Electrocardiosignal measuring device and electrocardiosignal measuring system

Abstract

In a multi-channel electrocardiogram measuring device including a plurality of electrocardiogram measuring sections for measuring an electrocardiogram, it is made possible to obtain a clear electrocardiogram while suppressing noise. An electrocardiogram measuring section (13) includes a positive and negative pair of electrode bodies (20, 21) configured as a capacitively coupled electrode and capable of being disposed in a non-contact state on a human body, a signal amplifying section (23) that amplifies electrical signals from the two electrode bodies (20, 21) and outputs the signals as electrocardiogram signals, and an inverting output section (28) that inverts common mode signals of the electrical signals from the two electrode bodies (20, 21) and outputs the signals as inverted signals. When the electrocardiogram measuring section (13) in which the inverted signals from the inverting output section (28) are input to the positive electrode body (20) is defined as a first channel (13A) and the electrocardiogram measuring section (13) in which the inverted signals from the inverting output section (28) are input to the negative electrode body (21) is defined as a second channel (13B), the two channels (13A, 13B) are simultaneously present.

Description

Technical Field

[0001] This invention relates to an electrocardiogram (ECG) signal measuring device for measuring ECG signals related to heartbeats, and an ECG signal measuring system including the ECG signal measuring device. Background Technology

[0002] In recent years, the demand for measuring electrocardiogram (ECG) signals in various environments has been increasing. For example, in Japan in 2019, the average age of drivers in the transportation industry was around 50, 10 years older than the average age across all industries, leading to an increasing trend of accidents caused by underlying circulatory system diseases. Currently, the measure taken is to check drivers' health status before they drive, such as at company offices, but it's difficult to monitor changes in their physical condition while driving. The transportation industry hopes to measure ECG signals during driving. Furthermore, the demand for health management is also increasing among employees in office environments such as clerical work. For example, by analyzing the ECG signals (waveforms) of drivers and employees while driving or at work, it's possible to calculate indices related to the autonomic nervous system. These indices can then be used to analyze symptoms of illness, fatigue, and mental stress, which are related to the sympathetic nervous system. These indices are useful for detecting chronic fatigue and mental stress caused by work-related activities.

[0003] In addition, the number of strokes of unknown origin, accounting for about 30% of all stroke cases, is increasing in recent years. Recent studies suggest that atrial fibrillation (AF) is a highly probable trigger for this type of stroke. AF refers to a condition where the atria of the heart spasm and fail to pump blood effectively. When AF occurs, blood clots are more likely to form in the atria. If a portion of this clot travels to the brain and blocks a blood vessel, a stroke can occur. While measuring the electrocardiogram (ECG) can measure changes in heart rate (beats per minute) over time, detecting paroxysmal AF requires continuous ECG measurements over a long period.

[0004] However, in environments such as vehicles and offices, the subjects being measured are not at rest. Therefore, the effects of driving and environmental electrical noise must be considered during electrocardiogram (ECG) measurements. Furthermore, during prolonged ECG signal measurements, it is necessary to reduce the physical strain on the subject. To address this, Patent Document 1 discloses a technique for measuring ECG signals using capacitively coupled electrodes that do not require direct contact with the body surface. Patent Document 1 proposes an ECG measuring device (ECG signal measuring device) comprising two sets of electrodes: direct electrodes and capacitively coupled electrodes. The direct electrodes are positioned on the vehicle's steering wheel, contacting the driver's skin to detect the driver's body potential (electrical signal). The capacitively coupled electrodes are positioned on the vehicle's seat, detecting the driver's body potential in an electrically insulated state. The driver's ECG signal is measured based on the potentials detected by the direct electrodes and the capacitively coupled electrodes.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2013-85753 Summary of the Invention

[0008] The technical problem that the invention aims to solve

[0009] However, in ECG signal measurement devices like those in Patent Document 1, which simultaneously use direct electrodes that directly contact the skin and capacitively coupled electrodes that do not directly contact the skin, the contact condition and contact area between the steering wheel and the palm skin are constantly changing. Therefore, frequent changes in the intensity of the ECG signal measured by the direct electrodes or intermittent ECG signals are unavoidable, making it difficult to stably measure ECG signals using direct electrodes. This is especially true for commercial vehicles such as trucks, buses, and taxis, where it's almost impossible to always hold the steering wheel with both hands, and large vehicles, which are mostly manual transmission vehicles, are generally handled with only one hand. Furthermore, large vehicles often use a push-pull steering method, in which the skin contact condition changes slightly.

[0010] Regarding the measurement of electrocardiogram (ECG) signals while driving large vehicles, in the inventors' verification, the time during which ECG signals could be measured using the direct electrodes on the steering wheel was less than 10% of the verification time, and the direct electrodes were almost unable to measure ECG signals. Furthermore, when the body twists while the steering wheel is released, the buttocks leave the seat, and a state where ECG signals could not be measured at all was observed. Thus, according to the inventors' verification, it is difficult to stably measure ECG signals using the ECG signal measuring device of Patent Document 1. In addition, noise increases when the body makes large movements such as operating the steering wheel, making it difficult to obtain a clear ECG signal waveform.

[0011] The purpose of this invention is to provide an electrocardiogram (ECG) signal measuring device that can stably measure ECG signals and suppress noise to obtain clear ECG signals.

[0012] Another object of the present invention is to provide an electrocardiogram (ECG) measuring device that can measure ECG signals while working in a seated position in a moving vehicle or office environment, etc., in a state of suppressing physical burden.

[0013] Another object of the present invention is to provide an electrocardiogram (ECG) measurement system that can easily confirm the ECG signal of the subject from a remote location.

[0014] Technical means to solve the problem

[0015] The present invention relates to a multi-channel electrocardiogram (ECG) signal measuring device comprising multiple ECG measuring units 13 for measuring ECG signals. The device is characterized in that each ECG measuring unit 13 includes a pair of positive and negative electrode bodies 20 and 21 constituting capacitively coupled electrodes that can be disposed on the human body without contact with the body; a signal amplification unit 23 that amplifies the electrical signals from the two electrode bodies 20 and 21 and outputs them as ECG signals; and an inverting output unit 28 that inverts the common-mode signal of the electrical signals from the two electrode bodies 20 and 21 and outputs it as an inverted signal. The inverted signal output from the inverting output unit 28 is input to either the positive or negative electrode body 20 or 21. Furthermore, when the ECG measuring unit 13 input to the positive electrode body 20 is designated as a first channel 13A, and the ECG measuring unit 13 input to the negative electrode body 21 is designated as a second channel 13B, the ECG signal measuring device simultaneously has two channels 13A and 13B.

[0016] The electrocardiogram (ECG) signal measuring device has a base 7 for supporting or being worn by a human body, on which electrodes 20 and 21 are mounted. As such, the electrode bodies 20 and 21 are configured to... Figure 3 The configuration shown employs the following arrangement: the positive electrode bodies 20 (20A, 20B) of the first and second channels 13A, 13B are positioned offset to one side of the vertical reference line R1 relative to the substrate 7 in the horizontal direction; the negative electrode bodies 21 (21A, 21B) of the first and second channels 13A, 13B are positioned offset to the other side of the vertical reference line R1; and the positive and negative electrode bodies 20A, 21A of the first channel 13A and the positive and negative electrode bodies 20B, 21B of the second channel 13B are arranged alternately in the vertical direction. Furthermore, the "alternating arrangement" is not limited to... Figure 3 The channels shown are in a 2-column configuration, but configurations with 3 or more channels are also included. The same applies to the following configurations.

[0017] Other configurations of electrode bodies 20 and 21 can also be such as Figure 9 The configuration is as follows: the positive electrode bodies 20 (20A, 20B) constituting the first and second channels 13A, 13B are positioned relative to the horizontal reference line R2 of the substrate 7, biased towards one side in the vertical direction; the negative electrode bodies 21 (21A, 21B) constituting the first and second channels 13A, 13B are positioned relative to the vertical reference line R2, biased towards the other side in the vertical direction; and the positive and negative electrode bodies 20A, 21A constituting the first channel 13A and the positive and negative electrode bodies 20B, 21B constituting the second channel 13B are arranged alternately in the left and right direction.

[0018] The electrocardiogram measurement unit 13 includes a noise removal unit 24 for removing noise contained in the electrocardiogram signal output from the signal amplification unit 23.

[0019] The base 7 is the backrest 10 of the chair 8, and the positive and negative electrodes 20 and 21 of the electrocardiogram measurement unit 13 are provided on the front of the backrest 10.

[0020] The base 7 is a top 33 that can be worn on the upper body of the human body, and the positive and negative electrodes 20 and 21 of the electrocardiogram measurement unit 13 are provided on the top 33.

[0021] The electrocardiogram (ECG) signal measurement system of the present invention is characterized by comprising: an ECG signal measuring device 2 as described above for measuring ECG signals; a recording server 3 connected to the ECG signal measuring device 2 via a communication line 5 for recording the ECG signals measured by the ECG signal measuring device 2; and a terminal device 4 connected to the recording server 3 via the communication line 5, capable of acquiring the ECG signals recorded in the recording server 3. Furthermore, the ECG signal measuring device 2 includes a wireless communication unit 16 for establishing wireless communication with the communication line 5.

[0022] Invention Effects

[0023] In the electrocardiogram (ECG) signal measuring device of the present invention, an inverting output unit 28 is provided, which inverts the common-mode signal of the electrical signals from the positive and negative electrode bodies 20 and 21 constituting capacitively coupled electrodes and outputs it as an inverted signal. The inverted signal output from the inverting output unit 28 is input to either the positive or negative electrode body 20 or 21. Thus, by inverting the electrical signals from the electrode bodies 20 and 21 that are superimposed with noise through the inverting output unit 28, and feeding them back to the human body as an inverted signal via the electrode bodies 20 and 21, the noise reduction effect brought about by the so-called RLD (Right Leg Drive) method is achieved, thereby obtaining a clearer ECG signal. Furthermore, in the case of an RLD-dedicated electrode body in addition to the positive and negative electrode bodies 20 and 21, there is a risk that the contact state between the RLD-dedicated electrode body and the human body may be released, or that the RLD-dedicated electrode body may be significantly removed from the human body, resulting in the loss of the noise reduction effect brought by the RLD method. However, by providing an inverted signal to the electrode bodies 20 and 21 that constitute the capacitively coupled electrode body for measuring electrocardiogram signals as described in this invention, the contact state of the RLD-dedicated electrode body will not be affected, and the noise reduction effect based on the RLD method can be stably exerted, thus obtaining a clearer electrocardiogram signal more stably.

[0024] Furthermore, the inverted signal from the inverting output unit 28 is input to the ECG measurement unit 13 of the positive electrode 20 and designated as the first channel 13A. The inverted signal from the inverting output unit 28 is input to the ECG measurement unit 13 of the negative electrode 21 and designated as the second channel 13B. At this time, the ECG signal measuring device has two channels 13A and 13B. In this way, inverted signals can be applied to both the positive and negative electrodes 20 and 21 simultaneously in one ECG signal measuring device. Therefore, compared with the method of applying inverted signals to only one electrode 20 and 21, the noise reduction effect brought by the RLD method can be more reliably utilized, and a clearer ECG signal can be obtained.

[0025] On the substrate 7 used to support the human body or worn by the human body, the electrode bodies 20 and 21 are preferably configured as follows: Figure 3The arrangement is as shown. Specifically, it is preferable to adopt the following configuration: the positive electrodes 20 (20A, 20B) of the first and second channels 13A, 13B are positioned offset to one side of the vertical reference line R1 relative to the substrate 7 in the horizontal direction, while the negative electrodes 21 (21A, 21B) of the first and second channels 13A, 13B are positioned offset to the other side of the vertical reference line R1 in the horizontal direction. Furthermore, the positive and negative electrodes 20A, 21A constituting the first channel 13A and the positive and negative electrodes 20B, 21B constituting the second channel 13B are arranged alternately vertically. Therefore, the positive and negative electrodes 20, 21 to which the inverted signal is applied are not offset to either the horizontal or vertical direction, allowing the inverted signal to be applied to a wider area of ​​the body, thus further reducing noise and improving the signal-to-noise ratio (SN ratio). Consequently, stable measurement of the electrocardiogram (ECG) signal is possible, and a clearer ECG signal can be obtained. Because the positive and negative electrodes 20 and 21 of the first and second channels 13A and 13B are arranged in the same direction, electrical signals of the same phase can be detected in the two channels 13A and 13B.

[0026] The configuration of electrodes 20 and 21 on substrate 7 can also be adopted as follows: Figure 9 The arrangement is as shown. Specifically, it is preferable to adopt the following configuration: the positive electrodes 20 (20A, 20B) constituting the first and second channels 13A, 13B are positioned offset from the horizontal reference line R2 relative to the substrate 7, biased towards one side in the vertical direction; the negative electrodes 21 (21A, 21B) constituting the first and second channels (13A, 13B) are positioned offset from the vertical direction relative to the aforementioned reference line R2; and the positive and negative electrodes 20A, 21A constituting the first channel 13A and the positive and negative electrodes 20B, 21B constituting the second channel 13B are arranged side-by-side. In this configuration, the positive and negative electrodes 20, 21 to which the inverted signal is applied will not be biased towards either side in the horizontal or vertical direction, allowing the inverted signal to be applied to a wider area of ​​the human body. Therefore, noise can be further reduced and the signal-to-noise ratio (SN ratio) improved, thereby enabling stable measurement of the electrocardiogram (ECG) signal and obtaining a clearer ECG signal. Because the positive and negative electrodes 20 and 21 of the first and second channels 13A and 13B are arranged in the same direction, electrical signals of the same phase can be detected in the two channels 13A and 13B.

[0027] The electrocardiogram (ECG) measurement unit 13 may include a noise removal unit 24 for removing noise contained in the ECG signal output from the signal amplification unit 23. Thus, noise can be removed from the ECG signal amplified by the signal amplification unit 23, thereby contributing to the clarity of the ECG signal.

[0028] The substrate 7 can be the backrest 10 of a chair 8. The positive and negative electrodes 20 and 21 of the electrocardiogram (ECG) measuring unit 13 are provided on the front of the backrest 10. Thus, the person being measured only needs to sit on the chair 8 and lean against the backrest 10 to measure their own ECG signal. Therefore, for drivers in motion or office workers, their ECG signals can be measured stably and in a state of reduced physical strain.

[0029] The substrate 7 can be a shirt 33 that can be worn on the upper body of the human body. The positive and negative electrodes 20 and 21 of the electrocardiogram measurement unit 13 are provided on the shirt 33. Thus, the positive and negative electrodes 20 and 21 can be placed on the torso simply by wearing the shirt 33, so even if the electrocardiogram signal is measured for a long time, the burden on the measurement subject can be reduced. In addition, it has the advantage of not restricting movement and being able to measure electrocardiogram signals while driving a vehicle.

[0030] The electrocardiogram (ECG) signal measurement system of the present invention includes: an ECG signal measuring device 2 for measuring ECG signals; a recording server 3 connected to the ECG signal measuring device 2 via a communication line 5 for recording the ECG signals measured by the ECG signal measuring device 2; and a terminal device 4 connected to the recording server 3 via the communication line 5, capable of acquiring the ECG signals recorded in the recording server 3. The ECG signal measuring device 2 includes a wireless communication unit 16 for establishing wireless communication with the communication line 5. Therefore, the ECG signals of the subject can be monitored remotely. For example, when the subject is a truck or bus driver, the ECG signals during vehicle operation can be easily checked at a remote location such as a company office. Attached Figure Description

[0031] Figure 1 This is a block diagram showing the overall electrocardiogram signal measuring device of Embodiment 1 of the present invention.

[0032] Figure 2 This is a conceptual diagram representing the overall structure of an electrocardiogram (ECG) signal measurement system, which includes ECG signal measurement devices.

[0033] Figure 3 This is a front view showing the configuration of an electrocardiogram (ECG) signal measuring device mounted on a chair.

[0034] Figure 4 This is a back view showing the relationship between the ECG signal measuring device and the contact area of ​​the body.

[0035] Figure 5The waveforms of the electrocardiogram (ECG) signals from one of the two ECG measurement units are shown. (a) The ECG signal waveform is obtained when the signal amplification unit is fed back using electrodes of different polarities in the two ECG measurement units. (b) The ECG signal waveform is obtained when the signal amplification unit is fed back using electrodes of the same polarity in the two ECG measurement units.

[0036] Figure 6 This is a diagram showing an example of the waveform of an electrocardiogram (ECG) signal measured by an ECG signal measuring device.

[0037] Figure 7 The second embodiment of the present invention is shown in a front view of a vest in which an electrocardiogram signal measuring device is mounted.

[0038] Figure 8 It is a trend chart obtained by calculating the long-term average heart rate based on the electrocardiogram signal obtained from the electrocardiogram signal measuring device and plotting it.

[0039] Figure 9 The diagram shown is Embodiment 3 of the present invention and illustrates other configurations of the electrode body. Detailed Implementation

[0040] (Example 1)

[0041] Figures 1 to 6 This is Embodiment 1, illustrating the electrocardiogram (ECG) signal measuring device and the ECG signal measuring system constructed including the device of the present invention. In this embodiment, front-back, left-right, and up-down directions follow... Figure 3 The crossed arrows shown, along with the markings near each arrow indicating front, back, left, right, up, and down. Figure 2 In this system, the electrocardiogram (ECG) signal measurement system 1 consists of an ECG signal measuring device 2, a system server (recording server) 3 for recording the ECG signals obtained by the ECG signal measuring device 2, and a terminal device 4 capable of acquiring the ECG signal data recorded in the system server 3. The system server 3 and the terminal device 4 are connected to a communication line 5, such as the Internet, and are able to communicate with each other. The terminal device 4 is a laptop computer.

[0042] Figure 3In the accompanying drawing, reference numeral 8 represents the seat (chair) of a vehicle such as a truck, bus, or taxi where the subject of the measurement sits. The seat 8 has a seating surface 9 supporting the buttocks and a backrest 10 (base 7) supporting the torso. In this embodiment, the electrocardiogram (ECG) signal measuring device 2 is mounted on the backrest 10. By mounting the ECG signal measuring device 2 on the vehicle seat 8 in this manner, the ECG signal of the subject sitting on the seat 8 (e.g., a truck driver) can be measured. Furthermore, the chair 8 can be an office chair or a legless chair, in addition to a vehicle seat; the important thing is that the subject can sit comfortably and lean back. When the chair 8 is an office chair, the ECG signal of the subject sitting on the office chair (e.g., an office worker in a company) can be measured.

[0043] like Figure 1 As shown, the electrocardiogram (ECG) signal measuring device 2 includes: two ECG measuring units 13 and 13 for measuring ECG signals; an analog-to-digital converter 15 (hereinafter referred to as A / D converter 15) for converting the ECG signals measured by the ECG measuring units 13 and 13, which consist of voltage-modulated analog signals (hereinafter referred to as analog signals), into ECG signals consisting of digital signals; a wireless communication unit 16 for establishing wireless communication between the ECG signal measuring device 2 and the communication line 5; and a power supply unit 17 for supplying driving power to the ECG measuring units 13 and 13 and the wireless communication unit 16. The wireless communication unit 16 can be configured as wireless communication using the IEEE 802.15.1 standard, which is a short-range wireless communication standard, or as wireless communication using a cellular method (mobile phone communication network). The power supply unit 17 is preferably configured as a primary battery or a secondary battery. In addition, if driving power can be supplied from a vehicle battery, the power supply unit 17 can be a vehicle battery; if the chair 8 is an office chair installed indoors, and driving power can be supplied from mains power, the power supply unit 17 can also be mains power.

[0044] As described below, in the two electrocardiogram (ECG) measurement units 13, 13, the electrodes 20 and 21 to which the inverted signals are input are positive and negative electrodes. Here, the ECG measurement unit 13 to which the inverted signal is applied to the positive electrode 20 is designated as the first channel 13A, and the ECG measurement unit 13 to which the inverted signal is applied to the negative electrode 21 is designated as the second channel 13B. The basic structure of the ECG measurement units 13 in the two channels 13A and 13B is the same, therefore, the same parts are marked with the same reference numerals and their descriptions are omitted. However, for the parts constituting the ECG measurement unit 13 of the first channel 13A, "A" is added to the end of the reference numerals. Similarly, for the parts constituting the ECG measurement unit 13 of the second channel 13B, "B" is added to the end of the reference numerals.

[0045] Figure 1In the first channel 13A, the electrocardiogram (ECG) measurement unit 13 includes a pair of positive and negative electrode bodies 20A (20) and 21A (21) composed of capacitively coupled electrodes for detecting electrical signals from the torso, and a signal processing unit 22A (22) for processing the electrical signals detected by the positive and negative electrode bodies 20A and 21A to obtain an ECG signal. The signal processing unit 22A includes an instrumentation amplifier (signal amplification unit) 23A (23) connected to the positive and negative electrode bodies 20A and 21A, a noise removal unit 24A (24) for removing noise contained in the ECG signal output from the instrumentation amplifier 23A, and a differential amplifier 25A (25) for amplifying and outputting the noise-removed ECG signal. The positive electrode body 20A is connected to the positive input terminal of the instrumentation amplifier 23A, and the negative electrode body 21A is connected to the negative input terminal of the instrumentation amplifier 23A. The noise removal unit 24A removes line noise and interference noise contained in the electrocardiogram signal output from the instrumentation amplifier 23A, and is composed of a high-pass filter 26A (26) and a low-pass filter 27A (27).

[0046] The instrumentation amplifier 23A includes an inverting output section 28A (28) that inverts the common-mode signal of the electrical signals input from the positive and negative electrodes 20A and 21A, outputting it as an inverted signal. The inverting output section 28A is connected to one input terminal of the feedback amplifier 29A (29). The other input terminal of the feedback amplifier 29A is connected to a reference voltage circuit, and the output terminal of the feedback amplifier 29A is connected to the positive electrode 20A. In this embodiment, the output terminal of the feedback amplifier 29A is connected to the cable connecting the positive electrode 20A and the instrumentation amplifier 23A. However, the output terminal of the feedback amplifier 29A can also be directly connected to the positive electrode 20A.

[0047] In the ECG measurement section 13 of the second channel 13B on the other side, the output terminal of the feedback amplifier 29B (29) is connected to the cable that connects the negative electrode 21B to the instrumentation amplifier 23B. However, the output terminal of the feedback amplifier 29B can also be directly connected to the negative electrode 21B.

[0048] The signal processing units 22A and 22B and the A / D conversion unit 15, which constitute the two electrocardiogram (ECG) measurement units 13 and 13, are fixed to the lower center of the rear surface of the backrest 10 when housed in the ECG measurement circuit box 30. Additionally, the aforementioned wireless communication unit 16 and power supply unit 17 are fixed to the left and right sides of the ECG measurement circuit box 30 (see reference 1). Figure 3 ).

[0049] like Figure 3As shown, the positive and negative electrode bodies 20 (20A, 20B) and 21 (21A, 21B) of the first and second channels 13A and 13B are respectively formed in a disk shape and fixed to the front surface of the backrest 10. The positive electrode body 20A of the first channel 13A is disposed on the upper left side of the backrest 10, and the negative electrode body 21A is disposed on the upper right side of the backrest 10. The positive electrode body 20B of the second channel 13B is disposed on the lower left side of the backrest 10, and the negative electrode body 21B is disposed on the lower right side of the backrest 10.

[0050] In addition, such as Figure 3 As shown, in the first channel 13A located on the upper side, the positive and negative electrode bodies 20A and 21A constituting this channel 13A are positioned at approximately the same height. Similarly, in the second channel 13B located on the lower side, the positive and negative electrode bodies 20B and 21B constituting this channel 13B are positioned at approximately the same height. Based on the above description, within the backrest 10, the positive and negative electrode bodies 20A and 21A of the first channel 13A and the positive and negative electrode bodies 20B and 21B of the second channel 13B are arranged vertically. Furthermore, the positive and negative electrode bodies 20 (20A, 20B) and 21 (21A, 21B) are positioned symmetrically about the left and right along the vertical reference line R1 of the backrest 10.

[0051] The positive and negative electrode bodies 20 (20A, 20B) and 21 (21A, 21B) are each formed of stainless steel plates with a diameter of 80mm and a thickness of 0.05mm, and are fixed to the front surface of the backrest 10 using male and female Velcro fasteners (not shown). The center-to-center distance between the left and right electrode bodies 20 (20A, 21A, 20B, 21B) is preferably set to 130-150mm; in this embodiment, it is set to 130mm. Furthermore, the center-to-center distance between the up and down electrode bodies 20 (20A, 20B) and 21 (21A, 21B) is preferably set to 90-120mm; in this embodiment, it is set to 100mm. Furthermore, the electrodes 20 and 21 are preferably configured such that the heart of the object being measured in a seated posture is located between the height positions of the first channel 13A and the second channel 13B. In this embodiment, the height dimension from the upper surface of the seating surface 9 to the center of the positive and negative electrodes 20A and 21A of the first channel 13A is set to 400mm. The positive and negative electrodes 20 (20A, 20B) and 21 (21A, 21B) can be made of stainless steel plates, or other materials such as gold-plated flexible circuit boards, conductive rubber plates, or textiles made of conductive fibers. Furthermore, they are not limited to circular shapes; they can also be elliptical or polygonal.

[0052] When the vehicle driver, who is being measured, sits on the seat surface 9 and leans against the backrest 10, the positive and negative electrodes 20 (20A, 20B) and 21 (21A, 21B) of the electrocardiogram measurement units 13, 13A and 13B of the two channels 13A and 13B are positioned on the back of the torso through clothing (see reference). Figure 4 Electrical signals can be detected using the positive and negative electrode bodies 20 (20A, 20B) and 21 (21A, 21B) that constitute the capacitively coupled electrode.

[0053] The electrical signals detected by the electrodes 20A and 21A of the first channel 13A are processed by the signal processing unit 22A to become electrocardiogram (ECG) signals. Specifically, the detected electrical signals are converted into ECG signals composed of analog signals amplified 100 times by the instrumentation amplifier 23A. These ECG signals are then filtered by a high-pass filter 26A and a low-pass filter 27A to remove line noise and interference noise, and subsequently amplified 11 times by the differential amplifier 25A. Similarly, the electrical signals detected by the electrodes 20B and 21B of the second channel 13B are processed by the signal processing unit 22B to become ECG signals. Specifically, the detected electrical signals are converted into ECG signals composed of analog signals amplified 100 times by the instrumentation amplifier 23B. These ECG signals are then filtered by a high-pass filter 26B and a low-pass filter 27B to remove line noise and interference noise, and subsequently amplified 11 times by the differential amplifier 25B.

[0054] The electrocardiogram (ECG) signals, composed of analog signals, measured by the first and second channels 13A and 13B, are converted into digital signals by the A / D converter 15. The converted ECG signals are then transmitted to the system server 3 via wireless communication established between the wireless communication unit 16 and the communication line 5. The system server 3 records and stores the acquired ECG signals in its built-in storage unit. In the A / D converter 15, the analog ECG signals are converted into 8-bit or 16-bit digital signals. This is to facilitate subsequent waveform analysis of the ECG signals and to reduce the load on wireless communication.

[0055] When detecting electrical signals, the inverting output section 28A of the first channel 13A outputs an inverted signal obtained by inverting the common-mode signal of the electrical signal input to the instrumentation amplifier 23A. This inverted signal is fed back to the positive electrode 20A via the feedback amplifier 29A. Thus, the influence of the common-mode signal of the electrical signals detected by electrodes 20A and 21A can be removed from the differential input, and therefore the noise contained in the electrical signals detected by electrodes 20A and 21A can be reduced using the so-called RLD (Right Leg Drive) method. Similarly, the inverting output section 28B of the second channel 13B outputs an inverted signal obtained by inverting the common-mode signal of the electrical signal input to the instrumentation amplifier 23B. This signal is fed back to the negative electrode 21B via the feedback amplifier 29B. Thus, the influence of the common-mode signal of the electrical signals detected by electrodes 20B and 21B can be removed from the differential input, and therefore the noise contained in the electrical signals detected by electrodes 20B and 21B can be reduced using the RLD method.

[0056] As described above, in this embodiment, an inverted signal is input to the electrodes (positive electrode 20A and negative electrode 21B) located at opposite corners of the four positive and negative electrode bodies 20 and 21 fixed to the backrest 10, thereby reducing noise more reliably.

[0057] Figure 5 (a) represents the waveform of the electrocardiogram (ECG) signal obtained when out-of-phase signals are input to electrodes of different poles. Figure 5 (b) shows the waveform of the electrocardiogram (ECG) signal when an out-of-phase signal is input to electrodes of the same polarity. Based on the waveforms of (a) and (b), it can be seen that in the lower waveform (b), although the peak of the R wave can be identified, the distinct peaks of the P and T waves cannot be identified. In contrast, in the upper waveform (a), distinct peaks can be identified for the R, P, and T waves. Specifically, the P wave in the ECG waveform reflects the electrical excitation of the atria, the R wave reflects the electrical excitation of the ventricles, and the T wave reflects the repolarization process of the excited ventricular myocardial cells.

[0058] The electrocardiogram (ECG) signals recorded in system server 3 can be obtained using terminal device 4. Figure 6 This indicates that a portion of the electrocardiogram (ECG) signal recorded in system server 3 is displayed as a waveform on terminal device 4. The upper waveform (a) is the ECG signal waveform measured using the first channel 13A, and the lower waveform (b) is the ECG signal waveform measured using the second channel 13B. Figure 4As shown, in the configuration of the positive and negative electrodes 20 (20A, 20B) and 21 (21A, 21B) of this embodiment, the positive and negative electrodes 20B and 21B of the second channel 13B are positioned close to the heart of the subject being measured. Therefore, it can be seen that the peak value of the lower waveform (b) is higher, but an electrocardiogram signal with approximately the same waveform can still be measured. Furthermore, the terminal device 4 measures the heartbeat interval based on the acquired electrocardiogram signal and performs time-domain or frequency-domain analysis, thereby calculating autonomic nerve indicators, sympathetic nerve indicators, etc., derived from the waveform and heart rate variability. Additionally, it is possible to confirm changes in heart rate over time based on the electrocardiogram signal. For example, by continuously monitoring the electrocardiogram signals of truck and bus drivers, and notifying the driver of an abnormal condition when an abnormality is detected in the electrocardiogram signal, accidents caused by poor physical condition can be prevented in advance.

[0059] As described above, the ECG signal measuring device of this embodiment includes an inverting output unit 28, which inverts the common-mode signal of the electrical signals from the positive and negative electrode bodies 20 and 21 constituting the capacitively coupled electrodes and outputs it as an inverted signal. The inverted signal output from the inverting output unit 28 is input to the positive and negative electrode bodies 20 and 21, so the noise reduction effect brought about by the so-called RLD method can be utilized, and thus a clearer ECG signal can be obtained. In addition, for example, in the case where there are RLD-dedicated electrode bodies in addition to the positive and negative electrode bodies 20 and 21, there is a risk that the contact state between the RLD-dedicated electrode body and the human body may be released, or the RLD-dedicated electrode body may be significantly removed from the human body, resulting in the loss of the noise reduction effect brought about by the RLD method. However, by providing an inverted signal to the electrode bodies 20 and 21 constituting the capacitively coupled electrodes for measuring ECG signals as in this embodiment, it is not affected by the contact state of the RLD-dedicated electrode body, etc., and the noise reduction effect based on the RLD method can be stably utilized, so a clearer ECG signal can be obtained more stably. In particular, since the two sets of electrodes 20 and 21 of the first and second channels 13A and 13B are arranged on the torso of the object being measured, even if one of them has a problem detecting the electrical signal, the other can be used as a backup. Furthermore, because the positive and negative electrodes 20 and 21 of the first and second channels 13A and 13B are arranged in the same direction, electrical signals of the same phase can be detected in both channels 13A and 13B.

[0060] Furthermore, when the inverted signal from the inverting output unit 28 is input to the ECG measurement unit 13 of the positive electrode 20 as the first channel 13A, and the inverted signal from the inverting output unit 28 is input to the ECG measurement unit 13 of the negative electrode 21 as the second channel 13B, the ECG signal measuring device simultaneously includes two channels 13A and 13B. This allows inverted signals to be applied to both the positive and negative electrodes 20 and 21. Therefore, compared to applying inverted signals to only one electrode 20 or 21, the noise reduction effect brought by the RLD method can be utilized more reliably, resulting in a clearer ECG signal (see reference). Figure 5 (a)

[0061] Furthermore, the inverted signal from the inverted output section 28A of the first channel 13A is input to the positive electrode 20A, and the inverted signal from the inverted output section 28B of the second channel 13B is input to the negative electrode 21B. Therefore, compared to applying the electrical signal from the adjacent electrodes 20A and 21A, a noise-reducing electrical signal can be applied to a larger area of ​​the body surface, reducing noise in the electrical signals detected by the positive and negative electrodes 20 (20A, 20B) and 21 (21A, 21B) and improving the signal-to-noise ratio (SN ratio). Thus, the ECG signal measuring device 2 according to this embodiment can stably measure ECG signals, thereby reducing the detection of noise and obtaining clear ECG signals.

[0062] The positive electrodes 20 (20A, 20B) of the first and second channels 13A, 13B are positioned offset to one side of the vertical reference line R1 relative to the backrest 10 (base 7) in the left-right direction. The negative electrodes 21 (21A, 21B) of the first and second channels 13A, 13B are positioned offset to the other side of the vertical reference line R1 in the left-right direction. The positive and negative electrodes 20A, 20B constituting the first channel 13A and the positive and negative electrodes 21A, 21B constituting the second channel 13B are arranged alternately vertically. Therefore, the positive and negative electrodes 20, 21 to which the inverted signal is applied are not offset to either the left-right or vertical direction, allowing for the application of an inverted signal over a wider area of ​​the body, further reducing noise and improving the signal-to-noise ratio (SN ratio). This enables stable measurement of the electrocardiogram (ECG) signal and provides a clearer ECG signal. Because the positive and negative electrode bodies 20 and 21 of the first and second channels 13A and 13B are arranged in the same direction, electrical signals of the same phase can be detected in the two channels 13A and 13B.

[0063] The signal processing unit 22 includes a noise removal unit 24 for removing noise contained in the electrocardiogram signal output from the signal amplification unit 23, so that noise can be removed from the electrocardiogram signal amplified by the signal amplification unit 23, thereby achieving clarity of the electrocardiogram signal.

[0064] The positive and negative electrodes 20 and 21 of the first and second channels 13A and 13B are disposed on the front surface of the backrest 10 of the chair 8, so the subject can measure their own electrocardiogram signal simply by sitting on the chair 8 and leaning against the backrest 10. Thus, for drivers in moving vehicles or office workers, their electrocardiogram signals can be measured stably and in a state of reduced physical strain.

[0065] Furthermore, the electrocardiogram (ECG) signal measurement system of this embodiment includes: an ECG signal measuring device 2 for measuring ECG signals; a system server 3 connected to the ECG signal measuring device 2 via a communication line 5 for recording the ECG signals measured by the ECG signal measuring device 2; and a terminal device 4 connected to the system server 3 via a communication line 5 for acquiring the ECG signals recorded in the system server 3. The ECG signal measuring device 2 includes a wireless communication unit 16 for establishing wireless communication with the communication line 5. Therefore, the ECG signals of the measurement object can be remotely monitored. For example, when the measurement object is a truck or bus driver, the ECG signals of the vehicle while driving can be easily checked at a remote location such as a company office.

[0066] Furthermore, when this ECG signal measuring device is used to measure ECG signals, it can stably obtain clear ECG signals, thus contributing to Goal 3 (Good Health and Well-being) of the United Nations Sustainable Development Goals (SDGs).

[0067] (Example 2)

[0068] Figure 7 and Figure 8 This illustrates Embodiment 2 of the present invention. The difference between this embodiment and Embodiment 1 is that the base 7 is a vest (shirt) 33, on which an electrocardiogram (ECG) signal measuring device 2 is mounted. The vest 33 includes a back piece 34 and left and right front pieces 35 and 36, which can be opened and closed via a zipper 37. On the inner side of the left front piece 35, a positive electrode 20A of the first channel 13A and a positive electrode 20B of the second channel 13B are arranged vertically, and an ECG measuring circuit box 30 housing signal processing units 22A and 22B is fixed below the positive electrode 20B. Furthermore, on the inner side of the right front piece 36, a negative electrode 21A of the first channel 13A and a negative electrode 21B of the second channel 13B are arranged vertically, and a wireless communication unit 16 and a power supply unit 17 are fixed below the negative electrode 21B. All other aspects are the same as in Embodiment 1; therefore, the same reference numerals are used for the same components, and their descriptions are omitted.

[0069] The subject wears a vest 33, allowing the positive and negative electrodes 20 (20A, 20B) and 21 (21A, 21B) of the two channels 13A and 13B to be positioned on the front of the torso, i.e., the chest. Electrocardiogram (ECG) signals can be measured regardless of the subject's movement or posture. Because the ECG signal measuring device 2 uses capacitively coupled electrodes to detect electrical signals in the torso, ECG signals can be measured non-invasively through clothing.

[0070] This section illustrates an example of using a vest 33 equipped with an electrocardiogram (ECG) signal measurement device 2 to detect paroxysmal atrial fibrillation. The subject was a 70-year-old male with underlying conditions including hypertension and diabetes, suspected of having paroxysmal atrial fibrillation. The subject was observed wearing the vest 33 of this embodiment over his underwear and living quietly indoors. ECG signal measurements were performed for 24 hours starting at 00:00 AM (until 00:00 AM the following day). Based on the measured ECG signals, the heart rate was averaged over a 5-second moving average, and the average was plotted against time to obtain the following result: Figure 8 The graph shows the trend of average heart rate over a long period of time. Figure 8 The graph shows the time from 4 AM to 8 PM. According to the graph, the subject's resting heart rate was 70 to 80 beats per minute, and two abnormal heart rates exceeding 150 beats per minute, including atrial fibrillation, were observed for more than one hour, typical signs of paroxysmal atrial fibrillation.

[0071] As described above, according to this embodiment, the positive and negative electrodes 20 and 21 can be easily positioned on the chest (torso) simply by wearing a vest 33, thus minimizing the burden on the subject even when measuring electrocardiogram (ECG) signals for extended periods. Furthermore, it has the advantage of allowing ECG signals to be measured without restricting movement, even during daily life or while driving.

[0072] In the above embodiment, the positive and negative electrode bodies 20A and 21A of the first channel 13A are arranged on the upper side of the front surface of the backrest 10, and the positive and negative electrode bodies 20B and 21B of the second channel 13B are arranged on the lower side, but they can also be reversed.

[0073] Alternatively, it can be like Figure 9 As shown, the positive and negative electrode bodies 20A and 21A of the first channel 13A are arranged vertically on one side (left side in the example shown) of the front surface of the backrest 10, and the positive and negative electrode bodies 20B and 21B of the second channel 13B are arranged vertically on the other side (right side in the example shown).

[0074] Specifically, the positive electrode 20A of the first channel 13A is disposed on the upper left side of the backrest 10, and the negative electrode 21A is disposed on the lower left side of the backrest 10. The positive electrode 20B of the second channel 13B is disposed on the upper right side of the backrest 10, and the negative electrode 21B is disposed on the lower right side of the backrest 10.

[0075] In addition, such as Figure 9 As shown, the positive electrodes 20A and 20B of the first channel 13A and the second channel 13B located on the upper side are set at approximately the same height. Similarly, the negative electrodes 21A and 21B of the first channel 13A and the second channel 13B located on the lower side are also set at approximately the same height. Based on the above description, within the backrest 10, the positive and negative electrodes 20A and 21A of the first channel 13A and the positive and negative electrodes 20B and 21B of the second channel 13B are arranged horizontally. Furthermore, the positive and negative electrodes 20 (20A, 20B) and 21 (21A, 21B) are positioned symmetrically above and below each other along a horizontal reference line R2, separated by the backrest 10.

[0076] Because the positive electrodes 20 (20A, 20B) constituting the first and second channels 13A, 13B are positioned offset from the horizontal reference line R2 relative to the backrest 10 (base 7) in one direction, and the negative electrodes 21 (21A, 21B) constituting the first and second channels (13A, 13B) are positioned offset from the vertical reference line R2 in the other direction, and the positive and negative electrodes 20A, 21A constituting the first channel 13A and the positive and negative electrodes 20B, 21B constituting the second channel 13B are arranged side-by-side, the positive and negative electrodes 20, 21 to which the inverted signal is applied are not offset to either side, allowing the inverted signal to be applied to a wider area of ​​the human body, further reducing noise and improving the signal-to-noise ratio. Therefore, stable measurement of the electrocardiogram (ECG) signal is possible, and a clearer ECG signal can be obtained. Because the positive and negative electrode bodies 20 and 21 of the first and second channels 13A and 13B are arranged in the same direction, electrical signals of the same phase can be detected in the two channels 13A and 13B.

[0077] The electrocardiogram (ECG) measurement unit 13 is configured to include two sets of channels, 13A and 13B, but more than three sets of channels can be provided as long as there is space. The noise removal unit 24 may include either a high-pass filter 26 or a low-pass filter 27. The ECG signal measurement device 2 and the system server 3 may also use wired communication.

[0078] Explanation of reference numerals in the attached figures

[0079] 1. Electrocardiogram (ECG) signal measurement system

[0080] 2. Electrocardiogram (ECG) signal measurement device

[0081] 3. Server used for recording (system server)

[0082] 4. Terminal device

[0083] 5. Communication lines

[0084] 7. Matrix

[0085] 8. Chairs (seats)

[0086] 10 Backrest

[0087] 13. Electrocardiogram Measurement Department

[0088] 13A First Passage

[0089] 13B Second Channel

[0090] 16. Wireless Communications Department

[0091] 20 (20A, 20B) positive electrode body

[0092] 21 (21A, 21B) negative electrode body

[0093] 22 Signal Processing Department

[0094] 23. Signal Amplification Section (Instrumentation Amplifier)

[0095] 24 Noise Removal Unit

[0096] 28 Inverting output terminal

[0097] 33 Top (Vest)

Claims

1. A multi-channel electrocardiogram (ECG) signal measuring device comprising multiple ECG measuring units (13) for measuring ECG signals, characterized in that: It includes an electrocardiogram measurement unit (13) as the first channel (13A) and an electrocardiogram measurement unit (13) as the second channel (13B). The electrocardiogram (ECG) measurement unit (13), which serves as the first channel (13A), includes: a pair of positive and negative electrodes (20A, 21A) that constitute capacitively coupled electrodes and can be disposed on the human body in a non-contact state; a signal amplification unit (23A) that amplifies the electrical signals from the two electrodes (20A, 21A) and outputs them as ECG signals, wherein the positive input terminal of the signal amplification unit (23A) is connected to the positive electrode (20A) and the negative input terminal is connected to the negative electrode (21A); and an inverting output unit (28A) that inverts the common-mode signal of the electrical signals from the two electrodes (20A, 21A) and outputs it as an inverted signal, wherein the inverted signal output from the inverting output unit (28A) is input to the positive electrode (20A). The electrocardiogram (ECG) measurement unit (13), which is the second channel (13B), includes: a pair of positive and negative electrodes (20B, 21B) that constitute a capacitively coupled electrode and can be disposed on the human body in a state of non-contact with the human body; a signal amplification unit (23B) that amplifies the electrical signals from the two electrodes (20B, 21B) and outputs them as ECG signals, wherein the positive input terminal of the signal amplification unit (23B) is connected to the positive electrode (20B) and the negative input terminal is connected to the negative electrode (21B); and an inverting output unit (28B) that inverts the common-mode signal of the electrical signals from the two electrodes (20B, 21B) and outputs it as an inverted signal, wherein the inverted signal output from the inverting output unit (28B) is input to the negative electrode (21B).

2. The electrocardiogram signal measuring device as described in claim 1, characterized in that: It has a base (7) for supporting a human body or being worn by a human body, wherein electrode bodies (20, 21) are mounted on the base (7). The positive electrodes (20 (20A, 20B)) of the first and second channels (13A, 13B) are positioned relative to the substrate (7) along the vertical reference line (R1) and offset to one side in the horizontal direction. The negative electrode bodies (21 (21A, 21B)) of the first and second channels (13A, 13B) are positioned at a location offset from the reference line (R1) in the left-right direction. Furthermore, the positive and negative electrode bodies (20A, 21A) of the first channel (13A) and the positive and negative electrode bodies (20B, 21B) of the second channel (13B) are arranged alternately in the vertical direction.

3. The electrocardiogram signal measuring device as described in claim 1, characterized in that: It has a base (7) for supporting a human body or being worn by a human body, wherein electrode bodies (20, 21) are mounted on the base (7). The positive electrode bodies (20 (20A, 20B)) constituting the first and second channels (13A, 13B) are positioned relative to the horizontal reference line (R2) of the substrate (7) and offset from one side in the vertical direction. The negative electrode bodies (21 (21A, 21B)) constituting the first and second channels (13A, 13B) are positioned at a location offset from the reference line (R2) in the vertical direction. Furthermore, the positive and negative electrode bodies (20A, 21A) constituting the first channel (13A) and the positive and negative electrode bodies (20B, 21B) constituting the second channel (13B) are arranged alternately in the left-right direction.

4. The electrocardiogram signal measuring device according to any one of claims 1 to 3, characterized in that: The electrocardiogram measurement unit (13) includes a noise removal unit (24) for removing noise contained in the electrocardiogram signal output from the signal amplification unit (23).

5. The electrocardiogram signal measuring device as described in any one of claims 2 to 4, characterized in that: The base (7) is the backrest (10) of the chair (8). Positive and negative electrodes (20, 21) of the electrocardiogram measurement unit (13) are provided on the front surface of the backrest (10).

6. The electrocardiogram signal measuring device according to any one of claims 2 to 4, characterized in that: The base (7) is a top (33) that can be worn on the upper body of the human body. The positive and negative electrodes (20, 21) of the electrocardiogram measurement unit (13) are provided on the top (33).

7. An electrocardiogram (ECG) signal measurement system, characterized in that, include: The electrocardiogram (ECG) measuring device (2) as described in any one of claims 1 to 6 for measuring ECG signals; The server (3) for recording is connected to the electrocardiogram signal measuring device (2) via a communication line (5) and is used to record the electrocardiogram signal measured by the electrocardiogram signal measuring device (2); and The terminal device (4) is connected to the recording server (3) via a communication line (5) and is able to obtain the electrocardiogram signals recorded in the recording server (3). The electrocardiogram signal measuring device (2) includes a wireless communication unit (16) for establishing wireless communication with the communication line (5).

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