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CN-121971757-A - Method and system for dynamically determining expiration time and breathing machine

CN121971757ACN 121971757 ACN121971757 ACN 121971757ACN-121971757-A

Abstract

The application provides a method, a system and a breathing machine for dynamically determining expiration time, which comprises the steps of executing expiration maintaining operation once after starting ventilation for I periods, executing expiration maintaining operation once every K times, counting the latest T times of endogenous end expiratory positive pressure results, calculating the number of bits of the latest T times of endogenous end expiratory positive pressure results as Pm, adjusting expiration time according to the measurement results, wherein the expiration time is increased by a first extension time if 1cm H 2 O<Pm≤5cmH 2 O, the expiration time is increased by a second extension time if 5cm H 2 O<Pm≤10cmH 2 O, and the expiration time is increased by a third extension time if Pm is more than 10cm H 2 O. The application has the advantages of capturing the true endogenous PEEP value in the most natural and unconscious state, ensuring the objectivity and reliability of the monitoring data, fundamentally guaranteeing the ventilation safety while pursuing the curative effect and avoiding invalid or harmful continuous intervention.

Inventors

  • MENG GUIFANG
  • LIU JIALONG
  • HAN WENLAN
  • ZHANG GUOQIANG
  • CHANG ZHIGANG

Assignees

  • 北京谊安医疗系统股份有限公司

Dates

Publication Date
20260505
Application Date
20251216

Claims (10)

  1. 1. A method of dynamically determining expiration time, comprising: Step 1, after ventilation is started for I periods, performing an expiration maintaining operation, and then performing the expiration maintaining operation every K times; step 2, counting the latest T endogenous positive end expiratory pressure results, and calculating the median thereof to be recorded as Pm; According to the measurement result, the expiration time is adjusted by increasing the expiration time by a first extension time if 1cm H 2 O<Pm≤5cmH 2 O, by a second extension time if 5cm H 2 O<Pm≤10cmH 2 O, and by a third extension time if Pm >10cm H 2 O.
  2. 2. The method according to claim 1, wherein the value range of I is 2-10, the value range of K is a random number between 20-60, the value range of T is 3-5, the first extension time is 0.5 seconds, the second extension time is1 second, and the third extension time is 1.5 seconds.
  3. 3. The method of claim 1, wherein the expiration-keeping operation is performed by measuring an endogenous positive end-expiratory pressure by an expiration-blocking method, closing the expiration valve in the absence of spontaneous breathing, observing a gradual rise in airway pressure from positive end-expiratory pressure to a steady level, the rising pressure being the endogenous positive end-expiratory pressure, and invalidating the measurement if spontaneous breathing occurs during the measurement.
  4. 4. The method of dynamically determining expiration time according to claim 1, further comprising: before ventilation begins, adult exhalation time was set to 2.5 seconds and child exhalation time was set to 2 seconds.
  5. 5. The method of dynamically determining expiration time according to claim 1, further comprising: And when the next expiration maintaining operation after expiration time adjustment is performed, evaluating the effect of the last expiration time adjustment, if the result of the endogenous end expiratory positive pressure measured during evaluation is smaller than Pm, the adjustment is effective, otherwise, the adjustment is ineffective, and the expiration time is restored to the value before adjustment.
  6. 6. The method of dynamically determining expiration time of claim 5, wherein the evaluating the effect of the last expiration time adjustment further comprises: if the continuous N times of adjustment are not effective, the expiration holding operation and expiration time adjustment are suspended to be performed for the next set hour, and are resumed after the set hour.
  7. 7. The method for dynamically determining expiration time according to claim 6, wherein the value of N is 3-5, and the set time is 24 hours.
  8. 8. A system for dynamically determining expiration time, based on the method of any one of claims 1-7, the system comprising: an expiration holding operation module for performing an expiration holding operation once after starting ventilation for I cycles, and then performing an expiration holding operation once every K times, and The expiration time adjusting module is used for counting the latest T endogenous positive end expiratory pressure results and calculating the number of bits recorded as Pm, and adjusting expiration time according to the measurement results, wherein the expiration time is increased by a first extension time if 1cm H 2 O<Pm≤5cmH 2 O, the expiration time is increased by a second extension time if 5cm H 2 O<Pm≤10cmH 2 O, and the expiration time is increased by a third extension time if Pm is more than 10cm H 2 O.
  9. 9. The dynamically determined expiration time system of claim 8, wherein the system further comprises: And the expiration time adjustment evaluation module is used for evaluating the effect of the previous expiration time adjustment when the next expiration after expiration time adjustment is kept, if the endogenous end expiratory positive pressure result measured during evaluation is smaller than Pm, the adjustment is effective, otherwise, the adjustment is ineffective, and the expiration time is restored to the value before adjustment.
  10. 10. A ventilator comprising a system as claimed in claim 8 or 9.

Description

Method and system for dynamically determining expiration time and breathing machine Technical Field The application belongs to the field of respirators, and particularly relates to a method and a system for dynamically determining expiration time and a respirator. Background Accurate setting of expiration time is a key ring in mechanical ventilation, directly related to ventilation safety and efficacy. The exhalation time in the current ventilation mode is mostly a fixed parameter preset by an operator, and an automatic regulation mechanism based on real-time physiological feedback is lacked. Airway resistance, lung compliance and metabolic demand of patients vary dynamically during the course of the disease, and a fixed expiration time cannot be accommodated, possibly leading to under-ventilation or over-ventilation and the risk of developing hemodynamic disorders. The ultimate goal of the expiration time setting is to ensure that the gas in the lungs is substantially expired before the end of one inhalation to the beginning of the next inhalation, returning the respiratory system pressure to the set PEEP level. If this goal is not achieved, a serious series of consequences will occur. The most immediate result is the generation of endogenous PEEP (also known as Auto-PEEP or PEEPi), i.e., entrapment of gas within the alveoli, resulting in unexpected pressure. This can result in hemodynamic inhibition, increased intrathoracic pressure, impeded venous reflux, susceptibility to drop in cardiac output and hypotension, increased work of breathing, increased effort required by the user to overcome endogenous PEEP to trigger the next inhalation, resulting in man-machine dyssynchrony and respiratory muscle fatigue, excessive lung expansion, and increased risk of ventilator-related lung injury. Adequate expiration time is a necessary condition for the removal of carbon dioxide from the body. In addition, insufficient exhalation time can lead to CO 2 retention (hypercapnia), especially in obstructive airways diseases. Disclosure of Invention The application aims to overcome the defect that the expiration time in the prior art adopts preset fixed parameters and lacks an automatic regulation mechanism based on real-time physiological feedback. In order to achieve the above object, the present application proposes a method for dynamically determining expiration time, comprising: Step 1, after ventilation is started for I periods, performing an expiration maintaining operation, and then performing the expiration maintaining operation every K times; step 2, counting the latest T endogenous positive end expiratory pressure results, and calculating the median thereof to be recorded as Pm; According to the measurement result, the expiration time is adjusted by increasing the expiration time by a first extension time if 1cm H 2O<Pm≤5cmH2 O, by a second extension time if 5cm H 2O<Pm≤10cmH2 O, and by a third extension time if Pm >10cm H 2 O. As an improvement of the method, the value range of the I is 2-10, the value range of the K is a random number between 20-60, the value range of the T is 3-5, the first extension time is 0.5 seconds, the second extension time is 1 second, and the third extension time is 1.5 seconds. As an improvement of the method, the expiration maintaining operation is to measure the endogenous end expiratory pressure by using an expiration blocking method, the end expiratory valve is closed under the premise of no spontaneous breathing, the airway pressure is observed to gradually rise from the end expiratory pressure to a stable level, the rising pressure is the endogenous end expiratory pressure, and if spontaneous breathing occurs during the measurement, the measurement is invalid. As an improvement of the above method, further comprising: before ventilation begins, adult exhalation time was set to 2.5 seconds and child exhalation time was set to 2 seconds. As an improvement of the above method, further comprising: And when the next expiration maintaining operation after expiration time adjustment is performed, evaluating the effect of the last expiration time adjustment, if the result of the endogenous end expiratory positive pressure measured during evaluation is smaller than Pm, the adjustment is effective, otherwise, the adjustment is ineffective, and the expiration time is restored to the value before adjustment. As an improvement of the above method, the evaluating the effect of the last exhalation time adjustment further comprises: if the continuous N times of adjustment are not effective, the expiration holding operation and expiration time adjustment are suspended to be performed for the next set hour, and are resumed after the set hour. As an improvement of the method, the value range of N is 3-5, and the set time is 24 hours. The application also provides a system for dynamically determining expiration time, which is realized based on the method, and comprises the following steps: an expir