KR102269411B1 - Electrocardiography Device - Google Patents

Abstract

The present invention relates to an electrocardiogram measuring device (measuring sensor) that an individual can use in association with a smartphone. The electrocardiogram measuring apparatus according to the present invention has three electrodes, two amplifiers receiving an electrocardiogram signal from the first and second electrodes among the three electrodes, and is connected to each output terminal of the two amplifiers to receive an analog signal An AD converter for converting a digital signal, a microcontroller for receiving the digital signal of the AD converter, and a communication means for transmitting the digital signal, wherein the microcontroller receives power from a battery built in the electrocardiogram measuring device, The microcontroller controls the AD converter and the communication means, and the two amplifiers each amplify one ECG signal, and include an ECG measuring device, characterized in that it measures two ECG signals at the same time.

Description

Electrocardiography Device

The electrocardiogram can be easily obtained in order to analyze the condition of a patient's heart and provides a waveform of an electrical signal containing very useful information, that is, an electrocardiogram. An electrocardiograph can be considered to be composed of an electrocardiogram measuring device (measuring sensor) and a computer. Meanwhile, in recent years, almost all individuals use a smartphone. Smartphones can be thought of as computers that can communicate wirelessly and offer great displays. Therefore, the combination of an electrocardiogram measuring device (measuring sensor) and a smartphone can be an excellent electrocardiograph. The present invention relates to an electrocardiogram measuring device (measuring sensor) that an individual can use in association with a smartphone. The present invention is a device for measuring an electrocardiogram, and according to International Patent Classification (IPC), A61B 5/04 to which Detecting, measuring or recording bioelectric signals of the body or parts thereof belongs classified into classes.

An electrocardiogram is a useful device that can conveniently diagnose a patient's heart condition. Electrocardiography can be classified into several types according to the purpose of use. As an electrocardiograph for hospitals to obtain as much information as possible, a 12-channel electrocardiograph using 10 wet electrodes is used as a standard. The patient monitoring device is used to continuously measure the heart condition of a patient while a small number of wet electrodes are attached to the patient's body. The Holter ECG and Event recorder that users can move and use by themselves have the following essential features. These features include a compact, battery-powered storage device that stores the measured data and a communication device that can transmit the data. Holter ECG mainly uses 4 to 6 wet electrodes and cables connected to these electrodes and provides multi-channel ECG. However, Holter ECG has a disadvantage that the user feels inconvenience because the wet electrode connected to the cable is attached to the body. Electrocardiography, such as the recently disclosed patch type, is a type in which electrodes must be continuously attached to the body.

On the other hand, the event recorder allows the user to carry and measure the ECG on the spot when he/she feels an abnormality in the heart. Therefore, the event recorder is small and does not mainly include a cable for connecting electrodes, and includes dry electrodes on the surface of the event recorder. The event recorder according to the prior art was mainly a 1-channel, that is, a 1-lead electrocardiograph that measures one ECG signal by contacting both hands to two electrodes, respectively.

The electrocardiogram measuring device that the present invention seeks, that is, required, should be convenient for the individual to use, provide accurate and abundant electrocardiogram measurements, and should be small enough to be easily carried. A device required for convenient personal use must be able to transmit data through wireless communication with a smartphone. The device required for this must be battery operated. In order to increase battery usage time and to miniaturize the device, the device must not include a display and the electrocardiogram should be displayed on the smartphone.

In order to provide accurate and abundant ECG measurement values, two limb leads are directly measured simultaneously in the present invention. As will be described later, in the present invention, four leads can be calculated and provided from two limb measurements measured at the same time. In general, the terms “channel” and “lead” are used interchangeably in relation to the electrocardiogram. The word "simultaneously" in relation to the electrocardiogram should be used very carefully. The word "simultaneously" means not "sequentially". In other words, measuring two leads at the same time should literally mean measuring two ECG voltages at any one moment. To be more specific, if lead II is sampled while sampling the lead I voltage at a constant sampling cycle, each point of sampling lead II must be performed within a time shorter than the sampling period from each point of sampling lead I. have. Also note the use of the word "measurement". The word "measurement" should only be referred to as a measurement when it is actually measuring a physical quantity. In digital measurement, one measurement should actually mean one AD conversion. As will be described later, if, for example, Lead I and Lead III are measured in an electrocardiogram measurement, Lead II can be calculated according to Kirchhoff voltage law. In this case, lead II must be accurately expressed as “calculated”, and confusion arises when expressed as “measured”.

One of the most difficult problems in ECG measurement is to remove power line interference included in the ECG signal. A well-known method for eliminating power line interference is the Driven Right Leg (DRL) method. Practically all electrocardiographs eliminate power line interference with the DRL method. A disadvantage of the DRL method is that one DRL electrode must be attached to the right foot or the lower right part of the torso. The DRL electrode may be replaced with a ground electrode. Therefore, in order to measure two limbs using the DRL method, in the prior art, four electrodes including the DRL electrode must be in contact with the body. However, an important problem here is that the DRL electrode must be in contact with the right lower abdomen, which requires the use of a cable or increases the size of the device. That is, it is difficult to make an electrocardiogram measuring device that measures two leads using DRL electrodes the size of a credit card. Also, it is important to note that if the DRL electrode is adjacent to another electrode and is in contact with the human body, the voltage of the DRL electrode contains the ECG signal component, and thus the voltage of the adjacent electrode is distorted. It is very difficult to eliminate power line interference without using DRL electrodes, and it is necessary to use a special circuit (In-Duk Hwang and Jhon G. Webster, Direct Interference Canceling for Two-Electrode Biopotential Amplifier, IEEE Transaction on Biomedical Engineering, Vol. 55, No. 11, pp. 2620-2627, 2008) In order to remove power line interference using a conventional filter, a fairly large Q (Quality factor) may be required, and manufacturing and calibration of such a filter may be difficult. have.

The dry electrode has a large electrode impedance, and the dry electrode causes greater power line interference. However, in the ECG measurement for the convenience of the user, it is necessary to use a dry electrode attached to the case surface of the ECG measurement device instead of using a wet electrode connected to a cable. In addition, it is necessary to reduce the number of dry electrodes for user convenience. It is also required that the DRL electrode not touch the right foot or the lower right part of the torso. However, in the prior art, it has been difficult to provide an electrocardiogram measuring device that does not use a cable, uses a minimum number of electrodes, and removes power line interference.

In order to solve the above problems and necessity, in the present invention, for the convenience of the user, a dry electrode is not used, and two amplifiers associated with the two limbs are used to measure the two limbs simultaneously (simultaneously). Three electrodes are used. The electrocardiogram apparatus according to the present invention provides a plate-shaped electrocardiogram apparatus having two dry electrodes separated from each other on one surface and one dry electrode on the other surface for user's convenience. In addition, the present invention provides a power line interference cancellation method for not using a DRL electrode.

As will be described later, the present invention includes three electrodes, the power line interference current flows concentrated through one electrode, and two amplifiers connected to the remaining two electrodes except for the electrode among the three electrodes are used, The two amplifiers each amplify one electrocardiogram signal, and disclose an electrocardiogram measuring device characterized in that the two electrocardiogram signals are simultaneously measured. Here, one amplifier means amplifying one signal, and in an actual configuration, one amplifier may mean a cascaded multiple amplification stage or an aggregate composed of active filters.

As described below, the prior art did not provide the technical solution provided by the present invention and did not accurately describe it.

Righter (US Pat. No. 5,191,891, 1993) obtained only one ECG signal by equipping a watch-type device with three electrodes.

Amluck (DE 201 19965, 2002) discloses an electrocardiogram with two electrodes on the top and one electrode on the bottom, but measuring only one lead. Also, unlike the present invention, Amluck has a display and input/output buttons.

Wei et al. (US Pat. No. 6,721,591, 2004) use a total of six electrodes, including the RL electrode, which is a ground electrode. Wei et al. disclosed a method of calculating the remaining 8 leads by measuring 4 leads.

Kazuhiro (JP2007195690, 2007) provided a device including a display with four electrodes including a ground electrode.

Tso (US Pub. No. 2008/0114221, 2008) disclosed a meter comprising three electrodes. However, Tso touches two electrodes simultaneously with one hand to measure one limb, for example, Lead I. In this way, one lead is measured at a time, so to obtain three limb leads, three measurements must be performed sequentially. Tso also directly measured the augmented limb lead, which does not need to be measured directly, and a separate platform was used for this measurement.

Chan et al. (US Pub. No. 2010/0076331, 2010) disclose a watch comprising three electrodes. However, Cho et al. measure three leads using three differential amplifiers. Chan et al also use three filters coupled to each of the amplifiers to reduce noise in the signal.

Bojovic et al. (US Pat. No. 7,647,093, 2010) describe a method for calculating a 12-lead signal by measuring three special (non-standard) leads. However, in order to measure 3 leads with one limb lead (Lead I) and two special (non-standard) leads from the chest, 5 electrodes with 1 ground electrode on both sides of the plate-like device and 3 amplifiers are used. be prepared

Saldivar (US Pub. No. 2011/0306859, 2011) discloses a cradle for a cellular phone. The Saldivar has three electrodes on one side of the cradle. However, Saldivar uses a lead selector to measure one lead sequentially by connecting two of the three electrodes to one differential amplifier 68 (Figure 4C and paragraphs). That is, Saldivar 3 Measure each lead sequentially, one at a time.

Berkner et al. (US. Pat. No. 8,903,477, 2014) used three or four electrodes disposed on both sides of a plate-like device to calculate a 12-lead signal through sequential measurements performed while moving the device sequentially. it's about However, it does not provide a specific measurement method including how each electrode is internally connected. For example, the roles of the left foot and the right foot are different in ECG measurement, but Berkner does not distinguish whether the foot is the left foot or the right foot because Berkner describes one electrode as contacting the lower limb or lower torso. This ambiguity is also shown in Stage 1 of Figure 6. When using three electrodes, only one lead can be measured at a time by placing one electrode on the right foot. Also, Berkner fails to provide a detailed structure and form of the device he claims. Most importantly, Berkner uses one amplifier 316 and one filter module 304. If one amplifier 316 and one filter module 304 are used, for example, to measure two leads, two measurements are made sequentially. Specifically, Berkner states, "In a three-electrode system, the reference electrode is different and alternates in each lead measurement. This is done by means of designated software or hardware, optionally including switches," (... so in a system comprising only 3 electrodes, the reference electrode is different and shifts for each lead measurement. This may be done by a designated software and/or hardware optionally comprising a switch. The above technique shows that Berkner uses one amplifier 316 and one filter 304 to measure one lead at a time. That is, the method of Berkner et al. is not related to the method of simultaneously measuring two leads using three electrodes and two amplifiers presented in the present invention.

Amital (US Pub. No. 2014/0163349, 2014) generates a common mode cancellation signal from three electrodes in a device equipped with four electrodes and transmits the common mode cancellation signal to the other electrode (see claim 1) to remove the common mode signal. This is the traditional DRL method well known before Amital.

Thomson et al. (US Pub. No. 2015/0018660, 2015) disclosed a smartphone case with three electrodes attached thereto. Thomson's smartphone case has a hole in the front so that you can see the smartphone screen. However, it does not show how to measure two leads at the same time using two amplifiers. In addition, since Thomson's device uses ultrasonic communication, there is a disadvantage that a communication problem may occur even if the smartphone and the device are even a little (about 1 foot) apart. In addition, Thomson's smartphone case may not be able to use the existing smartphone case if the user changes the smartphone.

Drake (US Pub. No. 2016/0135701, 2016) has three electrodes on one side of a plate-like mobile device to provide 6 leads. However, Drake states that “comprises one or more amplifiers configured to amplify analog signals received from the three electrodes” (paragraphs [0025] and claim 4, “comprises one or more amplifiers configured to amplify analog signals received from the three electrodes”). ) is described as Therefore, Drake is ambiguous about the essential part of the invention: how many amplifiers are used and how to connect the amplifiers. Drake also notes, "The ECG device 102 can include a signal processor 116, which can be configured to perform one or more signal processing operations on the signals received from the right arm elctrode 108, from the left arm electrode 110, and from the left leg electrode 112" (paragraph [0025]). Therefore, the Drake receives three signals. It is also ambiguous whether Drake receives the three signals simultaneously or sequentially. Drake also describes "Various embodiments disclosed herein can relate to a handheld electrocardiographic device for simultaneous acquisition of six leads." (paragraph [0019]). Here, Drake uses the word "simultaneous" in an inaccurate, inappropriate, and ambiguous way. The structure of the Drake device can be considered similar to that of the Thomson device. Drake places three electrodes on one side of the device. Therefore, like the above Thomson et al., it is difficult to simultaneously contact the three electrodes with both hands and the body.

The device of Saldivar (WO 2017/066040, 2017) uses a Lead Selection Stage 250 to connect three electrodes to one amplifier 210. In addition, Saldivar takes 6 measurements sequentially, one by one, to obtain 6 leads. That is, Saldivar does not measure multiple leads simultaneously. Saldivar also directly measures the three augmented limb leads sequentially.

The present invention has been devised in response to the above problems and needs, and is an electrocardiogram using two amplifiers associated with the two limbs in order to simultaneously measure two limbs with one ECG device having three electrodes. We want to provide a device. Simultaneous measurement of two limbs is of great medical importance. This is because sequentially measuring two leads takes more time and is inconvenient. More importantly, two limbs measured at different times may not correlate with each other and may confound detailed arrhythmia discrimination. The electrocardiogram apparatus according to the present invention includes a plate-shaped electrocardiogram apparatus having two dry electrodes separated from each other on one surface and one dry electrode on the other surface for user's convenience. In addition, the present invention provides a power line interference cancellation method for not using a DRL electrode. The present invention discloses a convenient method for measuring an electrocardiogram in which both hands are in contact with two electrodes and one electrode is in contact with the body, and an electrocardiogram measuring device having a suitable structure.

The appearance, usage method, operation principle, and configuration of the electrocardiogram device according to the present invention for the above-mentioned problems are as follows. The present invention solves the above problems through systematic circuit design and software production.

1 shows an electrocardiogram measuring apparatus 100 according to the present invention. The electrocardiogram measuring apparatus 100 includes three electrodes 111 , 112 , and 113 on the surface. Two electrodes 111 and 112 spaced apart from each other at a predetermined interval are installed on one side of the electrocardiogram measuring device 100 , and one electrode 113 is installed on the other side of the electrocardiogram measuring device 100 .

2 illustrates a method for a user to measure an electrocardiogram in a 6-channel mode using the electrocardiogram measuring apparatus 100 according to the present invention. The user holds the electrodes 111 and 112 provided on one side of the electrocardiogram measuring apparatus 100 with both hands, respectively, and brings the electrode 113 provided on the other side into contact with the user's left lower abdomen (or left leg). In this way, when three electrodes are brought into contact with the human body, two limb leads can be measured, and as described below, four leads can be calculated and additionally obtained. The measurement method of FIG. 2 is the method provided by the present invention in order to most conveniently obtain an electrocardiogram of 6 channels. The present invention also provides an apparatus most suitable for the measurement method of FIG. 2 . The principle of the measurement method is as follows.

Traditional 12-lead ECG is described, for example, in [ANSI/AAMI/IEC 60601-2-25:2011, Medical electrical equipment-part 2-25: Particular requirements for the basic safety and essential performance of electrocardiographs]. Among the traditional 12-lead ECGs, the three limb leads are defined as follows. Read I = LA-RA, read II = LL-RA, read III = LL-LA. In the above equations, RA, LA, and LL are the voltages of the right arm, left arm, left leg, or the body region close to these limbs, respectively. In this case, in order to remove power line interference, a right leg (DRL) electrode is typically used in the prior art. From the above relationship, one limb may be obtained from the other two limbs. For example, Lead III = Lead II - Lead I. The three Augmented limb leads are defined as follows. aVR=RA-(LA+LL)/2, aVL=LA-(RA+LL)/2, aVF=LL-(RA+LA)/2. Therefore, three augmented limb leads can be obtained from two limb leads. For example, it can be obtained as aVR= -(I+II)/2. Therefore, if you measure two limbs, you can calculate the remaining four leads. Therefore, the present invention discloses an apparatus for simultaneously measuring two leads using three electrodes and two amplifiers to provide six leads. Here, one amplifier means to amplify one signal, and in an actual configuration, one amplifier may be composed of a plurality of amplification stages cascaded in series or an aggregate of active filters. A standard 12-lead ECG consists of the 6 leads and 6 precordial leads from V1 to V6.

MCL (Modified Chest Leads) is very useful medically because it is similar to the above precordial leads. On the other hand, in the principle of the present invention, the voltage of one of the three electrodes not connected to the amplifier becomes substantially the same as the circuit common in the signal frequency band. Therefore, the electrocardiogram measuring apparatus 100 according to the present invention is suitable for measuring one MCL among six MCLs from MCL1 to MCL6. This is because each MCL is the voltage at the position of the corresponding precordial lead based on the voltage of the body part to which the left hand is connected.

3 shows a method for a user to measure MCL1 using the electrocardiogram apparatus according to the present invention in the MCL mode. Using the electrocardiogram device according to the present invention, for example, in order to measure MCL1, the user holds the electrodes 111 and 112 provided on one side of the electrocardiogram measuring device 100 with both hands, respectively, as shown in FIG. 3 and the other side Just contact the electrode 113 provided in the MCL position (for example, the V1 position when measuring MCL1). In the present invention, in order for the user to measure the MCLn, the user may contact the electrode 113 to the MCLn position of the user's body, that is, the Vn position.

Hereinafter, one embodiment of the electrocardiogram measuring apparatus according to the present invention will be described with reference to FIGS. 4 and 5 . 4 is an electrical equivalent circuit model for explaining the principle and embodiment of removing power line interference in the electrocardiogram measuring apparatus according to the present invention. 5 is an electrical equivalent circuit model of an embodiment of simultaneously measuring two channels of an electrocardiogram using two single-ended input amplifiers in the electrocardiogram measuring apparatus according to the present invention.

A current source 450 was used to model the power line interference in FIG. 4 . In addition, in FIG. 4 , the human body was modeled with three electrode resistors 431 , 432 , and 433 connected to each other at one point. Also, in FIG. 5 , one ECG signal was modeled as one voltage source 461 and 462 existing between two electrode resistors. Since three electrodes are used in the present invention, it is modeled as having two ECG voltage sources 461 and 462 in the human body in FIG. 5 . This is because there are three ECG voltages in three electrodes (this is because the number of cases in which two electrodes are selected among three electrodes is three), but only the two ECG voltages are independent. The modeling of the power line interference of FIG. 4 and the modeling of the ECG signal of FIG. 5 are simplified. However, the above models are suitable to clarify the problem to be solved. The models also clearly indicate what should be devised in the present invention. Also, using the above models, the present invention can be easily understood. The present invention was devised based on the above models. Since the prior art did not use the above models, the prior art could not accurately suggest a solution to the problem.

The present invention may be expressed in various embodiments as will be described later. However, various embodiments of the present invention are commonly based on the following principles of the present invention. The principles of the present invention are devised in the present invention for the purposes of the present invention. The principle of the present invention is different from the DRL used in the prior art in that it does not use a DRL electrode.

A problem that has not been solved in the conventional electrocardiogram measuring apparatus that does not use a DRL electrode and that is essential to be solved is to eliminate or reduce power line interference. Power line interference in the electrocardiogram measuring apparatus is generated by a current source having a substantially infinite output impedance as the output impedance is quite large as shown in FIG. 4 . (In FIG. 4, the power line interference current source is indicated by 450.) Therefore, in order to remove the power line interference, it is required to minimize the impedance looking into the human body from the power line interference current source. The impedance looking into the human body from the power line interference current source is the sum of the impedance of the human body itself and the impedance of the electrocardiogram measuring device. In the end, it is required to minimize the impedance of the ECG measuring device that looks through the three electrodes. Meanwhile, between the electrode used to measure the electrocardiogram and the human body, so-called electrode impedance or electrode resistance (431, 432, 433 in FIG. 4) exists. Therefore, in order to minimize the effect of electrode impedance and measure the ECG voltage, the ECG measuring device must have a high impedance. Therefore, the ECG measuring device must satisfy two contradictory conditions, which must have a low impedance in order to remove power line interference and have a high impedance in order to measure the ECG voltage.

A method that can be considered possible to satisfy the two opposite conditions is, for example, when three electrodes are used, three resistors having a large value are connected to the three electrodes, respectively, and the other end of the three resistors is connected. is bundled together with one point, and the common mode signal of the three electrodes is negatively fed back to the single point where three resistors are bundled. However, this method is difficult to use in practice. This is because the impedance of the power line interference current source is large, so that the magnitude of the power line interference current is not reduced. Therefore, the power line interference voltage induced in the three resistors in this case is still quite large. Or the amplifier may be saturated. In addition, since the magnitude of the power line interference current is not reduced and the impedance of each electrode may be different, different power line interference voltages are induced at each electrode to be quite high. Therefore, even if a differential amplifier is used, it is difficult to remove the power line interference induced in each electrode. This was the difficulty of the prior art.

Therefore, in the present invention, the power line interference current is concentrated and flows to only one electrode among the electrodes installed in the electrocardiogram measuring device. To do this, in a state in which three electrodes are connected to the human body, the impedance of the power line interference current source looking through the one electrode through the electrocardiogram measuring device is minimized. Then, the power line interference voltage (indicated as 440 in FIG. 4 ) induced in the human body by the power line interference current source is minimized. Then, since the power line interference voltage induced to the human body is minimized, the input impedance of the other electrode of the ECG measurement device can be increased, and the ECG voltage can be accurately measured. At this time, an important point is that the single electrode should not be used for measurement because the power line interference voltage is induced to be high in the one electrode through which the power line interference current is concentrated. Therefore, in the present invention, when three electrodes are used, two electrodes and two amplifiers receiving the ECG signals from the two electrodes are used for measurement. In particular, it should be noted that in the ECG measuring device using three electrodes, two differential amplifiers cannot be used because only two electrodes are used for measurement. Also, it should be noted that when negative feedback is used, if negative feedback is performed in all frequency bands, the ECG signal is generated on the feedback electrode side and mixed with the power line interference voltage, so negative feedback should be performed only at the power line interference frequency. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the detailed description of the present invention will be described with reference to the drawings.

In FIG. 4 and subsequent drawings, the electrocardiogram measuring apparatus 100 according to the present invention shows only a part of the apparatus 100 according to the present invention for convenience. In FIG. 4, the electrocardiogram measuring apparatus 100 according to the present invention includes three electrodes 111, 112, 113 and two amplifiers 411 and 412. In FIG. 5, the two amplifiers 411 and 412 used in the present invention are not differential amplifiers, but single-ended input amplifiers.

가 큰 특징이 있다. 도 4에서 대역통과필터 413의 입력 임피던스는 상당히 큰 것으로 가정한다. An important feature of the embodiment shown in FIG. 4 of the present invention is that the electrocardiogram measuring apparatus 100 according to the present invention includes a bandpass filter 413 . An input of the bandpass filter 413 is connected to one electrode 112 . The output of the bandpass filter 413 is fed back to the electrode 113 through the resistor 423 . The resonant frequency, ie, the peak frequency, of the bandpass filter 413 is the same as the frequency of the power line interference. In addition, the band pass filter 413 is

has great features. In FIG. 4 , it is assumed that the input impedance of the bandpass filter 413 is quite large.

인 저항 421과 422를 통하여 회로공통으로 연결된다. 저항 421과 422는 증폭기 411과 412의 입력 임피던스로 간주할 수 있다. In the present invention, two of the three electrodes have a value

It is connected in common through the phosphor resistors 421 and 422. Resistors 421 and 422 can be considered the input impedances of amplifiers 411 and 412.

로 표시하였다. 4, 430 is a model of a human body. A contact resistance commonly referred to as electrode impedance exists between the human body and the electrode. In FIG. 4 , the electrode impedances (electrode resistance) existing between the human body 430 and the three electrodes 111, 112, and 113 are shown as resistors 431, 432, and 433, respectively. The element values of the electrode resistors 431, 432, and 433 are respectively

indicated as

은 인체 430과 상기 3개의 전극 111, 112, 113을 통하여 본 발명에 의한 심전도 장치 100의 회로공통으로 흐른다. 상기 3개의 전극 111, 112, 113을 통하여 흐르는 전력선 간섭 전류를 각각

으로 나타내면 키르히호프의 전류 법칙에 의하여 다음이 성립한다. 4, 450 is a power line interference current source commonly used in power line interference modeling. Current from power line interference current source 450

flows through the human body 430 and the three electrodes 111, 112, and 113 in the circuit of the electrocardiogram device 100 according to the present invention. The power line interference current flowing through the three electrodes 111, 112, and 113, respectively

If expressed as , according to Kirchhoff's current law, the following holds.

로 나타내었다. 도 4에서

는 각각 전극 111, 112, 113의 전력선 간섭 전압을 나타낸다. 상기 식 1에서 각각의 전류는 다음과 같다.Power line interference induced in the human body 430 for circuit analysis

indicated as 4 in

denotes the power line interference voltage of the electrodes 111, 112, and 113, respectively. In Equation 1, each current is as follows.

를 사용하여 구하였다. 여기서Equation 4 above is the resistance value of the resistor 423.

was obtained using . here

는 상기 대역통과필터 413의 전달함수이다. 위 식들을 이용하면 다음을 얻는다.from above

is the transfer function of the bandpass filter 413. Using the above formulas, we get:

In the present invention, the element values of the circuit of Fig. 4 are used so that the following approximations (Equations 7 and 8) are possible. Equations 7 and 8 are important elements of the present invention.

Then the following approximation is established:

From Equation 9 above, we get:

이면 아래가 성립한다.In Equation 10, if there is no feedback, i.e. if

If this is the case, the following holds

의 영향을 피드백 양(the amount of feedback) 즉

으로 감소시키는 것을 알 수 있다. 따라서 대역통과필터의 공진주파수에서의 이득의 크기

이면

이 된다. 이상과 같이 본 발명에서 전력선 간섭을 제거하는 원리를 증명하였다. Comparing Equation 10 and Equation 11, we obtain the power line interference current with the effect of the present invention.

the effect of the amount of feedback i.e.

It can be seen that decreases to Therefore, the magnitude of the gain at the resonant frequency of the bandpass filter

back side

becomes this As described above, the principle of removing power line interference in the present invention has been demonstrated.

Using Equation 2 and Equation 10, we can check:

에 대하여 다음의 결과를 얻는다. 위 결과로부터

과

을 사용할 수 있다.now

We get the following result for from the above results

and

can be used

From Eqs. 12 and 13, it can be seen that

가 크면 거의 모든 전력선 간섭 전류가 피드백이 되는 전극 (도 4에서는 전극 113)을 통하여 흐르므로 피드백이 되는 전극은 전력선 간섭에 오염되는 한편 피드백이 되지 않는 전극 (도 4에서는 전극 111과 112)은 전력선 간섭의 영향을 거의 받지 않는 것을 의미한다. 이것은 심전도 측정을 위하여는 피드백이 되는 전극은 사용하지 말고 피드백이 되지 않는 전극만을 사용해야 함을 의미한다. 따라서 전극 111과 전극 113에 입력이 연결되는 차동증폭기 혹은 전극 112와 전극 113에 입력이 연결되는 차동증폭기를 사용하면 전력선 간섭의 영향을 제거하지 못한다. This is a result of feedback

If is large, almost all the power line interference current flows through the feedback electrode (electrode 113 in FIG. 4), so the feedback electrode is contaminated by power line interference, while the non-feedback electrode (electrodes 111 and 112 in FIG. 4) is the power line This means that it is hardly affected by interference. This means that for the ECG measurement, only the non-feedback electrode should be used, not the feedback electrode. Therefore, if a differential amplifier having an input connected to the electrode 111 and an electrode 113 or a differential amplifier having an input connected to the electrode 112 and the electrode 113 is used, the influence of power line interference cannot be eliminated.

는 각각 전극 111, 112, 113의 심전도 신호 전압을 나타낸다. 중첩의 원리를 이용하여 이 등가회로를 해석하여 전극 112의 전압

을 구하면 다음과 같다.Hereinafter, the principle of obtaining two ECG channel signals using three electrodes according to the present invention will be described. 5 is an equivalent circuit for measuring an electrocardiogram using the electrocardiogram apparatus according to the present invention. in Figure 5

denotes the ECG signal voltages of the electrodes 111, 112, and 113, respectively. By analyzing this equivalent circuit using the principle of superposition, the voltage of the electrode 112 is

If you get , you get:

은 병렬 저항의 값을 나타낸다. 앞에서와 마찬가지로 식 15에서 식 7과 식 8의 조건을 가정하는 것이 가능하다. 그러면 전압

는 다음과 같이 근사된다..In Equation 15 above, the symbol

is the value of the parallel resistance. As before, it is possible to assume the conditions of Equations 7 and 8 in Equation 15. then the voltage

is approximated as

은 다음과 같다.Therefore, under the conditions of Equations 7 and 8, the voltage

Is as follows.

이면

임을 알 수 있다. From the above equation, in the signal band

back side

it can be seen that

이다. 도 7은 도 6의 상기 대역통과필터를 사용하였을 때 주파수가 40Hz 이하에서 98%의 정확도로

를 구할 수 있음을 보여준다. 6 shows the frequency response of the bandpass filter used in the electrocardiogram measuring apparatus according to the present invention. 6, the gain at the resonant frequency of the bandpass filter is 20

to be. FIG. 7 shows an accuracy of 98% at a frequency of 40 Hz or less when the bandpass filter of FIG. 6 is used.

shows that it can be obtained.

을 구하면 다음과 같다.Similarly, the voltage on electrode 1

If you get , you get:

은 다음과 같이 근사된다.Using the conditions in Equations 7 and 8, the voltage

is approximated as

를 구할 수 있다. 식 20으로부터 대역통과필터의 영향 없이

를 구할 수 있음을 알 수 있다.The above equation was obtained using Equation 16. From the above expression, we get the following Equation 20, and by

can be obtained From Equation 20, without the influence of the bandpass filter

It can be seen that .

Thus, the principle of obtaining signals of two ECG channels using two single-ended amplifiers according to the present invention has been described.

을 실현하기 위해서는 대역통과필터의 전달함수

에 대한 보정 혹은 보상을 할 수 있다.8 is an electrical equivalent circuit model for explaining the principle and embodiment of removing power line interference using a common mode signal of two electrodes in the electrocardiogram measuring apparatus according to the present invention. Naturally, even when a common mode signal is used, the power line interference current flows concentratedly through the feedback electrode, and the power line interference voltage is high in the electrode. 9 is an electrical equivalent circuit model of an embodiment in which two channels of an electrocardiogram are simultaneously measured using one differential amplifier and one single-ended input amplifier in the method of FIG. 8, that is, when power line interference is removed using a common mode signal. . Two ECG voltages can be obtained as before when using two single-ended input amplifiers. When the peak value of the bandpass filter is large, in the signal band

In order to realize , the transfer function of the bandpass filter

can be corrected or compensated for.

를 갖는 저항 1023을 통하여 회로공통에 연결하여 전력선 간섭 전류를 집중시키는 방법이다. 전력선 간섭 전류를 더욱 집중시키기 위해서는 상기 전극을 회로공통에 직접 연결할 수 있다. 이 방법은 대역통과필터를 사용하는 앞의 방법보다는 전력선 간섭 제거 효과가 작다. 하지만 이 방법도 본 발명에 의한 전력선 간섭 감소 원리를 적용하는 것이다. 또한 도 10의 실시예도 본 발명에 의한 두개의 심전도 신호를 전력선 간섭 전류가 집중되어 흐르는 전극을 제외한 두개의 전극에 연결되는 두개의 증폭기를 사용하여 동시에 구하는 방법을 사용한다. 도 10의 실시예에서는 하나의 차동증폭기와 하나의 싱글 엔디드 입력 증폭기를 사용한다. 이상과 같이 본 발명에 의하여 전력선 간섭을 제거하면서 두개의 전극으로부터 심전도 신호를 받는 두개의 증폭기를 사용하여 두개의 심전도 신호를 동시에 측정하는 실시예에 대하여 기술하였다. 10 shows a small resistance value of one electrode without using a bandpass filter compared to FIG.

It is a method of concentrating the power line interference current by connecting to the common circuit through a resistor 1023 with In order to further concentrate the power line interference current, the electrode can be directly connected to the circuit common. This method has a smaller power line interference cancellation effect than the previous method using a bandpass filter. However, this method also applies the power line interference reduction principle according to the present invention. Also, the embodiment of FIG. 10 uses a method of simultaneously obtaining two electrocardiogram signals according to the present invention using two amplifiers connected to two electrodes except for the electrode through which the power line interference current flows. In the embodiment of Fig. 10, one differential amplifier and one single-ended input amplifier are used. As described above, an embodiment in which two electrocardiogram signals are simultaneously measured using two amplifiers receiving electrocardiogram signals from two electrodes while eliminating power line interference according to the present invention has been described.

The electrocardiogram measuring apparatus according to the present invention provides six electrocardiogram leads obtained simultaneously using the smallest number of electrodes (specifically, three electrodes). When the electrocardiogram measuring apparatus according to the present invention is used in the MCL mode, one limb and one MCL can be measured.

The portable electrocardiogram measuring device according to the present invention is a device in the form of a credit card that is convenient to carry and can obtain a plurality of electrocardiograms most conveniently regardless of time and place, and communicates with a smart phone wirelessly, so it is suitable for the present invention It can be conveniently used without practical restrictions on the distance between the ECG measurement device and the smartphone.

In addition, the electrocardiogram measuring device according to the present invention is not in use, all circuits except the current sensor are powered off, only the microcontroller enters a sleep mode (sleep mode), when in use, power is supplied only to the necessary circuits and the microcontroller Since the controller enters the activation mode, the power consumption of the battery built into the ECG device can be reduced to the maximum.

In addition, the electrocardiogram measuring device according to the present invention does not include a mechanical power switch or a selection switch, so that it can be miniaturized and thin, unnecessary hassle for the user to use the switch, the possibility of failure and a finite lifespan of the switch, It does not cause an increase in the manufacturing price.

In addition, since the electrocardiogram apparatus according to the present invention does not include a display such as an LCD, it does not cause a malfunction and deterioration of the display, an increase in manufacturing cost, and is convenient to carry because it is small.

1 is a perspective view of an electrocardiogram measuring device having three electrodes according to the present invention;
2 is a method for measuring an electrocardiogram in 6-channel mode using the electrocardiogram measuring apparatus according to the present invention.
3 is a method for measuring an electrocardiogram in MCL mode using the electrocardiogram measuring device according to the present invention.
4 is an electrical equivalent circuit model for explaining the principle and embodiment of removing power line interference in the electrocardiogram measuring device according to the present invention.
5 is an electrical equivalent circuit model of an embodiment in which two channels of an electrocardiogram are simultaneously measured using two single-ended input amplifiers in the electrocardiogram measuring apparatus according to the present invention;
6 is a frequency response of a bandpass filter used in the electrocardiogram measuring apparatus according to the present invention.
7 is a frequency response of one signal channel in the electrocardiogram measuring apparatus according to the present invention.
8 is an electrical equivalent circuit model for explaining the principle and embodiment of removing power line interference using a common mode signal in the electrocardiogram measuring apparatus according to the present invention.
9 is an electrical equivalent circuit of an embodiment for simultaneously measuring two channels of an electrocardiogram using one differential amplifier and one single-ended input amplifier when power line interference is removed using a common mode signal in the electrocardiogram measuring apparatus according to the present invention; Model.
10 is another embodiment of simultaneously measuring two channels of an electrocardiogram using one differential amplifier and one single-ended input amplifier in the electrocardiogram measuring apparatus according to the present invention;
11 is a block diagram of a circuit built in the electrocardiogram measuring device according to the present invention.
12 is an operation flowchart of the electrocardiogram measuring apparatus according to the present invention.
13 is an initial screen of a smartphone when a smartphone app is executed to use the electrocardiogram measuring device according to the present invention;
14 is a flowchart of a smartphone app when using the electrocardiogram measuring device according to the present invention.
15 is an electrocardiogram measuring device according to the present invention provided with a blood test strip insertion hole;
16 is a perspective view of an electrocardiogram measuring device having four electrodes according to the present invention.

Hereinafter, an embodiment according to the present invention will be described with reference to the drawings. In the present embodiment, the electrocardiogram (ECG) measuring device is described as including three electrodes, but is not limited thereto, and the electrocardiogram (ECG) measuring device may be a device including three or more electrodes. An important embodiment of the present invention has already been described above using Figs. 4 to 10 in order to explain the principle of the present invention.

The portable electrocardiogram measuring device according to the present invention is preferably in the form of a credit card and has a thickness of 6 mm or less in order to increase portability. Since the portable electrocardiogram measuring device according to the present invention is portable, it uses a battery, and when a CR2032 type battery is used, the use time of about 2 years is possible.

In addition, there is no mechanical power switch or selection switch for miniaturization of the portable electrocardiogram measuring device, and a display is not used to reduce power consumption.

In the portable electrocardiogram measuring device according to the present invention, a current sensor may be used in order not to use a mechanical power switch or a selection switch. The current sensor is always supplied with power required for operation, and when an event occurs, it waits to generate an output signal. When a user touches a plurality of electrodes to a human body to measure an electrocardiogram, a loop through which current can flow is created. Therefore, when the human body is electrically connected to the current sensor, the current sensor causes a minute current to flow through the human body, and the current sensor detects the minute current and generates an output signal. In order to increase the battery usage time, when the portable electrocardiogram device is not used, only the current sensor operates, the remaining circuits are powered off, and the microcontroller stands by in a sleep mode. At this time, when an event of touching the two electrodes with both hands occurs and the current sensor generates an output signal, the microcontroller is activated to power on the electrocardiogram circuit. The current sensed by the current sensor is supplied from a battery provided in the portable electrocardiogram measuring device and is characterized in that it is a direct current.

The electrocardiogram measuring apparatus 100 according to the present invention may include a function of measuring blood characteristics such as a blood glucose level, a ketone level, or an International Normalized Ratio (INR). Therefore, in the present embodiment, the electrocardiogram measuring apparatus 100 will be described as an example for measuring the electrocardiogram and blood characteristics together. The blood glucose level or ketone level can be measured using an amperometric method. The INR is a measure indicating the tendency of blood coagulation and can be measured using an electrical impedance method for capillary blood, an amperometric method, a mechanical method, and the like. One blood test strip insertion hole into which a blood test strip required for the blood characteristic test can be inserted may be provided in the case of the electrocardiogram measuring device according to the present invention.

In the embodiment of the electrocardiogram measuring apparatus 100 according to the present invention, a thermometer function may be included. In order to include a thermometer function in the electrocardiogram measuring apparatus 100 according to the present invention, a suitable form is a contact type, and a suitable temperature sensor is a thermistor. In order to measure body temperature using the electrocardiogram measuring device 100 according to the present invention including a thermometer function, the user brings the part of the electrocardiographic measuring device 100 to which the temperature sensor is attached to the user's forehead or armpit. In order to accurately measure body temperature, the temperature of the skin should not be changed by the part of the electrocardiogram measuring apparatus 100 to which the temperature sensor is attached.

11 is a block diagram of a circuit built in the electrocardiogram measuring apparatus 100 according to the present invention. Although not all blocks are shown in FIG. 11 to clarify the present invention, the electrocardiogram measuring apparatus according to the present invention may include a current sensor, a blood test circuit, and a blood test strip insertion hole. The function and operation of each block of FIG. 11 are as follows. When the user touches the pair of electrodes 111 and 112 with both hands, the ECG current sensor allows a minute current to flow through the both hands and detects the minute current flowing through the both hands. Then, the current sensor generates a signal to change the microcontroller 1180 from the sleep mode to the active mode. Then, the microcontroller 1180 turns on the electrocardiogram measuring circuit 1160 and the AD converter 1170 . The electrocardiogram measuring circuit 1160 amplifies two electrocardiogram signals in two amplifiers to generate two outputs. The AD converter 1170 receives two outputs of the electrocardiogram measuring circuit 1160, and the outputs of the AD converter 1170 are transmitted to the smart phone 210 through the wireless communication means 1190 and the antenna 1192. is sent The smart phone 210 that has received the data displays a plurality of ECG waveforms. When the measurement for a certain period of time is finished, the microcontroller 1180 enters the sleep mode and waits for the next touch of both hands. Each of the blocks shown in FIG. 11 can be implemented in the prior art using commercially available parts.

12 is an operation flowchart of the electrocardiogram measuring apparatus 100 according to the present invention when measuring an electrocardiogram. In order to measure the electrocardiogram, the user contacts the pair of electrodes 111 and 112 of the electrocardiogram measuring apparatus 100 with both hands ( 1210 ). Then, the current sensor sensing a minute current flowing through the human body between both hands generates an output signal (1215). This output signal generates an interrupt of the microcontroller 1180 to activate the microcontroller 1180. (1220). The activated microcontroller 1180 activates the wireless communication means 1190 . A case in which the wireless communication means 1190 is a Bluetooth low energy device will now be described. The wireless communication means 1190 of the electrocardiogram measuring device 100 advertises as a Bluetooth low energy peripheral ( 1225 ). At this time, the smart phone scanning as a Bluetooth low energy central device discovers the electrocardiogram measuring device 100 and attempts to connect. At this time, when the electrocardiogram measuring device 100 approves the connection, the smart phone and the electrocardiographic measuring device 100 are connected to Bluetooth low energy ( 1230 ). At this time, the electrocardiogram measuring apparatus 100 may check whether the user has actually touched the electrocardiogram measuring button of the smart phone in order to measure the electrocardiogram ( 1235 ).

Now, when it is confirmed that the ECG measurement is requested, the microcontroller 1180 turns on the ECG measurement circuit 1160 (1240). This can be performed by connecting the output pin of the microcontroller 1180 to the electrocardiogram measuring circuit 1160 and setting the voltage of the output pin to High. Next, it is checked whether the pair of electrodes 111 and 112 are being touched by both hands using the current sensor ( 1245 ). In this step, the microcontroller 1180 is to determine when to start the ECG measurement, that is, when to start the AD conversion. That is, it is to check whether both hands are in continuous contact with the electrodes 111 and 112 .

After the above process, the microcontroller 1180 starts to measure the electrocardiogram (1250). That is, the microcontroller 1180 performs AD conversion in accordance with a preset AD conversion cycle and brings the AD conversion result. In the present invention, two ECG signals are measured. The measured electrocardiogram data is transmitted to the smart phone 210 (1255), and when a preset measurement time, for example, 30 seconds, elapses, the microcontroller 1180 enters the sleep mode (1260).

All circuits of FIG. 11 are driven by a battery built in the electrocardiogram measuring device 100 . 11 may not have any mechanical power switch, mechanical selection switch, or display. 11 , when the electrocardiogram measuring apparatus 100 does not measure, the electrocardiogram current sensor and the microcontroller 1180 each consume approximately 1 uA, and all other blocks are completely powered off.

The electrocardiogram measuring apparatus 100 according to the present invention is used together with the smart phone 210 . 13 shows an initial screen of a smartphone when the smartphone app according to the present invention is executed. When the smartphone app is executed, touch buttons 1331 , 1332 , 1334 , 1336 , 1342 , 1344 , 1346 , and 1350 are displayed on the display 1320 of the smartphone 210 . Buttons 1331 , 1332 , 1334 , and 1336 related to the electrocardiogram are configured in the electrocardiogram box 1330 . When the electrocardiogram measuring apparatus 100 according to the present invention includes a function of measuring blood characteristics, buttons 1342 , 1344 , and 1346 related to blood characteristics are configured in the blood glucose box 1340 . In order to measure the ECG, the user selects and touches one of the ECG measurement mode buttons 1331 and 1332 to be measured. The user touches the button 1331 when measuring the electrocardiogram in 6-channel mode. The user touches button 1332 when measuring ECG in MCL mode. Then, when the user touches the pair of electrodes 111 and 112 of the electrocardiogram measuring device 100 with both hands, the electrocardiogram measuring device 100 measures the electrocardiogram as described above. The data appears in the form of a chart on the smartphone display 1320 and is stored in the smartphone 210. To view the ECG measurement data stored in the past in the form of a chart again, touch the open button 1334. Stored as a doctor or hospital To send data, touch the send button 1336. The setting button 1350 is touched to record the user's name, date of birth, gender, address, etc. or to set options.

14 is a flowchart of a smartphone app according to the present invention. For convenience, only the process of measuring the electrocardiogram is described. As shown in FIG. 14 , the flow when measuring the electrocardiogram consists of two stems: a central stem 1422 , 1424 , 1426 , 1428 , 1430 , 1432 and a Bluetooth low energy (BLE) stem 1452 , 1454 . When the app is started, various buttons appear on the smartphone display 1320 ( 1410 ), and then the BLE stems 1452 and 1454 for performing Bluetooth low energy communication are started. A user who wants to measure an electrocardiogram touches one of the electrocardiogram measuring buttons 1331 and 1332 ( 1422 ).

When the user touches one of the ECG measurement buttons 1331 or 1332 ( 1422 ), an ECG measurement request signal is transmitted to the BLE stems 1452 and 1454 ( 1424 ). In addition, a message to contact the electrodes according to the electrocardiogram measurement mode is displayed on the smartphone display 1320 ( 1424 ). The BLE stems 1452 and 1454 transmit an ECG measurement request signal to the ECG measurement apparatus 100 ( 1454 ).

The electrocardiogram measuring apparatus 100 that has received the electrocardiogram measurement request signal transmits the measured electrocardiogram data to the BLE stems 1452 and 1454 again by performing the electrocardiographic measuring task described in FIG. 12 . The BLE stems 1452 and 1454 transmit the ECG data received from the ECG measuring device 100 to the central stems 1422 , 1424 , 1426 , 1428 , 1430 , and 1432 . The central stem 1422 , 1424 , 1426 , 1428 , 1430 , 1432 now receives the electrocardiogram data ( 1426 ). The received electrocardiogram data is displayed in the form of a chart on the smartphone display 1320 in the central stems 1422 , 1424 , 1426 , 1428 , 1430 , and 1432 ( 1428 ). When all electrocardiogram measurements are completed, the measured electrocardiogram data is stored in a file format in the smartphone storage device (1430). While the measured electrocardiogram data is being displayed in the form of a chart on the smartphone display 1320, the smartphone app waits for the user to end the app by pressing the app end button (1432).

According to the present invention, the user can obtain the desired result without any abnormality with respect to the number of cases of all possible operation sequences using the electrocardiogram measuring device 100 without any mechanical switch, selection switch, or display and the smartphone app with simplified usage. can be provided

As described above, the present invention has been specifically described with respect to a case where an electrocardiogram is measured using a single portable electrocardiogram measuring device 100 and a smartphone app, but the electrocardiogram measuring device 100 according to the present invention is not limited thereto. Several additional metrics can be measured.

As described above, the electrocardiogram measuring apparatus 100 according to the present invention may include an additional function of measuring blood characteristics. In this case, one embodiment of the electrocardiogram measuring device 1500 to which the function of measuring blood characteristics according to the present invention is added includes a blood characteristic test strip insertion hole 1510 into which a blood characteristic test strip 1520 can be inserted. It is configured and its form is as shown in FIG. 15 . As described above, the electrocardiogram measuring apparatus 100 according to the present invention may use the wireless communication means 1190 . Accordingly, the electrocardiogram measuring apparatus 100 according to the present invention is set to transmit a signal at regular time intervals, and when the strength of the signal received from the smartphone is smaller than a set value, the smartphone generates an alarm signal. can

So far, the electrocardiogram measuring apparatus 100 according to the present invention has been described as being implemented in a plate shape. However, since the electrocardiogram measuring device according to the present invention uses a minimum filter in principle, the circuit configuration is simple and thus can be manufactured in a compact size. Therefore, the electrocardiogram measuring apparatus according to the present invention has a characteristic that the power consumption of the battery is small. Therefore, the electrocardiogram measuring apparatus 100 according to the present invention is suitable to be implemented as a watch type.

In the embodiment of the electrocardiogram measuring device according to the present invention, the electrocardiogram measuring device 100 has been described as including three electrodes, but according to the present invention, in another embodiment of the electrocardiographic measuring device, four electrodes can be included. have. The principle of operation of the electrocardiogram measuring apparatus according to the present invention including the four electrodes is the same as the previous description for the case including three electrodes. It is important to note that the electrocardiogram measuring device including four electrodes according to the present invention is composed of three amplifiers that receive an electrocardiogram signal from three electrodes, and the three amplifiers amplify one electrocardiogram signal, respectively, so that the device can simultaneously operate three It actually measures the ECG signal.

The electrocardiogram measuring apparatus including the four electrodes can be easily implemented by the above description. The method of using the electrocardiogram including the four electrodes according to the present invention is almost the same as the method of using the electrocardiogram measuring apparatus 100 including the three electrodes according to the present invention. The three electrocardiogram signals measured by the electrocardiogram measuring apparatus including four electrodes according to the present invention include, for example, two limb leads and one MCL. Alternatively, the three electrocardiogram signals may be one limb lead and two MCLs. One embodiment of an electrocardiogram measuring apparatus according to the present invention including the four electrodes is shown in FIG. 16 . In FIG. 16 , four electrodes 111 , 112 , 113 , and 114 are installed on two wide surfaces of a plate shape, two each on one wide surface.

As described above, the electrocardiogram measuring apparatus according to the present invention has been specifically described, but the present invention is not limited thereto, and the present invention may be changed into various forms consistent with the intention of the present invention.

- Industrial applicability

The electrocardiogram measuring device according to the present invention is convenient to carry, can be easily used regardless of time and place, and can be used in a portable electrocardiogram measuring device capable of obtaining electrocardiogram information of multiple channels.

Claims (5)

In the electrocardiogram measuring device for measuring two electrocardiogram signals, the electrocardiogram measuring device comprises:
The first electrode, the second electrode and the third electrode in contact with three parts of the body;
two amplifiers receiving electrocardiogram signals from the first electrode and the second electrode;
an AD converter connected to each output terminal of the two amplifiers to convert an analog signal into a digital signal;
a microcontroller for receiving the digital signal of the AD converter; and
communication means for transmitting the digital signal;
The microcontroller receives power from a battery built into the electrocardiogram measuring device,
The microcontroller controls the AD converter and the communication means,
The two amplifiers amplify one ECG signal, respectively, and measure the two ECG signals at the same time,
A power line interference current is concentrated on the third electrode of the electrocardiogram measuring device,
The two amplifiers of the electrocardiogram measuring device consist of a single-ended input amplifier,
Electrocardiogram measuring apparatus, characterized in that the two amplifiers each receive one ECG signal from the first electrode and the second electrode.
In the electrocardiogram measuring device for measuring two electrocardiogram signals, the electrocardiogram measuring device comprises:
The first electrode, the second electrode and the third electrode in contact with three parts of the body;
two amplifiers receiving electrocardiogram signals from the first electrode and the second electrode;
an AD converter connected to each output terminal of the two amplifiers to convert an analog signal into a digital signal;
a microcontroller for receiving the digital signal of the AD converter; and
communication means for transmitting the digital signal;
The microcontroller receives power from a battery built into the electrocardiogram measuring device,
The microcontroller controls the AD converter and the communication means,
The two amplifiers amplify one ECG signal, respectively, and measure the two ECG signals at the same time,
A power line interference current is concentrated on the third electrode of the electrocardiogram measuring device,
The two amplifiers consist of one differential amplifier and one single-ended input amplifier,
The electrocardiogram measuring apparatus, characterized in that the electrocardiogram signals of the first electrode and the second electrode are input to the single differential amplifier.
3. The method of claim 1 or 2,
The electrocardiogram measuring device is plate-shaped, and the first and second electrodes among the three electrodes are formed on one surface of the case of the electrocardiogram measuring device so that the user can contact both hands of the user, and the third electrode is It is formed on the other surface of the case so as to be in contact with the user's body, and the user checks the two ECG signals on the screen of the smart phone.
3. The method of claim 1 or 2,
The electrocardiogram measuring device includes a current sensor that flows a microcurrent when a plurality of electrodes come into contact with the human body and generates an output by sensing the microcurrent.
3. The method of claim 1 or 2,
The electrocardiogram measuring device is an electrocardiogram measuring device, characterized in that it is a watch type.

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