SU843942A1 - Shaper of pulse lockout pulses - Google Patents

Description

The aim of the invention is to increase the reliability of pulse beat emission by adapting to low-frequency interference.

The goal is achieved by introducing a voltage repeater and a low-pass filter into the pulse sync pulse shaper containing a parametric filter, a comparator and a differentiator connected to it, and the parametric filter output is connected through a voltage repeater to the inputs of the comparator and a filter of frequency frequencies, the output of which is connected to the second input of the comparator.

FIG. 1 shows a structural diagram of a pulse synch pulse generator; in fig. 2 is a graph, illustrating the work of a parametric filter.

The synchronizer clock coaxers the parametric filter 1, whose input is the input to the device. The output of the parametric filter 1 is connected to the input of the repeater 2 voltage. The output of the repeater 2 is connected through a low-pass filter 3 to one of the inputs of the comparator 4, and the other input of the comparator 4 is connected to the output of the repeater 2 directly. The output of comparator 4 is connected to the input of differentiator 5. The output of differentiator 5 is the output of the device.

Shaper pulse sync pulse works as follows.

A two-pulse pulse signal is applied to filter I, which eliminates additional extremes of the pulse wave in one heartbeat period, converting the signal into a uniform one. The signal from a pair of metric filter 1 flow to a voltage follower 2, which has a gain of voltage K 7 1 n, is used to decouple the parametric filter and low pass filter 3. From the output of the repeater 2, the voltage of the pulse signal is fed through a low-pass filter 3, which provides for the separation of the low-frequency noise signal from the full signal, to one of the inputs of the comparator 4, and to the other input of the comparator 4, the signal is output from the output of the voltage follower 2 directly. Such an inclusion eliminates both the constant component of the signal and the loudspeaker, whose frequency range lies below the pulse beats, since the comparator only processes the changes of the differential input signal by comparing the PZ ELBOW signal with the interference voltage. When the differential input signal exceeds a certain value (threshold) at the output of com.parator 4, rectangular pulses are generated. The pulse frequency at the comparator output corresponds to the pulse frequency, while the duration of these pulses depends on the amplitude of the pulse signal.

The pulses from the output of the comparator 4 are fed to the differentiator 5. Differentiator 5, which is a high-pass RSfilter, serves to receive from the rectangular pulses from the output of the comparator 4 short-term radio polar pulses (sync pulse pulses) arising at the moment of action of the front and section coal impulses. The sequence of pulses of one polarity (positive or negative) from the output of differentiator 5 carries information about the temporal parameters of pulse beats (period, frequency) and their changes.

Parametric filter 1 consists of

the dynamic load of the photodetector of the pulse sensor, the resistance of which depends on the amplitude of the alternating component of the signal, and the capacitor inserted in the PC integrating circuit.

With an increase in the amplitude of the input signal, the resistance of the dynamic load decreases (i.e., the charge current increases) and compensation decreases in the charge current of the condenser caused by an increase in the voltage of the capacitor. Similarly, the more the AM input current signal is mixed, the lower the resistance of the dynamic load becomes, and therefore the discharge current increases. Thus, depending on the signal amplitude, the cutoff frequency of this filter changes. Parametric filter 1 alters the pulse waveform, allowing you to get rid of

from additional extremes of the pulse wave (incisur, early diastolic rise) over one period of heartbeat, slightly reducing the high-frequency components in the spectrum of the pulse signal corresponding to the leading edge (anacrot) of the pulse signal.

FIG. Figure 2 shows the effect of the parametric filter on the pulse waveform. The curve a - corresponds to the signal from the photodetector of the pulse sensor. Curve b - corresponds to the signal at the output of the parametric filter.

In addition, it should be noted that this filter allows to suppress interference, the frequency of which is higher than pulse beats, for example, interference from industrial frequency lighting devices.

Shaper clock pulses has a high sensitivity and noise immunity. The use of such a driver in devices for measuring the temporal parameters of pulse beats (pulse meters, arrhythmia indicators, measuring instruments for the period of heart contraction) due to the high sensitivity

and the noise immunity of the latter makes it possible to reliably monitor and measure the patient's pulse beats regardless of the state of the skin of the place where the sensor is applied, the degree of pressure of the sensor to the organ, the weak blood filling of blood vessels, and also makes it possible to eliminate the absolute immobility of the organ with the sensor. The reliability of pulse sync pulse shaping on each pulse beat is especially important in devices with a digital readout with discrete information display.

Form m u l and n 3 o b

Shaper pulse sync pulse containing a parametric filter,

a comparator and a differentiator connected to it, characterized in that, in order to increase the reliability of the emission of pulse beats by adapting to low-frequency interference, a voltage follower and a low-pass filter are inserted in it, the parametric filter output connected via a voltage follower to the comparator and filter inputs low frequencies, the output of which is connected to the second input of the comparator.

Sources of information taken into account in the examination

1. Authors certificate of the USSR L1 464304, cl. A 61 B 5/02, 1972.

2. US patent number 3228391, MKI 128-205, publ. 1971 (prototype).

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Time / 1 uz.Z

Claims (1)

Claim A pulse clock generator containing a parametric filter, a comparator and a differentiator connected to it, characterized in that, in order to increase the reliability of pulse beat detection by adapting to low-frequency interference, a voltage follower and a low-pass filter are introduced into it, and the output of the parametric filter is connected through a voltage follower to the inputs of the comparator and low-pass filter 10, the output of which is connected to the second input of the comparator.