CN116317290A - Catheter pump motor - Google Patents

Abstract

The purpose of the present invention is to provide a catheter pump motor that can reduce the flow rate of flushing fluid entering the blood while preventing blood from entering the motor. A rotor and a stator are coaxially arranged in the casing, and the rotor includes a fixedly connected rotating shaft. and the rotor core, the two ends of the rotating shaft form an axial limit and circumferential rotation cooperation with the inner wall of the housing through bearings, the distal end of the rotating shaft protrudes to the outside of the housing and is fixedly connected with the impeller, and the rotating shaft on the side near the impeller and the A rubber sleeve is arranged between the casings. By installing a rubber sleeve between the rotating shaft and the housing, the gap between the rotating shaft and the housing can be reduced or even completely blocked. If flushing liquid enters, the gap between the rotating shaft and the housing becomes smaller, without changing the outlet pressure. Under the premise, the flow rate at the outlet can be reduced, the purpose of reducing the amount of flushing fluid entering the blood can be achieved, the increase of blood pressure or the burden on the heart can be avoided, and it is beneficial to improve the success rate of heart surgery.

Description

catheter pump motor

This application is a divisional application of the previous application (name of invention: "catheter pump motor", application date: November 7, 2022, application number: 202211140338.8).

technical field

The invention relates to the technical field of medical devices, in particular to an improvement of the motor structure of a catheter pump.

Background technique

As a type of ventricular assist device, a catheter pump can be introduced percutaneously into the heart and can be configured to assist or replace the natural heart pumping function by circulatory pumping or continuous pumping of blood. Provides hemodynamic support. A catheter pump includes a catheter connected to an external support device, a motor, an impeller, a cannula, a pigtail, a blood inflow port, and a blood outflow port. When in use, the pigtail tube and part of the cannula with the blood inlet extend into the left ventricle, and the blood outlet, motor and other components are located in the aortic tube, and the motor drives the impeller to rotate to deliver the blood in the left ventricle to the left ventricle. in the aorta. As the core component of the catheter pump --- motor, including the housing, the rotating shaft is placed in the housing through bearings or supports, the rotor core is fixed on the rotating shaft and forms synchronous rotation, the outer circumference of the rotor core is provided with a stator, and the impeller is fixed It is connected to the distal end of the rotating shaft and rotates synchronously with the rotating shaft to suck blood. Since gaps inevitably exist between the rotating shaft and the casing, and between the rotating shaft and the bearing or supporting member, when the impeller pumps blood, blood will enter these gaps and coagulate to form a thrombus, blocking the rotation of the rotating shaft.

In order to solve the above problems, the most commonly used method in the industry is to reversely inject the flushing fluid, such as the Chinese patent application titled "Heart Surgery Pumping Motor" (public number: CN114915109A), that is, from the proximal end of the motor (the side away from the impeller) ) Inject normal saline, a certain concentration of heparin and other flushing fluids to resist the entry of blood into the motor casing, and the cleaning fluid will eventually flow out from the gap between the distal shaft and the bearing or support on the side adjacent to the impeller, and mix with blood into the human body . However, excessive flushing fluid entering the human body may cause blood pressure to increase or increase the burden on the heart, which is undesirable during cardiac surgery and postoperative rehabilitation, and may affect the effect of surgery.

Contents of the invention

The purpose of the present invention is to provide a catheter pump motor which can reduce the flow of flushing fluid entering the blood while preventing the blood from entering the motor.

In order to achieve the above object, the technical solution adopted by the present invention is: a catheter pump motor, including a housing, a rotor and a stator are coaxially arranged in the housing, the rotor includes a fixedly connected rotating shaft and a rotor core, and the two shafts The end forms an axial limit and circumferential rotation fit with the inner wall of the housing through a bearing. The distal end of the rotating shaft protrudes to the outside of the housing and is fixedly connected with the impeller. A rubber sleeve is arranged between the rotating shaft near the impeller side in the housing and the housing. .

The bearings at both ends of the rotating shaft are ball bearings. The outer ring of the bearing at the far end is fixed to the inner wall of the housing. The rubber sleeve is fixed on the inner ring of the bearing and seals the gap between the inner ring and the rotating shaft. The bearing clearance enters the interior of the motor and exits the clearance between the outer and inner rings of the distal bearing.

The rubber sleeve is fixed on the distal end surface of the inner ring.

The rubber sleeve includes an annular rubber ring sheathed on the rotating shaft, the inner ring of the annular rubber ring extends inwardly from the far end and has a built-in lip, and the built-in lip adheres to and seals against the outer wall of the rotating shaft.

In the above solution, by providing a rubber sleeve between the rotating shaft and the housing, the gap between the rotating shaft and the housing can be reduced or even completely blocked. If flushing liquid enters, the gap between the rotating shaft and the housing becomes smaller Under the premise of not changing the outlet pressure, the outlet flow rate can be reduced, so as to reduce the amount of flushing fluid entering the blood, avoid the increase of blood pressure or the aggravation of the heart burden, and help to improve the success rate of heart surgery.

Description of drawings

Fig. 1 is a sectional view among the present invention;

Fig. 2 is a partially enlarged schematic diagram in Fig. 1;

Fig. 3 is a perspective view of the rubber sleeve in Fig. 1 .

Detailed ways

For ease of understanding, first of all, we define the orientations involved in the following: "proximal end" and "proximal side" refer to the side close to the operator/doctor, and "far end" and "far side" refer to the The side far away from the operator/doctor is the side close to the heart. The present invention will be further discussed in detail below in conjunction with FIGS. 1-3 .

A catheter pump motor, comprising a casing 10, a rotor 20 and a stator 30 are coaxially arranged in the casing 10, the rotor 20 includes a fixedly connected rotating shaft 21 and a rotor core 22, and the two ends of the rotating shaft 21 pass through bearings 40 The inner wall of the housing 10 forms an axial limit and a circumferential rotation fit. The distal end of the rotating shaft 21 protrudes outside the housing 10 and is fixedly connected with the impeller 50. The shaft 21 near the impeller side in the housing 10 and the housing 10 A rubber sleeve 60 is arranged between them. By installing a rubber sleeve 60 between the rotating shaft 21 and the housing 10, the gap between the rotating shaft 21 and the housing 10 can be reduced or even completely blocked. If the gap between the rotating shaft 21 and the housing 10 is completely blocked, the blood cannot It enters the inside of the motor, so there is no need to set up flushing equipment; if the gap between the shaft 21 and the housing 10 is only reduced instead of completely blocked, there is still the possibility of blood entering the inside of the motor, so flushing equipment is still required equipment, but because the gap between the rotating shaft 21 and the housing 10 is reduced, the flow at the outlet can be reduced without changing the outlet pressure (because only when the pressure of the flushing fluid is greater than the pressure of the blood can the blood be blocked), The purpose of reducing the amount of flushing fluid entering the blood is achieved, the increase of blood pressure or the aggravation of the burden on the heart is avoided, and it is beneficial to improve the success rate of heart surgery.

The general practice in the industry is that the proximal end of the rotating shaft 21 uses a bearing, and the far end uses a common support, such as a ceramic sleeve, so that the gap at the far end is large, causing too much flushing fluid to enter the blood. In order to solve this problem, refer to Fig. 1-As shown in Figure 3, the bearings 40 at both ends of the rotating shaft 21 are ball bearings, and the outer ring 41 of the bearing 40 on the far end side is fixed to the inner wall of the housing 10, and can be glued or other methods to ensure a stable connection. Eliminate the gap between the outer ring 41 and the housing 10, the rubber sleeve 60 is fixed on the inner ring 42 of the bearing 40 and seals the gap between the inner ring 42 and the rotating shaft 21, and the flushing liquid cannot flow from the inner ring 42 and the rotating shaft 21 Therefore, the flushing fluid can only enter the motor from the gap of the proximal bearing 40 and flow out from the tiny gap between the outer ring 41 and the inner ring 42 of the distal bearing 40 . The gap between the outer ring 41 and the inner ring 42 is very small, so as to ensure that the pressure of the flushing fluid is greater than the pressure of the blood, the amount of the flushing fluid entering the blood is reduced, and the success rate of the operation is improved.

Further, as shown in FIG. 2 , the rubber sleeve 60 is fixed on the distal end surface of the inner ring 42 , and the assembly of this structure is very simple.

The specific structure is shown in Figure 3. The rubber sleeve 60 includes an annular rubber ring 63 sleeved on the rotating shaft 21. The inner distal end of the inner ring of the annular rubber ring 63 extends inwardly with a built-in lip 64. The built-in lip 64 is connected to the outer wall of the rotating shaft 21. Fitted and sealed to prevent blood from entering the motor from the gap between the outer ring 41 and the rotating shaft 21 .

Claims (2)

1. A catheter pump motor, comprising a housing (10), a rotor (20) and a stator (30) are coaxially arranged in the housing (10), and the rotor (20) includes a fixedly connected rotating shaft (21) and the rotor core (22), the two ends of the rotating shaft (21) form an axial limit and circumferential rotation cooperation with the inner wall of the housing (10) through the bearing (40) or the supporting member, and the distal end of the rotating shaft (21) protrudes To the outside of the housing (10) and fixedly connected to the impeller (50), it is characterized in that: a rubber sleeve (60) is arranged between the rotating shaft (21) on the side of the impeller in the housing (10) and the housing (10); The bearings (40) at both ends of the rotating shaft (21) are ball bearings, the outer ring (41) of the bearing (40) at the far end side is fixed to the inner wall of the housing (10), and the rubber sleeve (60) is fixed on the On the inner ring (42) of the bearing (40) and seal the gap between the inner ring (42) and the rotating shaft (21), the flushing fluid enters the interior of the motor from the gap of the proximal bearing (40) and flows from the outer ring ( 41) The gap with the inner ring (42) flows out; The rubber sleeve (60) is fixed on the distal end surface of the inner ring (42). 2. The catheter pump motor according to claim 1, characterized in that: the rubber sleeve (60) includes an annular rubber ring (63) sleeved on the rotating shaft (21), and the inner ring distal end of the annular rubber ring (63) faces A built-in lip (64) is extended inside, and the built-in lip (64) is bonded and sealed to the outer wall of the rotating shaft (21).

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