JP2016185288A - Portable electrocardiograph and computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a portable electrocardiograph that is easy to use for a user and can measure electrocardiogram easily.SOLUTION: A portable electrocardiograph is attached to a living body and measures a pulse and electrocardiogram of the living body. The portable electrocardiograph includes: a pulse detector for detecting a signal relating to a pulse of the living body at a position where it is attached to the living body; an interface for receiving a signal corresponding to a potential difference of the living body from a plurality of electrodes attached to the living body; an electrocardiograph for outputting an electrocardiogram of the living body using the signal corresponding to the potential difference of the living body; and a signal processing circuit for analyzing a frequency component of the pulse signal, and when the state of the heart of the living body determined from the frequency component corresponds to a predetermined irregular pulse state, measures an electrocardiogram using the output of the electrocardiograph.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a portable electrocardiograph.

  According to Japanese medical statistics, the first cause of death for Japanese is malignant neoplasm, and the second is heart disease.

  In order to identify heart disease, it is effective to measure electrocardiogram. When measuring electrocardiogram, it is necessary to attach a plurality of electrodes to the body of the subject while the subject is lying on the bed. And the apparatus utilized for such an electrocardiogram measurement is often relatively large. As the population ages more and more in the future, the proportion of people with heart disease may increase rapidly. In order to continue a healthy life, it is necessary to constantly grasp the health condition using electrocardiograms.

  In recent years, small electrocardiographs are being developed. For example, Patent Document 1 discloses a portable electrocardiograph. The user can measure the electrocardiogram by placing the electrode of the portable electrocardiograph on the finger and the chest.

  Here, “portable” means “can be carried by hand”.

JP 2009-82364 A

  In the portable electrocardiograph described in Patent Literature 1, due to the electrode arrangement, the user needs to press the portable electrocardiograph against the chest in a form that pushes the chest. Since the clothes had to be turned up, it was necessary to select a place to use, and it took some time to use. Therefore, there is a need for an electrocardiograph that can be used immediately when the patient feels sick and wants to measure the electrocardiogram or to measure the electrocardiogram just in case. Or, there was a need for an electrocardiograph that could be used immediately when the portable electrocardiograph prompted the measurement.

  Also, arrhythmia symptoms do not always appear, and even if a patient who feels abnormal goes to the hospital, the arrhythmia often subsides during the examination. As a result, the electrocardiogram at the time of abnormality (onset of arrhythmia) may not be measured. In such a case, it is helpful to perform electrocardiogram measurement at the onset of arrhythmia outside medical hours and save the data.

  The present invention has been made to solve the above-described problems, and provides a portable electrocardiograph that is easier to use for a user and that can more easily measure an electrocardiogram.

  A portable electrocardiograph according to an embodiment of the present invention is a portable electrocardiograph that is mounted on a living body and capable of measuring a pulse and an electrocardiogram of the living body, and the biological body is mounted at the mounting position on the living body. A pulse detector for detecting a signal related to the pulse of the body, an interface for receiving a signal corresponding to the potential difference of the living body from a plurality of electrodes attached to the living body, and a signal corresponding to the potential difference of the living body When an electrocardiograph that outputs the electrocardiogram of the living body and a frequency component of the pulse signal are analyzed, and the state of the heart of the living body specified from the frequency component corresponds to a predetermined arrhythmia state, A signal processing circuit for measuring the electrocardiogram using an output of the electrocardiograph.

  In one embodiment, the portable electrocardiograph further includes a control circuit that controls output of at least one of sound, light, image, and text, and the state of the heart of the living body corresponds to a predetermined arrhythmia state. The signal processing circuit outputs a warning signal, and in response to receiving the warning signal, the control circuit controls the output of at least one of the sound, light, image and character.

  In one embodiment, the signal processing circuit measures the electrocardiogram using the output of the electrocardiograph after at least one of the sound, light, image, and character is output.

  In one embodiment, the portable electrocardiograph further includes an input device that receives an input of a user who is the living body, and after the output of at least one of the sound, light, image, and character, the input device When receiving the user's input, the signal processing circuit measures the electrocardiogram using the output of the electrocardiograph.

  In one embodiment, the interface receives a signal corresponding to the potential difference of the living body from each of the plurality of electrodes in a wired or wireless manner.

  In one embodiment, the portable electrocardiograph includes a housing that houses the pulse detector, the interface, the electrocardiograph, and the signal processing circuit, a first electrode that is the plurality of electrodes, and a first electrode. Two electrodes, wherein the first electrode is attached to the surface of the casing, the second electrode is accommodated inside the casing so that the second electrode can be pulled out from the interior of the casing, and the interface includes the first electrode A signal corresponding to the potential difference of the living body is received by wire from the electrode and the second electrode.

  In one embodiment, the portable electrocardiograph includes a housing that houses the pulse detector, the interface, the electrocardiograph, and the signal processing circuit, a first electrode that is the plurality of electrodes, and a first electrode. Two electrodes, the first electrode is attached to the surface of the housing, the second electrode is provided with a battery and a wireless communication circuit, and the interface is wired from the first electrode to the living body. A signal corresponding to the potential difference is received, and a signal corresponding to the potential difference of the living body is received wirelessly from the second electrode.

  In one embodiment, the signal processing circuit stores the measured electrocardiographic data in a recording medium.

  In one embodiment, the recording medium is detachable from the portable electrocardiograph.

  In one embodiment, the signal processing circuit performs a Fourier transform on the pulse signal, and uses an output of the electrocardiograph when a fundamental frequency specified from the pulse frequency is less than a first threshold value TH1. To measure the electrocardiogram.

  In one embodiment, when the signal processing circuit performs a Fourier transform on the pulse signal and determines that the fundamental frequency specified from the pulse frequency is greater than a second threshold TH2, the output of the electrocardiograph The electrocardiogram is measured using.

  In one embodiment, the signal processing circuit Fourier-transforms the pulse signal, the pulse frequency includes a fundamental frequency, and the pulse frequency includes at least one frequency that is a multiple of the fundamental frequency. When the determination is made, the electrocardiogram is measured using the output of the electrocardiograph.

  In one embodiment, the signal processing circuit performs Fourier transform on the pulse signal and determines that the fundamental frequency is not included in the pulse frequency, using the output of the electrocardiograph. Measure ECG.

  In one embodiment, a frequency that is a multiple of the fundamental frequency is in the range of 6 to 17 Hz.

  In one embodiment, the first threshold value TH1 is 1 Hz.

  In one embodiment, the second threshold value TH2 is 2.5 Hz.

  In one embodiment, a frequency that is a multiple of the fundamental frequency is in the range of 6 to 17 Hz.

  A computer program according to an embodiment of the present invention is a computer program executed by the signal processing circuit included in the portable electrocardiograph according to any one of the above-described embodiments, and the computer program includes the signal processing. Analyzing a frequency component of a signal related to the pulse of the living body in a circuit; determining whether an analysis result of the frequency component corresponds to a predetermined arrhythmia condition; and corresponding to the arrhythmia condition Then, the step of measuring the electrocardiogram of the living body using the output of the electrocardiograph is executed.

  According to the portable electrocardiograph according to the exemplary embodiment, it is detected from the signal related to the pulse whether or not the state of the heart corresponds to the arrhythmia state. Measure electricity. This is useful for early detection of disease and physical condition management.

It is a figure which shows the basic component of an electrocardiogram waveform. It is a figure which shows the example of a normal adult electrocardiogram. It is a figure which shows the electrocardiogram waveform example of a bradyarrhythmia. It is a figure which shows the example of the electrocardiogram waveform of a tachyarrhythmia. It is a figure which shows the 1st electrocardiogram waveform example of atrial fibrillation. It is a figure which shows the 2nd example of an electrocardiogram waveform of atrial fibrillation. It is a figure which shows the example of a waveform of extrasystole. It is a figure which shows the example of a waveform of supplementary contraction. It is a figure which shows the waveform example of the pulse wave of a normal adult. It is a figure which shows the correspondence of the basic component (a) of a pulse wave, and the basic component (b) of an electrocardiogram waveform. It is a figure which shows the relationship between the pulse wave (a) in the atrial fibrillation shown to FIG. 2D, and an electrocardiogram waveform (b). 1 is an external front view of an electrocardiograph 10 having a pulse measurement function according to an exemplary embodiment of the present invention. 1 is a side view of an electrocardiograph 10 according to an exemplary embodiment of the present invention. It is a figure which shows the electrocardiograph 10 when the electrode 20b is pulled out from the housing | casing 12. FIG. 2 is a diagram illustrating a hardware configuration example of an electrocardiograph 10. FIG. It is a flowchart which shows the procedure of the process of the electrocardiograph. It is a figure which shows the power analysis result for every frequency component obtained by performing a Fourier-transform process to the waveform of a pulse wave. It is a figure which shows the example of a display of the display 504 during the period (step S1 of FIG. 8) in which the pulse detector 100 is detecting the pulse. It is a figure which shows the example of a presentation of the measurement result in step S5 of FIG. It is a figure which shows the example of a presentation of the measurement result when it reaches step S9 through step S7 of FIG. It is a figure which shows the example of a display when a user inputs the instruction | indication of whether to perform an electrocardiogram measurement. It is a figure which shows the user during the period which is performing the electrocardiogram measurement. FIG. 6 is a diagram showing a configuration example of an electrocardiograph 11 in which an electrode 20c is arranged on the outer surface of a belt 16 instead of the electrode 20b (FIG. 6B and the like). 2 is a diagram showing a side surface of an electrocardiograph 11. FIG. 2 is a diagram illustrating an example of use of an electrocardiograph 11. FIG. It is a figure which shows the radio | wireless electrode 20d and the interface 202d implement | achieved as a radio | wireless communication circuit. It is a figure which shows the usage example of an electrocardiograph when performing electrocardiogram measurement using the electrode 20a provided in the electrocardiograph and the radio | wireless electrode 20d arrange | positioned at the arm of the right hand. It is a figure which shows the radio | wireless electrode 20d affixed on the user's chest. It is a figure which shows the electrode 20a and radio | wireless electrode 20d which were provided in the user's both arms.

  Hereinafter, embodiments of a portable electrocardiograph according to the present invention will be described with reference to the accompanying drawings.

  In the following, the electrocardiogram waveform and the pulse wave waveform will be described first, and then the knowledge obtained by the present inventors will be described.

(Electrocardiogram and pulse waveform)
FIG. 1 shows the basic components of an electrocardiographic waveform. The basic components include waveform components named P, Q, R, S, and T waves, respectively.

  Note that at least two electrodes are required for measurement of the electrocardiogram waveform. This is because the electrocardiogram waveform reflects the difference in potential measured at each electrode, that is, the potential difference.

  The first appearing P wave indicates the atrial excitement process. In normal cases, the right atrium is first excited, followed by the left atrium. P waves reflect those processes. Subsequent QRS waves represent ventricular excitement. The T wave reflects the process in which the ventricular muscle excitement fades away. Each wave of PQRST appears so as to straddle the horizontal axis (base line) shown in FIG.

  2A to 2G show various electrocardiographic waveform examples. For convenience, “P” or “R” is added to the position of the P wave or R wave.

  FIG. 2A shows an example of a normal adult ECG waveform. In the example of the electrocardiogram waveform shown in FIG. 2A, each wave of P-QRS-T appears with a constant shape and timing. Such a state is called “sinus rhythm”. For a normal adult, the sinus rhythm is, for example, 60-150 times / minute.

  2B to 2G show examples of waveforms corresponding to arrhythmia.

  FIG. 2B shows an example of an electrocardiogram waveform of bradyarrhythmia, and FIG. 2C shows an example of an electrocardiogram waveform of tachyarrhythmia. As for the ECG waveforms of bradyarrhythmia and tachyarrhythmia, each P-QRS-T wave appears in a certain shape and timing. However, the timing (interval) is different from the sinus rhythm. The heart rate of bradyarrhythmia is slower than sinus rhythm, for example, less than 60 times / minute. The heart rate of tachyarrhythmia is faster than sinus rhythm, for example faster than 150 beats / minute.

  FIG. 2D shows a first electrocardiographic waveform example of atrial fibrillation. As shown in FIG. 2D, in this example, the basic waveform appears at a substantially constant period, but a fine wave overlaps between them. More specifically, attention should be paid to the baseline of the electrocardiographic waveform (corresponding to the horizontal axis in FIG. 1). A lot of waveforms that vibrate finely appear on the baseline, and the P wave is not clear. In this example, a period of 400 to 1000 times or more (a harmonic of 6 Hz to 17 Hz or higher) is superimposed on a basic waveform of 1 to 2.5 Hz per minute.

  FIG. 2E shows a second ECG waveform example of atrial fibrillation. In this example, there is no fundamental period, and a period of 400 to 1000 times or more (a harmonic of 6 Hz to 17 Hz or more) is superimposed per minute. It is difficult to identify specific frequency components and they are widely distributed.

  FIG. 2F shows an example waveform of extrasystole. The third R wave (dashed line) appears to the right as viewed from the left end of the waveform earlier than planned. However, after that, it often returns to the original sinus rhythm. It can be said that tachycardia has partially occurred.

  FIG. 2G shows a waveform example of replenishment contraction. A third R wave (dashed line) appears to the right as viewed from the left end of the waveform later than planned. It can be said that the pulse is flying. However, after that, it often returns to the original sinus rhythm. It can be said that bradycardia is partially generated.

  Arrhythmias can be classified from a clinical point of view, such as those that cause a fatal condition if not dealt with immediately, those that are dangerously prone to transition to fatal arrhythmias, or those that are not urgent and require only follow-up.

  For example, among the arrhythmias, the arrhythmias shown in FIGS. 2D and 2E are thought to cause cerebral infarction because they tend to form thrombus or are fatal. Therefore, it is very important to confirm such arrhythmia early.

  On the other hand, the arrhythmia shown in FIG. 2B, FIG. 2C, FIG. 2F, and FIG. 2G can be said to be a mild symptom compared with the arrhythmia of FIG. 2D and FIG. 2E.

  As will be appreciated from the above description, it is not always necessary to confirm the electrocardiographic waveform for every arrhythmia. It is necessary to check the electrocardiographic waveform for a specific arrhythmia.

  Next, the pulse wave will be described with reference to FIG.

  FIG. 3 shows a waveform example of a normal adult pulse wave. A pulse wave is a waveform that captures changes in blood pressure and volume in the peripheral vasculature associated with the pulsation of the heart. It is said that information having the same meaning as the electrocardiogram RR interval can be obtained indirectly by measuring the movement of peripheral blood vessels, not the movement of the heart itself.

  FIG. 4 shows the correspondence between the basic component (a) of the pulse wave and the basic component (b) of the electrocardiographic waveform. Corresponding to one heart beat, a basic component (a) of a pulse wave and a basic component (b) of an electrocardiogram waveform appear. Therefore, any arrhythmia in FIGS. 2B to 2G can be reflected in the pulse wave. This correspondence relationship is an example. Depending on the measurement site of the pulse wave, for example, the positional relationship between the peak of the pulse wave and the peak of the R wave can change.

  For example, FIG. 5 shows the relationship between the pulse wave (a) and the electrocardiogram waveform (b) in the atrial fibrillation shown in FIG. 2D. When attention is paid to the position surrounded by the broken line, it is understood that a fine waveform appearing in the vicinity of the base line of the electrocardiographic waveform also appears in the pulse wave.

(Knowledge obtained by the present inventors)
The inventors of the present application first noticed that a pulse wave can be measured more easily than an electrocardiogram.

  For example, an electrocardiogram waveform is acquired using at least two electrodes. The subject places, for example, one electrode on the chest near the heart and the other electrode on a part of the body. The electrocardiograph measures the potential difference of each electrode and acquires its impedance (chest impedance) as an electrocardiographic waveform. In order to perform electrocardiogram measurement by chest guidance, it is necessary to apply an electrode to the chest near the heart.

  On the other hand, the pulse wave is acquired using a pulse wave sensor attached to a part of the living body (for example, fingertip, earlobe or wrist). For example, an optical pulse wave sensor has an infrared light source and a light receiving element. Near-infrared light emitted from the light source is transmitted or reflected in the body and detected by the light receiving element. Since the amount of light absorption changes as the blood vessel volume changes, the intensity of the received light changes. The pulse wave sensor outputs an electrical signal corresponding to a change in light intensity as a pulse wave.

  As an example, it can be said that an electrocardiogram in which a plurality of electrodes must be attached to a plurality of locations including the chest near the heart with respect to a pulse wave that can be measured only by being wound around the wrist is somewhat troublesome.

  On the other hand, the electrocardiogram is a result of measuring a myoelectric potential difference caused by the pulsation of the heart. By utilizing the electrocardiogram, the electrical activity of the heart can be monitored more directly.

  The inventors of the present application focused on the fact that pulse wave measurement is relatively simple, and that electrocardiogram measurement is important depending on the arrhythmia. It was concluded that electrocardiogram measurement should be performed when there is a suspicion of corresponding to a predetermined arrhythmia while simply measuring heart activity using pulse waves. The inventors of the present application have determined that the “predetermined arrhythmia” is atrial fibrillation that is considered particularly necessary for electrocardiogram measurement. Therefore, it is only necessary that the state corresponding to FIGS. 2D and 2E can be determined from the pulse wave.

  Whether there is a possibility of atrial fibrillation may be determined by the regularity of the frequency component of the pulse wave. “Regularity of the frequency component of the pulse wave” means whether the pulse wave mainly has a single frequency component. For example, in FIG. 2E, it can be said that a specific frequency component does not exist. On the other hand, in FIG. 2D, although the R wave appears relatively regularly, it contains a lot of fine waveforms appearing near the base line, that is, high frequency components.

  Hereinafter, an embodiment of the present invention made based on the above-described knowledge will be described.

(Embodiment)
FIG. 6A is an external front view of an electrocardiograph 10 having a pulse measurement function according to an exemplary embodiment of the present invention. The electrocardiograph 10 can be carried and used by being wound around a user's wrist like a wristwatch, for example. The electrocardiograph 10 having such a size and weight that it can be carried by hand is called “portable”.

  The electrocardiograph 10 can measure a user's pulse and electrocardiogram. The electrocardiograph 10 measures a user's pulse and analyzes the frequency component of the pulse signal. When the state of the user's heart specified from the frequency component corresponds to a predetermined arrhythmia state (for example, atrial fibrillation), the electrocardiograph 10 measures the electrocardiogram.

  The electrocardiograph 10 includes a housing 12, a belt 16, and a display 504.

  The housing 12 accommodates hardware that constitutes the electrocardiograph 10. For example, the housing 12 houses an electrode, a pulse detector, an interface, an electrocardiograph, and a signal processing circuit which will be described later.

  The belt 16 fixes the electrocardiograph 10 around the wrist of the user. The display 504 displays various information. In the example of FIG. 6A, a clock is displayed on the display 504. As will be described later, the measurement result can be displayed on the display 504.

  FIG. 6B is a side view of the electrocardiograph 10. In the following, in this document, the components already described are denoted by the same reference numerals in the drawings, and the description thereof is omitted.

  The electrocardiograph 10 has a pulse detector 100 and electrodes 20a and 20b.

  The pulse detector 100 detects a signal related to the pulse of the user at a position worn by the user. The “signal related to the pulse” is a signal representing the pulse wave waveform shown in FIG. 3, for example. Alternatively, the “signal related to the pulse” may be information on a positive peak that is greater than or equal to a predetermined value, or a negative peak that is less than or equal to a predetermined value, and the time when the peak is reached. Any information that can identify the frequency of the pulse of the user may be used. In the following description, it is assumed that the “signal related to the pulse” is a signal representing a pulse wave waveform as shown in FIG. The signal representing the pulse wave waveform is converted into a discrete digital signal when it is processed inside the electrocardiograph 10, but for the sake of easy understanding, the waveform of an analog continuous signal will be described.

  The electrodes 20a and 20b are provided for electrocardiogram measurement in an electrocardiograph that will be described later. The electrode 20a is provided on the back side of the housing 12, and contacts the user's wrist when the electrocardiograph 10 is attached to the user's wrist.

  The electrode 20b is housed inside the housing 12 so that it can be pulled out from the slot 14 of the housing 12. The electrode 20b is normally housed inside the housing 12, and is pulled out from the slot 14 of the housing 12 by the user at the time of electrocardiogram measurement, for example.

  FIG. 6C shows the electrocardiograph 10 when the electrode 20 b is pulled out from the housing 12. The electrode 20 b is connected to a connector interface (not shown) inside the housing 12 through a lead wire 22.

  FIG. 7 shows a hardware configuration example of the electrocardiograph 10.

  The electrocardiograph 10 includes a pulse detector 100, an electrocardiograph 200, a signal processing unit 300, a storage device 400, a display processing circuit 500, and an input device 600. These elements are connected to each other via a bus line L and can exchange data with each other. Each circuit is supplied with electric power from a battery (not shown). These hardwares are housed in the housing 12 of the electrocardiograph 10 as shown in FIG. 6A.

  The pulse detector 100 includes an infrared light source 102, an infrared sensor 104, and an AD conversion circuit 106. Since the detection principle of the signal related to the pulse by the pulse detector 100 has already been described, the description thereof will be omitted.

  The infrared light source 102 emits near infrared light. The infrared sensor 104 receives incident infrared light and outputs an analog electrical signal corresponding to the amount of light. This analog electrical signal is a pulse related signal. The AD conversion circuit 106 converts the output analog electric signal into a digital signal and sends it to the signal processing unit 300 via the bus line L. For example, when a signal related to the received pulse indicates the fifth change in blood flow, the CPU 302 (described later) of the signal processing unit 300 determines the average pulse rate per minute (5 × 60 / T) is calculated.

  The electrocardiograph 200 includes interfaces 202a and 202b, a current source 204, a biological amplifier 206, and an AD conversion circuit 208.

  The interfaces 202a and 202b are connection terminals, respectively, and receive signals corresponding to the potential difference at the mounting position from the electrodes 20a and 20b mounted on the user.

  The electrocardiograph 200 includes a current source 204, a biological amplifier 206, and an AD conversion circuit 208. The biological amplifier 206 measures the potential difference and impedance between the electrodes 20a and 20b. At the time of impedance measurement, the current source 204 is measured while passing a weak current. The potential difference measurement or the impedance measurement is switched by control from the signal processing unit 300. The AD conversion circuit 208 converts the measured data from an analog signal to a digital signal, and sends the data to the CPU 302 of the signal processing unit 300 via the bus line L.

  The signal processing unit 300 includes a CPU 302, a RAM 304, and a ROM 306. The CPU 302 is a semiconductor integrated circuit that performs digital signal processing. A program 308 is expanded in the RAM 304. The program 308 is stored in the ROM 306 and is read from the ROM 306 to the RAM 304 when the electrocardiograph 10 is activated.

  The program 308 describes an instruction code group that realizes the processing of the flowchart shown in FIG. 8 described later, and is executed by the CPU 302. The CPU 302 analyzes each signal output from the pulse detector 100 and the electrocardiograph 200 according to the instruction code described in the computer program 308, sends the measurement data and the analysis result to the storage device 400, and records them. accumulate.

  The storage device 400 includes a recording control circuit 402 and a recording medium 404. The recording control circuit 402 stores the data received from the signal processing unit 300 via the bus line L in the recording medium 404. The storage device 400 is, for example, a flash memory device. The recording control circuit 402 and the recording medium 404 correspond to a memory controller and a memory cell of the flash memory device, respectively. The recording medium 404 may be, for example, a flash memory card. In that case, the recording medium 404 is detachable from the electrocardiograph 10.

  Arrhythmia symptoms do not always appear. For example, when paroxysmal atrial fibrillation and persistent atrial fibrillation occur, the former may experience an abnormality and go away at the visit even if the patient goes to the hospital. Therefore, it is very meaningful to store arrhythmia data at the onset of arrhythmia.

  The display processing circuit 500 includes a display control circuit 502 and a display 504.

  The display control circuit 502 receives a display command and display data from the signal processing unit 300, processes the display data, and displays images and / or characters on the display 504. The display processing circuit 500 is, for example, a graphic processing circuit (GPU).

  The display 504 is a display device using, for example, a liquid crystal panel, an organic EL panel, or electronic paper.

  The display processing circuit 500 is an example of a configuration for presenting information to the user. As another example, a sound control circuit and a speaker for outputting sound may be used, or a power supply circuit and a light source for turning on and off the light source may be used. The electrocardiograph 10 includes a control circuit that controls output of at least one of sound, light, image, and text, and may have hardware (speaker, light source, display, etc.) necessary for output.

  The input device 600 receives user input. In the present embodiment, it is assumed that input device 600 is touch screen panel 602 arranged so as to overlap the display. However, this is an example. The input device 600 and the display 504 may be an in-cell touch screen panel display in which a touch sensor is incorporated in a pixel of the display. Alternatively, the input device 600 may be a hardware button or a switch.

  FIG. 8 is a flowchart showing a processing procedure of the electrocardiograph 10.

  In step S1, the pulse detector 100 starts pulse detection in response to an instruction from the CPU 302. The pulse detector 100 detects the pulse wave (a) shown in FIG. 3 and FIG. 5, for example.

  In step S2, the CPU 302 performs frequency analysis using the obtained pulse wave waveform. For example, the CPU 302 performs a Fourier transform process on the obtained pulse wave, and extracts the power of each frequency component included in the pulse wave.

  For example, FIG. 9 shows a power analysis result for each frequency component obtained by subjecting the waveform of the pulse wave to Fourier transform processing. For the convenience of understanding, the scale of the vertical axis in this drawing is highlighted.

  Refer to FIG. 8 again.

  Subsequent steps S3a and S3b are processes for determining which of FIGS. 2A to 2G the subject's heart condition corresponds to.

  In step S3a, the CPU 302 determines whether or not the fundamental frequency power exists in the analysis result of the pulse wave frequency. The “basic frequency” is a frequency having a power equal to or greater than a predetermined value (threshold value) TH0. When the power of a plurality of frequencies indicates the threshold value TH0 or more, the highest power frequency among them is the fundamental frequency. In accordance with such rules, the CPU 302 determines the presence / absence of a fundamental frequency. If the fundamental frequency exists, the process proceeds to step S3b, and if not, the process proceeds to step S5. The case where there is no fundamental frequency means that there is a possibility of atrial fibrillation corresponding to FIG. 2E.

  In step S3b, the CPU 302 determines whether or not the high frequency band W is included. In the exemplary embodiment, the high frequency band W is 6 to 17 Hz. Typically, at least one multiple component (harmonic component) of the fundamental frequency falls in the high frequency band W. It should be noted that specific numerical values in the following description are also examples and other values can be adopted.

  Whether or not the high frequency band W is included can be determined, for example, based on whether or not the average of the power of each frequency included in the high frequency band W is greater than or equal to a predetermined value. If the CPU 302 determines that the high frequency band W is included, the process proceeds to step S5. The inclusion of the high frequency band W means that there is a possibility of atrial fibrillation corresponding to FIG. 2D.

  In step S4, the CPU 302 branches the process to step S6, S7 or S8 according to the value of the fundamental frequency. That is, the CPU 302 branches to the process of step S6 if the value of the fundamental frequency is less than the threshold value TH1 (for example, 1 Hz), and branches to the process of step S7 if it is greater than the threshold value TH2 (for example, 2.5 Hz). Otherwise (threshold value TH1 or more and threshold value TH2 or less), the process branches to step S8. Since step S4 is performed through step S3b, the fundamental frequency is greater than the threshold value TH2 and less than 6 Hz.

  In step S <b> 5, the CPU 302 determines that the user's heart condition is likely to cause atrial fibrillation as shown in FIG. 2D or 2E, and presents the result to the user via the display 504.

  In step S6, S7 or S8, the CPU 302 determines that the user's heart condition is bradycardia, tachycardia or normal, respectively. As already explained, bradycardia and tachycardia mean that the user's heart is in an arrhythmia state.

  In step S <b> 9, the CPU 302 presents the determination result to the user via the display 504. At this time, the CPU 302 may present a display and selection option that allows the user to further determine whether or not to perform electrocardiogram measurement.

  When the user wants to perform electrocardiogram measurement, the user instructs measurement of the electrocardiogram.

  In step S <b> 10, the CPU 302 receives a user instruction via the input device 600.

  In step S <b> 11, the electrocardiograph 200 starts measuring electrocardiograms in response to an instruction from the CPU 302. The electrocardiograph 200 measures the electrocardiogram shown in FIGS. 2A to 2G, for example.

  In step S <b> 12, the CPU 302 presents the electrocardiogram measurement result to the user via the display 504.

  Hereinafter, display examples of the display 504 will be described with reference to FIGS. 10 to 12B.

  FIG. 10 shows a display example of the display 504 during the period in which the pulse detector 100 detects a pulse (step S1 in FIG. 8). The display 504 switches the clock image to the illustrated characters and images. The illustrated star mark 510 indicates a process currently being performed. During the period in which frequency analysis is performed after heartbeat measurement, the star mark 510 is displayed next to the word “under analysis”.

  FIG. 11 shows an example of presentation of the measurement result in step S5 of FIG. The CPU 302 displays character information shown in FIG. 11 via the display 504. At the same time, the CPU 302 outputs a preset melody via a speaker (not shown). Thereby, the user can know that the electrocardiogram measurement is continued, and can recognize that it is necessary to install an electrode for that purpose.

  As understood from the display example of FIG. 11, in this embodiment, when it is determined that there is a high risk of atrial fibrillation, the CPU 302 forcibly shifts to an electrocardiogram measurement process. This is because atrial fibrillation is considered high risk as described above. However, the process of forcibly shifting to the electrocardiogram measurement process is an example of the operation. Instead of performing the electrocardiogram measurement process, the user may be informed of the high risk.

  FIG. 12A shows an example of presenting a measurement result when step S9 is reached after step S7 in FIG. The CPU 302 displays the character information shown in FIG. 12A via the display 504. The CPU 302 asks the user whether to continue the electrocardiogram measurement.

  FIG. 12B shows a display example when the user inputs an instruction as to whether or not to perform electrocardiogram measurement. The user touches the display of “Yes” or “No” on the display 504. When the touch screen panel 602 detects that the display of “Yes” is touched, the CPU 302 executes electrocardiogram measurement. Prior to execution, the CPU 302 may further change the display on the display 504 and ask the user to set the electrodes. On the other hand, when the touch screen panel 602 detects that the display of “No” is touched, the CPU 302 ends the process.

  FIG. 13 shows the user during the period when the electrocardiogram is being measured. The electrode 20a disposed on the back surface of the electrocardiograph 10 is in contact with the user's wrist. On the other hand, the electrode 20b is pulled out of the housing 12 by the user and attached to the chest near the user's heart.

The exemplary embodiments of the present invention have been described above. The following advantages are obtained by the above configuration and operation.
(1) First, since the heart activity is monitored by the heartbeat (pulse), the measurement is relatively simple. Since it is not necessary to always use an electrode unlike the electrocardiogram measurement, the wearability and portability of the electrocardiograph 10 are improved.
(2) Since it switches to the electrocardiographic measurement using an electrode in a predetermined arrhythmia state (abnormal heart rate), a timely electrocardiographic measurement can be realized.
(3) Instead of a simple wristband in which the electrodes are simply arranged, the electrodes are provided so that they can be pulled out from the housing. As a result, the storability is enhanced and the electrodes can be easily mounted near the heart, so that accurate electrocardiographic measurement is effectively realized.

(Embodiment 2)
In this embodiment, a modified example of the position where the electrode is provided will be described.

  FIG. 14A shows a configuration example of the electrocardiograph 11 in which the electrode 20c is arranged on the outer surface of the belt 16 instead of the electrode 20b (FIG. 6B and the like). FIG. 14B shows the side of the electrocardiograph 11. The position of the electrode 20a is the same as in the example of the first embodiment. The “outer surface” refers to a surface exposed to the outside when the electrocardiograph 11 is worn on the user's wrist.

  The electrode 20c is connected to a lead wire 24 laid inside the belt 16, and the lead wire 24 is connected to the interface 202b (FIG. 7).

  FIG. 15 shows an example of use of the electrocardiograph 11. After wearing the electrocardiograph 11, the user bends his arm and presses the electrode 20c against the chest near the heart. Since the electrode 20c is disposed on the outer surface of the belt 16, it is not necessary to turn up the clothes. The user can press the electrode to the chest relatively easily by simply inserting the arm on which the electrocardiograph 11 is attached from the hem of the clothes around the chest. As in the example of the first embodiment, it is not necessary to pull out the electrode 20b and store it after the measurement, which improves convenience. In addition, since the user's operation during measurement can be reduced, it is easy to maintain a resting state in the electrocardiogram measurement.

(Embodiment 3)
In this embodiment, a configuration example of an electrocardiograph using a wireless electrode will be described.

  FIG. 16 shows the wireless electrode 20d and the interface 202d realized as a wireless communication circuit. Only the electrocardiograph 201 is shown in FIG. Other configurations of the electrocardiograph 10 are the same as those shown in FIG. 7, for example.

  The radio electrode 20d can be used in place of the above-described radio electrode 20b or 20c. The radio electrode 20d may be used together with the electrode 20b or 20c.

  The radio electrode 20d includes a battery 20d-1 and a radio communication circuit 20d-2 in addition to an electrode plate (not shown). Information on the potential difference measured by the electrode plate is transmitted using the wireless communication circuit 20d-2 driven by the power from the battery 20d-1.

  The interface 202d receives a signal corresponding to the potential difference of the living body wirelessly transmitted from the electrode 20d.

  FIG. 17 shows an example of use of an electrocardiograph when an electrocardiogram is measured using an electrode 20a provided on the electrocardiograph and a radio electrode 20d arranged on the arm of the right hand. The potential signal obtained from the radio electrode 20d is transmitted to the electrocardiograph 10 by radio waves and used for electrocardiogram measurement.

  The user can directly view the waveform on the display 504 of the electrocardiograph 10 during the electrocardiogram measurement. In addition, since it is easy to obtain an electrocardiogram from a location close to the heart, higher accuracy can be obtained.

  As a first modification of the present embodiment, an adhesive material may be applied to the radio electrode 20d and attached to the chest of the user. FIG. 18 shows the radio electrode 20d attached to the chest of the user. According to this modification, the radio electrode 20d can always be placed on the chest near the heart, so that electrocardiogram measurement can be started from any point in time, and the electrocardiogram can be constantly monitored.

  As a second modification of the present embodiment, the radio electrode 20d may be attached to the arm on the opposite side to the electrode 20a. FIG. 19 shows the electrode 20a and the radio electrode 20d provided on both arms of the user. This modification is useful for electrocardiogram measurement without performing chest guidance. Also according to this modification, the measurement of the electrocardiogram can be started from an arbitrary time point, and the electrocardiogram can be constantly monitored. Compared with the example of FIG. 18, since the electrodes are attached to the arm rather than the chest, the uncomfortable feeling is reduced.

  This specification discloses the respiration rate measuring method, measuring system, and computer program described in the following items.

[Item 1]
A portable electrocardiograph attached to a living body and capable of measuring the pulse and electrocardiogram of the living body,
A pulse detector for detecting a signal related to the pulse of the living body at a mounting position on the living body;
An interface for receiving a signal corresponding to a potential difference of the living body from a plurality of electrodes mounted on the living body;
An electrocardiograph that outputs the electrocardiogram of the living body using a signal corresponding to the potential difference of the living body;
When the frequency component of the pulse signal is analyzed, and the state of the heart of the living body specified from the frequency component corresponds to a predetermined arrhythmia state, the electrocardiograph is output using the output of the electrocardiograph. A portable electrocardiograph equipped with a signal processing circuit for measuring a signal.

  According to the portable electrocardiograph of item 1, it is detected from the signal related to the pulse whether or not the state of the heart corresponds to the arrhythmia state, and when it corresponds to the predetermined arrhythmia state, the electrocardiogram is measured. First, since a signal related to a pulse that is relatively easy to measure is used, it is not necessary to always use an electrode as in the case of electrocardiogram measurement. Therefore, the wearability and portability of the portable electrocardiograph are improved. Since the electrocardiogram is measured in the case of a predetermined arrhythmia state (abnormal heartbeat), timely electrocardiogram measurement can be realized. This is useful for early detection of disease and physical condition management.

[Item 2]
A control circuit for controlling the output of at least one of sound, light, image and character;
When the state of the heart of the living body corresponds to a predetermined arrhythmia state, the signal processing circuit outputs a warning signal,
The portable electrocardiograph according to item 1, wherein the control circuit controls an output of at least one of the sound, light, image, and character in response to receiving the warning signal.

[Item 3]
3. The portable electrocardiograph according to item 2, wherein the signal processing circuit measures the electrocardiogram using the output of the electrocardiograph after at least one of the sound, light, image, and character is output. .

[Item 4]
An input device for receiving an input from a user who is the living body;
After at least one of the sound, light, image, and character is output, when the input device receives the user's input, the signal processing circuit uses the output of the electrocardiograph to output the electrocardiogram. Item 4. The portable electrocardiograph according to item 3.

[Item 5]
5. The portable electrocardiograph according to any one of items 1 to 4, wherein the interface receives a signal corresponding to the potential difference of the living body from each of the plurality of electrodes in a wired or wireless manner.

[Item 6]
A housing that houses the pulse detector, the interface, the electrocardiograph, and the signal processing circuit;
A first electrode and a second electrode, which are the plurality of electrodes,
The first electrode is attached to the surface of the housing,
The second electrode is housed in the housing so that the second electrode can be pulled out from the housing,
Item 6. The portable electrocardiograph according to Item 5, wherein the interface receives a signal corresponding to a potential difference of the living body by wire from the first electrode and the second electrode.

  According to the portable electrocardiograph of item 6, the electrode is provided so that it can be pulled out from the inside of the housing. As a result, the storability is enhanced and the electrodes can be easily mounted near the heart, so that accurate electrocardiographic measurement is effectively realized.

[Item 7]
A housing that houses the pulse detector, the interface, the electrocardiograph, and the signal processing circuit;
A first electrode and a second electrode, which are the plurality of electrodes,
The first electrode is attached to the surface of the housing,
The second electrode includes a battery and a wireless communication circuit,
Item 6. The portable electrocardiograph according to Item 5, wherein the interface receives a signal corresponding to the potential difference of the living body by wire from the first electrode, and receives a signal corresponding to the potential difference of the living body wirelessly from the second electrode. .

[Item 8]
The portable electrocardiograph according to any one of items 1 to 7, wherein the signal processing circuit stores the measured electrocardiographic data in a recording medium.

[Item 9]
Item 9. The portable electrocardiograph according to item 8, wherein the recording medium is detachable from the portable electrocardiograph.

[Item 10]
The signal processing circuit performs Fourier transform on the pulse signal, and measures the electrocardiogram using the output of the electrocardiograph when the fundamental frequency specified from the pulse frequency is less than a first threshold TH1. The portable electrocardiograph according to any one of items 1 to 9.

[Item 11]
The signal processing circuit performs Fourier transform on the pulse signal, and determines that the fundamental frequency specified from the pulse frequency is greater than a second threshold value TH2, using the output of the electrocardiograph. The portable electrocardiograph according to any one of items 1 to 9, which measures electricity.

[Item 12]
The signal processing circuit performs Fourier transform on the pulse signal, and determines that the pulse frequency includes a fundamental frequency and the pulse frequency includes at least one frequency that is a multiple of the fundamental frequency. The portable electrocardiograph according to any one of items 1 to 9, wherein the electrocardiogram is measured using an output of an electrometer.

[Item 13]
The signal processing circuit performs Fourier transform on the pulse signal and, when it is determined that the fundamental frequency is not included in the pulse frequency, measures the electrocardiogram using an output of the electrocardiograph, Item 10. The portable electrocardiograph according to any one of items 1 to 9.

[Item 14]
The portable electrocardiograph according to item 10, wherein the first threshold value TH1 is 1 Hz.

[Item 15]
12. The portable electrocardiograph according to item 11, wherein the second threshold value TH2 is 2.5 Hz.

[Item 16]
13. The portable electrocardiograph according to item 12, wherein a frequency that is a multiple of the fundamental frequency is in the range of 6 to 17 Hz.

[Item 17]
A computer program executed by the signal processing circuit provided in the portable electrocardiograph according to any one of items 1 to 16,
The computer program is stored in the signal processing circuit.
Analyzing a frequency component of a signal related to the pulse of the living body;
Determining whether the analysis result of the frequency component corresponds to a predetermined arrhythmia condition;
When the arrhythmia condition is met, a computer program that executes the step of measuring the electrocardiogram of the living body using the output of the electrocardiograph.

  The present invention can be used for a device that measures the pulse and electrocardiogram of a living body. Since arrhythmia can be detected from the state of the pulse and the electrocardiogram can be measured at almost any place and timing when the arrhythmia occurs, it is useful for early detection of disease and physical condition management. The present invention can also be used as a computer program for such a device.

DESCRIPTION OF SYMBOLS 10, 11 Electrocardiograph 12 Case 16 Belt 20a, 20b, 20c Electrode 20d Wireless electrode 100 Pulse detector 200 Electrocardiograph 202a, 202b Wired interface 202d Wireless interface 300 Signal processing unit 400 Storage device 500 Display processing circuit 600 Input apparatus

Claims (17)

A portable electrocardiograph attached to a living body and capable of measuring the pulse and electrocardiogram of the living body,
A pulse detector for detecting a signal related to the pulse of the living body at a mounting position on the living body;
An interface for receiving a signal corresponding to a potential difference of the living body from a plurality of electrodes mounted on the living body;
An electrocardiograph that outputs the electrocardiogram of the living body using a signal corresponding to the potential difference of the living body;
When the frequency component of the pulse signal is analyzed, and the state of the heart of the living body specified from the frequency component corresponds to a predetermined arrhythmia state, the electrocardiograph is output using the output of the electrocardiograph. A portable electrocardiograph equipped with a signal processing circuit for measuring a signal. A control circuit for controlling the output of at least one of sound, light, image and character;
When the state of the heart of the living body corresponds to a predetermined arrhythmia state, the signal processing circuit outputs a warning signal,
The portable electrocardiograph according to claim 1, wherein in response to receiving the warning signal, the control circuit controls at least one output of the sound, light, image, and character.   The portable electrocardiograph according to claim 2, wherein after at least one of the sound, light, image, and character is output, the signal processing circuit measures the electrocardiogram using an output of the electrocardiograph. Total. An input device for receiving an input from a user who is the living body;
After at least one of the sound, light, image, and character is output, when the input device receives the user's input, the signal processing circuit uses the output of the electrocardiograph to output the electrocardiogram. The portable electrocardiograph according to claim 3, which is measured.   5. The portable electrocardiograph according to claim 1, wherein the interface receives a signal corresponding to a potential difference of the living body from each of the plurality of electrodes in a wired or wireless manner. A housing that houses the pulse detector, the interface, the electrocardiograph, and the signal processing circuit;
A first electrode and a second electrode, which are the plurality of electrodes,
The first electrode is attached to the surface of the housing,
The second electrode is housed in the housing so that the second electrode can be pulled out from the housing,
The portable electrocardiograph according to claim 5, wherein the interface receives a signal corresponding to a potential difference of the living body from the first electrode and the second electrode in a wired manner. A housing that houses the pulse detector, the interface, the electrocardiograph, and the signal processing circuit;
A first electrode and a second electrode, which are the plurality of electrodes,
The first electrode is attached to the surface of the housing,
The second electrode includes a battery and a wireless communication circuit,
The portable electrocardiograph according to claim 5, wherein the interface receives a signal corresponding to the potential difference of the living body by wire from the first electrode, and receives a signal corresponding to the potential difference of the living body wirelessly from the second electrode. Total.   The portable electrocardiograph according to claim 1, wherein the signal processing circuit stores the measured electrocardiographic data in a recording medium.   The portable electrocardiograph according to claim 8, wherein the recording medium is detachable from the portable electrocardiograph.   The signal processing circuit performs Fourier transform on the pulse signal, and measures the electrocardiogram using the output of the electrocardiograph when the fundamental frequency specified from the pulse frequency is less than a first threshold TH1. The portable electrocardiograph according to any one of claims 1 to 9.   The signal processing circuit performs Fourier transform on the pulse signal, and determines that the fundamental frequency specified from the pulse frequency is greater than a second threshold value TH2, using the output of the electrocardiograph. The portable electrocardiograph according to claim 1, which measures electricity.   The signal processing circuit performs Fourier transform on the pulse signal, and determines that the pulse frequency includes a fundamental frequency and the pulse frequency includes at least one frequency that is a multiple of the fundamental frequency. The portable electrocardiograph according to claim 1, wherein the electrocardiogram is measured using an output of an electrometer.   The signal processing circuit performs Fourier transform on the pulse signal and, when it is determined that the fundamental frequency is not included in the pulse frequency, measures the electrocardiogram using an output of the electrocardiograph, The portable electrocardiograph according to any one of claims 1 to 9.   The portable electrocardiograph according to claim 10, wherein the first threshold value TH1 is 1 Hz.   The portable electrocardiograph according to claim 11, wherein the second threshold value TH2 is 2.5 Hz.   The portable electrocardiograph according to claim 12, wherein a frequency that is a multiple of the fundamental frequency is in the range of 6 to 17 Hz. A computer program executed by the signal processing circuit provided in the portable electrocardiograph according to any one of claims 1 to 16,
The computer program is stored in the signal processing circuit.
Analyzing a frequency component of a signal related to the pulse of the living body;
Determining whether the analysis result of the frequency component corresponds to a predetermined arrhythmia condition;
When the arrhythmia condition is met, a computer program that executes the step of measuring the electrocardiogram of the living body using the output of the electrocardiograph.

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