SU599796A1 - Impedance-type pneumograph - Google Patents

Description

The infra-frequency signal of the pneumogram is emitted by the torus. With the output of the detector 4 is connected to the input of the amplifier 5 low frequency. The input of the two-threshold comparator 6 (level detector) is used to connect the source of the reference signal of the volume of air flow in the form of a breather of air flow during breathing. A regulator of 7 thresholds was connected to a two-threshold comparator, equipped with a scale digitized in units of volume. The output of the two-threshold comparator 6 is connected to the input of the driver 8 pulses. The output of amplifier 5 of a small frequency (amplifier of an impedance pneumogram) and the output of the imaging device 8 pulses are connected to the inputs of the mixer 9 of signals, the output of which is intended to connect the recorder, ensuring that it is recorded with an impedance pneumogram with marked pulses

The impedance pneumograph works as follows.

The electrodes 1 are fixed on the patient's chest in places, providing them with the maximum useful signal and the most linear dependence of the change in impedance AZ on the change in AV volumes. At the same time, to convert the impedance pneumogram, a pref is used (expiratory air volume diverter to an electrical sigpal, the electrical output of which is connected to the input of the compiler 6. From the electrodes 1 high frequency, proportional to the impedance of the chest, not the amplifier 3 to the high frequency, and from the output of the amplifier 3 after amplification, the output signal is fed to the input of the detector 4, where an infra-low frequency signal is released, corresponding to a change in respiratory volumes, the impedance waveform (see phi 2, plot a). From the output of the detector 4, the signal of the impedance neurogram is fed to the input of the low-frequency amplifier 5, which amplifies the signal of the impedance pneumogram to the level required for recording. Using the controller 7, the thresholds Ui and Uz of the two-threshold comparator 6 are set. the difference between the thresholds of the comparator Uz-Ui .U (see Fig. 2, Fig. a, d) will be directly proportional to the respiratory airflow volume A1 / (see Fig. 2, plot e) and correspond to the readings of the scale of the regulator 7. point in time when the output electric s The airflow converter used in the calibration reaches the level equal to the threshold voltage Ui, and the output of the comparator 6 (level detector) is the corresponding signal that is fed to the input of the pulse former 8. At this point, the imaging unit 8 forms a short pulse Uui (with a duration of approximately the average duration of the inspiratory phase). The signals of the imuls tag are shown “in the elura b of FIG. 2. The impulse mark from the output of the imaging unit 8 is fed to one of the inputs of the mixer 9 signals simultaneously with the signal of the impedance pneumogram Ipn. In the mixer 9 of the signals, the impulse label UM formed at time ii is superimposed on the impedance pneumogram signal (see Fig. 2, diagram c). With the further increase of the exhaled volume by the value AV, the level of the electrical signal of the converter at time t t The Uz level detector and driver 8 forms the next UM2 pulse tag. Thus, automatic impedance calibration is provided.

pneumograms in units of volume. Indeed, the reproducible pneumogram of the curve recorded by the recorder contains pulse marks, the distance between which corresponds to a known volume determined by the position of the threshold detector of the level detector (two threshold comparator). After the calibration is made, long-term measurement of respiratory volumes is possible without the use of a transducer.

respiratory airflows as well

performance of various diagnostic tests

provided that the location of the electrodes is not

is changing.

The use of the device in clinical practice will make it possible to improve the diagnosis of the condition, increase the efficiency of monitoring the respiratory function of sick and newborns, and can be used in rehabilitation, thanks to the possibility of prolonged

time without difficulty breathing (without masks, without mouthpieces, etc.) to control volumetric parameters characterizing the respiratory function. The device can also be useful in conducting research, for example, when using the influence of extreme environmental factors on the body. A pneumogram electrical signal containing calibration marks is convenient for entry into a computer.

Claims (1)

1. US patent No. 3347223, CL. 128-2, publ. 1966. FIG. one but  A (s)