CN115227964A

CN115227964A - Flow velocity control method and device

Info

Publication number: CN115227964A
Application number: CN202211146937.0A
Authority: CN
Inventors: 范晓生; 余顺周
Original assignee: Shenzhen Core Medical Technology Co Ltd
Current assignee: Shenzhen Core Medical Technology Co Ltd
Priority date: 2022-09-21
Filing date: 2022-09-21
Publication date: 2022-10-25
Anticipated expiration: 2042-09-21
Also published as: CN115227964B

Abstract

The application provides a flow velocity control method and a flow velocity control device, wherein the method comprises the following steps: acquiring a first pressure and a second pressure, wherein the first pressure is the fluid pressure in the flushing cavity, and the second pressure is the blood pressure in the ventricular assist device; when the first difference value exceeds a preset range, calculating the target pressure of the flushing cavity, wherein the first difference value is the difference value between the first pressure and the second pressure, and the target pressure is greater than the second pressure; determining a target irrigation fluid flow rate into the irrigation lumen based on the target pressure; the rinse flow rate is maintained at the target rinse flow rate. When the difference of the fluid pressure in the flushing cavity and the blood pressure in the ventricular assist device exceeds the preset value, the fluid pressure in the flushing cavity is adjusted by adjusting the flow rate of flushing liquid, so that the pressure barrier between the blood in the ventricular assist device and the motor is kept in a stable state, and the safe operation of the ventricular assist device is ensured.

Description

Flow velocity control method and device

Technical Field

The present disclosure relates to the field of control technologies, and in particular, to a method and an apparatus for controlling a flow rate.

Background

The interventional Ventricular Assist Device (VAD) has the advantages of small volume, high rotating speed, easy implantation, small operation trauma and only short-term assistance, and is mainly used for protecting the high-risk PCI (percutaneous coronary intervention) operation. The ventricular assist system generally includes an interventional ventricular assist device, a controller, and an irrigation fluid device for maintaining a pressure barrier between blood and the motor by connecting the irrigation device to the motor using a pressure created by the irrigation fluid in a direction opposite to the direction of blood flow to isolate the blood from the motor and prevent blood from entering the motor.

However, during the starting and operation of the left ventricular assist device, the pressure of blood in the left ventricular assist device may change due to the adjustment of the rotation speed or other reasons, so that the pressure barrier between the blood and the motor may also change, thereby affecting the operation of the left ventricular assist device.

Disclosure of Invention

The embodiment of the application provides a flow rate control method and a flow rate control device, which can ensure that a pressure barrier between blood and a motor in a ventricular assist device keeps a stable state by adjusting the flow rate of flushing fluid in real time, thereby ensuring the safe operation of the ventricular assist device.

In a first aspect, an embodiment of the present application provides a flow rate control method, including:

acquiring a first pressure and a second pressure, wherein the first pressure is the fluid pressure in the flushing cavity, and the second pressure is the blood pressure in the ventricular assist device;

when a first difference value exceeds a preset range, calculating a target pressure of the flushing cavity, wherein the first difference value is a difference value between the first pressure and the second pressure, and the target pressure is greater than the second pressure;

determining a target irrigation fluid flow rate into the irrigation lumen based on the target pressure;

maintaining the flush fluid flow rate at the target flush fluid flow rate.

In a second aspect, an embodiment of the present application provides a flow rate control device, including:

an obtaining unit for obtaining a first pressure and a second pressure, wherein the first pressure is a fluid pressure in an irrigation cavity, and the second pressure is a blood pressure in the ventricular assist device;

the calculating unit is used for calculating a target pressure of the flushing cavity when a first difference value exceeds a preset range, wherein the first difference value is a difference value between the first pressure and the second pressure, and the target pressure is greater than the second pressure;

a determination unit for determining a target flushing fluid flow rate into the flushing chamber based on the target pressure;

and the control unit is used for maintaining the flow rate of the flushing liquid as the target flushing liquid flow rate.

In a third aspect, an embodiment of the present application provides an electronic device, which includes a processor, a memory, a communication interface, and one or more programs, which are stored in the memory and configured to be executed by the processor, and which include instructions for performing some or all of the steps described in the method of the first aspect.

In a fourth aspect, the present application provides a computer-readable storage medium storing a computer program for electronic data exchange, wherein the computer program causes a computer to perform some or all of the steps described in the method of the first aspect.

In a fifth aspect, the present application provides a computer program product, where the computer program product includes a non-transitory computer-readable storage medium storing a computer program, where the computer program is operable to cause a computer to perform some or all of the steps described in the method according to the first aspect of the present application. The computer program product may be a software installation package.

According to the technical scheme, a first pressure and a second pressure are obtained, the first pressure is the fluid pressure in the flushing cavity, and the second pressure is the blood pressure in the ventricular assist device; when the first difference value exceeds a preset range, calculating the target pressure of the flushing cavity, wherein the first difference value is the difference value between the first pressure and the second pressure, and the target pressure is greater than the second pressure; determining a target irrigation fluid flow rate into the irrigation lumen based on the target pressure; the rinse flow rate is maintained at the target rinse flow rate. When the difference of the fluid pressure in the flushing cavity and the blood pressure in the ventricular assist device exceeds the preset value, the fluid pressure in the flushing cavity is adjusted by adjusting the flow rate of flushing liquid, so that the pressure barrier between the blood in the ventricular assist device and the motor is kept in a stable state, and the safe operation of the ventricular assist device is ensured.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a ventricular assist system provided in an embodiment of the present application;

FIG. 2 is a schematic structural view of an irrigation fluid device according to an embodiment of the present disclosure;

FIG. 3 is a schematic flow chart of a flow rate control method provided in an embodiment of the present application;

FIG. 4 is a schematic flow chart illustrating a process for determining a target irrigation fluid flow rate into an irrigation lumen based on a target pressure according to an embodiment of the present disclosure;

FIG. 5 is a schematic illustration of a flow rate profile for irrigation fluid provided by an embodiment of the present application;

fig. 6 is a block diagram of functional units of a flow rate control device according to an embodiment of the present disclosure;

fig. 7 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

In order to better understand the technical solutions of the present application, the following description is given for clarity and completeness in conjunction with the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, but not all embodiments. All other embodiments obtained by a person skilled in the art without making any inventive step on the basis of the description of the embodiments of the present application belong to the protection scope of the present application.

The terms "first," "second," and the like in the description and claims of the present application and in the above-described drawings are used for distinguishing between different objects and not for describing a particular order. Furthermore, the terms "include" and "have," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, software, product, or apparatus that comprises a list of steps or elements is not limited to those listed but may include other steps or elements not listed or inherent to such process, method, product, or apparatus.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein may be combined with other embodiments.

In the present application, as shown in FIG. 1, a ventricular assist system includes an interventional ventricular assist device, an external controller, and an irrigation fluid device. The ventricular assist device is implanted in a patient across an aortic valve of the patient's heart such that a proximal end of the ventricular assist device is located within the aorta and a distal end of the ventricular assist device is located within the left ventricle, whereby blood in the left ventricle is pumped into the aorta by the ventricular assist device to provide partial or complete assist to the circulatory system of the heart. Wherein the controller and the flushing liquid device are positioned outside the body, and the controller is used for realizing the functions of controlling the ventricular auxiliary device and the flushing device, displaying data, detecting faults, alarming, recording data and the like. The flushing fluid device is used to maintain a pressure barrier between the blood and the motor, by connecting the flushing line of the flushing device to the motor bearings in the ventricular assist device, isolating the blood from the motor using fluid pressure created by the flushing fluid in a direction opposite to the direction of blood flow, preventing blood from entering the motor.

As shown in FIG. 2, the flushing device comprises a flushing liquid bag, a driving motor, a flushing cavity and a flushing pipeline. The flushing liquid bag is connected with a flushing pipeline, and the flushing pipeline is connected with the flushing cavity. The flushing pipeline passes through the driving motor, so that the flow speed of flushing liquid is controlled by controlling the movement of the driving motor, wherein the rotation of the driving motor drives the shaft to rotate after passing through the mechanical transmission device (a gear speed reducing mechanism), the peristaltic sheets generate wavy movement by the cam on the shaft according to a certain time sequence, the flushing pipeline between the peristaltic sheets and the extrusion plate is extruded by the peristaltic sheets, and liquid in the flushing pipeline is subjected to continuous thrust which is related to the movement time sequence of the peristaltic sheets, so that the liquid flows, and the flowing effect of the flushing liquid is achieved. The flushing fluid is input into the flushing cavity through the flushing pipeline, the motor shaft in the ventricular assist device is connected to the output port of the flushing cavity, and certain pressure is formed by the flushing fluid flowing into the motor shaft and flowing in the direction opposite to the flowing direction of the blood through the fluid pressure in the flushing cavity, so that the blood is isolated from the motor, and the blood is prevented from entering the motor.

Illustratively, the irrigation fluid device further includes a sensor assembly including a pressure sensor disposed within the irrigation lumen. In the operation process of the flushing device, the pressure sensor monitors the pressure in the flushing cavity in real time, and when the pressure in the flushing cavity changes beyond the range, the pressure in the flushing cavity can be controlled by adjusting the flow rate of the flushing liquid in real time, so that the pressure barrier between blood and the motor is maintained.

Further, the sensor assembly further comprises a pressure sensor disposed at the blood flow outlet of the ventricular assist device for detecting the pressure of blood pumped by the ventricular assist device. When the difference value of the detected pressure in the flushing cavity and the blood pressure exceeds the range in the operation process of the ventricular assist device, the pressure in the flushing cavity can be controlled by adjusting the flow rate of the flushing liquid in real time, so that the pressure barrier between the blood and the motor is maintained.

In the present application, the ventricular assist device uses the motor shaft to support the rotation of the motor, and a certain gap is provided between the motor and the motor shaft in order to reduce the influence of friction between the motor and the motor shaft on the ventricular assist device. However, since the motor of the interventional ventricular assist device is disposed in the human body, blood may flow into the motor from the gap. The normal work of the motor can be influenced by the entering of a large amount of blood, so that the problems of load increase, transmission failure and the like are caused. Therefore, in the intervention type ventricular assist system, the washing liquid is usually filled to prevent the blood from entering into the motor of the ventricular assist device, and the heat generated when the motor shaft runs can be discharged through the washing liquid. However, for different users, the rotational speeds of the motors of the ventricular assist devices set by the users may be different, and the blood pressures of the users themselves may also be different, so that the blood pressure pumped by the ventricular assist device of each user is different, and the rotational speeds of the motors required in different scenes (such as an operation scene and a daily use scene) may be different, and the speed of the motors may also be adjusted according to the physical conditions of the users, so that the blood pressure pumped by the ventricular assist device may change during the operation of the ventricular assist device, and this change may change the pressure barrier formed between the flushing fluid pressure and the blood pressure, and when the difference between the flushing fluid pressure and the blood pressure exceeds the maximum value of the range, the fluid pressure of the flushing fluid may exceed the pressure borne by the flushing line and/or the ventricular assist device, thereby damaging the flushing device and/or the ventricular assist device; when the difference between the pressure of the irrigation fluid and the pressure of the blood is below the minimum of the range, blood may enter the motor, damaging the motor.

In order to solve the problems, the application provides a flow rate control method, which is characterized in that the difference between the fluid pressure in a flushing cavity and the blood pressure pumped by a ventricular assist device is monitored in real time, and when the difference exceeds a preset range, the flow rate of flushing fluid is adjusted to maintain a pressure barrier between the blood in the ventricular assist device and a motor, so that the phenomenon that the pressure of the flushing fluid is too large or too small is avoided, and the safe operation of the ventricular assist device is ensured.

In conjunction with the above description, the present application is described below from the perspective of method examples.

Referring to fig. 3, fig. 3 is a flow chart illustrating a flow rate control method according to an embodiment of the present disclosure, applied to the ventricular assist system shown in fig. 1. As shown in fig. 3, the method includes the following steps.

S310, obtaining a first pressure and a second pressure, wherein the first pressure is the fluid pressure in the flushing cavity, and the second pressure is the blood pressure in the ventricular assist device.

In the embodiment of the present application, the first pressure may be obtained in real time by a pressure sensor disposed in the flushing chamber, and the second pressure may be obtained in real time by a pressure sensor disposed at a blood outlet of the ventricular assist device, so that when the second pressure and/or the first pressure changes, the pressure barrier between the blood and the motor is maintained by adjusting the flow rate of the flushing fluid.

For example, for a ventricular assist device that does not have a pressure sensor at the blood outlet of the ventricular assist device (i.e., a sensorless ventricular assist device), it may acquire a first pressure in real time via a pressure sensor disposed within the flush chamber and estimate a second pressure by acquiring a motor speed of the ventricular assist device.

For example, for an irrigation fluid device without a pressure sensor in the irrigation chamber and a ventricular assist device without a pressure sensor at the blood outlet of the ventricular assist device, it may estimate the first pressure by obtaining the speed of the drive motor of the irrigation fluid device and estimate the second pressure by obtaining the speed of the motor of the ventricular assist device.

Wherein the flow rate of the rinsing liquid is related to the movement speed of the driving motor, wherein the faster the driving motor rotates, the faster the flow rate of the rinsing liquid will be. Under the condition that the outflow flow rate of the flushing cavity is unchanged and the fluid pressure in the flushing cavity is kept balanced, when the inflow flow rate of the flushing liquid is increased by increasing the rotating speed of the driving motor, the fluid pressure in the flushing cavity can be gradually increased, so that the fluid pressure of the flushing liquid flowing into the motor shaft is increased. Similarly, under the condition that the outflow flow rate of the flushing cavity is unchanged and the fluid pressure in the flushing cavity is kept balanced, when the inflow flow rate of the flushing liquid is reduced by reducing the rotating speed of the driving motor, the fluid pressure in the flushing cavity can be gradually reduced, so that the fluid pressure of the flushing liquid flowing into the motor shaft is also reduced.

In one example, estimating the second pressure based on a motor speed of the ventricular assist device includes: acquiring a blood parameter set of a target user and the current motor speed of a ventricular assist device, wherein the target user is a user implanted with the ventricular assist device, and the blood parameter set comprises the blood pressure and the blood viscosity of a human body; determining a first blood pressure corresponding to the current motor speed according to a mapping relation between the motor speed and the blood pressure; determining the pressure weight of a target user according to the blood pressure and the blood viscosity of the human body; estimating the second pressure based on the pressure weight and the first blood pressure.

Specifically, the blood pressure and the blood viscosity of the human body of the user are not different, but the blood flow rates of different blood pressures and blood viscosities of the human body are different at the same motor speed, so that the blood pressure and the blood viscosity of the human body are different from each other, and the influence of different blood pressures and blood viscosities on the blood pressure in the ventricular assist device is different. The first blood pressure corresponding to the current motor speed is determined through the mapping relation between the motor speed of the ventricular assist device and the output blood pressure, and then the pressure weight of the target user is determined according to the influence of the blood pressure and the blood viscosity of the human body on the blood flow speed. Finally, the first blood pressure is corrected according to the pressure weight, so that an estimated second pressure is obtained.

In one example, the electronics can also estimate the first pressure based on a rotational speed of a drive motor of the irrigation fluid device. The electronic equipment can determine the mapping relation between the rotating speed of the driving motor and the flow rate of the flushing liquid according to the parameters of the driving motor acquired in advance, so that the flow rate of the flushing liquid corresponding to the rotating speed of the current driving motor is determined according to the mapping relation; acquiring flushing fluid parameters and flushing cavity parameters, wherein the flushing fluid parameters can comprise the volume of a flushing fluid bag, the concentration of glucose solution and the concentration of heparin concentrated solution, and the flushing cavity parameters can comprise the volume of a flushing cavity and the diameter of a flushing cavity output pipeline; determining the influence factor a of the flushing liquid according to the parameters of the flushing liquid, and estimating the flow rate of the flushing liquid output by the flushing cavity according to the diameter of the output pipeline of the flushing cavity

According to the volume of the irrigation fluid bag andestimating the flow rate of the flushing fluid input into the flushing chamber

(ii) a Finally according to the flow rate of the flushing liquid output by the flushing cavity

Flow rate of flushing fluid supplied to the flushing chamber

And estimating the first pressure by the influence factor a of the rinsing liquid. Wherein the first pressure may be expressed as: a is

。

S320, when a first difference value exceeds a preset range, calculating a target pressure of the flushing cavity, wherein the first difference value is a difference value between the first pressure and the second pressure, and the target pressure is greater than the second pressure.

Wherein, the electronic device may pre-store a variation range (i.e. a preset range) of a difference between the fluid pressure in the flushing chamber and the blood pressure in the ventricular assist device. After the first pressure and the second pressure are obtained, the difference value of the first pressure and the second pressure is compared with the minimum value and the maximum value of the preset range. If the first difference is larger than the maximum value in the preset range, the fluid pressure in the current flushing cavity is over high, the ventricular assist device and/or the flushing fluid device can be damaged, and the pressure in the flushing cavity needs to be reduced; if the first difference is less than the minimum value within the predetermined range, it indicates that the current fluid pressure in the flushing chamber is too low and blood may enter the motor, requiring an increase in the pressure in the flushing chamber.

In this embodiment, when the first difference exceeds the preset range, the target pressure corresponding to the second pressure within the preset range may be determined according to the second pressure, and the flow rate of the flushing fluid may be adjusted according to the target pressure, so that the blood and the motor maintain a stable pressure barrier within the preset range. Wherein the fluid pressure in the flush chamber needs to be greater than the blood pressure of the ventricular assist device, i.e. the target pressure is greater than the second pressure, to prevent blood from entering the motor through the gap.

Optionally, the calculating the target pressure of the flushing cavity includes: determining a target pressure range corresponding to the second pressure according to the mapping relation between the blood pressure and the differential pressure range; determining at least one set of parameter pairs for maintaining fluid pressure balance within the irrigation lumen based on the target pressure range, each set of parameter pairs comprising (fluid pressure, irrigation fluid flow rate); obtaining at least one proportioning parameter of the flushing fluid; calculating at least one target weight based on the at least one proportioning parameter, wherein each set of target weight is respectively an influence weight corresponding to the flushing liquid flow rate in one set of parameter pair; calculating the target pressure based on the fluid pressures in the at least one set of parameter pairs and the at least one target weight.

When the blood pressure in the ventricular assist device changes, such as starting, stopping or restarting the ventricular assist device, or adjusting the motor speed of the ventricular assist device, a target pressure range within a preset range corresponding to the changed blood pressure (i.e., the second pressure) can be determined according to a mapping relationship between the preset blood pressure and the differential pressure range, and then a suitable target pressure is selected within the target pressure range.

Wherein, when the second pressure is not changed and the first difference is maintained within the preset range, at least one of the conditions (fluid pressure, flow rate of the flushing fluid) for maintaining the fluid pressure in the flushing chamber in a balanced state may be included. For example, assuming that the preset range is set to (80, 350), at the first pressure of 350 mmHg, when the second pressure is shifted from 120mmHg to 300mmHg, a target pressure range of (380 mmHg,650 mmHg) may be obtained, and within the target pressure range, the pair of parameters for maintaining the fluid pressure in the flushing chamber in equilibrium within the target pressure range by adjusting the flow rate of the flushing fluid may include: (400 mmHg, 15ml/h), (520 mmHg, 10ml/h), (580 mmHg, 7ml/h), (620 mmHg, 5ml/h).

The flushing liquid can be set with a plurality of proportioning parameters, such as the volume of the flushing liquid bag, the concentration of glucose solution, the concentration of heparin solution and the like. Different flushing liquid proportioning parameters can influence the density of the flushing liquid, and further influence the pressure of the flushing liquid; meanwhile, different flushing liquid proportioning parameters at different flushing liquid flow rates can also cause blockage in different degrees, so that different flushing liquid parameter proportioning has different influences on each parameter pair for maintaining the fluid pressure balance in the flushing cavity. The method and the device can obtain the volume of the flushing fluid bag of the currently set flushing fluid, the ratio of the glucose liquid concentration to the heparin solution concentration, calculate the glucose ratio of the flushing fluid according to the ratio parameters, and further determine the mapping relation between the flow rate of the flushing fluid and the weight according to the glucose ratio, so that the corresponding target weight of each group of parameter pairs is determined according to the mapping relation.

Further, after calculating the target weight of each set of parameter pairs, the average weighted value of the at least one set of parameter pairs can be calculated, thereby obtaining the target pressure. The target pressure may be expressed as: p =

Where n is the number of parameter pairs,

for the fluid pressure in the parameter pair of the jth group,

is the target weight corresponding to the jth group of parameter pairs, and j is a positive integer.

In the embodiment of the application, when the blood pressure in the ventricular assist device changes, the influence of the proportioning parameter of the current flushing liquid on the fluid pressure in the flushing cavity is considered, and the fluid pressure in the flushing cavity corresponding to the changed blood pressure in the ventricular assist device is calculated according to one or more parameter pairs for maintaining the fluid pressure balance in the flushing cavity, so that not only can the pressure barrier between the blood in the ventricular assist device and the motor be maintained, but also the problem of sending blockage in the flushing cavity can be reduced, and the operation safety of the ventricular assist system is improved.

S330, determining the flow rate of the target flushing liquid flowing into the flushing cavity based on the target pressure.

After the target pressure is determined, the flow speed of the flushing liquid can be adjusted for multiple times according to the target pressure, so that the fluid pressure in the flushing cavity can be kept at the target pressure under the condition that the flow speed of the flushing liquid is unchanged, and the pressure barrier between blood in the ventricular assist device and the motor is kept stable.

Alternatively, as shown in fig. 4, the step S330 of determining the target flow rate of the flushing fluid flowing into the flushing cavity based on the target pressure includes the following steps.

S410, obtaining a first flow rate, wherein the first flow rate is the flow rate of the flushing liquid flowing into the flushing cavity currently.

The first flow rate is a flow rate corresponding to a state where the fluid pressure in the flushing chamber remains unchanged when the blood pressure in the ventricular assist device is unchanged, that is, the first flow rate is a flow rate of the flushing fluid maintained at the fluid pressure in the previous flushing chamber. By calculating the target pressure, the flow rate may be adjusted to increase or decrease the fluid pressure within the irrigation lumen based on the first flow rate. Specifically, when the target pressure is higher than the first pressure, the flow rate of the flushing liquid can be increased to increase the fluid pressure in the flushing cavity; when the target pressure is less than the first pressure, the irrigation fluid flow rate may be reduced to reduce the fluid pressure within the irrigation lumen.

S420, adjusting the first flow rate to a second flow rate, wherein the second flow rate is a corresponding flow rate of the flushing liquid when the first pressure in the flushing cavity is equal to the target pressure.

After the target pressure is determined, in order to adjust the fluid pressure in the irrigation chamber to the target pressure in a minimum amount of time, the irrigation fluid flow rate may be increased or decreased in a minimum amount of time, i.e., the acceleration of the irrigation fluid flow rate may be increased as much as possible during this time, so that the fluid pressure in the irrigation chamber reaches the target pressure as quickly as possible.

Specifically, when the target pressure is greater than the first pressure, the first flow rate is increased to a second flow rate in a shortest time, so that when the flow rate of the flushing liquid reaches the second flow rate, the fluid pressure in the flushing cavity reaches the target pressure; when the target pressure is less than the first pressure, the first flow rate is reduced to a second flow rate in a minimum time such that the fluid pressure within the irrigation chamber reaches the target pressure when the irrigation fluid flow rate reaches the second flow rate. Subsequently, as the acceleration of the flow rate of the flushing liquid is reduced, when the first flow rate is lower than the second flow rate, the pressure of the fluid in the flushing cavity is continuously increased within a period of time; the fluid pressure within the flush chamber continues to decrease for a period of time when the first flow rate is greater than the second flow rate.

S430, adjusting the second flow rate for multiple times within a first time period to obtain n third flow rates and n fourth flow rates, wherein the third flow rates are flushing liquid flow rates corresponding to the situation that the fluid pressure in the flushing cavity is smaller than or larger than a first preset pressure, the fourth flow rates are flushing liquid flow rates corresponding to the situation that the fluid pressure in the flushing cavity is larger than or smaller than a second preset pressure, the first preset pressure is larger than the target pressure, and n is a positive integer.

When the pressure of the fluid in the flushing cavity reaches the target pressure, the flow speed of the input flushing liquid in the flushing cavity is still larger than the flow speed of the output flushing liquid in the flushing cavity, so that the pressure of the fluid in the flushing cavity can be continuously increased or reduced within a period of time. When the fluid pressure in the flushing cavity is overlarge relative to the target pressure, the flow speed of the flushing liquid is reduced until the fluid pressure in the flushing cavity is smaller than the target pressure; when the fluid pressure in the flushing cavity is too small relative to the target pressure, the flow rate of the flushing liquid is increased again until the fluid pressure in the flushing cavity is larger than the target pressure, and then the flow rate of the flushing liquid is continuously and circularly increased and decreased according to the method until the preset time is reached or the fluid pressure in the flushing cavity is converged to the target pressure.

It should be noted that the first preset pressure and the second preset pressure are within a target differential pressure range, and the first preset pressure and the second preset pressure may be pressures that are greater than or less than a fixed value of the target pressure, for example, when the target pressure is greater than the first pressure, a difference between the first preset pressure and the target pressure may be a constant, and a difference between the target pressure and the second preset pressure is the constant; or the first preset pressure is the product of the target pressure and a constant larger than 1, and the second preset pressure is the quotient of the target pressure and the constant larger than 1, and the like. When the target pressure is lower than the first pressure, a difference between the second preset pressure and the target pressure may be a constant, and a difference between the target pressure and the first preset pressure is the constant; or the second preset pressure is the product of the target pressure and a constant greater than 1, and the first preset pressure is the quotient of the target pressure and the constant greater than 1, and the like. The embodiment of the present application does not limit this.

Optionally, the adjusting the second flow rate multiple times within the first time period to obtain n third flow rates and n fourth flow rates includes: adjusting the flow rate of the flushing liquid from the ith-1 th fourth flow rate to the ith third flow rate, wherein i is a positive integer less than or equal to n; adjusting the flow rate of the flushing liquid from the ith third flow rate to an ith fourth flow rate; let i = i +1 and repeat the above steps until the duration exceeds the first time period; wherein the i-1 th fourth flow rate is the second flow rate when i = 1.

Wherein, in the in-process of adjusting the fluid pressure that rinses the intracavity to target pressure, along with the change of the fluid pressure that rinses the intracavity, the flush fluid velocity of flow that flows out and rinses the intracavity also can change, consequently adjust the fluid pressure that rinses the intracavity to target pressure is a dynamic change process, can not only reduce the flush solution velocity of flow and make the fluid pressure that rinses the intracavity keep stable through direct increase in the short time.

The present application enables maintaining the fluid pressure within the irrigation chamber near a target pressure by calculating an average of the irrigation fluid flow rate while continuously varying the pressure fluctuations of the fluid within the irrigation chamber over a first time period. The method comprises the following specific steps: under the condition that the target pressure is higher than the first pressure, when the first flow rate is increased to the second flow rate, the acceleration of the flow rate of the flushing liquid is gradually reduced (namely the flow rate of the flushing liquid is slowly increased), the flow rate of the flushing liquid input into the flushing cavity is still higher than the flow rate of the flushing liquid output from the flushing cavity in the process, and the fluid pressure in the flushing cavity is still continuously increased; when the fluid pressure in the flushing cavity is increased to a first preset pressure, recording the flow rate of the flushing fluid corresponding to the moment as a third flow rate; then, gradually reducing the flow speed of the flushing liquid from the third flow speed until the fluid pressure in the flushing cavity is reduced to a second preset pressure, and recording the corresponding flow speed of the flushing liquid as a fourth flow speed; and gradually increasing the flow rate of the flushing liquid from the fourth flow rate to increase the fluid pressure in the flushing cavity to a first preset pressure, and then continuously decreasing and increasing the flow rate of the flushing liquid according to the mode until the duration reaches a first time period, thereby obtaining n recorded third flow rates and n recorded fourth flow rates.

S440, calculating the flow rate of the target flushing liquid based on the n third flow rates and the n fourth flow rates.

In the process of adjusting the flow rate of the rinse solution for multiple times, the change of the flow rate of the rinse solution is gradually slowed down along with time, so that the n third flow rates may be different, and the n fourth flow rates may also be different. The flow rate of the irrigation liquid corresponding to the situation that the fluid pressure in the irrigation cavity approaches the target pressure is represented by calculating the average value of the n third flow rates and the n fourth flow rates.

Wherein said calculating the target rinse flow rate based on the n third flow rates and the n fourth flow rates comprises: plotting the adjustment of the flow rate of the flushing liquid from the second flow rate to the n third flow rates and the n fourth flow rates over the first time period; integrating the curve to obtain the area enclosed by the curve and the coordinate axis; and calculating the ratio of the area to the first time period to obtain the flow rate of the target flushing liquid.

Specifically, during the adjustment of the flow rate of the rinsing liquid for the first period of time, the flow rate of the rinsing liquid is mapped in real time into a coordinate system with the abscissa as time and the ordinate as the flow rate of the rinsing liquid to form a curve v (t) of the flow rate of the rinsing liquid with respect to time, as shown in fig. 5. The curve is then integrated

Calculating the area enclosed by the curve and the abscissa and the ordinate, and further calculating the average area in the first time period, thereby obtaining the target flushingThe liquid flow rate.

In one possible example, the determining a target irrigation fluid flow rate into the irrigation lumen based on the target pressure comprises: acquiring a first flow rate, wherein the first flow rate is the current flow rate of flushing liquid flowing into the flushing cavity; adjusting the first flow rate to a second flow rate, wherein the second flow rate is a corresponding flow rate of the flushing fluid when the first pressure in the flushing cavity is equal to the target pressure; adjusting the flow rate of the flushing liquid from a second flow rate to an ith third flow rate, wherein i is a positive integer less than or equal to n, and the ith third flow rate is the corresponding flow rate of the flushing liquid when the fluid pressure in the flushing cavity is less than or greater than the ith first preset pressure; adjusting the flow rate of the flushing liquid from the ith third flow rate to the ith fourth flow rate, adjusting the flow rate of the flushing liquid from the ith fourth flow rate to the (i + 1) th third flow rate, wherein the ith fourth flow rate is the corresponding flow rate of the flushing liquid when the fluid pressure in the flushing cavity is greater than or less than the ith second preset pressure, and making i = i +1, and repeating the step until the ith first preset pressure or the ith second preset pressure is equal to the target pressure, so as to obtain the target flow rate of the flushing liquid.

After the target pressure is determined, the flow rate of the flushing fluid can be increased or decreased as much as possible in the shortest time to obtain the second flow rate, so that the fluid pressure in the flushing chamber reaches the target pressure as soon as possible. And then, the flow rate is increased continuously, the flow rate of the flushing liquid is reduced, so that the fluid speed in the flushing cavity approaches to the target pressure continuously, and finally the flow of the flushing liquid corresponding to the convergence of the fluid speed to the target pressure is determined as the flow rate of the flushing liquid.

In this application, the difference between the ith first preset pressure and the ith second preset pressure and the target pressure are respectively equal, and the difference between the ith first preset pressure and the target pressure is greater than the difference between the (i + 1) th first preset pressure and the target pressure, and the difference between the ith second preset pressure and the target pressure is greater than the difference between the (i + 1) th second preset pressure and the target pressure. That is, the first preset pressures and the second preset pressures are equal difference series with equal tolerance absolute values, and the ith first preset pressure and the ith second preset pressure are within the target differential pressure range.

Specifically, when the target pressure is greater than the first pressure, the first flow rate is increased to the second flow rate in a minimum time such that the fluid pressure within the irrigation chamber reaches the target pressure when the irrigation fluid flow rate reaches the second flow rate. Then slowly increasing the flow rate of the flushing liquid, and increasing the fluid pressure in the flushing cavity to a first preset pressure; then gradually reducing the flow speed of the flushing liquid until the fluid pressure in the flushing cavity is reduced to a first second preset pressure; and gradually increasing the flow rate of the flushing liquid to increase the fluid pressure in the flushing cavity to a second first preset pressure, then gradually decreasing the flow rate of the flushing liquid to decrease the fluid pressure in the flushing cavity to a second preset pressure, sequentially circulating until the ith first preset pressure or the ith second preset pressure is equal to the target pressure, and finally determining the flow rate of the flushing liquid corresponding to the ith first preset pressure or the ith second preset pressure which is equal to the target pressure as the flow rate of the flushing liquid.

And S340, maintaining the flow rate of the flushing liquid as the target flushing liquid flow rate.

In the present application, when the fluid pressure in the flushing chamber is maintained at the target pressure, if the blood pressure in the ventricular assist device is not changed, the flow rate of the flushing fluid is maintained at the target flow rate of the flushing fluid, so that the pressure barrier between the blood in the ventricular assist device and the motor can be maintained within a preset range, and the safety of the ventricular assist device can be improved.

It can be seen that the present application provides a flow rate control method by obtaining a first pressure and a second pressure, the first pressure being a fluid pressure in an irrigation chamber, the second pressure being a blood pressure in a ventricular assist device; when the first difference value exceeds a preset range, calculating the target pressure of the flushing cavity, wherein the first difference value is the difference value between the first pressure and the second pressure, and the target pressure is greater than the second pressure; determining a target irrigation fluid flow rate into the irrigation lumen based on the target pressure; the rinse flow rate is maintained at the target rinse flow rate. When the difference of the fluid pressure in the flushing cavity and the blood pressure in the ventricular assist device exceeds the preset value, the fluid pressure in the flushing cavity is adjusted by adjusting the flow rate of flushing liquid, so that the pressure barrier between the blood in the ventricular assist device and the motor is kept in a stable state, and the safe operation of the ventricular assist device is ensured.

In one possible example, after the maintaining the flush fluid flow rate at the target flush fluid flow rate, the method further comprises: obtaining a fifth flow rate and a third pressure, wherein the fifth flow rate is the flow rate of the flushing liquid flowing into the flushing cavity in a second time period, the third pressure is the fluid pressure in the flushing cavity in the second time period, and the second time period is later than the first time period; determining whether an adverse event has occurred with the flush chamber based on the fifth flow rate and the third pressure; and alarming when an adverse event occurs in the flushing cavity.

Wherein, this application can also detect whether the adverse events takes place among the flush fluid device through the change of real-time detection flush fluid velocity of flow and the change of the fluid pressure in the washing chamber. Specifically, the flow rate of the flushing liquid and the fluid pressure in the flushing cavity in a second time period after the first time period are acquired, and whether the flushing liquid device has an adverse event is judged by comparing a fifth flow rate and a third pressure acquired in the second time period with a target flow rate and a target pressure of the flushing liquid maintained in the first time period respectively.

Optionally, the determining whether an adverse event occurs in the flushing chamber according to the fifth flow rate and the third pressure includes: if the third pressure is greater than a target pressure, the difference between the third pressure and the target pressure is greater than a first preset difference, the fifth flow rate is less than the target flushing fluid flow rate, and the difference between the target flushing fluid flow rate and the fifth flow rate is greater than or equal to a second preset difference, determining that a blockage event occurs in the flushing cavity; and if the third pressure is less than the target pressure, the difference between the target pressure and the third pressure is greater than the first preset difference, the fifth flow rate is greater than the target flushing fluid flow rate, and the difference between the fifth flow rate and the target flushing fluid flow rate is greater than or equal to the second preset difference, determining that a leakage event occurs in the flushing cavity.

Among other things, adverse events may include clogging events and leakage events. When there is an occlusion event in the flush line or the flush chamber, the electronics may continuously decrease the flow rate of the flush fluid in order to maintain the pressure barrier between the blood in the ventricular assist device and the motor within a predetermined range, but the fluid pressure in the flush chamber may continuously increase while the flow rate of the flush fluid is continuously decreased. Therefore, when the fluid pressure in the flushing cavity is increased to a certain value and the flow rate of the flushing liquid is reduced to a certain value, namely low flow rate and high pressure are generated, the blockage event in the flushing liquid device is judged. Similarly, when there is a leakage event in the flushing pipeline or the flushing cavity, the electronic device can continuously increase the flow rate of the flushing liquid in the process of adjusting the flow rate of the flushing liquid due to the change of the fluid pressure in the flushing cavity, but the fluid pressure in the flushing cavity can continuously decrease instead under the condition of continuously increasing the flow rate of the flushing liquid. Thus, when the fluid pressure in the irrigation chamber increases to a certain value and the irrigation fluid flow rate decreases to a certain value, i.e., a high flow rate and a low pressure occur, it is determined that a blockage event exists in the irrigation fluid device.

In the present application, after the fluid pressure in the flushing chamber is maintained at the target pressure, if the flow rate of the flushing liquid controlled in the subsequent second time period and the fluid pressure in the flushing chamber are compared with the target flow rate of the flushing liquid and the target pressure maintained after the first time period, and if the variation trend thereof exceeds a preset value, the existence of an adverse event is determined according to a specific variation condition.

Specifically, when the third pressure is greater than the target pressure, the fifth flow rate is less than the target flushing fluid flow rate, the difference between the third pressure and the target pressure is greater than the first preset difference, and the difference between the target flushing fluid flow rate and the fifth flow rate is greater than the second preset difference, it indicates that a low-flow-rate high-pressure condition exists, and therefore it is determined that a blockage event has occurred in the flushing fluid device. And when the third pressure is smaller than the target pressure, the fifth flow rate is larger than the flow rate of the target flushing liquid, the difference value between the target pressure and the third pressure is larger than a first preset difference value, and the difference value between the fifth flow rate and the flow rate of the target flushing liquid is larger than a second preset difference value, indicating that the conditions of high flow rate and low pressure exist, and therefore determining that a liquid leakage event occurs in the flushing liquid device.

The above description has introduced the solution of the embodiment of the present application mainly from the perspective of the method-side implementation process. It is understood that the network device comprises corresponding hardware structures and/or software modules for performing the respective functions in order to realize the above functions. Those of skill in the art will readily appreciate that the present application is capable of hardware or a combination of hardware and computer software implementing the various illustrative elements and algorithm steps described in connection with the embodiments provided herein. Whether a function is performed as hardware or computer software drives hardware depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

Referring to fig. 6, fig. 6 is a block diagram of functional units of a flow rate control apparatus 600 according to an embodiment of the present application, where the apparatus 600 is applied to the ventricular assist system shown in fig. 1, and the apparatus 600 includes: an acquisition unit 610, a calculation unit 620, a determination unit 630, and a control unit 640; wherein the content of the first and second substances,

the obtaining unit 610 is configured to obtain a first pressure and a second pressure, where the first pressure is a fluid pressure in the flushing chamber, and the second pressure is a blood pressure in the ventricular assist device;

the calculating unit 620 is configured to calculate a target pressure of the flushing chamber when a first difference value exceeds a preset range, where the first difference value is a difference value between the first pressure and the second pressure, and the target pressure is greater than the second pressure;

the determination unit 630, configured to determine a target flushing fluid flow rate flowing into the flushing cavity based on the target pressure;

the control unit 640 is configured to maintain the flow rate of the flushing fluid at the target flushing fluid flow rate.

Optionally, in determining the target flow rate of the irrigation solution flowing into the irrigation cavity based on the target pressure, the determining unit 630 is specifically configured to: acquiring a first flow rate, wherein the first flow rate is the current flow rate of flushing liquid flowing into the flushing cavity; adjusting the first flow rate to a second flow rate, the second flow rate being a corresponding irrigation fluid flow rate when the first pressure in the irrigation cavity is equal to the target pressure; adjusting the second flow rate for multiple times within a first time period to obtain n third flow rates and n fourth flow rates, wherein the third flow rates are flushing liquid flow rates corresponding to the situation that the fluid pressure in the flushing cavity is smaller than or larger than a first preset pressure, the fourth flow rates are flushing liquid flow rates corresponding to the situation that the fluid pressure in the flushing cavity is larger than or smaller than a second preset pressure, the first preset pressure is larger than the target pressure, and n is a positive integer; calculating the target irrigation fluid flow rate based on the n third flow rates and the n fourth flow rates.

Optionally, in terms of adjusting the second flow rate multiple times within the first time period to obtain n third flow rates and n fourth flow rates, the determining unit 630 is specifically configured to: adjusting the flow rate of the flushing liquid from the ith-1 th fourth flow rate to the ith third flow rate, wherein i is a positive integer less than or equal to n; adjusting the flow rate of the flushing liquid from the ith third flow rate to an ith fourth flow rate; let i = i +1 and repeat the above steps until the duration exceeds the first time period; wherein the i-1 th fourth flow rate is the second flow rate when i = 1.

Optionally, in calculating the target flushing fluid flow rate based on the n third flow rates and the n fourth flow rates, the determining unit 630 is specifically configured to: plotting the adjustment of the flow rate of the flushing liquid from the second flow rate to the n third flow rates and the n fourth flow rates over the first time period; integrating the curve to obtain the area enclosed by the curve and the coordinate axis; and calculating the ratio of the area to the first time period to obtain the flow rate of the target flushing liquid.

Optionally, in terms of calculating the target pressure of the flushing cavity, the calculating unit 620 is specifically configured to: determining a target pressure range corresponding to the second pressure according to the mapping relation between the blood pressure and the differential pressure range; determining at least one set of parameter pairs for maintaining fluid pressure balance within the irrigation lumen based on the target pressure range, each set of parameter pairs comprising (fluid pressure, irrigation fluid flow rate); obtaining at least one proportioning parameter of the flushing fluid; calculating at least one target weight based on the at least one proportioning parameter, wherein each set of target weight is respectively an influence weight corresponding to the flushing liquid flow rate in one set of parameter pair; calculating the target pressure based on the fluid pressures in the at least one set of parameter pairs and the at least one target weight.

Optionally, after maintaining the flow rate of the flushing liquid as the target flow rate of the flushing liquid, the obtaining unit 610 is further configured to: obtaining a fifth flow rate and a third pressure, the fifth flow rate being a flow rate of the flushing fluid flowing into the flushing lumen over a second time period, the third pressure being a fluid pressure within the flushing lumen over the second time period, the second time period being later than the first time period;

the determining unit 630 is further configured to: determining whether an adverse event has occurred with the flush chamber based on the fifth flow rate and the third pressure;

the control unit 640 is further configured to: and alarming when an adverse event occurs in the flushing cavity.

Optionally, in determining whether an adverse event occurs in the flushing chamber according to the fifth flow rate and the third pressure, the determining unit 630 is specifically configured to: if the third pressure is greater than a target pressure, the difference between the third pressure and the target pressure is greater than a first preset difference, the fifth flow rate is less than the target flushing fluid flow rate, and the difference between the target flushing fluid flow rate and the fifth flow rate is greater than or equal to a second preset difference, determining that a blockage event occurs in the flushing cavity; and if the third pressure is less than the target pressure, the difference between the target pressure and the third pressure is greater than the first preset difference, the fifth flow rate is greater than the target flushing fluid flow rate, and the difference between the fifth flow rate and the target flushing fluid flow rate is greater than or equal to the second preset difference, determining that a leakage event occurs in the flushing cavity.

It should be appreciated that the apparatus 600 herein is embodied in the form of a functional unit. The term "unit" herein may refer to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (e.g., a shared, dedicated, or group processor) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that support the described functionality. In an optional example, it may be understood by those skilled in the art that the apparatus 600 may be embodied as an electronic device in the foregoing embodiment, and the apparatus 600 may be configured to perform each process and/or step corresponding to the electronic device in the foregoing method embodiment, and in order to avoid repetition, details are not described here again.

The device 600 of each scheme has the functions of realizing the corresponding steps executed by the electronic equipment in the method; the functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software comprises one or more modules corresponding to the functions; for example, the acquisition unit 610 may be replaced by a transceiver; the calculation unit 620, the determination unit 630, and the control unit 640 may be replaced by processors, which perform transceiving operations and related processing operations in the respective method embodiments, respectively.

In an embodiment of the present application, the apparatus 600 may also be a chip or a chip system, for example: system on chip (SoC). Correspondingly, the calculating unit 620, the determining unit 630 and the controlling unit 640 may be processing circuits of the chip, and are not limited herein.

Referring to fig. 7, fig. 7 is a schematic structural diagram of an electronic device according to an embodiment of the present disclosure, where the electronic device includes: a processor, memory, and a communications interface, and one or more programs; the one or more programs are stored in the memory and configured to be executed by the one or more processors.

The program includes instructions for performing the steps of: acquiring a first pressure and a second pressure, wherein the first pressure is the fluid pressure in the flushing cavity, and the second pressure is the blood pressure in the ventricular assist device; when a first difference value exceeds a preset range, calculating a target pressure of the flushing cavity, wherein the first difference value is a difference value between the first pressure and the second pressure, and the target pressure is greater than the second pressure; determining a target irrigation fluid flow rate into the irrigation lumen based on the target pressure; maintaining the flush fluid flow rate at the target flush fluid flow rate.

All relevant contents of each scene related to the method embodiment may be referred to the functional description of the corresponding functional module, and are not described herein again.

It will be appreciated that the memory described above may include both read-only memory and random access memory, and provides instructions and data to the processor. A portion of the memory may also include non-volatile random access memory. For example, the memory may also store device type information.

In the embodiment of the present application, the processor of the above apparatus may be a Central Processing Unit (CPU), and the processor may also be other general processors, digital Signal Processors (DSP), application Specific Integrated Circuits (ASIC), field Programmable Gate Arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

It is to be understood that reference to "at least one" in the embodiments of the present application means one or more, and "a plurality" means two or more. "and/or" describes the association relationship of the associated object, indicating that there may be three relationships, for example, a and/or B, which may indicate: a alone, A and B together, and B alone, wherein A and B may be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of the singular or plural items. For example, at least one (one) of a, b, or c, may represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple.

And, unless stated to the contrary, the embodiments of the present application refer to the ordinal numbers "first", "second", etc., for distinguishing a plurality of objects, and do not limit the sequence, timing, priority, or importance of the plurality of objects. For example, the first information and the second information are different information only for distinguishing them from each other, and do not indicate a difference in the contents, priority, transmission order, importance, or the like of the two kinds of information.

In implementation, the steps of the above method may be performed by integrated logic circuits of hardware in a processor or by instructions in the form of software. The steps of a method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware processor, or may be implemented by a combination of hardware and software elements in a processor. The software elements may be located in ram, flash, rom, prom, or eprom, registers, among other storage media that are well known in the art. The storage medium is located in a memory, and a processor executes instructions in the memory, in combination with hardware thereof, to perform the steps of the above-described method. To avoid repetition, it is not described in detail here.

Embodiments of the present application further provide a computer storage medium, where the computer storage medium stores a computer program for electronic data exchange, and the computer program makes a computer execute part or all of the steps of any one of the methods as described in the above method embodiments.

Embodiments of the present application also provide a computer program product comprising a non-transitory computer readable storage medium storing a computer program operable to cause a computer to perform some or all of the steps of any of the methods as described in the above method embodiments. The computer program product may be a software installation package.

It should be noted that, for simplicity of description, the above-mentioned method embodiments are described as a series of acts or combination of acts, but those skilled in the art will recognize that the present application is not limited by the order of acts described, as some steps may occur in other orders or concurrently depending on the application. Further, those skilled in the art should also appreciate that the embodiments described in the specification are preferred embodiments and that the acts and modules referred to are not necessarily required in this application.

In the foregoing embodiments, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to the related descriptions of other embodiments.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus may be implemented in other manners. For example, the above-described embodiments of the apparatus are merely illustrative, and for example, the above-described division of the units is only one type of division of logical functions, and there may be other divisions when actually implementing, for example, a plurality of units or components may be combined or may be integrated into another system, or some features may be omitted, or not implemented. In addition, the shown or discussed coupling or direct coupling or communication connection between each other may be through some interfaces, indirect coupling or communication connection between devices or units, and may be in an electrical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the elements may be selected according to actual needs to achieve the purpose of the solution of the embodiments of the present application.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated unit may be stored in a computer readable memory if it is implemented in the form of a software functional unit and sold or used as a stand-alone product. Based on such understanding, the technical solution of the present application may be substantially or partially contributed by the prior art, or all or part of the technical solution may be embodied in a software product, which is stored in a memory and includes several instructions for causing a computer device (which may be a personal computer, a server, or a TRP, etc.) to execute all or part of the steps of the method of the embodiments of the present application. And the aforementioned memory comprises: a U-disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a removable hard disk, a magnetic or optical disk, and other various media capable of storing program codes.

Those skilled in the art will appreciate that all or part of the steps in the methods of the above embodiments may be implemented by associated hardware instructed by a program, which may be stored in a computer-readable memory, which may include: flash disk, ROM, RAM, magnetic or optical disk, and the like.

The foregoing detailed description of the embodiments of the present application has been presented to illustrate the principles and implementations of the present application, and the above description of the embodiments is only provided to help understand the method and the core concept of the present application; meanwhile, for a person skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.

Claims

1. A method of flow rate control, the method comprising:

when a first difference value exceeds a preset range, calculating a target pressure of the flushing cavity, wherein the first difference value is the difference value between the first pressure and the second pressure, and the target pressure is greater than the second pressure;

maintaining the flush fluid flow rate at the target flush fluid flow rate.

2. The method of claim 1, wherein said determining a target irrigation fluid flow rate into the irrigation lumen based on the target pressure comprises:

acquiring a first flow rate, wherein the first flow rate is the current flow rate of flushing liquid flowing into the flushing cavity;

adjusting the first flow rate to a second flow rate, the second flow rate being a corresponding irrigation fluid flow rate when the first pressure in the irrigation cavity is equal to the target pressure;

adjusting the second flow rate for multiple times within a first time period to obtain n third flow rates and n fourth flow rates, wherein the third flow rates are flushing liquid flow rates corresponding to the situation that the fluid pressure in the flushing cavity is smaller than or larger than a first preset pressure, the fourth flow rates are flushing liquid flow rates corresponding to the situation that the fluid pressure in the flushing cavity is larger than or smaller than a second preset pressure, the first preset pressure is larger than the target pressure, and n is a positive integer;

calculating the target irrigation fluid flow rate based on the n third flow rates and the n fourth flow rates.

3. The method of claim 2, wherein said adjusting said second flow rate a plurality of times over a first time period resulting in n third flow rates and n fourth flow rates comprises:

adjusting the flow rate of the flushing liquid from the ith-1 th fourth flow rate to the ith third flow rate, wherein i is a positive integer less than or equal to n;

adjusting the flow rate of the flushing liquid from the ith third flow rate to an ith fourth flow rate;

let i = i +1 and repeat the above steps until the duration exceeds the first time period;

wherein the i-1 th fourth flow rate is the second flow rate when i = 1.

4. The method of claim 2, wherein the calculating the target rinse flow rate based on the n third flow rates and the n fourth flow rates comprises:

plotting the adjustment of the flow rate of the flushing liquid from the second flow rate to the n third flow rates and the n fourth flow rates over the first time period;

integrating the curve to obtain the area enclosed by the curve and the coordinate axis;

and calculating the ratio of the area to the first time period to obtain the flow rate of the target flushing fluid.

5. The method of claim 1, wherein the calculating the target pressure of the flush lumen comprises:

determining a target pressure range corresponding to the second pressure according to the mapping relation between the blood pressure and the differential pressure range;

determining at least one set of parameter pairs for maintaining fluid pressure balance in the irrigation cavity according to the target pressure range, wherein each set of parameter pairs comprises (fluid pressure, irrigation fluid flow rate);

obtaining at least one proportioning parameter of the flushing fluid;

calculating at least one target weight based on the at least one proportioning parameter, wherein each set of target weight is respectively an influence weight corresponding to the flushing liquid flow rate in one set of parameter pair;

calculating the target pressure based on the fluid pressures in the at least one set of parameter pairs and the at least one target weight.

6. The method of any of claims 2-5, wherein after the maintaining the flush fluid flow rate at the target flush fluid flow rate, the method further comprises:

obtaining a fifth flow rate and a third pressure, the fifth flow rate being a flow rate of the flushing fluid flowing into the flushing lumen over a second time period, the third pressure being a fluid pressure within the flushing lumen over the second time period, the second time period being later than the first time period;

determining whether an adverse event has occurred with the flush chamber based on the fifth flow rate and the third pressure;

and alarming when an adverse event occurs in the flushing cavity.

7. The method of claim 6, wherein said determining whether an adverse event has occurred with said flush lumen based on said fifth flow rate and said third pressure comprises:

if the third pressure is greater than a target pressure, the difference between the third pressure and the target pressure is greater than a first preset difference, the fifth flow rate is less than the target flushing fluid flow rate, and the difference between the target flushing fluid flow rate and the fifth flow rate is greater than or equal to a second preset difference, determining that a blockage event occurs in the flushing cavity;

and if the third pressure is smaller than the target pressure, the difference value between the target pressure and the third pressure is larger than the first preset difference value, the fifth flow rate is larger than the target flushing liquid flow rate, and the difference value between the fifth flow rate and the target flushing liquid flow rate is larger than or equal to the second preset difference value, determining that a liquid leakage event occurs in the flushing cavity.

8. A flow rate control device, characterized in that,

the acquiring unit is used for acquiring a first pressure and a second pressure, wherein the first pressure is the fluid pressure in the flushing cavity, and the second pressure is the blood pressure in the ventricular assist device;

9. An electronic device comprising a processor, a memory and a communication interface, the memory storing one or more programs, and the one or more programs being executable by the processor, the one or more programs including instructions for performing the steps in the method of any of claims 1-7.

10. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program for electronic data exchange, wherein the computer program causes a computer to perform the steps of the method according to any one of claims 1-7.