KR102389907B1 - Method and system for measuring electrocardiogram using wearable device - Google Patents

Abstract

In the electrocardiogram measuring system using a wearable device, the electrocardiogram measuring system comprises a photopigometer, an electrocardiograph installed in the wearable device, or an electrocardiograph separate and portable from the wearable device, the photoplethysmometer comprising at least one LED and at least one a light bulk wave measuring circuit including one photodiode; an AD converter connected to an output terminal of the optical bulk wave measuring circuit to convert an analog signal into a digital signal; wireless communication means for transmitting and receiving data; and a microcontroller for performing optical bulk wave measurement by controlling the optical bulk wave circuit and the wireless communication means, wherein the microcontroller continuously analyzes the measured optical bulk wave to extract optical volume parameters, and The occurrence of an alarm is determined using the optical bulk wave parameters, and an alarm is generated according to the determination result. The electrocardiograph includes: three dry electrocardiogram measuring electrodes; and two amplifiers for amplifying two electrocardiogram signals induced to two electrocardiogram electrodes among the three electrocardiogram electrodes.

Description

Electrocardiogram measurement method and system using wearable device

The present invention relates to a method and system for measuring an electrocardiogram using a wearable device, and more particularly, to a single photoplethysmometer: heart rate (HR), heart rate variability (HRV), and breathing rate (BR). ), when an arrhythmia symptom is detected by continuously analyzing It is about methods and systems.

An electrocardiograph (ECG) 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. A hospital ECG can be used only when a user visits a hospital. The ECG measurement unit of the Patient Monitor 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 patient monitoring device includes a photoplethysmograph (PPG), and usually includes a function for generating an alarm by a photoplethysmograph or an electrocardiogram measuring unit. The Holter ECG and Event recorder that users can move 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 7 wet electrodes and cables connected to these electrodes and provides multi-channel ECG. However, Holter ECG has a disadvantage in 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. Accordingly, 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 ECG measurement system that the present invention seeks, that is, required, should be convenient for the individual to use, provide accurate and abundant ECG 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 smart phone or the like. The device required for this must be battery operated.

In order to provide accurate and abundant ECG measurements, in the present invention, two limb leads are directly measured simultaneously. 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 instant in time. 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. there is. Also note the use of the word “measurement”. The word “measurement” should be referred to as a measurement only when a physical quantity is actually measured. In digital measurement, one measurement should actually mean one AD conversion. As will be described later, when, 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 expressed as “calculated” to be accurate, 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, so at least one cable and at least one additional electrode must be used, or the size of the device is increased. In other words, it is difficult to make an electrocardiogram measuring device that measures two leads using DRL electrodes the size of a credit card or a smart watch type. 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, so 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 John 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, it may be required that Q (Quality factor) be fairly large, and the fabrication and calibration of a plurality of such filters is It can be difficult.

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 is 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, no cables are used, but dry electrodes are used, and in order to measure the two limbs simultaneously (simultaneously), two amplifiers associated with the two limbs and Three electrodes are used. The electrocardiogram apparatus according to the present invention provides a plate-shaped or watch-type 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. The present invention also 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 excluding the electrode among the three electrodes are used, The two amplifiers each amplify one electrocardiogram signal, and disclose an electrocardiogram measuring unit, 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 with three electrodes in a watch-type device.

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 including 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, 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 (Fig. 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-shaped 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, in ECG measurement, the roles of the left foot and the right foot are different, 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 notes, “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 communication problems 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 “consists of one or more amplifiers to amplify analog signals received from three electrodes” (paragraphs [0025] and claim 4, “comprises one or more amplifiers configured to amplify analog signals received from the three electrodes”) Therefore, Drake is ambiguous about the essential part of the invention, namely how many amplifiers are used and how to connect the amplifiers. Also, Drake said, “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]), where Drake uses the word "simultaneous" inaccurate, inappropriate, and indefinitely. . The structure of the Drake device can be considered similar to that of the Thomson device. The 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. Also, Saldivar takes 6 measurements, one in sequence, to get 6 leads. In other words, Saldivar does not measure multiple leads simultaneously. Saldivar also directly measures the three augmented limb leads sequentially.

A photoplethysmometer uses an LED to emit light into the skin and measure the reflected or transmitted light. Photoplethysmometers built into modern smart watches can provide heart rate, HRV, and respiration rate. HRV provides a lot of information about an individual's health status. HRV is used for sleep analysis or stress analysis, and is also used to detect arrhythmias such as atrial fibrillation. In general, HRV analysis was performed using ECG, but recently, it is also performed using a photoplethysmometer. The photoplethysmometer included in the patient monitoring device measures the oxygen saturation and generates an alarm when the oxygen saturation decreases. The ECG measurement unit of the patient monitoring device generates an alarm when the heart rate calculated using the measured ECG signal is out of the normal range. When an alarm is generated from the patient monitoring device, the medical staff can take appropriate action on the patient.

Measuring blood sugar or electrocardiograph (ECG), respectively, has been commercialized for a long time. However, a person who wants to measure a plurality of test items including blood sugar and an electrocardiogram is inconvenient to carry a blood glucose meter and an electrocardiograph separately. Therefore, there is a need for a device capable of measuring blood sugar and an electrocardiogram with one device. Devices that can measure blood sugar and ECG must be implemented in a small size, have a small volume, and since most of them are operated by batteries, they must consume less power for long-term use.

A device capable of measuring blood glucose and ECG requires a power switch, a selection switch is required to select blood glucose measurement and ECG measurement, and a display showing measurement data is required. However, the mechanical power switch, selection switch, and display increase the volume or area of the device, consume battery power, and limit miniaturization.

In addition, if the blood glucose measurement circuit and the ECG measurement circuit of the device that can measure blood sugar and ECG are separately configured and the power supply is not separately controlled, all circuits will operate when the power is turned on, resulting in increased power consumption. It is necessary to make only the circuit of

Arrhythmia is a terrifying disease that threatens human health and causes an increase in medical expenses. For example, atrial fibrillation, which is common enough for 2% of the population in developing countries, can cause blood clots and increase the risk of stroke. Using an electrocardiogram for hospital use can accurately diagnose arrhythmias. However, arrhythmias may not always be present in patients with arrhythmias and are often intermittent. A Holter electrocardiograph or event recorder can be used to detect intermittent arrhythmias. A Holter electrocardiograph is usually used for one to two days, but it is very likely that no arrhythmias are detected during this period. The user can then carry an event recorder and measure ECG anytime and anywhere at the moment when symptoms are suspected. However, arrhythmias can be silent or asymptomatic, in which case the user does not know when to use the event recorder to measure the ECG.

Recently, a method for diagnosing an arrhythmia using a photoplethysmometer embedded in a wearable device has been reported. Therefore, an accurate arrhythmia diagnosis is possible by continuously detecting the expression of arrhythmia using a wearable photoplethysmometer and measuring the ECG using an event recorder when an arrhythmia is detected. Albert (David E. Albert, Discordance Monitoring, US PAT. 9,839, 363 B2, Date of Patent: Dec. 12, 2017) detects arrhythmias using an activity level sensor (eg, accelerometer) and a photoplethysmometer, and then the user A method for measuring one ECG signal using two electrodes and a wearable smart watch were disclosed. However, Albert did not disclose a method for measuring two ECG signals using three electrodes.

The photoplethysmometer and the electrocardiograph can be integrated into one smart watch. However, it may be necessary not to have an electrocardiogram built into the wearable watch.

The first reason is as follows. Many arrhythmia patients have diabetes. Therefore, it is necessary to fuse the electrocardiogram and the blood glucose system. However, in order to use the blood glucose meter, it is necessary to carry a separate strip case for putting a blood test strip and a needle for piercing the skin to obtain blood. Therefore, it is not a big advantage to have only a blood glucose meter built into the smart watch. More importantly, it is difficult to provide a blood test strip insertion hole in a smart watch. In this case, it is preferable to implement the blood glucose meter and the electrocardiograph as one wireless portable device. When the photoplethysmometer built into the smart watch generates an arrhythmia occurrence alarm, it is possible to measure the electrocardiogram using the wireless portable device, which is separate from the smart watch, and has a blood glucose meter and an electrocardiometer.

The second reason is that an existing smart watch including a photopilotometer but not an electrocardiograph can be used in the method of the present invention only by updating the software of the photopilotometer.

The third reason is that embedding an electrocardiogram in a smart watch results in special miniaturization technology and high manufacturing cost. A smart watch that includes only a photoplethysmometer can be used by even young people who are not related to arrhythmias, so it can be mass-produced and manufactured at a low cost. For these three reasons, it is not necessary to have a photoplethysmometer and an electrocardiometer in the smart watch together. Therefore, the electrocardiogram can be built into the smart watch or implemented separately.

The present invention has been devised by the above problems and needs, and the present invention provides a method for detecting the expression of arrhythmia using a photoplethysmometer and obtaining two electrocardiogram leads. In addition, the present invention discloses a method of embedding an electrocardiograph in a smart watch having a built-in photoplethysmometer and a case of not embedding the electrocardiograph.

The method for measuring an electrocardiogram using a wearable device according to the present invention comprises the steps of: periodically measuring a photoplethysmogram by a wearable device, which is worn on one hand of a user and has a built-in photoplethysmometer; extracting light volume parameters by analyzing the measured light volume wave; determining an alarm occurrence using the optical bulk wave parameters; and generating an alarm according to the determination result, wherein after the alarm is generated, the electrocardiograph installed in the wearable device or the electrocardiograph separate from the wearable device and portable is the user's left hand, right hand, left lower abdomen or receiving an electrocardiogram signal through a first electrocardiogram electrode and a second electrocardiogram electrode from among the three electrocardiogram electrodes each in contact with the left leg; and amplifying the two electrocardiogram signals input to the first and second electrocardiogram electrodes using two amplifiers built into the electrocardiogram.

In addition, the electrocardiogram measuring system using a wearable device according to the present invention includes a photopilotometer, an electrocardiograph installed in the wearable device, or an electrocardiograph that is separate from and portable from the wearable device, wherein the photoplethysmometer includes at least one a light bulk wave measuring circuit including an LED and at least one photodiode; an AD converter connected to an output terminal of the optical bulk wave measuring circuit to convert an analog signal into a digital signal; wireless communication means for transmitting and receiving data; and a microcontroller for performing optical bulk wave measurement by controlling the optical bulk wave circuit and the wireless communication means, wherein the microcontroller continuously analyzes the measured optical bulk wave to extract optical volume parameters, and The occurrence of an alarm is determined using the optical bulk wave parameters, and an alarm is generated according to the determination result. The electrocardiograph includes: three dry electrocardiogram measuring electrodes; and two amplifiers for amplifying two electrocardiogram signals induced to two electrocardiogram electrodes among the three electrocardiogram electrodes.

The electrocardiograph according to the present invention is convenient to carry and provides 6 electrocardiogram leads obtained at the same time using the smallest number of electrodes (specifically, three electrodes) most conveniently regardless of time and place. In the electrocardiogram measurement method according to the present invention, when a user develops an intermittent arrhythmia without subjective symptoms, the user receives an alarm from a photoplethysmometer to perform an electrocardiogram measurement.

1 is a perspective view of a smart watch having three electrodes according to the present invention;
2 is a perspective view of a portable electrocardiograph having three electrodes according to the present invention;
3 is a method for measuring an electrocardiogram in a 6-channel mode using the electrocardiogram measuring apparatus according to the present invention.
4 is an electrical equivalent circuit model for explaining the principle and embodiment of removing the 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 a block diagram of a circuit embedded in a smart watch according to the present invention.
9 is a flowchart of an arrhythmia alert generating program according to the present invention.
10 is a flowchart of an electrocardiogram measurement in a smart watch according to the present invention.

First, an object of the present invention is to provide an electrocardiogram including two amplifiers and three electrodes associated with the two limbs in order to measure two limbs simultaneously (simultaneously). 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 present invention provides a power line interference cancellation method for not using a DRL electrode. The present invention discloses a convenient electrocardiogram measuring method 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 a smart watch 100 according to the present invention. The smart watch 100 includes three electrodes 111 , 112 , and 113 provided on the surface of the band. Two electrodes 111 and 112 are installed on the outer surface of the band of the smart watch 100 , and one electrode 113 is installed on the inner surface of the band. As shown in FIG. 1 , at least one LED 121 and at least one photodiode 122 are provided on the bottom surface of the smart watch, that is, the surface in contact with the user's arm.

2 shows a wireless portable electrocardiograph 200 according to the present invention. The wireless portable electrocardiogram 200 includes three electrodes 211 , 212 , and 213 on the surface. Two electrodes 211 and 212 spaced apart from each other at a predetermined interval are installed on one side of the wireless portable electrocardiograph 200 , and one electrode 213 is installed on the other side of the wireless portable electrocardiograph 200 . The wireless portable electrocardiograph 200 according to the present invention of FIG. 2 is provided with a blood test strip insertion hole 230 into which the blood test strip 220 can be inserted to measure blood characteristics such as blood sugar.

In the present invention, the wireless portable electrocardiogram 200 is described as an example of measuring an electrocardiogram (ECG) and blood sugar, but is not limited thereto. A function of measuring International Normalized Ratio (INR) may be added and included. The blood glucose level or ketone level can be measured using an amperometric method. The above 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 220 capable of inserting a blood test strip required for the blood characteristic test may be provided in the case of the wireless portable electrocardiograph 200 as shown in FIG. 2 .

The wireless portable electrocardiograph 200 according to the present invention uses a current sensor 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 the user touches the electrocardiogram electrode or inserts a blood test strip into the strip insertion hole, it is electrically connected to the current sensor to complete a loop through which current can flow. Then, the current sensor causes a minute current to flow in the blood test strip or the blood test strip, and the current sensor senses the minute current to generate an output signal. When the wireless portable electrocardiograph 200 is not used, only the current sensor operates, the remaining circuits are powered off, and the built-in microcontroller stands by in a sleep mode. At this time, when an event of a user inserting a blood test strip or touching an electrode with both hands occurs and a current is sensed in the current sensor, the microcontroller is activated to power on the corresponding circuit.

A method of measuring an electrocardiogram using the smart watch 100 according to the present invention shown in FIG. 1 and the wireless portable electrocardiograph 200 shown in FIG. 2 is similar. 3 shows a method for a user to measure an electrocardiogram using the wireless portable electrocardiograph 200 according to the present invention. The user holds the electrode 111 and the electrode 112 provided on one side of the wireless portable electrocardiograph 200 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. 3 is a method provided by the present invention to most conveniently obtain an electrocardiogram of 6 channels. The present invention also provides an apparatus most suitable for the measurement method of FIG. 3 .

When the smart watch 100 of FIG. 1 is worn on one hand, one electrode 113 provided on the inner surface of the band comes into contact with the hand. When measuring the electrocardiogram, the other hand and the user's left lower abdomen (or left leg) are brought into contact with the two electrodes 111 and 112 provided on the outer surface of the band, respectively.

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 eliminate power line interference, a right leg (DRL) electrode is typically used in the prior art. From the above relationship, one of the three limbs can be obtained from the other two. 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.

Hereinafter, an 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 430 is modeled with three electrode resistors 431 , 432 , and 433 connected to each other at one point. In addition, in FIG. 5 , one ECG signal was modeled as one voltage source 461 and 462 existing between two electrode resistors. In the present invention, since three electrodes are used, it is modeled as having two ECG voltage sources 461 and 462 in the human body in FIG. 5 . This is because three ECG voltages exist in three electrodes (this is because the number of cases in which two electrodes are selected among three electrodes is three), but only 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. Because 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. 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 method 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 device 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. On the other hand, an impedance called electrode impedance or electrode resistance (431, 432, 433 in FIG. 4) exists between the electrode used to measure the electrocardiogram and the human body. 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. It is to negatively feed back the common mode signal of the three electrodes to the single point in which 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. In order 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 into the electrocardiogram measuring device through the single electrode 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 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 made 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 made only at the power line interference frequency. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the detailed description of the present invention will be described using drawings.

In FIG. 4 and subsequent drawings, the electrocardiogram measuring device 100 according to the present invention shows only a part of the electrocardiogram measuring device 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.

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 bandpass filter 413 has a large Q characteristic. 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. * 430 in FIG. 4 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. Power line interference current flowing through the three electrodes 111, 112, and 113, respectively

,

,

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

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.

here

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

is a 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 holds.

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

if

if

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 result

class

can be used

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

This is as a result of feedback | H(f) | 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 ECG measurement, use only the non-feedback electrode and not the feedback electrode. Therefore, if a differential amplifier having an input connected to the electrode 111 and the electrode 113 or a differential amplifier having an input connected to the electrode 112 and 113 is used, the effect 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:

는 다음과 같이 근사된다.In Equation 15, the symbol || represents 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 a frequency response of a 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

am. 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 of 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 fed back 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. If 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 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 is a resistor having a small resistance value of one electrode without using a bandpass filter compared to FIG.

It is a method of concentrating power line interference current by connecting to the common circuit through 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.

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 been previously described using Figs. 4 to 7 in order to explain the principle of the present invention.

8 is a block diagram of a circuit built in the smart watch 100 according to the present invention. In order to clarify the present invention, not all blocks are shown in FIG. The smart watch 100 according to the present invention includes an optical bulk wave measuring circuit 810 , at least one LED 121 connected to the optical bulk wave measuring circuit 810 , and at least one photodiode 122 . The duty ratio of the current flowing through the at least one LED 121 is very small so that power consumption is small. The duty ratio is controlled by the microcontroller 860 . At least one LED 121 emits light to the user's skin, and the light reflected from the user's skin is received by the at least one photodiode 122 . The reflected light includes optical bulk wave information. The current flowing through the at least one photodiode 122 is amplified by the optical bulk wave measuring circuit 810 . The amplified signal is converted into a digital signal by the AD converter 850 . The digital signal is transmitted to the microcontroller 860 . The microcontroller 860 analyzes the digital signal using the pre-built optical bulk wave analysis program described in FIG. 9 . At this time, if it is determined that arrhythmia symptoms have occurred, an alarm is generated. The alarm may be at least one of sound, light, and vibration.

When an alarm is generated, the microcontroller 860 turns on the electrocardiogram measuring circuit 840 . As described above, the three electrocardiogram electrodes 111 , 112 , and 113 are connected to the electrocardiogram measuring circuit 840 according to the present invention. The electrocardiogram measuring circuit 840 includes two amplifiers according to the present invention as described above. The electrocardiogram measuring circuit 840 amplifies the two electrocardiogram signals induced to the three electrocardiogram electrodes 111 , 112 , and 113 in the two amplifiers to generate two outputs. The AD converter 850 receives the two outputs of the electrocardiogram measuring circuit 840 , converts them into digital signals, and transmits them to the microcontroller 860 . The microcontroller 860 may display the outputs of the AD converter 850 on the display of the smart watch 100 . In addition, the microcontroller 860 may transmit the outputs of the AD converter 850 to a smart phone or the like through the wireless communication means 870 and the antenna 880 built in the smart watch 100 .

An electrocardiogram measurement process using the portable electrocardiograph 200 of FIG. 2 is as follows. When the user who has received the arrhythmia alert touches the pair of electrodes 211 and 212 with both hands, the electrocardiogram 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 built into the portable electrocardiograph 200 from the sleep mode to the activation mode. Then, the microcontroller powers on the electrocardiogram circuit and the AD converter. The electrocardiogram measuring circuit generates two outputs by amplifying two electrocardiogram signals in two amplifiers. The AD converter receives the two outputs of the electrocardiogram circuit, converts them into digital signals, and transmits them to the microcontroller. The microcontroller transmits the outputs of the AD converter to the smart phone through the wireless communication means and the antenna built into the portable electrocardiograph 200 . After the measurement for a certain period of time, the microcontroller enters the sleep mode and waits for the next touch of both hands.

9 shows the operation sequence of the alarm generating program using the optical bulk wave according to the present invention. The alarm generating program is performed by the microcontroller 860 built into the smart watch. A photoplethysmometer measures a photoplethysmogram signal ( 910 ). The microcontroller 860 built into the smart watch performs pre-processing including a process of removing noise included in the measured optical bulk wave signal ( 920 ). HRV extraction 930 for extracting HRV parameters using the preprocessed signal, HR extraction 932 for extracting HR parameters, and BR extraction 934 for extracting BR parameters are performed. In order to extract the HR parameter, the first or second differentiation of the optical bulk wave signal is performed, the position of the peak value is R, and the time between R and the next R (R-R interval) is first obtained. There are several ways to obtain HRV parameters. You can find the standard deviation of the R-R interval in the time domain. The BR parameter can be obtained by extracting the low-frequency component of the optical bulk wave. In the HRV determination 940, when the HRV increases or decreases by more than a preset value, it is determined as an arrhythmia. In the HR and BR determination 942, when the HR increases by more than a preset value without increasing the BR, it is determined as an arrhythmia. When it is determined as an arrhythmia in the HRV determination 940 or an arrhythmia in the HR and BR determination 942, an alarm is generated (950).

10 is a flowchart of an operation of the electrocardiograph embedded in the smart watch 100 according to the present invention when measuring the electrocardiogram. When an alarm is generated in the photoplethysmometer (1010), the microcontroller 860 turns on the electrocardiogram measuring circuit 840 (1020). This can be performed by connecting the output pin of the microcontroller 860 to the electrocardiogram measuring circuit 840 and setting the voltage of the output pin to High. Next, it is checked whether the pair of electrodes 111 and 112 are in contact with both hands using the current sensor (1030). When both hands are in contact, the microcontroller 860 starts to measure the electrocardiogram (1040). The microcontroller 860 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 may be transmitted to the smart phone (1050) and stored (1060) in a memory built into the smart watch 100. When a preset measurement time, for example, 30 seconds has elapsed, the microcontroller 860 sets the voltage of the output pin of the ECG measurement circuit 840 to Low to power off the ECG measurement circuit 840 (1070) and electrocardiogram. End measurement.

As described above, the electrocardiogram measuring method and system according to the present invention have 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.

The electrocardiograph embedded in the smart watch according to the present invention or a portable electrocardiograph carried separately from it is convenient to carry, can be easily used regardless of time and place, and can obtain electrocardiogram information of multiple channels. In particular, even when asymptomatic arrhythmias develop, users who have received an arrhythmia alert can perform an electrocardiogram measurement to receive an accurate diagnosis later.

Claims (20)

In the electrocardiogram measurement method using a wearable device,
The wearable device worn on one hand of the user includes a photoplethysmometer, a microcontroller, and an electrocardiograph,
The electrocardiogram measurement method,
periodically measuring, by the photoplethysmometer, a photoplethysmograph;
extracting, by the microcontroller, the light bulk wave parameters by analyzing the measured light bulk wave;
determining, by the microcontroller, the occurrence of arrhythmia using the optical volume wave parameters; and
Including; by the microcontroller generating an alarm according to the determination result;
when an alarm is generated, the microcontroller controlling the electrocardiograph to start electrocardiogram measurement;
receiving an electrocardiogram signal through a first electrocardiogram electrode and a second electrocardiogram electrode from among three electrocardiogram electrodes of the electrocardiogram that are in contact with the user's left hand, right hand, left lower abdomen, or left leg, respectively;
amplifying the two electrocardiogram signals input to the first electrocardiogram electrode and the second electrocardiogram electrode using two amplifiers of the electrocardiogram;
AD-converting the two amplified ECG signals; and
The microcontroller comprising the step of terminating the electrocardiogram measurement,
By additionally calculating and obtaining four electrocardiogram signals using only the measured two electrocardiogram signals, the signals of 6 channels of lead I, lead II, lead III, lead aVR, lead aVL, and lead aVF are obtained. ECG measurement method.
According to claim 1,
The electrocardiogram measuring method, characterized in that the optical volume wave parameters include heart rate, heart rate variability, and respiration rate.
According to claim 1,
In the step of determining the occurrence of the arrhythmia,
An electrocardiogram measuring method, characterized in that it is determined whether atrial fibrillation has occurred.
According to claim 1,
In the step of determining the occurrence of the arrhythmia,
An electrocardiogram measuring method, characterized in that it is determined whether the heart rate has increased without an increase in the respiratory rate.
According to claim 1,
In the step of determining the occurrence of the arrhythmia,
An electrocardiogram measuring method, characterized in that it is determined whether the heart rate variability is increased or decreased.
According to claim 1,
In the step of generating the alarm,
An electrocardiogram measuring method, characterized in that it uses at least one alarm of sound, light, and vibration.
According to claim 1,
Electrocardiogram measurement method, characterized in that the two amplifiers are single-ended input amplifiers.
delete According to claim 1,
The electrocardiograph comprises a blood characteristic measuring unit for measuring one or more of a blood glucose level, a ketone level, or an INR.

In the electrocardiogram measurement system using a wearable device,
The electrocardiogram measurement system includes a photoplethysmometer installed in the wearable device, a microcontroller, and an electrocardiograph,
The photoplethysmometer is
a light volume wave measuring circuit including at least one LED and at least one photodiode;
an AD converter connected to an output terminal of the optical bulk wave measuring circuit to convert an analog signal into a digital signal;
includes,
The microcontroller is
controlling the optical bulk wave measurement circuit to measure the optical bulk wave;
It continuously analyzes the measured light bulk wave to extract the light bulk wave parameters, uses the extracted light bulk wave parameters to determine the occurrence of arrhythmia, and generates an alarm according to the determination result.
The electrocardiogram is
3 dry electrocardiogram electrodes;
It characterized in that it comprises two amplifiers each amplifying two electrocardiogram signals induced to two electrocardiogram electrodes among the three electrocardiogram electrodes,
The microcontroller starts the ECG measurement after generating an alarm and ends the ECG measurement when the preset measurement time elapses,
By additionally calculating and obtaining four electrocardiogram signals using only the measured two electrocardiogram signals, the signals of 6 channels of lead I, lead II, lead III, lead aVR, lead aVL, and lead aVF are obtained. ECG measurement system.
11. The method of claim 10,
The electrocardiogram measuring system, characterized in that the optical volume wave parameters include heart rate, heart rate variability, and respiration rate.
11. The method of claim 10,
An electrocardiogram measuring system, characterized in that the arrhythmia occurrence determination is whether atrial fibrillation occurs.
11. The method of claim 10,
An electrocardiogram measuring system, characterized in that the determination of the occurrence of arrhythmia is whether or not the heart rate increases without an increase in the respiratory rate.
11. The method of claim 10,
An electrocardiogram measuring system, characterized in that the determination of the occurrence of arrhythmia is whether the heart rate variability is increased or decreased.
11. The method of claim 10,
An electrocardiogram measuring system, characterized in that the arrhythmia occurrence alarm is at least one of sound, light, and vibration.
11. The method of claim 10,
The electrocardiogram measurement system, characterized in that the two amplifiers are single-ended input amplifiers.
delete 11. The method of claim 10,
The electrocardiograph comprises a blood characteristic measuring unit for measuring one or more of a blood glucose level, a ketone level, or an INR.
11. The method of claim 10,
The electrocardiogram measuring circuit including the two amplifiers is powered on by the microcontroller after an arrhythmia alarm is generated and is then powered off when a preset measurement time elapses.
11. The method of claim 10,
The wearable device,
wireless communication means for wirelessly transmitting and receiving data;
further comprising,
The microcontroller controls the wireless communication means to transmit the information measured through the electrocardiograph to the outside.

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