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CN-122004827-A - Anti-interference method for pressure zero point calibration and blowing judgment of expiration detection device

CN122004827ACN 122004827 ACN122004827 ACN 122004827ACN-122004827-A

Abstract

The invention relates to the technical field of medical expiration detection equipment, in particular to an anti-interference method for pressure zero point calibration and blowing judgment of an expiration detection device. The method comprises the steps of sampling a pressure sensor for multiple times under the condition of no blowing, solving a mean value, storing the mean value as a zero offset, subtracting the zero offset from the reading of the pressure sensor to obtain gauge pressure or differential pressure during blowing judgment, performing first-order low-pass filtering on the gauge pressure or the differential pressure, judging blowing triggering when the filtered pressure exceeds a set threshold value, and not updating a filtering state and outputting a historical filtering value or a reference value when the reading of the pressure sensor exceeds a reasonable interval so as to avoid false triggering. By adopting the method, the influence of baseline deviation caused by assembly drift, temperature drift and gas circuit micro-leakage on the air blowing judgment can be reduced, the false triggering risk caused by instantaneous noise or communication abnormality is reduced, and the method is suitable for various pressure triggering-based expiration sampling and detecting equipment.

Inventors

  • DONG YANYAN

Assignees

  • 北京宜善医学科技有限公司

Dates

Publication Date
20260512
Application Date
20260212

Claims (10)

  1. 1. A pressure zero point calibration and blowing judgment anti-interference method of an expiration detection device is characterized by comprising the following steps of sampling a pressure sensor for multiple times under the condition of no blowing, solving a mean value according to the result of the multiple times of sampling, storing the mean value as zero point offset, subtracting the zero point offset from the current reading of the pressure sensor to obtain gauge pressure or differential pressure during blowing judgment, performing first-order low-pass filtering on the gauge pressure or differential pressure to obtain a filtered pressure value, judging that blowing is triggered when the filtered pressure value exceeds a set threshold, and updating a filtering state without adopting the reading when the reading of the pressure sensor exceeds a preset reasonable interval, outputting a historical filtering value or a reference value and outputting the historical filtering value or the reference value.
  2. 2. The method of claim 1, wherein the plurality of samples are not less than 10 samples and not more than 200 samples.
  3. 3. The method of claim 1, wherein the zero offset is determined after power-up of the device or before each start of detection.
  4. 4. The method of claim 1, wherein a default zero offset is used as the zero offset when the number of valid samples in the plurality of samples is less than a predetermined ratio.
  5. 5. The method of claim 1, wherein the first order low pass filter has a filter coefficient in the range of 0.1 to 0.5.
  6. 6. The method of claim 1, wherein the reasonable interval is an absolute pressure value range or a zero-calibrated gauge pressure value range, and the lower limit is not lower than 200 mbar and the upper limit is not higher than 3500 mbar.
  7. 7. The method of claim 1, wherein the output historical filtering value is the last valid filtering result or the output reference value is a reference value corresponding to standard atmospheric pressure when the reading of the pressure sensor exceeds the reasonable interval.
  8. 8. The method of claim 1, wherein the set threshold is a gauge pressure or a differential pressure in the range of 50 mbar to 200 mbar.
  9. 9. An expiration detection device is characterized by comprising a pressure sensor, a memory, a controller, a gas circuit assembly, a gas blowing interface and a data processing module, wherein the pressure sensor is used for collecting blowing pressure, the memory is used for storing zero point offset, historical filtering values or reference values, the controller is connected with the pressure sensor and the memory and is configured to execute the method of any one of claims 1 to, the gas circuit assembly is in fluid communication with the pressure sensor and is used for guiding blowing gas, the gas blowing interface is arranged at an inlet end of the gas circuit assembly and is used for a user to perform blowing operation, and the data processing module is used for processing or transmitting pressure data or blowing triggering results output by the controller.
  10. 10. The apparatus of claim 9, wherein the pressure sensor is a gauge pressure sensor or a differential pressure sensor and is connected to the controller via I2C, SPI or an analog quantity.

Description

Anti-interference method for pressure zero point calibration and blowing judgment of expiration detection device Technical Field The invention relates to the technical field of medical expiration detection equipment, in particular to an anti-interference method for pressure zero point calibration and blowing judgment of an expiration detection device, which is used for performing zero point calibration on a pressure sensor and inhibiting abnormality and false triggering in the blowing judgment. Background The pressure sensor is used for monitoring the blowing pressure in the medical expiration detection equipment, and when the pressure exceeds a set threshold value, the sampling or detection process is triggered. The pressure sensor is easy to have the following problems in actual use: Firstly, zero point drift is caused by assembly difference, temperature drift or gas circuit micro leakage, and if calibration is not carried out, reading deviates from zero point when no blowing is carried out, and threshold judgment deviation or false triggering is easily caused; Secondly, the pressure has pulsation or instantaneous peak in the blowing process, if the original reading is directly compared with a threshold value, the judgment result can be unstable; thirdly, the abnormal communication, electromagnetic interference or accidental error data of the sensor can cause obvious jump of the reading, and if the reading is directly participated in judgment, false triggering or false closing flow can be caused; fourth, only make a zero calibration when powering up, zero can drift after long-time operation or environmental change, lack the mechanism of recalibration before detecting. Therefore, it is necessary to provide a pressure zero calibration and air blowing determination anti-interference method, which performs zero calibration on a pressure sensor under the condition of no air blowing, and combines filtering and anomaly suppression in air blowing determination so as to reduce false triggering and improve determination stability. Disclosure of Invention 1. Object of the invention The invention aims to provide a pressure zero point calibration and air blowing judgment anti-interference method of an expiration detection device, which is characterized in that a pressure sensor is sampled for a plurality of times under the condition of no air blowing, an average value is obtained to serve as a zero point offset, the zero point offset is subtracted from a reading during air blowing judgment, first-order low-pass filtering is carried out, and when the reading exceeds a reasonable interval, a historical filtering value or a reference value is output without updating a filtering state, so that the influence of zero point drift and instantaneous abnormality on air blowing judgment is reduced, and the judgment accuracy and stability are improved. Technical proposal In order to achieve the aim of the invention, the invention constructs a blowing judgment technical scheme based on the combination of zero calibration, filtering treatment and abnormal suppression from the generation characteristics of pressure signals and interference sources in the expiration detection process. The technical scheme comprises a zero point calibration stage, a pressure judgment stage and an abnormal data suppression stage in the whole structure. In the zero calibration stage, the pressure sensor is sampled for a plurality of times under the condition of no blowing, and the sampling result is subjected to statistical processing to obtain a stable zero offset, so that baseline drift caused by assembly difference, temperature change or gas circuit micro-leakage is compensated in subsequent detection. And in the pressure judging stage, subtracting the zero offset from the pressure reading acquired in real time to obtain calibrated gauge pressure or differential pressure data, and performing low-pass filtering processing on the data to inhibit pressure fluctuation caused by airflow pulsation or instantaneous peak in the blowing process, so as to obtain a stable pressure signal for blowing judgment. In the abnormal data suppression stage, the current reading of the pressure sensor is reasonably judged, when the reading is detected to exceed a preset reasonable interval, updating of the filtering state is suspended, and a historical filtering result is kept or a preset reference value is output as a current judgment basis, so that abnormal reading is prevented from participating in subsequent filtering and threshold comparison. Through the cooperative work of the stages, the invention can effectively inhibit the influence of zero drift, transient abnormality and communication interference on the air blowing judgment result while ensuring the air blowing judgment sensitivity, thereby forming an air blowing judgment mechanism with higher stability. Advantageous effects Compared with the prior art, the invention has the following beneficial effects: the a