WO2024109422A1

WO2024109422A1 - System and method for estimating position of interventional blood pump

Info

Publication number: WO2024109422A1
Application number: PCT/CN2023/126158
Authority: WO
Inventors: 吕骁; 吕世文; 古珮瑶
Original assignee: 上海炫脉医疗科技有限公司
Priority date: 2022-11-24
Filing date: 2023-10-24
Publication date: 2024-05-30
Also published as: CN115779260A

Abstract

The present application relates to an interventional blood pump and a method for estimating the position of an interventional blood pump system. During the operation of the interventional blood pump system within a patient, an induced current, generated by the interventional blood pump system under the action of blood in the heart, is received. The magnitude and/or direction of the induced current changes as the interventional blood pump system operates. The induced current forms a time-varying periodic pattern with respect to time. On the basis of at least one of the magnitude, direction, and valley points of the induced current in the time-varying periodic pattern, the position of the interventional blood pump system within the patient is determined.

Description

System and method for estimating the position of an invasive blood pump

This application claims priority to the Chinese patent application filed with the China Patent Office on November 24, 2022, with application number 202211484638.8, the entire contents of which are incorporated by reference into this application.

Technical Field

The present application relates to the field of medical devices, for example, to a system and method for estimating the position of an invasive blood pump.

Background technique

At present, the incidence and mortality of cardiovascular diseases in China are gradually increasing. Severe cardiovascular diseases such as myocardial infarction and its complications directly threaten the life safety of patients and require emergency surgical treatment. It is estimated that the incidence of acute myocardial infarction in my country is about 45 to 55 per 100,000, and it is still on the rise. Since the development of heart failure is relatively slow, most of the time it is due to the accumulation of various symptoms of patients over many years, the heart gradually loses its pumping function, and various functions gradually weaken, accompanied by heart enlargement, mainly left ventricular enlargement, which has a great negative impact on the patient's quality of life and clinical treatment. The treatment options in related technologies include drug therapy, auxiliary devices and heart transplantation, but different treatment methods face great challenges.

Regarding the cardiac surgery treatment options in the related art, interventional cardiac treatment surgery is a common treatment option, which uses a stable hemodynamic assist device in conjunction with the surgery. The heart pump (also known as an interventional blood pump) that assists the heart's ejection function is the key. The position of the heart where the interventional blood pump is located during operation determines whether the surgery is successful. In the related art, the positioning of the interventional blood pump usually uses the image positioning method, but image positioning is not accurate in some cases and has the defect of unclear imaging. In addition, the use of dedicated sensors for positioning is also a common method, but such sensors are easily damaged and have high costs, and are not easy to maintain in the later stage, which poses certain risks to the surgery.

Summary of the invention

The present application provides an interventional blood pump system and a method for estimating the position of an interventional blood pump system for situations where it is difficult to determine the position of a blood pump using, for example, imaging or ultrasound technology, and where it is difficult to determine the position of a blood pump when a sensor fails.

According to one aspect of the present application, a method for estimating the position of an interventional blood pump system is provided, and during the operation of the interventional blood pump system in a patient's body, the method includes: receiving an induced current generated by the interventional blood pump system due to the action of intracardiac blood; wherein the magnitude and/or direction of the induced current changes with the operation of the interventional blood pump system, and the induced current forms a time-varying periodic diagram relative to time; and determining the position of the interventional blood pump system in the patient based on at least one of the magnitude, direction, and valley value of the induced current in the time-varying periodic diagram.

According to another aspect of the present application, an invasive blood pump system is provided, including a blood pump, a catheter, and a controller, wherein the controller is configured to execute the aforementioned method for estimating the position of the invasive blood pump system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a control logic diagram of a method for estimating the position of an invasive blood pump system according to an embodiment of the present application.

FIG. 2 a is a schematic diagram of the position of a blood pump in the heart when the blood pump has not reached the target position according to an embodiment of the present application.

FIG. 2 b is a waveform diagram of the first cycle when the blood pump does not reach the target position according to an embodiment of the present application.

FIG. 3 a is a schematic diagram of the position of the blood pump in the heart when it reaches the target position according to an embodiment of the present application.

FIG. 3 b is a waveform diagram of the second cycle when the blood pump reaches the target position according to an embodiment of the present application.

FIG. 4 a is a schematic diagram of the position of the blood pump in the heart when the blood pump exceeds the target position according to an embodiment of the present application.

FIG. 4 b is a waveform diagram of the third cycle when the blood pump exceeds the target position according to an embodiment of the present application.

FIG. 5 a is a schematic diagram of the overall structure of a blood pump according to an embodiment of the present application.

FIG. 5 b is another schematic diagram of the overall structure of a blood pump according to an embodiment of the present application.

FIG. 5 c is a schematic diagram of an integrated structure of a blood pump according to an embodiment of the present application.

FIG. 6 is a schematic diagram of the connection between a blood pump and a controller according to an embodiment of the present application.

The reference numerals in the accompanying drawings are as follows:

1-blood pump, 2-blade, 3-housing, 4-motor, 41-rotating shaft, 42-inner magnetic pole, 43-coil, 44-outer magnetic pole, 5-integrated structure, 6-blood inlet, 7-blood outlet, 8-catheter, 9-controller.

Detailed ways

In the following description of the drawings and specific embodiments, the details of one or more embodiments of the present application will be described. Similarly, it is understood that the phrases and terms used herein are for descriptive purposes and should not be considered restrictive. The use of "including", "comprising" or "having" and variations thereof herein is intended to openly include the items listed thereafter and their equivalents and additional items.

The present application will be described in more detail below with reference to different embodiments and examples of several aspects of the present application.

In the present application, the term “proximal end” or “proximal side” refers to an end or a side closer to a surgical operator, and the term “distal end” or “distal side” refers to an end or a side farther from a surgical operator.

As shown in FIG. 1 , a method for estimating the position of an invasive blood pump system according to an embodiment of the present application is shown. The method may be executed by the invasive blood pump system, for example, by a controller in the invasive blood pump.

During the operation of the interventional blood pump system in the patient, the natural cardiac ejection of the human body can drive the motor and blades in the blood pump to rotate; the rotation of the blades generates an induced current; the sensor in the motor measures the induced current; the controller in the blood pump receives the induced current and determines the curve characteristics of the induced current; the controller presents the induced current in the form of visual data on the operating end of the medical staff; the controller determines the position of the blood pump based on the curve characteristics of the induced current; the system program of the controller combines with a specific algorithm to display corresponding adjustment measures on the operating end of the medical staff for the medical staff to perform the next surgical operation.

The method for estimating the position of an interventional blood pump system provided in an embodiment of the present application includes: during the operation of the interventional blood pump system in a patient, receiving an induced current generated by the interventional blood pump system due to the action of intracardiac blood, wherein the magnitude and/or direction of the induced current changes with the operation of the interventional blood pump system, and the induced current forms a time-varying periodic diagram relative to time, and determining the position of the interventional blood pump system in the patient based on at least one of the magnitude, direction, and valley value of the induced current in the time-varying periodic diagram.

According to one embodiment, the induced current is received from a controller on the interventional blood pump system; and the time-varying periodic diagram is a waveform diagram, and the lowest value of the induced current in each cycle is the trough of each fluctuation cycle; when the trough is in the time-varying cycle When the lowest point is reached in the period graph, the induced current reaches a valley value, and the interventional blood pump system reaches the target position.

According to one embodiment, when the lowest value of the induced current is a negative value and the direction of the induced current alternates between a positive direction and a reverse direction, the interventional blood pump system is located at the target position, as shown in FIGS. 3a and 3b .

According to one embodiment, at least a first periodic waveform diagram and a second periodic waveform diagram appear in the time-varying periodic diagram; and, when the first periodic waveform diagram appears, the interventional blood pump system has not reached the target position, as shown in Figures 2a and 2b, and when the second periodic waveform diagram appears, the interventional blood pump system reaches the target position, as shown in Figures 3a and 3b.

According to one embodiment, the time-varying periodic diagram further includes a third periodic waveform diagram; and when the third periodic waveform diagram appears, the invasive blood pump system has exceeded the target position, as shown in FIGS. 4a and 4b .

According to one embodiment, the interventional blood pump system includes a blood inlet 6 and a blood outlet 7, as shown in Figure 5a; and, when the blood inlet 6 and the blood outlet 7 are both located in the aorta, as shown in Figure 2a, the time-varying periodic diagram is a first periodic waveform diagram, as shown in Figure 2b; when the blood inlet 6 is located in the left ventricle and the blood outlet 7 is located in the aorta, as shown in Figure 3a, the time-varying periodic diagram is a second periodic waveform diagram, as shown in Figure 3b; when the blood inlet 6 and the blood outlet 7 are both located in the left ventricle, as shown in Figure 4a, the time-varying periodic diagram is a third periodic waveform diagram, as shown in Figure 4b.

According to one embodiment, the lowest value of the induced current of the second periodic waveform is smaller than the lowest value of the induced current of the third periodic waveform, and the lowest value of the induced current of the third periodic waveform is smaller than the lowest value of the induced current of the first periodic waveform; and the highest value of the induced current of the second periodic waveform is the smallest among the highest values of the induced current of the three periodic waveforms.

According to an embodiment, a maximum value of the induced current in the first periodic waveform diagram is close to a maximum value of the induced current in the third periodic waveform diagram.

According to one embodiment, when the blood inlet 6 is located in the left ventricle and the blood outlet 7 is located in the aorta, the invasive blood pump system is located at the target position.

According to an embodiment, the variation amplitude of the induced current of the first periodic waveform is the smallest among the variation amplitudes of the three periodic waveforms.

According to one embodiment, the time-varying periodogram visually presents real-time data, waveform and current characteristic values of the induced current, wherein the current characteristic values include peak value, valley value, amplitude, frequency, rate of change, first-order derivative and second-order derivative.

According to one embodiment, the method provided by the present application is particularly important when the effect of determining the position of the interventional blood pump using medical images is not obvious, or when other sensors used to determine the position of the interventional blood pump fail.

According to one embodiment, the variation amplitude of the induced current generated when the blood inlet 6 and the blood outlet 7 are located in the left ventricle of the patient is greater than the variation amplitude of the induced current generated when the blood inlet 6 and the blood outlet 7 are located in the aorta of the patient.

According to one embodiment, an invasive blood pump system is provided, including a blood pump 1, a catheter 8 (the catheter 8 may be an elongated catheter) and a controller 9 (as shown in FIG. 6 ).

According to one embodiment, the blood pump 1 includes a blade 2, a housing 3 and a motor 4. As shown in FIGS. 5a and 5b, the motor 4 includes a rotating shaft 41, an inner magnetic pole 42, a coil 43 and an outer magnetic pole 44. The coil 43 and the outer magnetic pole 44 are fixed to the housing 3; and the blade 2, the rotating shaft 41 and the inner magnetic pole 42 are fixed together to form an integrated structure. Structure 5, as shown in Figure 5c.

According to one embodiment, when the interventional blood pump system enters the human body, when the blood pump is not driven by current, the blood fluid generated by the natural heart pumping of the human body impacts the blade 2, the integrated structure 5 rotates, and the rotation of the inner magnetic pole 42 changes the direction of the magnetic field formed by the inner magnetic pole 42 and the outer magnetic pole 44. The magnetic field and the coil 43 produce a cutting motion, and the coil 43 generates an induced current.

According to one embodiment, the controller has a built-in analog-to-electric conversion device, which converts the collected induced current into a digital signal and stores it in the memory of the controller.

According to one embodiment, the blade 2 is disposed at the distal end of the rotating shaft 41 .

According to one embodiment, the blood inlet 6 is arranged at the distal end of the blade 2 , and the blood outlet 7 is arranged at the proximal end of the blade 2 .

According to one embodiment, the controller determines the current curve characteristics of the induced current and presents the current curve and its characteristics on an operation interface of medical personnel so that the medical personnel can observe the physiological characteristics of the patient.

According to one embodiment, the controller has a determination function to programmatically determine the position of the interventional blood pump using the induced current curve and its characteristic value to reduce the number of determination steps for medical personnel; the system program of the controller combines with a specific algorithm to display corresponding adjustment measures at the operating end for medical personnel to perform the next surgical operation.

According to one embodiment, the motor has a built-in high-precision current sensor, and the current sensor is configured to collect the driving current of the motor and the induced current caused by the blood fluid impact generated by the natural heart pumping of the human body.

According to one embodiment, the controller has an automatic determination function, and monitors the patient in real time and determines the surgical status of the patient through the collected current data and the calculated multiple characteristic values, and executes the corresponding alarm function.

An exemplary use procedure and control logic of the heart assist system 1 according to one embodiment are as follows:

1. The blood pump 1 is delivered to the ascending aorta through the femoral artery, the descending aorta, and the aortic arch through a surgical operation, as shown in FIG2a , and the blood drives the blades 2 of the blood pump 1 to rotate, and the controller receives the induced current and displays a first cycle waveform, as shown in FIG2b ;

2. Continue to push the blood pump 1 toward the far end, the controller shows a second period waveform, the direction of the induced current in the second period waveform alternates between positive and reverse directions, and the blood pump 1 reaches the vicinity of the target position;

3. Adjust the position of the blood pump 1 so that the blood inlet 6 is located in the left ventricle and the blood outlet 7 is located in the aorta, as shown in FIGS. 3a and 3b ; if the third cycle waveform appears and the trough of the induced current is higher than the trough of the induced current in the second cycle waveform, as shown in FIGS. 4a and 4b , pull the blood pump 1 toward the proximal end; if the first cycle waveform appears and the amplitude of the induced current is smaller than the amplitude of the induced current in the second cycle waveform, push the blood pump 1 toward the distal end;

4. The blood pump 1 is started, and the motor 4 drives the blade 2 to rotate to achieve the blood pumping function;

5. The controller collects the current data of the motor 4 and stores it in the controller memory.

Artificial interventional blood pumps in related technologies generally determine the position of the blood pump body in the human body through image positioning or by setting a positioning sensor outside the motor. Image positioning is not accurate in some cases and has the defect of unclear imaging. Setting a positioning sensor not only increases the difficulty of the process, but also easily scratches the blood vessels during movement, reducing the safety of the operation and easily causing damage and failure of the sensor. This application avoids the above situation and discloses a method for estimating the position of the blood pump body in the human body. A method for calculating the position of an interventional blood pump system. First, the natural ejection of blood by the human body will drive the motor and blades of the blood pump to rotate. According to the electromagnetic induction phenomenon, the blood pump system can generate an induced current. Secondly, as the blood pump moves forward in the blood vessel, the magnitude and/or direction of the induced current changes with the change of the position of the blood pump. The induced current forms a time-varying periodic diagram relative to time. The controller in the blood pump determines the curve characteristics of the induced current and presents the induced current in the form of visualized data on the operating end of the medical staff. The controller can determine the position of the blood pump in the patient according to at least one of the magnitude, direction, and valley value of the induced current. Therefore, the operator can determine whether the blood pump system is located at the target position by observing the induced current curve characteristics at the operating end. This judgment method not only saves the need for additional positioning sensors, but also saves equipment production costs and increases the safety factor of the operation.

According to an idea of the present application, the time-varying periodic diagram of the present application is a waveform diagram. When the interventional blood pump system is in different positions, the position and shape of the induced current curve of the time-varying periodic diagram are different. When the lowest value of the induced current is a negative value, and the direction of the induced current alternates between positive and reverse directions, the interventional blood pump system is located at the target position, and the determination principle is as follows: during the systolic period of the human heart, the aortic valve opens, and the left ventricular blood is connected to the aortic blood. At this time, the blood flow direction is positive, and the direction of the generated induced current is also positive; during the diastolic period of the heart, the aortic valve closes, but because the blood pump crosses the aortic valve, the aortic valve cannot be completely closed. At this time, the aortic blood pressure is greater than the left ventricular blood pressure, and the blood fluid flows from the high-pressure area to the low-pressure area, causing a slight reflux phenomenon that causes the blades to reverse. At this time, the induced current corresponding to the blood pump motor is in the reverse direction. Therefore, for multiple consecutive and complete cardiac cycles, the direction of the induced current alternates between positive and reverse directions.

According to one concept of the present application, the interventional blood pump system includes a blood inlet and a blood outlet, and when the blood inlet and the blood outlet are both located in the aorta, the time-varying periodic diagram is a first periodic waveform diagram; when the blood inlet is located in the left ventricle and the blood outlet is located in the aorta, the time-varying periodic diagram is a second periodic waveform diagram; when the blood inlet and the blood outlet are both located in the left ventricle, the time-varying periodic diagram is a third periodic waveform diagram. The controller can determine the first periodic waveform diagram, the second periodic waveform diagram, or the third periodic waveform diagram based on the amplitude, peak, trough, or other current characteristic values of the induced current in the time-varying periodic diagram, thereby determining the position of the blood pump in the heart, and the basis for determination is also very intuitive and simple. The blood pump system is percutaneously intervened and passes through the aortic arch. The first cycle waveform appears first. The peaks and troughs of the first cycle waveform are both positive numbers with a small amplitude. Then the second cycle waveform appears, the lowest value of the induced current is a negative value, and the direction of the induced current alternates between positive and reverse directions, which means that the target position has been reached. If the third cycle waveform appears, and the lowest value of the induced current in the third cycle waveform is less than the lowest value of the induced current in the first cycle waveform, and the amplitude of the change is greater than that of the first cycle waveform, then the target position has been exceeded and the interventional blood pump system needs to be pulled proximally.

According to one concept of the present application, a time-varying periodogram visually presents the real-time data, waveform and current characteristic values of the induced current. The current characteristic values include peak value, valley value, amplitude, frequency, rate of change, first-order derivative and second-order derivative. These data can assist medical personnel in determining the position of the blood pump in the blood vessel, and can also analyze the patient's heart pumping condition.

According to one concept of the present application, the blood pump of the interventional blood pump system includes blades, a casing and a motor, the motor includes a rotating shaft, an inner magnetic pole, a coil and an outer magnetic pole, and the blades, the rotating shaft and the inner magnetic pole are fixed together to form an integrated structure. When the interventional blood pump system enters the human body, when the blood pump is not driven by electric current, the blood fluid generated by the natural heart pumping of the human body impacts the blades, and the integrated structure rotates. The rotation of the inner magnetic pole changes the direction of the magnetic field formed by the inner magnetic pole and the outer magnetic pole, and the magnetic field and the coil produce a cutting motion, and the coil generates an induced current, thereby utilizing the natural blood pumping of the human body without setting up other structures. The blood pump generates an induced current, thereby determining the position of the blood pump. The design is ingenious and has high clinical promotion value. In addition, the controller has a built-in analog-to-electric conversion device, which converts the collected induced current into a digital signal and stores it in the controller's memory. The data is backed up, and the humanization level is high.

Claims

A method for estimating a position of an invasive blood pump system during operation of the invasive blood pump system in a patient's body, the method comprising:

Receiving an induced current generated by the interventional blood pump system under the action of intracardiac blood; wherein the magnitude and/or direction of the induced current changes with the operation of the interventional blood pump system, and the induced current forms a time-varying periodic diagram relative to time;

The position of the invasive blood pump system in the patient is determined according to at least one of the magnitude, direction, and valley value of the induced current in the time-varying periodogram.
According to the method for estimating the position of an interventional blood pump system according to claim 1, wherein the induced current is received from a controller on the interventional blood pump system; the time-varying periodic diagram is a waveform diagram, and the lowest value of the induced current in each fluctuation cycle is the trough of each fluctuation cycle; when the trough reaches the lowest point in the time-varying periodic diagram, the induced current reaches the valley value, and the interventional blood pump system reaches the target position.
According to the method for estimating the position of an interventional blood pump system according to claim 1 or 2, wherein when the lowest value of the induced current is a negative value and the direction of the induced current alternates between a positive direction and a reverse direction, the interventional blood pump system is located at the target position.
According to the method for estimating the position of an interventional blood pump system according to claim 1, wherein at least a first periodic waveform diagram and a second periodic waveform diagram appear in the time-varying periodic diagram; when the first periodic waveform diagram appears, the interventional blood pump system has not reached the target position, and when the second periodic waveform diagram appears, the interventional blood pump system has reached the target position.
According to the method for estimating the position of an invasive blood pump system according to claim 4, wherein the time-varying periodic diagram also includes a third periodic waveform diagram; when the third periodic waveform diagram appears, the invasive blood pump system has exceeded the target position.
According to the method for estimating the position of an interventional blood pump system according to claim 5, the interventional blood pump system includes a blood inlet and a blood outlet; when the blood inlet and the blood outlet are respectively located in the aorta, the time-varying periodic graph is the first periodic waveform graph; when the blood inlet is located in the left ventricle and the blood outlet is located in the aorta, the time-varying periodic graph is the second periodic waveform graph; when the blood inlet and the blood outlet are respectively located in the left ventricle, the time-varying periodic graph is the third periodic waveform graph.
According to the method for estimating the position of an interventional blood pump system according to claim 5 or 6, wherein the lowest value of the induced current of the second periodic waveform is smaller than the lowest value of the induced current of the third periodic waveform, and the lowest value of the induced current of the third periodic waveform is smaller than the lowest value of the induced current of the first periodic waveform; the highest value of the induced current of the second periodic waveform is smaller than the highest value of the induced current of the first periodic waveform, and the highest value of the induced current of the second periodic waveform is smaller than the highest value of the induced current of the third periodic waveform.
The method for estimating the position of an interventional blood pump system according to claim 4 or 5, wherein the amplitude of change of the induced current of the first periodic waveform graph is smaller than the amplitude of change of the induced current of the second periodic waveform graph, and the amplitude of change of the induced current of the first periodic waveform graph is smaller than the amplitude of change of the induced current of the third periodic waveform graph.
The method for estimating the position of an invasive blood pump system according to claim 1, wherein the time-varying periodogram The real-time data, waveform and current characteristic values of the induced current are visually presented, and the current characteristic values include peak value, valley value, amplitude, frequency, rate of change, first-order derivative and second-order derivative.
An invasive blood pump system comprises a blood pump, a catheter and a controller, wherein the controller is configured to execute the method according to any one of claims 1-9.
According to the interventional blood pump system according to claim 10, the blood pump includes blades, a housing and a motor, the motor includes a rotating shaft, an inner magnetic pole, a coil and an outer magnetic pole, the coil and the outer magnetic pole are fixed on the housing; the blades, the rotating shaft and the inner magnetic pole are fixed together to form an integrated structure.
The interventional blood pump system according to claim 11, wherein, during the process of the interventional blood pump system entering the human body, when the blood pump is not driven by electric current, the blood fluid generated by the natural heart pumping of the human body impacts the blades, and the integrated structure rotates to generate an induced current.
The invasive blood pump system according to claim 12, wherein the controller has a built-in analog-to-electric conversion device, and the analog-to-electric conversion device is configured to convert the collected induced current into a digital signal and store it in the controller memory.