The inner diameter of the proximal end of the guide cone surface (221) is larger than the outer diameter of the guide section (11), and the inner diameter of the distal end of the guide cone surface (221) is smaller than the inner diameter of the guide section (11). The distal end of the guide cone surface (221) is smoothly connected to the inner wall of the retractable sheath (21).

3. The interventional delivery system of the foldable blood pump according to claim 2, characterized in that: The angle between the guide cone (221) and the axis is 10° to 60°.

4. The interventional delivery system of the foldable blood pump according to claim 2, characterized in that: A locking structure is provided on the sheath seat (22) on the distal side of the hemostatic valve (23). The locking structure and the proximal end of the dilator (30) form an axial limiting and circumferential limiting fit.

5. The interventional delivery system with a foldable blood pump according to claim 4, characterized in that: The locking structure is a threaded structure, including an internal thread on the inner wall of the sheath seat (22) near the hemostatic valve (23), and an external thread on the proximal end of the expander (30) that cooperates with the internal thread to form the locking structure.

6. The interventional delivery system with a foldable blood pump according to claim 1, characterized in that: The length of the internal constriction sheath (20) is 90cm to 120cm, the length of the dilator (30) is 95cm to 125cm, and the distal conical segment of the dilator (30) protrudes beyond the distal end of the internal constriction sheath (20).

7. The interventional delivery system with a foldable blood pump according to claim 1, characterized in that: The length of the externally retractable sheath (10) is equal to the sum of the length of the foldable shell in the retracted state and the length of the pig tail tube in the extended state.

8. The interventional delivery system of the foldable blood pump according to claim 1, characterized in that: The externally retractable sheath (10) is a tearable sheath.

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