Novel seven-lead dynamic electrocardiograph

Abstract

The utility model discloses a novel seven-lead dynamic electrocardiograph circuit which comprises an MCU, a storage unit, a display unit, a setting unit, an electrocardio analog front end AFE and a USB communication isolation unit, the storage unit, the display unit, the setting unit, the electrocardio analog front end AFE and the USB communication isolation unit are all connected with the MCU, the electrocardio analog front end AFE is connected with five electrodes, and the USB communication isolation unit is connected with the MCU. An analog circuit is arranged in the electrocardio analog front end AFE, and an isolating circuit is arranged in the USB communication isolating unit. The utility model has the advantages of small volume, low power consumption, low noise, high common mode rejection ratio and strong performance; the service life is long, the transmission speed is fast and the storage space is large.

Description

Technical Field

[0001] This utility model relates to the field of electrocardiogram (ECG) technology, specifically a novel seven-lead dynamic ECG. Background Technology

[0002] An electrocardiograph (ECG) is an instrument that acquires the bioelectrical signals generated by the excitation of the myocardium during cardiac activity through electrodes placed on the body surface. ECG machines can display and record electrocardiograms (ECGs). ECG machines can be categorized by their purpose into conventional ECG machines, Holter monitors, and cardiac monitors. Conventional ECG machines typically record only a few tens of seconds of the patient's ECG, and statistics show that they can only detect about ten percent of heart problems, with a high rate of missed diagnoses for arrhythmias, paroxysmal angina, and myocardial ischemia. Holter monitors can continuously record a patient's ECG for 24 hours, recording over 100,000 heartbeats, significantly improving the detection rate of arrhythmias, paroxysmal angina, and myocardial ischemia. Holter monitors are generally available in three-lead and twelve-lead versions.

[0003] Figure 1 The electrode placement positions for a three-lead Holter monitor are as follows:

[0004] It can be seen that the three-lead dynamic electrocardiograph has the problems of limited electrocardiogram information (only 3 leads) and the electrocardiogram is not a standard electrocardiogram (the electrode placement is not standard).

[0005] Figure 2 The electrode placement positions for a 12-lead Holter monitor are as follows:

[0006]

[0007]

[0008] The following table shows the lead definitions for a 12-lead Holter monitor:

[0009]

[0010]

[0011] Wilson endpoint WCT = (RA + LA + LL) / 3

[0012] Number of electrodes: 10: RA, LA, LL, RL, V1, V2, V3, V4, V5, V6

[0013] As can be seen, the placement of the three-lead leads differs from that of the twelve-lead limb leads. The electrocardiogram acquired by the three-lead Holter monitor is not a standard electrocardiogram, meaning it does not have standard leads I, II, III, aVL, aVR, aVF, and V. This can affect diagnosis. The twelve-lead Holter monitor requires 10 electrodes, resulting in more lead wires that are prone to tangling; each use requires 10 disposable electrode pads.

[0014] In summary, three-lead or twelve-lead Holter monitoring has the following disadvantages:

[0015] 1. The electrocardiograms acquired by the three-lead dynamic electrocardiograph are not standard electrocardiograms, which has an adverse effect on diagnosis.

[0016] 2. The amount of electrocardiogram information collected by the three-lead dynamic electrocardiograph is relatively small.

[0017] 3. A 12-lead dynamic electrocardiograph requires 10 electrodes, resulting in a large number of leads that are prone to tangling.

[0018] 4. A 12-lead dynamic electrocardiograph requires 10 disposable electrode pads, which will take a long time to wear and consume a lot of disposable electrode pads.

[0019] 5. A 12-lead Holter monitor requires data acquisition from 8 leads, with the remaining 4 leads obtained through calculation. Therefore, it stores a large amount of data and occupies significant storage space, which may result in slow data retrieval speeds.

[0020] 6. A 12-lead dynamic electrocardiogram requires the design of 8 acquisition channels, which involves complex hardware circuitry and occupies a lot of storage space, thus resulting in higher costs. Utility Model Content

[0021] The purpose of this invention is to provide a novel seven-lead dynamic electrocardiograph to solve the problems mentioned in the background art.

[0022] To achieve the above objectives, this utility model provides the following technical solution: a novel seven-lead dynamic electrocardiograph circuit, comprising an MCU, a storage unit, a display unit, a setting unit, an electrocardiogram analog front-end (AFE), and a USB communication isolation unit. The storage unit, display unit, setting unit, electrocardiogram analog front-end (AFE), and USB communication isolation unit are all connected to the MCU. The electrocardiogram analog front-end (AFE) is connected to five electrodes and has a built-in analog circuit. The USB communication isolation unit has a built-in isolation circuit.

[0023] Preferably, the analog circuit includes a terminal J1, a clock circuit, a reset circuit, and a shielding circuit, and the terminal J1, clock circuit, reset circuit, and shielding circuit are connected to the processor U6.

[0024] Preferably, terminal J1 is connected to a lead wire, which is connected to five electrodes via snap fasteners.

[0025] Preferably, the terminal J1 has six pins, namely RA, LA, LL, RL, V and SHIELD.

[0026] Preferably, the ECG analog front-end (AFE) includes an amplifier, a filter, and a 24-bit analog-to-digital converter.

[0027] Preferably, the clock circuit includes a crystal oscillator Y1, a capacitor C15, and a capacitor C16. The two pins of the crystal oscillator Y1 are connected to pins 23 and 24 of the processor U6, and the capacitors C15 and C16 are connected to the two pins of the crystal oscillator Y1.

[0028] Preferably, the reset circuit includes a resistor R9 and a capacitor C73, wherein the capacitor C73 is connected to pin 27 of the processor U6, and the resistor R9 is connected to the capacitor C73.

[0029] Preferably, the shielding circuit includes resistor R11, resistor R10, and capacitor C22. Resistor R11 is connected to pin 8 of processor U6, capacitor C22 is connected to pin 9 of processor U6, and resistor R10 is connected to both pins of capacitor C22.

[0030] Preferably, the isolation circuit includes a processor U9, whose UD+ and UD- pins are connected to a PC terminal.

[0031] Preferably, the DD+ and DD- pins of the processor U9 are connected to the MCU.

[0032] Compared with the prior art, the beneficial effects of this utility model are:

[0033] 1. This invention employs a highly integrated analog front-end (AFE) for electrocardiogram (ECG). This AFE integrates a three-channel high-performance preamplifier, filter, 24-bit analog-to-digital converter, Wilson terminals, and common-mode drivers. It features small size, low power consumption, low noise, and high common-mode rejection ratio.

[0034] 2. It adopts a low-power Cortex-M4 processor, supports floating-point calculations, and uses an advanced 55nm manufacturing process, resulting in low power consumption and high performance.

[0035] 3. It uses a large-capacity SLC NAND Flash memory to store ECG data, which can be erased 100,000 times, with high reliability, far exceeding the 10-year lifespan of medical devices.

[0036] 4. Powered by a single AA battery, it supports the acquisition of 24-hour Holter ECG or the real-time acquisition and transmission of 24-hour Holter ECG via Bluetooth.

[0037] 5. It adopts a 128*64 dot matrix monochrome LCD display screen, which can display the patient's electrocardiogram and has low power consumption.

[0038] 6. This utility model only requires 5 electrodes: RA, LA, RL, LL, and V, which saves 5 electrodes compared to a 12-lead dynamic electrocardiograph, making the structure simpler and the production cost lower.

[0039] 7. This utility model uses a low-power Bluetooth 5.3 module, which features low power consumption and fast data throughput.

[0040] 8. This utility model can be used in conjunction with a mobile APP to collect the patient's dynamic electrocardiogram in real time and upload it to the server via the mobile phone to achieve the purpose of real-time monitoring. Attached Figure Description

[0041] Figure 1 Diagram showing the electrode placement of an existing three-lead dynamic electrocardiograph;

[0042] Figure 2 Diagram showing the electrode placement of an existing 12-lead dynamic electrocardiograph.

[0043] Figure 3 This is a schematic diagram of the module relationship of this utility model;

[0044] Figure 4 This is a schematic diagram of the ECG simulation front-end module of this utility model;

[0045] Figure 5 This is a circuit diagram of the analog circuit of this utility model;

[0046] Figure 6 This is a circuit diagram of the isolation circuit of this utility model. Detailed Implementation

[0047] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0048] Please see Figures 3 to 6This utility model provides a technical solution: a novel seven-lead dynamic electrocardiograph circuit, including an MCU, a storage unit 100, a display unit 200, a setting unit 300, an analog front-end (AFE) 400, and a USB communication isolation unit 500. The storage unit 100, display unit 200, setting unit 300, AFE 400, and USB communication isolation unit 500 are all connected to the MCU. The MCU uses a low-power Cortex-M4 processor. The Cortex-M4 processor is configured with a highly integrated AFE chip via an SPI interface. The processor can read the ECG data collected by the AFE at sampling rates of 256 points / second, 512 points / second, or 1024 points / second and perform quantization processing. The collected ECG data, after data processing and quantization, forms an ECG, which can be displayed on a screen, stored in a large-capacity storage device, or uploaded to a mobile APP via Bluetooth. The ECG data from storage unit 100 can be read by ECG processing software on a computer via USB port. The read ECG data can then be played back, displayed, calculated, processed, and printed by the software. The ECG analog front-end 400 is connected to five electrodes: RA, LA, RL, LL, and V. The ECG analog front-end 400 has built-in analog circuitry, the USB communication isolation unit 500 has built-in isolation circuitry, and the setting unit 300 has physical buttons for setting time, sampling rate, etc.

[0049] In some specific embodiments of this utility model, the working voltage of this utility model is 3.3V, which is provided by the built-in battery unit. The battery unit can be a single AA battery or a rechargeable lithium battery, and there is no limitation here.

[0050] In some embodiments provided by this utility model, the ECG analog front-end 400 is a highly integrated circuit. The ECG analog front-end 400 has a built-in preamplifier 401, filter 402, and 24-bit analog-to-digital converter 403. The preamplifier 401, filter 402, and 24-bit analog-to-digital converter 403 are connected to the analog circuit to convert the signal into digital information.

[0051] In some specific embodiments provided by this utility model, the analog circuit includes a terminal J1, a clock circuit, a reset circuit, and a shielding circuit, and the terminal J1, clock circuit, reset circuit, and shielding circuit are connected to the processor U6.

[0052] Terminal J1 connects to the lead wires, which in turn connect to five electrodes via snaps. Terminal J1 has six pins: RA, LA, LL, RL, V, and SHIELD. Lead I ECG is acquired via LA-RA of terminal J1. The acquired signal is converted to 24-bit digital data by the preamplifier 401, filter 402, and 24-bit analog-to-digital converter 403 within the ECG analog front-end 400. Lead II ECG is acquired via LL-RA of J1. The acquired signal is converted to 24-bit digital data by PIN3-PIN2 of the ECG analog front-end 400 via the internal preamplifier 401, filter 402, and 24-bit analog-to-digital converter 403. Lead V ECG is acquired via V-WCT (the WCT endpoint inside the AFE) of J1. aVR, aVL, and aVF are calculated from leads I, II, and III, respectively. RL of J1 is the right leg drive electrode, which can suppress common-mode interference and improve anti-interference capability.

[0053] Specifically, the clock circuit includes crystal oscillator Y1, capacitor C15, and capacitor C16. Two pins of crystal oscillator Y1 are connected to pins 23 and 24 of processor U6. Capacitors C15 and C16 are connected to the two pins of crystal oscillator Y1. Capacitor C16 is also connected to pin 22 of processor U6 and is grounded through parallel capacitors C19 and C20.

[0054] Specifically, the reset circuit includes a resistor R9 and a capacitor C73. The capacitor C73 is connected to pin 27 of the processor U6. The resistor R9 is connected to the capacitor C73. The capacitor C73 is also connected to pin 26 of the processor U6 through a capacitor C26. The reset circuit is connected in parallel with pins 78 and 28 of the processor U66, and capacitors C17 and C18 are connected in parallel.

[0055] Specifically, the shielding circuit includes resistor R11, resistor R10, and capacitor C22. Resistor R11 is connected to pin 8 of processor U6, capacitor C22 is connected to pin 9 of processor U6, and resistor R10 is connected to both pins of capacitor C22.

[0056] In some specific embodiments provided by this utility model, the isolation circuit can provide 5000V DC isolation, which greatly improves the safety of patients and fully meets the safety requirements of GB9706.1-2020. Specifically, the isolation circuit includes a processor U9, and the UD+ pin (USB_UP_D+) and UD- pin (USB_UP_D-) of the processor U9 are connected to a PC terminal.

[0057] Specifically, the DD+ pin (USB_D+) and DD- pin (USB_D-) of the processor U9 are connected to the MCU.

[0058] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A novel seven-lead dynamic electrocardiograph, characterized in that, It includes an MCU, a storage unit, a display unit, a setting unit, an ECG analog front-end (AFE), and a USB communication isolation unit. The storage unit, display unit, setting unit, ECG analog front-end (AFE), and USB communication isolation unit are all connected to the MCU. The ECG analog front-end (AFE) is connected to five electrodes and has built-in analog circuitry. The USB communication isolation unit has built-in isolation circuitry. The analog circuit includes terminal J1, clock circuit, reset circuit, and shielding circuit. Terminal J1, clock circuit, reset circuit, and shielding circuit are connected to processor U6. Terminal J1 is connected to lead wires, which are connected to five electrodes via snaps. Terminal J1 has six pins, namely RA, LA, LL, RL, V, and SHIELD. The ECG analog front-end (AFE) includes an amplifier, a filter, and a 24-bit analog-to-digital converter.

2. The novel seven-lead dynamic electrocardiograph according to claim 1, characterized in that: The clock circuit includes a crystal oscillator Y1, a capacitor C15, and a capacitor C16. The two pins of the crystal oscillator Y1 are connected to pins 23 and 24 of the processor U6, and the capacitors C15 and C16 are connected to the two pins of the crystal oscillator Y1.

3. A novel seven-lead dynamic electrocardiograph according to claim 2, characterized in that: The reset circuit includes a resistor R9 and a capacitor C73. The capacitor C73 is connected to pin 27 of the processor U6, and the resistor R9 is connected to the capacitor C73.

4. A novel seven-lead dynamic electrocardiograph according to claim 3, characterized in that: The shielding circuit includes resistor R11, resistor R10, and capacitor C22. Resistor R11 is connected to pin 8 of processor U6, capacitor C22 is connected to pin 9 of processor U6, and resistor R10 is connected to both pins of capacitor C22.

5. A novel seven-lead dynamic electrocardiograph according to claim 4, characterized in that: The isolation circuit includes a processor U9, whose UD+ and UD- pins are connected to a PC terminal.

6. A novel seven-lead dynamic electrocardiograph according to claim 5, characterized in that: The DD+ and DD- pins of the processor U9 are connected to the MCU.

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