CN113030604A

CN113030604A - Atomizer dry burning prevention recognition application and circuit thereof

Info

Publication number: CN113030604A
Application number: CN202011503081.9A
Authority: CN
Inventors: 华健; 万宇阳
Original assignee: Shenzhen Feellife Atomization Medical Co ltd
Current assignee: Shenzhen Feellife Atomization Medical Co ltd
Priority date: 2020-12-18
Filing date: 2020-12-18
Publication date: 2021-06-25

Abstract

The invention discloses an atomizer dry burning prevention identification application, which comprises the following specific steps: (1) setting a sampling resistor on a branch of a switch circuit by taking an atomization circuit in the atomizer as the switch circuit, and detecting a circuit resonance signal; (2) after the atomizer is started, carrying out frequency scanning on the atomizing sheet within a corresponding range, and obtaining an amplitude-frequency curve equivalent curve H (f) of a circuit; (3) after the frequency sweep is finished, taking a resonance point to work, and continuously detecting a resonance feedback signal; (4) for the signal which cannot exceed the threshold Th, the process returns to the frequency sweeping stage; (5) calibrating the initial state of the atomizer. The method has the advantages that the inaccurate backtracking judgment process is added in the atomization process, so that the accuracy of liquid shortage judgment is improved; in addition, the atomization process can be used for reducing the problem of liquid residue, has an important effect in the liquid medicine atomization process, and the current optimal atomization frequency can be corrected by sweeping frequency again, so that the optimal atomization effect is achieved, and the effect of reducing electric quantity consumption is achieved.

Description

Atomizer dry burning prevention recognition application and circuit thereof

Technical Field

The invention relates to the field of medical atomizers, in particular to dry burning prevention identification application of an atomizer and a circuit thereof.

Background

With the development of medical technology, the aerosol inhalation therapy is mainly used for the treatment of respiratory diseases, the mode is that the liquid medicine is atomized into tiny particles, and the atomized medicine is inhaled into the respiratory tract and the lung for deposition by a patient through breathing, so that the focus can be directly reached, the medicine action is accelerated, and the purpose of painless, rapid and effective treatment is achieved. However, the most common problem of the atomizer during use is dry burning, which occurs in the atomizer in the absence of the liquid medicine. In order to prevent dry burning, the existing atomizer generally adopts a method of additionally arranging a probe and identifying whether the atomization of the liquid medicine of the atomizer is finished or not by an electrode plate or a method of detecting a voltage threshold of a feedback resistor. When the atomizing piece is atomizing, the atomizing piece goes out the fog mouth and has or not liquid adhere to and all can lead to the current change, judges through the current threshold value simply, not only be subject to the influence of device and atomizer circuit uniformity problem still can receive the current fluctuation that the influence of atomizing piece state produced when atomizing leads to judging the error, leads to the atomizing piece dry combustion method to break to be absorbed by the human body and lead to endangering. A chinese patent is now retrieved under the name atomizer dry-fire prevention method, device, atomizer and storage medium having patent number 202010331473.5, filed 2020, 4.24. In the patent, a preset scanning curve model diagram needs to be sampled and determined, and the preset scanning curve model diagram is stored in the atomizer. The accuracy and sampling model for a sampled protocol is related to the size of the sample, which affects the capacity of the nebulizer memory and thus the cost of the nebulizer, and the practical operation of the protocol is somewhat complicated.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide a method for increasing an inaccurate backtracking determination process in an atomization process, so as to improve the accuracy of liquid shortage determination; in addition, the atomization process can be used for reducing the problem of liquid residue, has an important effect in the liquid medicine atomization process, and the current optimal atomization frequency can be corrected by sweeping frequency again, so that the optimal atomization effect is achieved, and the dry burning prevention identification application and the circuit of the atomizer are reduced in electric quantity consumption.

In order to achieve the above object, the present invention provides an atomizer dry-fire prevention recognition application, wherein,

(1) setting a sampling resistor on a branch of a switch circuit by taking an atomization circuit in the atomizer as the switch circuit, and detecting a circuit resonance signal;

(2) after the atomizer is started, carrying out frequency scanning on the atomizing sheet within a corresponding range, and obtaining an amplitude-frequency curve equivalent curve H (f) of a circuit;

the above process of performing frequency scanning on the atomizing plate within the corresponding range is specifically as follows:

firstly, taking a resonance point coordinate Af, respectively finding a minimum coordinate on two sides of the resonance point, and recording as Ast and Asp;

then, calculating the horizontal distance from the resonance point Af to Ast and Asp, and finding a point far away from the resonance point and recording the point as Aff;

finally, calculating coordinates Af of the resonance point and a point Aff far away from the resonance point as a straight line L (f), calculating the size of an area enclosed by an equivalent curve H (f) of the amplitude-frequency curve and the straight line L (f), and taking the area on the upper side of the straight line as positive;

by judging the area, whether the atomizing sheet is dry-burned or not can be effectively judged; tests show that when water is contacted with the atomizing sheet, the impedance of the atomizing sheet is reduced, the Q value of the resonant circuit is reduced, the curve protrudes outwards at the resonant frequency, and the curve is expressed as a convex function; otherwise, the curve is inwards concave at the resonance frequency and is expressed as a concave function;

in the embodiment, the existence of liquid in the liquid medicine cup is determined by calculating the positive and negative of the area enclosed by the curve and the straight line;

S＝∫(H(f)-L(f))df

(3) after the frequency sweep is finished, taking a resonance point to work, and continuously detecting a resonance feedback signal;

the above process of continuously detecting the resonant feedback signal is as follows:

firstly, when the solution is free of bubbles, the signal is greatly reduced after the last drop of water adsorbed at the atomizing opening of the atomizing sheet is atomized;

in this case, only the difference operation d (k) ═ f (k) — f (k-1) needs to be performed on the signal, so as to remove the judgment interference caused by the baseline drift; the atomization sheet dry burning can be completed by judging the variation degree of D (k);

then, if the solution generates bubbles in the atomization process, when the liquid medicine is lower than the atomization opening of the atomization piece, a fluctuation signal is formed on the atomization piece, and the signal whole body slowly drops; at this time, the judgment of the dry burning of the atomized sheet cannot be made by the variability of D (k); therefore, while carrying out differential operation, the original signal is dynamically evaluated, the fluctuation degree of the signal is calculated, and the signal with the fluctuation degree exceeding a certain threshold Th is directly judged as dry burning of the atomizer; the evaluation of the degree of fluctuation is evaluated using the SD of the interval sliding window;

xk is the K window, D (K) is the K data, and w is the window width;

calculating sd (xk) to evaluate the degree of fluctuation;

(4) for the signal which cannot exceed the threshold Th, the process returns to the frequency sweeping stage; the frequency of the circuit is swept again to obtain a resonance point Af 2; judging the dry burning condition of the atomizer according to the flow in the step 2, additionally adding the frequency deviation calculation of an original resonance point Af and a new resonance point Af2, and judging dry burning when the frequency deviation exceeds a preset value PreF; the solution which cannot be judged is in a bubble shape, and the atomization can be actually continued, and at the moment, the atomization is carried out according to the new frequency Af 2;

(5) calibrating an initial state of the atomizer;

optionally, after the atomizer is produced, a water adding test can be carried out, and at the moment, the atomizer automatically records the characteristic curve of the atomizing sheet when water exists. When the water is not available, the atomizer can compare curves when the water is available, and the water shortage state of the atomizer can be judged by calculating the difference of the areas.

The other purpose is to provide an atomizer anti-dry-burning recognition circuit, which comprises a switch circuit connected with an atomizing sheet, and a sampling resistance module connected on a branch of the switch circuit for detecting circuit resonance signals; the sampling resistance module comprises a resonance control circuit and a feedback circuit which are respectively connected with the switch circuit; and a programmable logic device is arranged on the resonance control circuit.

The method has the advantages that an inaccurate backtracking judgment process is added in the atomization process, so that the accuracy of liquid shortage judgment is improved; in addition, the atomization process can be used for reducing the problem of liquid residue, has an important effect in the liquid medicine atomization process, and the current optimal atomization frequency can be corrected by sweeping frequency again, so that the optimal atomization effect is achieved, and the effect of reducing electric quantity consumption is achieved. Because the resonance characteristic curve is used for calculating the bandwidth and resonance point offset of the circuit, the bandwidth and frequency offset variability are compared, and the requirement on the circuit is reduced. The working curve is continuously sampled, the fluctuation degree and variability of signals are analyzed, characteristic curve analysis is combined, atomized dry combustion recognition capacity is improved, residual liquid is reduced, and meanwhile, the solution normally used by the existing scheme can be accurately judged. The inaccurate backtracking judgment process of judgment is added in the atomization process, and the accuracy of liquid shortage judgment is improved; in addition, the atomization process can be used for reducing the problem of liquid residue, has an important effect in the liquid medicine atomization process, and the current optimal atomization frequency can be corrected by sweeping frequency again, so that the optimal atomization effect is achieved, and the effect of reducing electric quantity consumption is achieved.

Drawings

FIG. 1 is a block schematic of the present invention;

FIG. 2 is a circuit diagram of the present invention;

fig. 3 is a block schematic diagram of the present invention.

FIG. 4 is a graph of unfired example 1;

FIG. 5 is a graph of dry-fire example 2;

FIG. 6 is a graph of bubble-free determination example 3;

fig. 7 is a graph of the presence of bubbles in the judgment example 4.

Detailed Description

The invention is described in further detail below with reference to the accompanying drawings.

As shown in fig. 1-3, an atomizer dry-burning prevention recognition application is disclosed, wherein (1) an atomization circuit in the atomizer is used as a switch circuit, a sampling resistor is set on a branch of the switch circuit, and circuit resonance signal detection is performed; (2) after the atomizer is started, carrying out frequency scanning on the atomizing sheet within a corresponding range, and obtaining an amplitude-frequency curve equivalent curve H (f) of a circuit;

then, calculating the horizontal distance from the resonance point to the Ast and the Asp, and finding a point far away from the resonance point and recording the point as Aff;

S＝∫(H(f)-L(f))df

xk is the K window, D (K) is the K data, and w is the window width;

calculating sd (xk) to evaluate the degree of fluctuation;

(5) calibrating an initial state of the atomizer;

An atomizer dry burning prevention recognition circuit comprises a switch circuit connected with an atomizing sheet, and a sampling resistance module connected on a branch of the switch circuit for detecting circuit resonance signals; the sampling resistance module comprises a resonance control circuit and a feedback circuit which are respectively connected with the switch circuit; and a programmable logic device is arranged on the resonance control circuit.

When the method is applied, the resonance characteristic curve is used for calculating the bandwidth and resonance point offset of the circuit, and the bandwidth and frequency offset variability are compared, so that the requirement on the circuit is reduced. The working curve is continuously sampled, the fluctuation degree and variability of signals are analyzed, characteristic curve analysis is combined, atomized dry combustion recognition capacity is improved, residual liquid is reduced, and meanwhile, the solution normally used by the existing scheme can be accurately judged. The inaccurate backtracking judgment process of judgment is added in the atomization process, and the accuracy of liquid shortage judgment is improved; in addition, the atomization process can be used for reducing the problem of liquid residue, has an important effect in the liquid medicine atomization process, and the current optimal atomization frequency can be corrected by sweeping frequency again, so that the optimal atomization effect is achieved, and the effect of reducing electric quantity consumption is achieved.

Example 1 is a non-fired example

As shown in fig. 4: the blue line is a sweep voltage sampling curve (amplitude-frequency characteristic equivalent curve). The resonance point Af (highest voltage value, the same applies below) is determined. The lowest point on either side of the resonance point, Ast/Asp, is determined. In the above table, the distances from Ast and Asp to Af are equal on the horizontal axis, so that Ast and Asp can take any point, Ast and Af are taken in the above table as straight lines, and the table is shown as an orange line. The area S1 enclosed by the blue curve and the orange line is calculated.

It is clear that S1>0, so the atomizer did not dry fire.

Example 2 Dry-burning example

As shown in fig. 5: the blue line is a sweep voltage sampling curve (amplitude-frequency characteristic equivalent curve). The resonance point Af (highest voltage value, the same applies below) is determined. The lowest point on either side of the resonance point, Ast/Asp, is determined. In the above table, Ast is farther on the horizontal axis than Asp to Af, so Ast and Af are taken as straight lines, and the orange line is shown. The area S2 enclosed by the blue curve and the orange line is calculated.

It is clear that S2<0, so the atomizer did not dry fire.

Example 3 is a bubble-free determination example

As shown in fig. 6: the blue curve is the original differential curve d (f), shifted 90 units in the y-axis. The orange curve is the raw voltage sample signal collected in real time. The signal is differentiated to obtain a difference function D (f). D (f) fluctuates in a certain range during normal atomization, and the judgment function is changed when D (f) fluctuates suddenly and continuously to be larger. In the above table, after the difference processing, D (f) is concentrated within the range of + -2 during the normal atomization. When the variation occurs, D (f) the instantaneous fluctuation ranges from 7 to-6, and the continuous fluctuation range becomes + -4. It can be judged that the atomizer is out of liquid.

Example 4 is an example of determination of presence of bubbles

As shown in fig. 7: the blue curve is the original differential curve d (f), shifted 40 units in the y-axis. The orange curve is the raw voltage sample signal collected in real time. The signal is differentiated to obtain a difference function D (f). D (f) fluctuates in a certain range during normal atomization, and the judgment function is changed when D (f) fluctuates suddenly and continuously to be larger. In the above table, after the difference processing, d (f) is concentrated in a certain range and stably changed during normal atomization. When the variation occurs, the instantaneous fluctuation range of D (f) is 20-40, and the continuous fluctuation range is about 3 times of the original range. Therefore, the contact point of the liquid medicine and the atomizing sheet can be judged to be in a bubble shape, the atomization can be stopped at the moment, if the atomization needs to be continued, the frequency sweeping stage needs to be returned, and the process is started from the beginning.

The prior art is compared with Chinese patent, the patent number is 202010331473.5, the application date is 2020, 4 and 24, and the patent name is atomizer dry burning prevention method, device, atomizer and storage medium.

First, the above-mentioned prior patent needs sampling to determine the preset scanning curve model diagram, and stores the diagram in the atomizer. The accuracy and sampling model for a sampled protocol is related to the size of the sample, which affects the capacity of the nebulizer memory and thus the cost of the nebulizer, and the practical operation of the protocol is somewhat complicated. The technical scheme of this patent application is the scheme that circuit components and parts electrical parameter changes and leads to the resonance curve to change when whether there is the liquid medicine, and whether there is the liquid medicine to the influence of atomizing piece be unanimous with prior art, therefore the curve change also the state unanimous. Under the existing atomization sheet manufacturing technology, the influence of the existence or non-existence of water on the curve of different atomization sheets can be expressed as consistency. In particular, a calibration can be added, and atomization is performed once with water, so as to record an effect model of the electric parameter of the atomization piece on the resonance curve of the circuit when the atomizer has water.

Secondly, the step of matching and judging the actual frequency sweep curve according to the preset frequency sweep curve comprises the following steps: determining a first current value according to an actual frequency sweep curve; the first current value is a current value corresponding to a first frequency in a preset frequency range; determining a first preset value according to a current value corresponding to the first frequency in the preset frequency sweep curve, and comparing the first current value with the first preset value; if the first current value is greater than the first predetermined value, it is determined as a mismatch. The first predetermined value is the maximum value in the sample, and according to the test result, the current of the atomizing sheet at the first current value is smaller than that of the atomizing sheet at the water existence state when the water exists, so that misjudgment is only increased when the judgment that the current is larger than the predetermined value is mismatching. The following is partial test data, and most of the data without the chemical liquid at the first current value is lower than the data with the chemical liquid, so that the chemical liquid is more easily recognized as dry-fire without the chemical liquid according to the above logic.

And thirdly, if the dry burning is judged to occur according to the real-time current value, executing the dry burning protection step, comprising the following steps of: step S510, judging whether the real-time current value falls into the dry burning protection interval. The dry burning protection interval is the range of the current value of the atomizing sheet flowing through the atomizing sheet under the non-dry burning state. If the real-time current value does not fall within the dry-fire protection interval, step S600 is executed. If the current value flowing through the atomizing sheet falls into the dry burning protection interval, no dry burning occurs; if the temperature does not fall into the dry burning protection interval, dry burning occurs, and the controller executes dry burning protection at the moment. If the real-time current value falls into the dry-fire protection interval, go back to step S400. In one embodiment, the real-time current value includes a plurality of current values obtained according to preset time, and the step of performing dry-fire protection if dry-fire is determined to occur according to the real-time current value includes: if the dry combustion is carried out or not is judged according to whether the single real-time current value falls into the dry combustion protection interval or not, a judgment error may occur, and the dry combustion protection is triggered by mistake. In order to improve the accuracy of dry burning detection, a plurality of real-time current values are obtained according to preset time for judgment. The preset time is a preset time range, for example, two or more real-time current values within 0.2S are acquired, and in one embodiment, the time intervals between two adjacent acquisition may be equal or unequal. Step S520, judging whether each real-time current value does not fall into the dry burning protection interval. If the plurality of real-time current values collected within the preset time do not fall into the dry burning protection interval, the dry burning of the atomizer can be determined. In one embodiment, if only no more than a preset proportion of the real-time current values fall into the dry-fire protection interval, and the rest of the real-time current values do not fall into the dry-fire protection interval, the atomizer is considered to be dry-fired. If yes, go to step S600. And after the atomizer is determined to be dry-burned, the controller executes dry-burning protection. In one embodiment, before the step of obtaining the real-time current value of the atomization sheet is executed, the method further includes: and S700, establishing a dry burning protection interval. The dry-fire protection interval may be different under the conditions of different atomizing sheets, different working frequencies, different capacities of atomized liquid and the like, so that the dry-fire protection interval needs to be established under the current working state. In one embodiment, a preset dry-fire protection interval may also be used for detection. The scheme adopts a fixed interval method to judge whether the current is in the interval or not so as to judge dry burning, and the embodiment of the scheme can show that the atomization current can have baseline drift in the atomization process, so that the method for directly judging whether the current falls in the fixed interval can have misjudgment to a great extent. And the sampling is needed to be evaluated, and the influence of the sample size is inevitable.

In addition, the method of the change point is adopted, only the follow-up data and the preorder data are needed to be compared, and the standard deviation is adopted to calculate the fluctuation degree, so that the change point can be determined, namely the liquid-free dry burning point. In addition, for the liquid which can generate bubbles, the scheme adopts the scheme of fluctuation degree evaluation for identification, signal fluctuation can be greatly increased in the liquid which is easy to generate bubbles, and the distribution condition of the fluctuation degree when the liquid with bubbles and the liquid without bubbles are close to dry burning can be used as a judgment condition only by testing. In addition, the technical scheme of this patent application increases the inaccurate backtracking judgment process of judgement in the atomization process, improves the accuracy that the liquid shortage was judged, in addition, this process can also be used for reducing the remaining problem of liquid, has the great effect in liquid medicine atomization process, and sweep frequency again can also revise current best atomization frequency, reaches best atomization effect, reduces the electric quantity consumption.

What has been described above are merely some embodiments of the present invention. It will be apparent to those skilled in the art that various changes and modifications can be made without departing from the inventive concept herein, and it is intended to cover all such modifications and variations as fall within the scope of the invention.

Claims

1. An atomizer anti-dry burning identification application, which comprises the following specific steps:

at this time, only the difference operation d (k) = f (k) — f (k-1) needs to be performed on the signal, so as to remove the judgment interference caused by the baseline drift; the atomization sheet dry burning can be completed by judging the variation degree of D (k);

xk is the K window, D (K) is the K data, and w is the window width;

calculating sd (xk) to evaluate the degree of fluctuation;

(5) calibrating an initial state of the atomizer;

after the atomizer is produced, a water adding test can be carried out once, and the atomizer automatically records the characteristic curve of the atomizing sheet when water exists.

2. The atomizer anti-dry-burning recognition application of claim 1, wherein in (5), when there is no water, the atomizer can compare the curve with water to calculate the difference of area to judge the water shortage state of the atomizer.

3. An atomizer dry burning prevention recognition circuit is characterized by comprising a switch circuit connected with an atomizing sheet and a sampling resistance module connected on a branch of the switch circuit and used for detecting circuit resonance signals;

the sampling resistance module comprises a resonance control circuit and a feedback circuit which are respectively connected with the switch circuit; and a programmable logic device is arranged on the resonance control circuit.