SU1641272A1 - Device for identifying ventricular extrasystoles - Google Patents

Abstract

The invention relates to medical technology. A device for isolating the ventricular extrasystoles performs the selection and indication of various types of ventricular extrasystoles, which manifest themselves in a change in the shape of the QRS electrocardiogram complex. The device includes an amplifier 1, a band-pass filter 2, a rectifier1 3, four comparators 4.7, 10 and 13, a standby multivibrator 5, averaging unit 6, a limiter 8, an adder 9, a classification unit 11 and a measurement and display unit 12. The purpose of the invention is to increase the reliability of diagnosis by increasing the number of analyzed forms of electrocardiogram. The device provides for the allocation of fourteen types of the form of a QRS complex and determines the number of cardiocomplexes of each type observed during the examination of the patient, which allows one to assess the degree of polytopicity of ventricular extrasystole. 6 ill. (L

Description

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Fig 1

The invention relates to medical technology, namely to devices for processing and analyzing electrocardiograms.

The aim of the invention is to increase the reliability of diagnostics by increasing the number of analyzed forms of electrocardiogram.

Fig. 1 is a block diagram of a device for isolating ventricular extrasystoles; Figures 2-4 show the structural electrical diagrams of a classification unit, a measurement and indication unit, and a control unit, respectively; Fig. 5 shows timing diagrams explaining the operation of the device; Fig. 6 shows the classes of electrocardiogram forms allocated by the device.

A device for isolating the ventricular extrasystoles contains (FIG. 1) a series-connected amplifier 1, whose input is connected to the device input bus, a band-pass filter 2, a rectifier 3, a first comparator 4, a waiting multivibrator 5, averaging unit 6 and a second comparator 7 connected in series limiter 8, adder 9, third comparator 10, block 1 I classification and block 12 of measurement and indication, the second input of which is connected to the output of the second comparator 7, and the fourth comparator 13, the output of which is connected to the second input of the block 11 classification, and the input - with the output of the adder 9, the second input of which is connected to the output of the rectifier 3, the input of which is connected to the input of the limiter .8.

In a preferred embodiment of the device, the classification unit 11 contains (FIG. 2) the control unit 14, the pulse distributor 15, the register unit 16, the inverter 17, nine delay elements 18-26, nineteen And 27 elements - 45, three OR elements 46 - 48 and fourteen triggers 49 -62. The measurement and display unit 12 may include fourteen identical channels, each of which contains, for example, a series-connected pulse counter 63, a decoder 64 and an indicator 65 made on LED arrays, and a LED (not shown) connected to the second input bus of the measurement unit 12 and indications (FIG. 3). The control unit 14 included in the classification unit 11 includes, for example, a pulse generator 66, a pulse counter 67, a trigger 68, an AND element 69 and a delay element 70 (FIG. 4), and the pulse distributor 15 of the classification unit 11 can be implemented on the basis of a counter-decoder; Block 6 averaging can be implemented as an integrator

A device for isolating ventricular extrasystoles works as follows.

The electrocardiogram (EX) Ua coming to the device input bus (figure 5) is amplified by amplifier 1 and fed to a band-pass filter 2, which suppresses low-frequency and high-frequency interference contained in the input signal (UV, figure 5). Low-frequency interference is mainly seen in the mainline drift of the EX-line, and high-frequency interference is usually caused by AC power and interference caused by the patient's muscle tremor. The band-pass filter 2 significantly reduces the drift of the isoline and the level of interference caused by muscle tremor, which increases noise immunity and reliability of the device’s release of ventricular extrasystoles. One light guide through filtering is almost impossible to separate from the ECS without distorting its shape, so the device detects and indicates the presence of a significant level of network interference in the input signal using the first comparator 4, the waiting multivibrator 5, averaging unit 6, the second comparator 7 and unit 12 measurement and display. The ECS from the output of the rectifier 3 (Ud, FIG. 5) is fed to the input of the first comparator 4. If the amplitude of the ECS exceeds the value of the reference voltage Ui, then the first comparator 4 is activated, the output of which causes the waiting multivibrator 5. The voltage at the output of the block b averaging is proportional to the response frequency of the standby multivibrator 5. If this voltage exceeds the threshold level Ua, then the second comparator 7 generates a signal indicating the presence of a high amplitude large amplitude interference signal in the input signal. The output signal of the second comparator 7 is fed to the second input of the measurement and indication unit 12, the indicator LED of which signals the presence of an increased level of network pickup, coming together with an EX to the input bus of the device.

Improving the reliability of diagnosis of ventricular premature beats is achieved in the device by identifying fourteen classes of the form of a QRS complex EX (F1-Fi). The rectified EKS (Ud, Fig. 5) is fed to the second input of the adder 9, to the first input of which the EKS is fed without the negative part (Uc, Fig. 5) from the output of the limiter 8. The total signal Uc (Fig. 5) is compared with the threshold levels Us and UA () the third 10 and fourth 13 comparators,

depending on the states of which, the classification unit 11 identifies the form of the QRS complex entering the device.

Possible variants of input EKS (IVX), the signals at the output of the adder 9 (Kvyh) and the corresponding codes produced by the classification unit 11 are shown in FIG. 6. The time diagrams presented in Fig. 5 reflect the passage of signals through the device chains for three variants of the input ECS (codes Аа, АА, АаА, where the symbol а denotes a low-amplitude tooth, and the symbol A - a high-amplitude tooth of the QRS complex EX).

The second input of the classification unit 11 receives pulses corresponding to the operation of the fourth comparator 13 with a lower threshold value IU. The fourth comparator 13 also operates when the amplitude of the teeth EX is greater than the threshold level Uz, therefore the inverter 17, the delay element 18 and the element 27 of the classification unit 11 (Fig. 2) separate the operation times of the third comparator 10 from the operation times of the fourth comparator 13. To the first input of the distributor, 15 pulses are supplied from the element OR 46, a signal that occurs when both the third comparator 10 and the fourth comparator 13 are triggered. The distributor 15 pulses on the first, second and third outputs generates a signal ly carrying information about the sequence order of pulses actuation comparators 10 and 13 (respectively the first, second or third operation for the passage of a QRS-complex ECS). Then, using elements 28 and 29 and triggers 49 and 50, the presence of the first response of comparators 10 and 13 (codes ai and AI in FIG. 2) is determined, and using elements 30 and 32 - 36 - the presence of the second and third operations of comparators 10 and 13 (codes 32 and A2, az and az, respectively). Next, the presence of the EX-forms corresponding to two-digit codes is fixed: Aa - element And 37 and trigger 51, AA - element And 33 and trigger 52, aA - element L 34 and trigger 53, behind element And 35 and trigger 54, and three-digit codes: Aaa - element And 38 and trigger 55, AaA - element And 39 and trigger 56, AAa - element And 40 and trigger 57, AAA - element And 41 and trigger 58, aAe - element And 42 and trigger 59, aAA - element And 43 and trigger 60, aaa - element And 44 and trigger 61, azA - element And 45 and trigger 62. The signals corresponding to the detected codes are fed to the inputs block 16 registers strobe recording information in

which is produced by the CT signal from the first output of the control unit 14 (Fig. 2). Such gating is necessary because in block 11 of the classification

a system of priorities is provided, prohibiting the analysis of one-digit codes in the case of the appearance of two-digit codes and the analysis of two-digit codes when generating three-digit codes during the operation of one and the same

same QRS complex. At the second output of the control unit 14, a signal R of the termination of the analysis of one QRS complex is generated, leading to the initial state triggers 49 - 62 of the classification unit 11.

In the control unit 14, the signal from the first output of the distributor 15 pulses, corresponding to the first triggering of the comparators 10 and 13, is triggered by the trigger 68 and the And element 69.

counter 64 pulses with clock pulses coming from the generator 66 pulses. Pulse counter 67 forms the time interval required for analyzing a single QRS complex. The duration of this interval is set by the pulse counter capacity 67 and can be chosen to be, for example, 180 ms. At the end of the analysis time, the pulse counter 67 generates a signal that goes to the first output bus of the control unit 14 as a gating signal (ST), and also goes through the delay element 70 to the second output bus of the control unit 14 as the end time analysis signal R of one QRSinterval . The delay time produced by the delay element 70 is determined by the recording time of information in the register block 16.

Elements 18-26 of the delay block 11

classifications are designed to effect flushes of triggers 49–62 by priority. The delay time p produced by each of the delay elements 18-26 is determined by the following relationships:

718-717,

719 717 + 727,

T20 D 15 (1) + 729 + 750 - (7 15 (2) + 748).

 + 715 (1),

722 721,

723 746 + 7 15 (2) - 722.

724 723,

725 746 + 7 15 (3) - (722 + 72), 726 725,

where t is the delay time when the signal passes through the 1st element of the classification block 11; 715 (1). 715 (2) 715 (h) "- delay time

signal during its passage from the first inlet, and the distributor 15 pulses.

before her first, second and third

output accordingly.

The block 11 classifying the form of a QRS complex in the form of F14 signals (FIG. 6) arrives at the first input of the measurement and indication unit 12, where for each class of the form, their presence, counting and digital indication of the number of recorded forms of the FORMER by classes are carried out all time analysis. The stable indication of the same form of the QRS complex and the absence of indication of the forms of other classes indicate that the FORMER is a normal form for the subject patient. Indication of several classes of the EX-form for one patient shows the presence of pathological forms of the QRS-complex, and counting the number of forms of the EX-different classes allows us to conclude about the degree of polytopes ™ ventricular extrasystoles.

Thus, the device provides enhanced functionality and increased reliability of diagnostics of ventricular extrasystoles due to an increase in the number of analyzed forms of electrocardiogram to fourteen types of the form of a QRS complex.

Claims (1)

Claims An apparatus for isolating ventricular extrasystoles comprising an amplifier, the input of which is connected to the input bus of the device, the series-connected rectifier, the first comparator, the waiting multivibrator, the averaging unit and the second comparator, and the series-connected classification unit and the measuring and indicating unit, in order to increase the diagnostics reliability by increasing the number of analyzed forms of electrocardiogram, A bandpass filter connected between the amplifier and the rectifier, a limiter connected in series, an adder and a third comparator whose output is connected to the first input of the classification unit, a fourth comparator whose output is connected to the second input of the classification unit, and the input to the output of the adder, the second input of which is connected to the output of the rectifier, the input of which is connected to the input of the limiter, and the output of the second comparator is connected to the second input of the measuring and display unit. FIG 4 Schig.5 FIG. 6