CN112915330B - Mechanical ventilation platform pressure measurement compliance evaluation method - Google Patents
Mechanical ventilation platform pressure measurement compliance evaluation method Download PDFInfo
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- CN112915330B CN112915330B CN202110208037.3A CN202110208037A CN112915330B CN 112915330 B CN112915330 B CN 112915330B CN 202110208037 A CN202110208037 A CN 202110208037A CN 112915330 B CN112915330 B CN 112915330B
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
- A61M16/0003—Accessories therefor, e.g. sensors, vibrators, negative pressure
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/08—Detecting, measuring or recording devices for evaluating the respiratory organs
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
- A61M16/021—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes operated by electrical means
- A61M16/022—Control means therefor
- A61M16/024—Control means therefor including calculation means, e.g. using a processor
Abstract
The invention provides a method for detecting the compliance of platform pressure measurement operation under mechanical ventilation, which is a method for identifying a compliance waveform obtained by breath holding operation of a doctor from waveforms of a breathing machine and accurately identifying whether the doctor is performing the breath holding operation and whether the breath holding operation is compliant or not by analyzing morphological characteristics of the waveform. The method specifically comprises the following steps: through continuous pressure and flow velocity waveform data sampling, a minimum value is found on the first-order difference of the flow velocity waveform, then the flow velocity waveform data form is detected, whether the operation is the breath-holding operation is judged, and finally the platform pressure and the compliance are determined by using a sliding window slope method. The method of the invention provides convenience for the doctor to analyze the waveform after holding the breath and reduces the workload of medical staff. If the device is applied to the breathing machine, a doctor can be reminded whether the breath holding operation just done meets the requirements or not in real time.
Description
Technical Field
The invention relates to a method for evaluating the compliance of a mechanical ventilation platform pressure measurement, and belongs to the field of medical signal processing.
Background
During invasive mechanical ventilation of critically ill patients using a ventilator, airway plateau pressure is an important respiratory mechanics index. The airway plateau pressure means that in the volume control ventilation and square wave air supply process, after the air suction reaches the peak pressure, the air suction end blocks the airway. As the flow immediately drops to zero, the peak airway pressure drops, and a plateau in pressure, plateau pressure (P), gradually occurs plat ). Phase(s)The plateau pressure can really reflect the maximum pressure in the alveoli, compared to the common peak airway pressure of a ventilator. Excessive plateau pressure increases the load on the pulmonary circulation.
The airway plateau pressure can be measured as the driving pressure to overcome elastic resistance, which is the direct power to drive the entire respiratory system to expand. When inhaling, the driving pressure resists the elastic resistance of the respiratory system, drives the lung tissue and the chest wall to expand, and the air enters the lung to complete the inhaling process. By driving pressure, the lung compliance which can accurately reflect the elasticity of lung tissues is further explored, more accurate lung compliance assessment is provided for clinical medical staff, and the lung compliance assessment is an important reference for understanding the progress of diseases and implementing mechanical ventilation treatment.
Normally, when measuring the plateau pressure, it is necessary to measure P from the pressure waveform by temporarily interrupting the flow of gas by the patient holding his breath after a set volume of gas has been inhaled during the breathing cycle plat . However, due to the irregular operation of doctors and the influence of factors such as spontaneous respiration of patients, the pressure waveform obtained under the breath holding operation is irregular, and the deviation of the platform pressure measurement is caused. Only a few experienced physicians have the ability to accurately identify whether the measurements meet the requirements, which greatly increases the workload of the physicians.
The invention aims to provide a method for evaluating the pressure measurement compliance of a mechanical ventilation platform, which accurately identifies whether the platform pressure measurement operation performed by a doctor is in compliance or not by analyzing waveform morphological characteristics and provides help for obtaining a more accurate platform pressure measurement result.
Disclosure of Invention
When the gas-holding operation is carried out by pressing the measuring platform, the invention provides a method for detecting the compliance of the platform pressure measuring operation under mechanical ventilation in order to solve the problems that the measurement of medical staff is not standard, the workload of the medical staff is increased and the like.
The technical scheme adopted by the invention for solving the technical problem is as follows:
1. a method for detecting the compliance of a platform pressure measurement operation under mechanical ventilation is characterized by comprising the following steps:
a. acquiring airway pressure and flow rate waveform sampling data of single breath under mechanical ventilation;
b. finding out all minimum values of which the flow velocity is smaller than a threshold Min on the first-order difference signal of the flow velocity waveform, sequentially judging every two minimum values according to the time sequence, and if the phase difference distance of adjacent minimum values is smaller than Dis, keeping one minimum value close to the edge; if only one or more than 3 minimum values exist after the judgment is finished, the detection of the single breath is not in compliance; if only two minimum values exist, according to the time sequence, the first peak value sampling point A of the two minimum values is regarded as the end of inspiration and the starting point of breath holding, and the second peak value sampling point B is regarded as the end of breath holding and the starting point of expiration.
c. Detecting the waveform form of the flow rate, and if the flow rate from the starting point of inspiration to the point A is constant and the flow rate from the point A to the point B is constant, judging that the doctor performs inspiration end breath holding operation during the respiration;
d. and determining M points on the pressure waveform from the point A to the point B on the waveform which detects that the doctor performs the operation of inhaling the tail breath, and regarding the M points to the point B as a detected pressure platform, wherein the fitting slope of the pressure platform is smaller than a threshold tau.
e. When the time from the point M to the point B exceeds t seconds or c% of the whole breathing cycle, the breathing waveform is in accordance with the requirement, namely the inspiration end breath-hold operation is in accordance with the specification. And then taking the average value of the waveform sampling points from the M point to the B point as the airway platform pressure.
Further, in the step a, continuous airway pressure and flow waveform sampling data are obtained by using a ventilator, and the sampling frequency is above 50 Hz.
Further, in the step b, the threshold Min is in the range of-15 to 0L/Min. The value range of Dis is 1-10 sampling points.
Further, in the step c, the flow rate is constant and is determined by the following method: the first-order difference waveform fluctuation of the flow velocity between the two points does not exceed a threshold value T, and the slope of linear fitting of the flow velocity sampling point does not exceed S, wherein S is a threshold value with the absolute value close to 0.
Further, T =0 to 3L/min, and S =0 to 0.1L/min.
Further, in the step d, the specific step of determining the M point is: find the first sample point to the right of the point A
Detection by sliding window slope method
Pressure waveform from point to point B: if the fitting slope of the data segments in all the windows is smaller than the threshold value tau, tau = 0-0.1 cmH 2 O/s, then determine
The point is the final M point. Otherwise handle
And moving the points backwards by a plurality of sampling points, and repeatedly using the sliding window slope method until the final M points are determined.
In step e, t =0 to 0.4s, c =0 to 10.
The steps are applied to continuous mechanical ventilation airway pressure and flow velocity waveforms, and the result of breath-holding operation meeting the requirements can be automatically obtained.
The invention has the following beneficial effects: a method for identifying a compliance waveform obtained by a doctor holding a breath from a waveform of a breathing machine accurately identifies whether the doctor holds the breath and whether the breath holding operation is compliant by analyzing morphological characteristics of the waveform. The waveform analysis after the breath holding operation is performed by a doctor is convenient, and the workload of medical staff is reduced. If the device is applied to the breathing machine, a doctor can be reminded whether the breath holding operation just done meets the requirements or not in real time.
Drawings
FIG. 1 is a schematic flow chart of the present invention.
FIG. 2 is a schematic diagram of the first order difference between the pressure waveform and the flow velocity waveform of the present invention.
FIG. 3 is a schematic representation of key points in the pressure and flow rate waveforms of the present invention.
Detailed Description
For a better understanding of the present invention, reference will now be made in detail to the present embodiments of the invention, which are illustrated in the accompanying drawings.
As shown in fig. 1, the method for evaluating the compliance of the pressure measurement of the mechanical ventilation platform of the present invention comprises the following steps of finding a minimum value on a first-order difference of a flow rate waveform by sampling continuous pressure and flow rate waveform data, detecting a data form of the flow rate waveform, judging whether the operation is a breath-hold operation, and finally determining the platform pressure and the compliance by using a sliding window slope method, wherein the method specifically comprises the following steps:
a. acquiring airway pressure and flow rate waveform sampling data of single breath, wherein the sampling frequency is above 50 Hz;
b. fig. 2 is a schematic diagram of a first-order difference between a pressure waveform and a flow velocity waveform, all minimum values with a flow velocity smaller than a threshold Min are found out on a first-order difference signal of the flow velocity waveform, and are sequentially judged two by two according to a time sequence, and if a difference distance between adjacent minimum values (minimum values) is smaller than Dis, one minimum value close to an edge (closer to a waveform endpoint) is reserved; if only one or more than 3 minimum values exist after the judgment is finished, the detection of the single breath is not in compliance; if only two minimum values exist, according to the time sequence, regarding the first peak value sampling point of the two minimum values as the inspiration ending and breath holding starting point (A), and regarding the second peak value sampling point as the breath holding ending and breath holding starting point (B);
c. detecting the waveform form of the flow rate, and if the flow rate from the starting point of inspiration to the point A is constant and the flow rate from the point A to the point B is constant, judging that the doctor performs inspiration end breath holding operation during the respiration;
d. and determining M points of the pressure waveform from the point A to the point B by a sliding window slope method on the waveform of the last breath operation of the doctor, and regarding the M points to the point B as a detected pressure platform.
e. When the time from the point M to the point B exceeds 0.4s or 10% of the whole breath cycle, the respiration waveform is in accordance with the requirement, namely the breath holding operation is in accordance with the requirement. And then taking the mean value of the waveforms from the M point to the B point as the airway plateau pressure.
The steps are applied to continuous mechanical ventilation airway pressure and flow velocity waveforms, and the result of breath holding operation meeting the requirements can be automatically obtained.
In the step a, continuous airway pressure and flow rate waveform sampling data are obtained by a respirator, and the sampling frequency is above 50 Hz.
In step b, min = -15L/Min, dis =10 sampling points, i.e. minimum values must all satisfy less than the threshold value-15L/Min first. If the difference distance between the adjacent minimum values is less than 10 sampling points, only one minimum value is reserved between the adjacent minimum values.
In the step c, the constant flow rate from the inspiration starting point to the point A specifically means that the fluctuation of a first-order difference waveform of the flow rate does not exceed a threshold value of 3L/min and the linear fitting slope of the flow rate sampling point does not exceed 0.1L/min x s; the flow rate from point A to point B was constant and was determined under the same conditions.
In the step d, the specific step of determining the M point is as follows: find the first sampling point to the right of the point A
Detection by sliding window slope method
Point to point B pressure waveform. The sliding window slope method refers to firstly processing
The pressure waveform from point to point B is divided into data segments with window length 5, denoted as { W } 1 ，W 2 ，…，W n As shown in fig. 3. If the fitting slope of the data segments in all the windows is less than the threshold value of 0.1cmH 2 O/s, then determine
The point is the final M point. Otherwise handle
The point is moved back by N sampling points and the sliding window slope method is repeated until the final M points are determined.
Hair brushT and c in the bright are set to 0.4s and 10% according to medical requirements; τ, S, min, dis, W and T, in the examples set to 0.1cmH based on experience 2 O/s, 0.1L/min s, -15L/min, 10, 5 and 3L/min. In application, however, the adjustment can be made according to the actual situation after analysis.
The invention relates to a method for identifying a compliance waveform obtained by a doctor holding a breath from a waveform of a breathing machine, which accurately identifies whether the doctor holds the breath and whether the breath-holding operation is compliant or not by analyzing morphological characteristics of the waveform. The waveform analysis after the breath holding operation is performed by a doctor is convenient, and the workload of medical staff is reduced. The method can be applied to a breathing machine in the future, can remind a doctor whether the breath holding operation just done meets the requirements or not in real time, and can better guide the implementation of further mechanical ventilation.
The waveform obtained by 610 times of air-lock operation is evaluated by an algorithm by using the method. The algorithm tests 22 compliant waveforms and 588 non-compliant waveforms. The physician expert finally evaluates and verifies that the compliance waveform is 20 and the non-compliance waveform is 590, which indicates that the algorithm has high sensitivity and specificity.
Claims (7)
1. A method for detecting the compliance of a platform pressure measurement operation under mechanical ventilation is characterized by comprising the following steps:
a. acquiring airway pressure and flow waveform sampling data of single breath under mechanical ventilation;
b. finding out all minimum values of which the flow velocity is smaller than a threshold Min on a first-order difference signal of the flow velocity waveform, sequentially judging every two minimum values according to the time sequence, and if the phase difference distance of adjacent minimum values is smaller than Dis, keeping one minimum value close to the edge; if only one or more than 3 minimum values exist after the judgment is finished, the detection of the single breath is not in compliance; if only two minimum values exist, according to the time sequence, regarding a first peak value sampling point A in the two minimum values as an inspiration ending and breath holding starting point, and regarding a second peak value sampling point B as a breath holding ending and breath holding starting point;
c. detecting the waveform form of the flow rate, and if the flow rate from the starting point of inspiration to the point A is constant and the flow rate from the point A to the point B is constant, judging that the doctor performs inspiration end breath holding operation during the respiration;
d. determining M points on a pressure waveform from the point A to the point B on the waveform which detects that the doctor performs inspiration end-shielding gas operation, and regarding the M points to the point B as a detected pressure platform, wherein the fitting slope of the pressure platform is smaller than a threshold tau;
e. when the time from the point M to the point B exceeds t seconds or c% of the whole breathing cycle, the breathing waveform meets the requirement, namely the last inspiration breath-hold operation meets the specification; and then taking the average value of the waveform sampling points from the M point to the B point as the airway platform pressure.
2. The method for detecting the compliance of the operation of platform pressure measurement under mechanical ventilation according to claim 1, wherein in step a, a ventilator is used to obtain continuous airway pressure and flow waveform sampling data, and the sampling frequency is above 50 Hz.
3. The method for detecting the compliance of the platform pressure measurement operation under the mechanical ventilation according to claim 1, wherein in the step b, the value of the threshold Min ranges from-15L/Min to 0L/Min; the value range of Dis is 1-10 sampling points.
4. The method for detecting the compliance of the operation of platform pressure measurement under mechanical ventilation according to claim 1, wherein in the step c, the flow rate is constant by specifically adopting the following method: the first-order difference waveform fluctuation of the flow velocity between the two points does not exceed a threshold value T, and the linear fitting slope of the flow velocity sampling point does not exceed S, wherein S is a threshold value with an absolute value close to 0.
5. The method of claim 4, wherein T = 0-3L/min and S = 0-0.1L/min.
6. The method for detecting the compliance of the mechanical sub-ventilation platform pressure measurement operation according to claim 1, wherein in the step d, the M point is determinedThe method comprises the following steps: find the first sample point to the right of the point A
Detection by sliding window slope method
Pressure waveform from point to point B: if the fitting slope of the data segments in all the windows is less than the threshold value tau, tau = 0-0.1 cmH 2 O/s, then determine
Taking the point as a final M point; otherwise is at the handle
The point is moved backwards by a plurality of sampling points, and the sliding window slope method is repeatedly used until the final M points are determined.
7. The method for detecting the compliance of the operation of the platform pressure measurement under the mechanical ventilation according to claim 1, wherein in the step e, t = 0-0.4 s and c = 0-10.
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4440177A (en) * | 1980-07-03 | 1984-04-03 | Medical Graphics Corporation | Respiratory analyzer system |
| US5148802A (en) * | 1989-09-22 | 1992-09-22 | Respironics Inc. | Method and apparatus for maintaining airway patency to treat sleep apnea and other disorders |
| US5632269A (en) * | 1989-09-22 | 1997-05-27 | Respironics Inc. | Breathing gas delivery method and apparatus |
| CN101484202A (en) * | 2006-05-12 | 2009-07-15 | Yrt有限公司 | Method and device for generating a signal that reflects respiratory efforts in patients on ventilatory support |
| CN103908713A (en) * | 2012-12-29 | 2014-07-09 | 北京谊安医疗系统股份有限公司 | Anaesthesia machine and detecting method for compliance of breathing machine system |
| CN104337520A (en) * | 2013-07-30 | 2015-02-11 | 陈德路 | Accurate recording and detecting method for breathing state and position of patient |
| CN108194249A (en) * | 2018-01-19 | 2018-06-22 | 湖南省湘电试验研究院有限公司 | A kind of turbine-generator units guide vane leak quantity measuring method and system |
| CN109107007A (en) * | 2018-07-10 | 2019-01-01 | 上海敏恒企业咨询有限公司 | A kind of intelligence APRVplus breathing machine ventilation system and application method |
| CN109876262A (en) * | 2019-03-29 | 2019-06-14 | 浙江大学 | A kind of breathing machine pipeline hydrops automatic testing method based on small echo |
| CN111563451A (en) * | 2020-05-06 | 2020-08-21 | 浙江工业大学 | Mechanical ventilation ineffective inspiration effort identification method based on multi-scale wavelet features |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8844527B2 (en) * | 2008-04-15 | 2014-09-30 | Resmed Limited | Methods, systems and apparatus for paced breathing |
| US8834387B2 (en) * | 2008-06-13 | 2014-09-16 | Sagatech Electronics Inc. | Detection of airway resistance |
| US11452829B2 (en) * | 2016-11-18 | 2022-09-27 | ResMed Pty Ltd | Methods and apparatus for ventilatory treatment of respiratory disorders |
-
2021
- 2021-02-24 CN CN202110208037.3A patent/CN112915330B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4440177A (en) * | 1980-07-03 | 1984-04-03 | Medical Graphics Corporation | Respiratory analyzer system |
| US5148802A (en) * | 1989-09-22 | 1992-09-22 | Respironics Inc. | Method and apparatus for maintaining airway patency to treat sleep apnea and other disorders |
| US5632269A (en) * | 1989-09-22 | 1997-05-27 | Respironics Inc. | Breathing gas delivery method and apparatus |
| US5148802B1 (en) * | 1989-09-22 | 1997-08-12 | Respironics Inc | Method and apparatus for maintaining airway patency to treat sleep apnea and other disorders |
| CN101484202A (en) * | 2006-05-12 | 2009-07-15 | Yrt有限公司 | Method and device for generating a signal that reflects respiratory efforts in patients on ventilatory support |
| CN103908713A (en) * | 2012-12-29 | 2014-07-09 | 北京谊安医疗系统股份有限公司 | Anaesthesia machine and detecting method for compliance of breathing machine system |
| CN104337520A (en) * | 2013-07-30 | 2015-02-11 | 陈德路 | Accurate recording and detecting method for breathing state and position of patient |
| CN108194249A (en) * | 2018-01-19 | 2018-06-22 | 湖南省湘电试验研究院有限公司 | A kind of turbine-generator units guide vane leak quantity measuring method and system |
| CN109107007A (en) * | 2018-07-10 | 2019-01-01 | 上海敏恒企业咨询有限公司 | A kind of intelligence APRVplus breathing machine ventilation system and application method |
| CN109876262A (en) * | 2019-03-29 | 2019-06-14 | 浙江大学 | A kind of breathing machine pipeline hydrops automatic testing method based on small echo |
| CN111563451A (en) * | 2020-05-06 | 2020-08-21 | 浙江工业大学 | Mechanical ventilation ineffective inspiration effort identification method based on multi-scale wavelet features |
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