CN103071213A - Leakage compensation method for single-loop non-invasive ventilators - Google Patents

Abstract

The invention relates to a leakage compensation method for single-loop non-invasive ventilators. The leakage compensation method is characterized in that the leakage compensation method includes the following steps: (1) a two-dimensional curve of the difference between the oxygen pressure at the front of a leaking tooling and the oxygen pressure at the rear of the leaking tooling and average leakage flow velocity is obtained by automatic calibration; (2) when a patient is ventilated in practice, actual leakage flow velocity is calculated; (3) implementation of leakage pressure compensation by the PID (Proportion Integration Differentiation) control algorithm: according to the obtained actual leakage flow velocity, the rotational speed of a turbofan is regulated, moreover, the turbofan and a pressure sensor are utilized to compose a PID control system, and by monitoring the difference between actual airway pressure and set pressure and feeding back and regulating PID parameters, the rotational speed of the turbofan is rapidly controlled until the set pressure value is reached.

Description

Single loop noninvasive ventilator gas leakage compensation method

Technical field

The present invention relates to a kind of single loop noninvasive ventilator gas leakage compensation method; be used for the accurate estimation to the gas leakage of single loop noninvasive ventilator; when supplying gas to the patient, give corresponding compensation, obtain required air leakage to guarantee the patient, belong to armarium manufacturing technology field.

Background technology

Under the noinvasive ventilating mode; because the portion gas of patient respiratory can spill the slit between face shield and people's mouth and nose; the actual flow that provides and survey of respirator all is provided for the actual suction of patient and Exhaled gasesS amount; need patient's gas leakage situation is estimated for this reason; when supplying gas, give certain affluence amount and compensate, obtain required ventilation to guarantee the patient.The gas leakage of existing double loop noninvasive ventilator is calculated by refluxing and is realized, and the single loop respirator does not reflux, and its air leakage can't accurately be estimated gas leakage by this mode, therefore is difficult to accurately determine compensation dosage.

Summary of the invention

For solving the accurate not problem of present domestic single loop noninvasive ventilator gas leakage compensation dosage, a kind of single loop noninvasive ventilator gas leakage compensation method is provided, be used for the accurate estimation to the gas leakage of single loop noninvasive ventilator, realization gives corresponding compensation to the accurate control of pressure and tidal volume when supplying gas to the patient.

Technical scheme of the present invention is as follows:

A kind of single loop noninvasive ventilator gas leakage compensation method is characterized in that, may further comprise the steps:

(1) by automatic calibration obtain the leaking gas two-dimensional curve of gas pressure difference and average gas leakage flow velocity before and after the frock: access gas leakage frock, gas pressure difference after calculating the gas pressure of gas leakage frock front end and passing through the gas leakage frock, and monitoring enters the initiatively tidal volume of mould lung when frock and access gas leakage frock are not leaked gas in access respectively, calculate average gas leakage flow velocity, obtain a two-dimensional curve between reference leakage device front and back pressure differential and the average gas leakage flow velocity, this curve is deposited in the readable and writable memory of controller;

Calculate reality gas leakage flow velocity during (2) to the actual ventilation of patient: the pressure of inspiration(Pi) before and after the calculating face shield is poor, and the two-dimensional curve of the pressure differential in the consults memory and the average flow velocity that leaks gas draws actual gas leakage flow velocity by difference arithmetic;

(3) realize the leakage pressure compensation by pid control algorithm: the rotating speed of adjusting turbofan according to the actual gas leakage flow velocity that draws, and utilize turbofan and pressure transducer to consist of the PID control system, by monitoring the difference between actual airway pressure and the setting pressure, feedback and pid regulator parameters are realized the quick control to the turbofan rotating speed, until reach setup pressure value.

The invention provides a kind of method of calculating air leakage by pressure differential before and after the gas leakage frock, the method can be used for the gas leakage of noninvasive ventilator gas leakage face shield and calculate, also can be used for airtight face shield and calculate with the matching used gas leakage of gas leakage frock, even can also be applied to the wound respirator.The method can realize the accurate Calculation of the gas leakage flow velocity of single loop noninvasive ventilator under different patient RC, and pressure of inspiration(Pi) can reach 1cmH2O in the following precision of 30cmH2O, and the above precision of 30cmH2O can reach 10%; By gas leakage result of calculation, can within 1-2 breathing cycle, control the air leakage fine compensation by PID, compensation precision reaches 0.1cmH2O.

Description of drawings

Fig. 1 is gas leakage flow velocity algorithm flow chart

Fig. 2 is gas leakage compensation flow chart

The specific embodiment

As shown in Figure 1, the present invention determines the gas leakage flow velocity at first by the following method:

1, by automatic calibration obtain the leaking gas two-dimensional curve of gas pressure difference and average gas leakage flow velocity before and after the frock:

Access gas leakage frock, gas pressure difference after calculating the gas pressure of gas leakage frock front end and passing through the gas leakage frock, and monitor respectively the tidal air metr that enters active mould lung when frock and access gas leakage frock are leaked gas in access and calculate average gas leakage flow velocity, obtain a two-dimensional curve between reference leakage device front and back pressure differential and the average gas leakage flow velocity, this curve is deposited in the readable and writable memory of controller;

Calculate actual gas leakage flow velocity when 2, giving the actual ventilation of patient:

The pressure of inspiration(Pi) that calculates the face shield front and back is poor, and the two-dimensional curve of the pressure differential in the consults memory and average gas leakage flow velocity draws the gas leakage flow velocity of reality by difference arithmetic.

Then according to the actual gas leakage flow velocity that draws, the rotating speed of the adjusting turbofan compensation of leaking gas, and utilize turbofan and pressure transducer formation PID control system, by pid control algorithm realization leakage pressure fine compensation, detailed process as shown in Figure 2:

By monitoring the difference between actual airway pressure and the setting pressure, feedback and pid regulator parameters are realized the quick control to the turbofan rotating speed, until reach setting pressure.Generally within 1-2 cycle, can reach setup pressure value.

Claims (1)

1. a single loop noninvasive ventilator gas leakage compensation method is characterized in that, may further comprise the steps:

(1) by automatic calibration obtain the leaking gas two-dimensional curve of gas pressure difference and average gas leakage flow velocity before and after the frock: access gas leakage frock, gas pressure difference after calculating the gas pressure of gas leakage frock front end and passing through the gas leakage frock, and monitoring enters the initiatively tidal volume of mould lung when frock and access gas leakage frock are not leaked gas in access respectively, calculate average gas leakage flow velocity, obtain a two-dimensional curve between reference leakage device front and back pressure differential and the average gas leakage flow velocity, this curve is deposited in the readable and writable memory of controller;

Calculate reality gas leakage flow velocity during (2) to the actual ventilation of patient: the pressure of inspiration(Pi) before and after the calculating face shield is poor, and the two-dimensional curve of the pressure differential in the consults memory and the average flow velocity that leaks gas draws actual gas leakage flow velocity by difference arithmetic;

(3) realize the leakage pressure compensation by pid control algorithm: the rotating speed of adjusting turbofan according to the actual gas leakage flow velocity that draws, and utilize turbofan and pressure transducer to consist of the PID control system, by monitoring the difference between actual airway pressure and the setting pressure, feedback and pid regulator parameters are realized the quick control to the turbofan rotating speed, until reach setup pressure value.

Images