Method for detecting expiratory tidal volumes and device using same

Abstract

The invention provides a method for detecting expiratory tidal volumes at a flow trigger of a ventilator and a device using the same. The method comprises the following steps: at the beginning of the action of expiration, detecting the first flow rate of gases inside inspiratory tubes of the ventilator, the second flow rate of gases inside the expiratory tubes of the ventilator and the pressure inside the expiratory tubes at a predetermined time interval at the same time; in accordance with the first flow rate and the second flow rate detected each time and the predetermined time interval, separately obtaining the expiratory tidal volume corresponding to each moment, wherein, the pressure detected each time is compared with the preset pressure, and the expiratory tidal volume at this time and the expiratory tidal volume in the expiratory phase at later time is set as 0 when the pressure is less than the preset pressure; and summarizing a plurality of expiratory tidal volumes to obtain the expiratory tidal volume of the whole inspiratory-expiratory phase. The invention realizes accurate measurement of the expiratory tidal volumes at the flow trigger of the ventilator.

Description

Technical field [0001] The present invention relates to the medical field, and more specifically, to a method for detecting expiratory tidal volume and a device for detecting expiratory tidal volume when the flow rate of a ventilator is triggered. Background technique [0002] The detection of the expiratory tidal volume triggered by the flow rate has always been a difficult point in the control of the ventilator. Currently, the commonly used calculation method is to calculate the expiratory tidal volume using the integral of the flow rate over time in the entire expiratory phase. Set the suction flow rate as F in , Expiratory flow rate F ex , Expiratory time T, expiratory tidal volume V T ,then This formula is based on the fact that continuous airflow has no effect on tidal volume after subtracting inspiratory and expiratory velocity. In fact, because different flow rate sensors are used for inhalation and exhalation, the collected flow rate data must have errors, so the result...

AI Technical Summary

Problems solved by technology

In fact, since different flow rate sensors are used for inhalation and exhalation, the collected flow rate data must have errors, so the result of integration often makes the error of respiratory tidal volume very large, generally more than 20%.

The flow waveform of the detected tidal volume in the prior art is as follows figure 1 shown, refer to figure 1 , after the expiratory action is completed, the influence of continuous airflow causes many stray waveforms to appear on the flow velocity waveform. When the tidal volume is integrated and calculated, the errors of the stray waveforms are included, so the calculated expiratory tidal volume cannot truly reflect The actual situation

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