Non-invasive ventilator oxygen concentration control method, oxygen concentration control system and related equipment

Abstract

The present application relates to the technical field of noninvasive respirator, in particular to a noninvasive respirator oxygen concentration control method, an oxygen concentration control system and related equipment.The noninvasive respirator oxygen concentration control method and the oxygen concentration control system adopt feedforward lookup table and feedback adaptive PI control to correct oxygen flow, when oxygen flow error occurs, the opening value of the oxygen proportional valve is quickly controlled, the required oxygen flow control amount is output, timely adjustment of the oxygen flow control amount is realized, and through feedback adaptive PI control, the steady-state error is eliminated, and accurate adjustment of the output oxygen flow control amount is ensured.

Description

Technical Field

[0001] This invention relates to the field of non-invasive ventilator technology, specifically to a method for controlling oxygen concentration in a non-invasive ventilator, an oxygen concentration control system, and related equipment. Background Technology

[0002] Currently, non-invasive ventilators generally use feedback control methods for oxygen concentration control. Traditional non-invasive ventilators use only a simple airway connection between the turbine and the airway. Although pressure control is easy to achieve, oxygen concentration control is slow, resulting in a problem of oxygen concentration control lag. This leads to an excessively long transition time to reach the oxygen concentration required by the patient, affecting the treatment effect.

[0003] Furthermore, the oxygen ratio control algorithm commonly employs a fixed-parameter PID algorithm, where the proportional gain (P), integral gain (I), and derivative gain (D) are all constants. This prevents feedforward control, adaptive control, and timely adjustment of oxygen concentration errors.

[0004] Based on the above-mentioned technical problems, there is an urgent need to provide a method for controlling oxygen concentration in a non-invasive ventilator, an oxygen concentration control system, and related equipment. Summary of the Invention

[0005] This invention provides a method for controlling oxygen concentration in a non-invasive ventilator, an oxygen concentration control system, and related equipment to solve the aforementioned technical problems.

[0006] In a first aspect, the present invention provides a method for controlling oxygen concentration in a non-invasive ventilator, comprising: setting a predetermined oxygen concentration value;

[0007] Calculate the total required oxygen flow rate based on the predetermined oxygen concentration;

[0008] The error value of the current oxygen flow rate is calculated based on the currently measured oxygen flow rate and the current required total oxygen flow rate; where...

[0009] When an error value for the current oxygen flow rate is generated, the oxygen flow rate is corrected through feedforward lookup table and feedback adaptive PI control, and the oxygen flow rate control quantity is output.

[0010] Secondly, the present invention provides a non-invasive ventilator oxygen concentration control system, which adopts the above-mentioned non-invasive ventilator oxygen concentration control method, and specifically includes an oxygen concentration setting module for setting a predetermined oxygen concentration value.

[0011] Total flow sensor, used to measure the total flow required at a given time;

[0012] The processor module is configured to calculate the required total oxygen flow rate based on a predetermined oxygen concentration; calculate the current oxygen flow rate error value based on the currently measured oxygen flow rate and the required total oxygen flow rate; and when a current oxygen flow rate error value is generated, correct the oxygen flow rate through feedforward lookup table and feedback adaptive PI control, and output the oxygen flow rate control quantity.

[0013] An oxygen proportional valve regulates the oxygen flow rate according to the oxygen flow control quantity.

[0014] Thirdly, the present invention provides a processor module for executing a non-invasive ventilator oxygen concentration control method.

[0015] Fourthly, the present invention provides a computer-readable storage medium storing a program, wherein when the computer executes the program, the non-invasive ventilator oxygen concentration control method is executed.

[0016] The beneficial effects of this invention are that the oxygen concentration control method, oxygen concentration control system and related equipment for non-invasive ventilators of this invention correct oxygen flow by adopting feedforward lookup table and feedback adaptive PI control. When oxygen flow error occurs, the opening value of the oxygen proportional valve is quickly controlled to output the required oxygen flow control amount, thereby realizing timely adjustment of the oxygen flow control amount. Furthermore, through feedback adaptive PI control, steady-state error is eliminated, ensuring accurate adjustment of the output oxygen flow control amount.

[0017] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a flowchart of the non-invasive ventilator oxygen concentration control method of the present invention;

[0021] Figure 2 This is a flowchart illustrating the software algorithm implementation of the non-invasive ventilator oxygen concentration control method of the present invention.

[0022] Figure 3 This is a flowchart of the oxygen concentration control system for the non-invasive ventilator of the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] In existing technologies, PID feedback control is commonly used to control the oxygen concentration of non-invasive ventilators. However, the proportional gain, integral time, and derivative time of the PID controller are usually set to constant values, which makes it impossible to adaptively adjust to errors and fluctuations that occur during actual use. In this embodiment, PI control is used, which can first perform feedforward control when errors occur to improve the adjustment speed, and simultaneously perform feedback control to quickly eliminate steady-state errors caused by adjustment.

[0025] Based on the above principles, this embodiment provides a method for controlling oxygen concentration in a non-invasive ventilator, such as... Figure 1 and Figure 2 As shown, it specifically includes:

[0026] Set a predetermined oxygen concentration value; calculate the current required total oxygen flow rate based on the predetermined oxygen concentration value; calculate the current oxygen flow rate error value based on the current measured oxygen flow rate and the current required total oxygen flow rate; when a current oxygen flow rate error value is generated, correct the oxygen flow rate through feedforward lookup table and feedback adaptive PI control, and output the oxygen flow rate control quantity.

[0027] In this embodiment, by employing feedforward lookup table and feedback adaptive PI control to correct oxygen flow, when oxygen flow error occurs, the opening value of the oxygen proportional valve is quickly controlled to output the required oxygen flow control quantity, thereby achieving timely adjustment of the oxygen flow control quantity. Furthermore, through feedback adaptive PI control, steady-state error is eliminated, ensuring accurate adjustment of the output oxygen flow control quantity.

[0028] In this embodiment, the method for calculating the required total oxygen flow rate based on a predetermined oxygen concentration value includes: the method for calculating the required total oxygen flow rate based on a predetermined oxygen concentration value O at time t. d (t) and the total flow rate L required at time t as measured by the total flow sensor. total Calculate the total oxygen flow rate L required at time t. d (t); that is,

[0029] In this embodiment, 0.21 and 0.79 are both adjustment constants.

[0030] e(t) = L d (t)-L o (t); where

[0031] e(t) is the oxygen flow error value at time t, L o (t) represents the oxygen flow rate measured at time t; and

[0032] When a current oxygen flow rate error value is generated, the oxygen flow rate is corrected through feedforward lookup table and feedback adaptive PI control. The methods for outputting the oxygen flow rate control quantity include:

[0033] The valve opening value is controlled by feedforward lookup table, and steady-state error is eliminated by feedback adaptive PI control.

[0034] In this embodiment, the method for controlling the valve opening value through feedforward lookup table includes:

[0035] The feedforward control quantity K is obtained by looking up a table. f f(t); specifically, K f Let f(t) be the scaling reduction constant, with a value of 0.9, used to prevent overshoot. f(t) = F(:,0), where F is the scaling matrix, and F = [u o O d ], where: f(t) is the calibrated value of oxygen concentration at time t with respect to valve opening, O d u is the predetermined oxygen concentration. o Here, f(t) represents the valve opening value; f(t) is the value selected in the first column of F, i.e.

[0036] Therefore, based on the predetermined oxygen concentration, the corresponding valve opening value is selected.

[0037] In this embodiment, the method for eliminating steady-state error through feedback adaptive PI control includes: obtaining the feedback control quantity.

[0038] in

[0039] K I (t) is the oxygen concentration feedback integral coefficient. This is the oxygen concentration feedback adaptive coefficient. for The derivative of K, where a1 is the oxygen concentration feedback forgetting factor, a2 is the oxygen concentration feedback amplification factor, and K p is the oxygen concentration feedback proportionality coefficient, and k1 is a constant.

[0040] In this embodiment, K I (t) is the oxygen concentration feedback integral coefficient, used to accelerate the integration process. k1 is set to 5 to reduce jitter. p This is the oxygen concentration feedback proportionality coefficient, with a value of 10.

[0041] a1 = 0.95 is the oxygen concentration feedback forgetting factor, which can reduce the influence of past oxygen flow control quantities on the calculation of feedback control quantities;

[0042] a2 = 2 is the oxygen concentration feedback amplification coefficient, used to double the adjustment amount of the oxygen flow error value, thus accelerating the adjustment speed; that is...

[0043] The feedback control quantity is:

[0044]

[0045] By eliminating steady-state errors through feedback adaptive PI control, accurate regulation of the output oxygen flow rate is ensured.

[0046] In this embodiment, the method for controlling the output oxygen flow rate includes:

[0047] u(t) = u(t-1) + Δu(t);

[0048] in

[0049] u(t) is the oxygen flow rate control quantity at time t, and u(t-1) is the oxygen flow rate control quantity at time t-1; that is...

[0050]

[0051] like Figure 3 As shown, this embodiment also provides a non-invasive ventilator oxygen concentration control system, employing the aforementioned non-invasive ventilator oxygen concentration control method, and specifically includes an oxygen concentration setting module for setting a predetermined oxygen concentration value; a total flow sensor for measuring the required total flow rate at a given time; a processor module configured to calculate the required total oxygen flow rate based on the predetermined oxygen concentration value; calculate the current oxygen flow rate error value based on the currently measured oxygen flow rate and the required total oxygen flow rate; wherein when a current oxygen flow rate error value is generated, the oxygen flow rate is corrected through feedforward lookup table and feedback adaptive PI control, and an oxygen flow rate control quantity is output; and an oxygen proportional valve performs oxygen flow rate adjustment according to the oxygen flow rate control quantity.

[0052] This embodiment also provides a processor module for executing a non-invasive ventilator oxygen concentration control method.

[0053] This embodiment also provides a computer-readable storage medium containing a program that, when executed by a computer, performs a method for controlling the oxygen concentration of a non-invasive ventilator.

[0054] In summary, the non-invasive ventilator oxygen concentration control method and oxygen concentration control system of the present invention corrects the oxygen flow rate by using feedforward lookup table and feedback adaptive PI control. When an oxygen flow rate error occurs, it quickly controls the opening value of the oxygen proportional valve and outputs the required oxygen flow rate control amount, thereby achieving timely adjustment of the oxygen flow rate control amount. Furthermore, through feedback adaptive PI control, it eliminates steady-state errors and ensures accurate adjustment of the output oxygen flow rate control amount.

[0055] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative; for example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0056] In addition, the functional modules in the various embodiments of the present invention can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0057] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A control system for a non-invasive ventilator oxygen concentration control method, characterized by, Comprising: an oxygen concentration setting module for setting an oxygen concentration predetermined value; a total flow sensor for measuring the required total flow at the corresponding time; a processor module configured to calculate the required total oxygen flow according to the oxygen concentration predetermined value; calculate the current oxygen flow error value according to the current measured oxygen flow and the required total oxygen flow; wherein when the current oxygen flow error value is generated, the oxygen flow is corrected by feedforward lookup table and feedback adaptive PI control, and the oxygen flow control amount is outputted; an oxygen proportional valve for executing oxygen flow adjustment according to the oxygen flow control amount; wherein the processor module is configured to calculate the required total oxygen flow according to the oxygen concentration predetermined value; that is The oxygen concentration set value O at time t d (t) and the total flow rate L required at time t measured by the total flow rate sensor total The total flow rate L of oxygen required at time t is calculated d (t); that is the processor module is further configured to calculate the current oxygen flow error value according to the current measured oxygen flow and the required total oxygen flow; that is e(t) = L d (t) - L o (t); wherein e(t) is the oxygen flow error value at time t, L o (t) is the measured oxygen flow at time t; and the processor module is further configured to correct the oxygen flow by feedforward lookup table and feedback adaptive PI control when the current oxygen flow error value is generated, and output the oxygen flow control amount; that is the valve opening value is controlled by feedforward lookup table, and the steady-state error is eliminated by feedback adaptive PI control; and The processor module is further configured to obtain the feedforward control amount K by looking up a table f f(t), and adjust the valve opening value according to the feedforward control amount K f f(t); wherein K f to scale down the constant, f(t) is the scale value of oxygen concentration at time t to the proportional valve opening degree; and The processor module is configured to eliminate steady-state error by a feedback adaptive PI control method; that is, obtaining a feedback control quantity wherein K I (t) is an oxygen concentration feedback integral coefficient, is an oxygen concentration feedback adaptive coefficient, is a derivative of , a1 is an oxygen concentration feedback forgetting factor, a2 is an oxygen concentration feedback amplification coefficient, K p is an oxygen concentration feedback proportional coefficient, k1 is a constant; and the oxygen flow control amount u(t) is outputted: u(t) = u(t-1) +△u(t); wherein wherein u(t) is the oxygen flow control amount at time t, and u(t-1) is the oxygen flow control amount at time t-1.

2. A processor module for executing the non-invasive respirator oxygen concentration control method in the control system of claim 1.

3. A computer-readable storage medium, characterized in that, The computer readable storage medium has a program saved therein, and when the computer executes the program, the non-invasive respirator oxygen concentration control method in the control system of claim 1 is executed.

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