An emergency, rapidly and minimally invasively implantable multi-stage catheter blood pump

Abstract

The present invention provides an emergency-type multi-stage catheter blood pump that can be rapidly implanted minimally invasively at the aortic valve position to provide left ventricular assistance and save the lives of patients with acute heart failure. The outer diameter of the catheter blood pump is about 4-5 mm, and it is composed of a multi-stage axial flow impeller, a guide vane and a first-stage mixed flow impeller. It can increase the flow rate and (or) lift of the blood pump to meet the working conditions of left ventricular assistance. Its pump casing, impeller, guide vane and transmission shaft are all made of tough materials, which can produce bending deformation and can operate in a bent state, which is convenient for minimally invasive implantation of the blood pump and ventricular assistance in curved blood vessels. During left ventricular assistance, the pump is minimally implanted by puncturing the aorta of the leg or arm, and enters the aortic arch using laparoscopic technology, reaches the aortic valve along the ascending aorta, and enters the left ventricle through the aortic valve. Its driving device is located outside the body, the inlet is located in the left ventricle, and the outlet is located in the ascending aorta or aortic arch. No inlet and outlet pipes are required, and left ventricular assistance is directly performed.

Description

Technical Field

[0001] The present invention relates to a medical device, in particular to a ventricular assist device for patients with heart failure, in particular to a ventricular assist device for rapid rescue of patients with acute heart failure. Background Art

[0002] Acute heart failure (AHF) refers to a clinical syndrome characterized by acute onset or worsening left ventricular dysfunction, resulting in decreased myocardial contractility and increased cardiac workload. This leads to a sudden decrease in cardiac output, increased pulmonary pressure, and increased peripheral circulatory resistance, leading to pulmonary congestion and acute pulmonary edema, possibly accompanied by tissue and organ hypoperfusion and cardiogenic shock. AHF is often life-threatening, with a high mortality rate, and requires emergency treatment. There are two main treatment options: 1. Restoring normal pumping function of the natural heart through methods such as electric shock; 2. Maintaining normal blood circulation through an extracorporeal circulation system. A cardiac assist device is an artificial organ that partially or completely replaces the function of the natural heart to maintain blood circulation, also known as an artificial heart. Technically, there are two main types of artificial hearts: 1. Artificial hearts developed using biomimetic principles, whose operating principles are similar to those of the natural heart; 2. Blood pumps that differ from the natural heart mechanism, primarily rotary blood pumps (also known as impeller pumps). The most typical example of the former is the diaphragm pump, which has inlet and outlet valves and relies on changes in the blood pump volume to transport blood. These pumps are typically driven by a bulky drive device. Currently, the more prominent commercial diaphragm pumps include the Berlin Heart, TCI, and Novacor. However, due to their large size, diaphragm pumps are not implantable, significantly limiting their development. Typical examples of the latter include axial flow pumps and centrifugal pumps. These utilize motors to rotate components such as impellers, promoting blood flow and achieving the purpose of transporting blood. These blood pumps do not require valves and offer advantages such as small size, light weight, simple structure, high reliability, and low cost. They are the primary development direction for implantable artificial hearts. Commercially available axial flow pumps include the Jarvik 2000, MicroMed DeBakey, and Thoratec Heartmate II, while commercially available centrifugal pumps include the Biomedicus BP series, Thoratec Heartmate III, and Tokyo Medical / Dental Centrifugal.

[0003] Most of the commercial artificial hearts mentioned above are invasively implanted blood pumps, primarily used as a last resort for patients with severe heart failure. However, for acute heart failure (CHF), which has the highest mortality rate among heart failure patients, invasive blood pump implantation procedures are lengthy and can easily lead to sudden death during the implantation process. Catheter pumps were developed to address this need. They can be minimally invasively implanted into the aortic valve to provide left ventricular support, reducing the time required for blood pump transplantation and helping patients with acute heart failure overcome their critical period. Compared to rotary impeller blood pumps, axial flow pumps can be smaller than centrifugal pumps, making them more suitable for minimally invasive implantation. Therefore, most catheter pump research utilizes axial flow pumps. However, due to the limitations of minimally invasive implantation, the impeller diameters of currently mature commercial catheter pumps are very small. To meet basic assistance requirements, the pump speed must be increased. Currently, commercial catheter pumps typically operate at speeds exceeding 20,000 rpm, with some even approaching 50,000 rpm. Furthermore, the flow rate is relatively low, typically around 2 L / min. Furthermore, high-speed blood pumps inevitably generate high shear stress, damaging the blood being transported. Optimizing the blood pump impeller alone makes it difficult to meet hemolysis requirements. Therefore, while meeting basic auxiliary requirements, reducing the blood pump speed and increasing flow rate are pressing challenges for catheter pumps. Summary of the Invention

[0004] The purpose of the present invention is to provide an emergency type multi-stage catheter blood pump with rapid minimally invasive implantation, the structure of which is as follows: Figure 1 As shown, the outer diameter of the blood pump is about 4-5mm. It consists of a multi-stage axial flow impeller, guide vanes and a first-stage mixed flow impeller. It can be quickly implanted into the aortic valve position through minimally invasive technology to assist the left heart. The pump casing, impeller, guide vanes and drive shaft are all made of tough materials, which can produce bending deformation and can operate in a bent state, which is convenient for minimally invasive implantation of the blood pump and ventricular assistance in curved blood vessels. During left heart assistance, the pump is minimally invasively implanted by puncturing the aorta of the leg or arm, and enters the aortic arch using laparoscopic technology. It reaches the aortic valve along the ascending aorta and passes through the aortic valve into the left ventricle. The inlet is located in the left ventricle and the outlet is located in the ascending aorta or aortic arch. No inlet or outlet pipes are required, and left heart assistance can be performed directly.

[0005] In order to achieve the above objectives, the present invention adopts the following technical solutions:

[0006] An emergency, rapidly minimally invasively implantable multi-stage catheter blood pump consists of a pump casing, a multi-stage axial flow impeller, a multi-stage guide vane, a mixed flow impeller, a sealing plug, a transmission shaft, and a drive device. It can be rapidly implanted at the aortic valve position to provide rapid left ventricular assistance to patients with acute heart failure.

[0007] Preferably, the pump casing of the blood pump shown is made of a tough material and can bend and deform. Its axial length is long and can extend from the implantation position to outside the body. The implantation end of the pump casing is a conical structure, and the conical side is a number of inlets of the blood pump. A circular hole is provided at the top of the implantation end, which facilitates the passage of the guide wire and the motor shaft during implantation and acts as a bearing when the blood pump is running.

[0008] Preferably, the multi-stage axial flow impeller of the blood pump can be designed with the number of stages according to working conditions. The axial flow impeller is in transmission connection with the transmission shaft and rotates along with the transmission shaft.

[0009] Preferably, the guide vanes of the blood pump are designed into multiple stages according to the number of axial flow impellers, and are located at the rear end of each stage of impellers. The guide vanes and the drive shaft are connected in a non-transmission manner, and the guide vanes do not rotate with the drive shaft. After the guide vanes are implanted, the outer diameter edge and the inner wall of the pump casing fit tightly together to play a fixing role.

[0010] Preferably, the mixed flow blades of the blood pump are located at the outlet of the blood pump casing, converting the axial flow of blood into radial flow, which flows out from the radial outlet. The mixed flow impeller and the transmission shaft are in transmission connection and rotates together with the transmission shaft.

[0011] Preferably, the sealing plug of the blood pump is located at the rear end of the mixed flow impeller and is tightly fitted between the pump casing and the shaft to prevent blood from flowing out of the body through the pump casing pipeline.

[0012] Preferably, the blood pump's drive shaft is made of a ductile material and has a long axial length, extending from the implant site to the outside of the body. Its outermost end is connected to the rotor of the drive unit, while its implanted end is fixedly connected to each impeller stage, loosely connected to the guide vanes, and tightly fitted with the sealing plug. The drive shaft has raised positioning features at the guide vanes and sealing plug to facilitate positioning during implantation.

[0013] Preferably, the driving device of the blood pump is generally a motor located outside the body, and the rotor is fixedly connected to one end of the transmission shaft outside the body to drive the shaft to rotate.

[0014] The multi-stage catheter blood pump described in this invention is a short-term, emergency, and minimally invasively implantable blood pump. It can be rapidly implanted using minimally invasive techniques and is primarily used to rescue patients with acute heart failure. Furthermore, by utilizing a multi-stage impeller design, this blood pump reduces the blood pump's rotational speed while still meeting the blood pump's auxiliary operating conditions, thereby improving its hemocompatibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Diagram of the implantation of a multi-stage catheter blood pump for emergency, rapid, minimally invasive implantation.

[0016] Figure 2 Schematic diagram of the structure of a multi-stage catheter blood pump that is rapidly and minimally invasively implanted for emergency use.

[0017] Figure 3 This is a schematic diagram of the structure of the catheter blood pump housing.

[0018] Figure 4 Schematic diagram of the mixed flow impeller structure of the catheter blood pump.

[0019] Figure 5 This is a schematic diagram of the structure of the catheter blood pump drive shaft.

[0020] Figure 6 A guidewire implantation device to assist in the implantation of a catheter-assisted blood pump.

[0021] Figure 7 Schematic diagram of the catheter blood pump implantation steps.

[0022] In the figure: 1-left ventricle, 2-right ventricle, 3-aorta, 4-pulmonary artery, 5-catheter blood pump, 5.1-pump casing, 5.2-multi-stage impeller, 5.3-multi-stage guide vanes, 5.4-mixed flow impeller, 5.5-drive shaft, 5.6-sealing plug, 6-motor, 7-guidewire, 8-guidewire implantation device. DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereto.

[0024] The emergency-type, rapidly implantable multi-stage catheter blood pump of the present invention is composed of a pump housing (5.1), a multi-stage impeller (5.2), a multi-stage guide vane (5.3), a mixed flow impeller (5.4), a transmission shaft (5.5), a sealing plug (5.6) and a motor (6). The pump housing (5.1) is made of a tough material and can bend and deform. Its axial length is relatively long. After the blood pump is implanted, the outer end extends out of the body. The implantation end of the pump housing is a conical structure. The conical side is the blood pump inlet. The top of the implantation end has a circular hole, which is convenient for the guide wire and the motor shaft to pass through during implantation and acts as a bearing when the blood pump is running. The impeller (5.2) can be designed as a multi-stage impeller according to requirements, fixedly connected to the shaft and rotating with the shaft. The guide vane (5.3) can be designed as a multi-stage guide vane according to requirements, which is non-fixedly connected to the shaft and does not rotate with the shaft. After implantation, the guide vane is tightly matched with the pump housing and plays a fixing role. The mixed flow impeller (5.4) is located on the pump housing of the blood pump. The outlet position guides the blood from axial flow to the radial outlet; the transmission shaft (5.5) is made of a tough material, has a very long axial length, extends to the outside of the body, is fixedly connected to the impeller, is non-fixedly connected to the guide vane, and is tightly matched with the sealing plug. Its implanted end passes through the circular hole at the top of the pump casing (5.1) and acts as a bearing, and its external end is fixedly connected to the rotor of the motor (6); the sealing plug (5.6) is located behind the mixed flow impeller, between the pump casing and the shaft, and is tightly matched with the pump casing and the shaft to prevent blood from flowing out of the body through the pump casing pipeline; the motor (6) is located outside the body after the blood pump is implanted, and is fixedly connected to the external end of the transmission shaft (5.5), driving the shaft and impeller to rotate.

[0025] Example:

[0026] Figure 7 This is an embodiment of the rapid minimally invasive implantation of a multi-stage catheter blood pump according to the present invention. In this embodiment, a guide wire implantation device (8) is first used to insert a guide wire (7) from the left upper arm brachial artery into the artery, until it reaches the aortic arch, and then enters the left ventricle through the aortic valve. Figure 7 (a); Then pass the circular hole at the top of the pump housing (5.1) through the guide wire and follow the guide wire (7) into the left ventricle, so that the inlet of the pump housing is located in the left ventricle and the outlet is located at the ascending aorta or aortic arch. Figure 7 (b); The third step is to withdraw the guide wire (7) from the left ventricle and blood vessels, such as Figure 7 (c); The fourth step is to connect the drive shaft (5.5) and the impeller (5.2), the guide vane (5.3), the mixed flow impeller (5.4), and the sealing plug (5.6) together, and insert them into the pump casing (5.1). Position the primary impeller at the pump casing inlet and the mixed flow impeller (5.4) at the pump casing outlet, as shown in FIG. Figure 7 (d); The fifth step is to fix the outer end of the transmission shaft (5.5) and the motor (6) rotor, such as Figure 7(d); The sixth step is to energize the motor (6) to rotate the transmission shaft (5.5), thereby driving the multi-stage impeller (5.2) and the mixed flow impeller (5.4) to rotate, so that blood flows from the left ventricle into the aorta, playing a role of ventricular assist.

Claims

1. An emergency, rapid, minimally invasively implanted multi-stage catheter blood pump, comprising a pump housing (5.1), a multi-stage impeller (5.2), a multi-stage guide vane (5.3), a mixed flow impeller (5.4), a transmission shaft (5.5), a sealing plug (5.6), and a drive device (6), characterized in that: The pump housing (5.1) has a very long axial length and can extend from the implantation position to the outside of the body. The implantation end of the pump housing is a conical structure. The conical side is provided with a plurality of blood pump inlets (5.11) for connecting to the left ventricle (1). The top of the implantation end is provided with a circular hole, which is convenient for the guide wire and the transmission shaft to pass through during implantation and acts as a bearing when the blood pump is running. The pump housing (5.1) is provided with a blood pump outlet (5.12) at the ascending aorta or aortic arch after implantation, which is used to connect to the aorta. A multi-stage impeller (5.2), a multi-stage guide vane (5.3) and a mixed flow impeller (5.4) are provided between the blood pump inlet (5.11) and the blood pump outlet (5.12). The number of stages of the multi-stage impeller (5.2) is set according to the working conditions. The first-stage impeller is located at the blood pump inlet (5.11). The multi-stage guide vanes (5.3) are respectively located at the multi-stage impeller. (5.2), the mixed flow impeller (5.4) is located at the blood pump outlet (5.12), converting the axial flow of blood into radial flow, which flows out from the radial blood pump outlet (5.12); the drive shaft (5.5) is fixedly connected to the multi-stage impeller (5.2) and the mixed flow impeller (5.4) inside the pump casing, and is non-fixedly connected to the multi-stage guide vane (5.3), and its external end is fixedly connected to the rotor of the driving device (6); the pump casing (5.1), the multi-stage impeller (5.2), the multi-stage guide vane (5.3), the mixed flow impeller (5.4) and the drive shaft (5.5) are all made of tough materials, can produce bending deformation, and operate in a bent state, the sealing plug (5.6) is located at the rear end of the mixed flow impeller (5.4), and is tightly matched between the pump casing (5.1) and the drive shaft (5.5) to prevent blood from flowing out of the body through the pump casing pipeline.

2. The emergency-type, rapid, minimally invasive implantable multi-stage catheter blood pump according to claim 1, characterized in that: The outer diameter edge of the multi-stage guide vane (5.3) is tightly matched with the inner wall of the pump casing to play a fixing role.

3. The emergency, rapid, minimally invasive, implantable multi-stage catheter blood pump according to claim 1, characterized in that: The transmission shaft (5.5) has a long axial length, extending from the implantation position to the outside of the body, with the outermost end connected to the rotor of the drive device (6). The front and rear ends of the multi-stage guide vanes (5.3) and the sealing plug (5.6) are provided with raised positioning devices, which help to position the guide vanes and the sealing plug during implantation.

4. The emergency, rapid, minimally invasive, implantable multi-stage catheter blood pump according to claim 1, characterized in that: The driving device (6) is generally a motor located outside the body, and its rotor is fixedly connected to one end of the transmission shaft (5.5) outside the body, driving the transmission shaft and the impeller to rotate.

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