SU829094A1 - Device for automatic search of stimulating pulse amplitude - Google Patents

Description

one

The invention relates to medicine, specifically, to sneHTpHuecky pacemakers.

A device is known for automatically searching for the amplitude of a stimulating pulse, which comprises an P-wave electrocardiogram extractor, a logic unit, a counter, a code-voltage converter, a programming unit, a delay unit, a stimulating pulse former, and an electrocardioscope. parameter of the amplitude of the stimulating pulse, control of the contractions caused by the electrocardioscope. At the same time, an increase in the diastolic poreg with prolonged stimulation caused temporary stimulation.

It is also known a device for automatically searching for the amplitude of a stimulating pulse, which contains a series-connected B-wave extractor of the electrocardiogram, a prohibition circuit, a delay line, a stimulating pulse shaper, and a counter 2.

However, this device is manufactured. It automatically searches for the amplitude of the stimulating pulse with low accuracy, which does not ensure the stability of the heart during pacing.

The purpose of the invention is to improve the accuracy of the automatic search for the amplitude of the stimulating pulse in order to ensure the stability of pacing.

This goal is achieved by introducing a multiplier and a control unit into the device, while the multiplier is connected to the output of the counter, the second input of which is connected to the first output of the control unit, the second and third outputs of which are connected to the inputs of the inhibit and multiplier The unit is connected to the outputs of the electrocardiogram R-teeth and delay lines, respectively. FIG. shows a block diagram of a device for automatically searching for the amplitude of a stimulating pulse; in fig. 2 is a plot of temporal evolution illustrating the operation of the device. The device contains an 1-8-teeth electrocardiogram selector connected to a prohibition circuit 2, a delay line 3, a stimulating pulse shaper 4, a counter 5, a direct serial link multiplier 6, a control unit 7 connected by inputs to a delay line 3 and an allocator 1 D - electrocardiogram teeth and exits with counter 5, multiplier 6 and with prohibition scheme 2. Counter 5 is made in the form of a digital shift shift register of amplitude with a code-voltage converter. The device operates as follows. When a natural QRS complex of an electrocardiogram appears from the 1 K-teeth electrocardiogram separator, the triggering signal t., 1 (FIG. 2b enters the first input of the prohibition circuit 2, and from its output to the delay line 3, where the delay time is set manually calculating the diastolic period of the cardiac cycle tj tj (Fig. 2c): From the output of line 3, the delays enter a signal to the input of the driver 4 stimulating pulses simultaneously and to the first input of the control unit 7 with memory at the time of the induced extrasystole and to the circuit 2 ban on the chain : the control unit 7 is the second input of circuit 2 per preta, closing it for the same time to prevent false triggering of circuit t, 2 g). From the output of shaper 4, a stimulating pulse C - "j (Fig. 2 e) is fed to the first input of counter 5 and with a minimum amplitude t (Fig. 2 g) is transmitted to a multiplier 6, from where it arrives with a constant amplitude tg (Fig. 2 h) on the patient. If the first cycle of the device does not cause a reciprocal contraction of the heart, i.e., there is no signal at the output of the 1 R-teeth of the electrocardiogram, then the following signal is the heart’s own electrical activity: will go to the first input of the control unit 7 and by means of it will shift the counter 5 along the circuit: the first output of the control unit 7 - the second input of the counter 5 by one cycle, increasing the amplitude by some value t (figure 2) and passing unchanged t through a factor of 6 t .. (Fig. 2 h) per patient. This cycle is repeated until a cardiac response is reached. With an effective working cycle of the device, for example, a third, the output of the 1 B-teeth of the electrocardiogram shows a signal (Fig. 2 b) of the extrasystoles. At that moment, the prohibition circuit 2 is closed t, (Fig. 2d), and at the first input of the control unit 7 the signal that caused the extrasystole is stored in memory, in addition, at the second input of the control unit 7 there is a signal of the extrasystole with 1 V - teeth. The time coincidence of the signals t .., tQ (Fig. 2 c and b) in the form of the M9 control signal t2 (Fig. 2 d) blocks further operation of the counter 5 and simultaneously along the circuit: the second output of the control unit 7 - the second input of the multiplier 6 changes gain amplitude magnitude and a half times, starting from the moment 1 (figure 2 h). Next, the device works with the found mode. With a large increase in the diastolic threshold during prolonged stimulation and disruption, its device will automatically continue to search for the required amplitude, as described. Thus, after several cycles of operation, the device finds the minimum effective amplitude of the stimulating impulse and then increases it by one and a half times, which ensures stability of cardiac contractions, but avoiding too much increase in the amplitude of the stimulating impulse that could cause ventricular fibrillation. The device provides high stability of pacing, patient safety and does not require highly skilled medical care.

Claims (2)

Invention Formula A device for automatically searching for the amplitude of a stimulating pulse, comprising successively connected ones. Electrocardiogram K-teeth extractor, inhibitor circuit, delay line, stimulating impulse shaper and counter, characterized in that, in order to increase the accuracy of the automatic search for the amplitude of the stimulating impulse to ensure the stability of electrocardiostimulation, a multiplier and control unit are inserted into It, This multiplier is connected to the output of the counter, the second input of which is connected to the first output of the control unit, the second and third outputs of which are connected to the inputs of the inhibit circuit and nozhitel and inputs nschego control unit respectively connected to outputs of discriminator H teeth electrocardiogram and delay lines. Sources of information taken into account in the examination 1, USSR Author's Certificate No. 374088, Cl, A 61 N 1/36, 1973. 2. USSR Author's Certificate No. 434948, class A 61 N l / 36. 1974.