Dry and wet electrode switching circuit and wearable device
By designing a wet and dry electrode switching circuit, automatic detection and switching are realized, solving the problem of cumbersome dry and wet and dry electrode switching in the prior art, and improving the user experience and the convenience of the equipment.
Patent Information
- Application Number
- CN202420458092.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-11
- Publication Date
- 2025-02-28
- Estimated Expiration
- 2034-03-11
AI Technical Summary
In the prior art, the switching of dry and wet electrodes is complicated, resulting in poor user experience and cumbersome replacement operations.
Design a dry and wet electrode switching circuit, detect the electrode type through the interface input terminal, and determine whether to switch to the corresponding acquisition circuit through the ADC acquisition signal, so as to realize automatic switching of dry and wet electrodes.
The seamless switching of dry and wet electrodes is achieved, and users can continue to wear the device without additional operations, improving the user experience and convenience of the device.
Smart Images
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Abstract
Description
Technical Field
[0001] The utility model relates to the field of electrocardiogram collection of wearable devices, and in particular to a dry-wet electrode switching circuit and a wearable device. Background Art
[0002] Electrocardiogram (ECG) is a technology that uses an electrocardiograph to record the graph of electrical activity changes generated by each cardiac cycle of the heart from the body surface. In modern medicine, hospital electrocardiographs or Holter are usually used to record the patient's electrocardiogram. At the same time, with the development of smart wearable devices in recent years, various wearable ECG recorders have gradually become popular. Existing wearable ECG recorders such as ECG watches, ECG clothes, heart rate belts and other devices focus on non-contact wear. Patients can wear them at home for a long time and record ECGs in real time over a long period of time. These devices usually set electrodes at the place where the skin contacts to collect human electrical signals; ECG electrodes are divided into dry electrodes and wet electrodes. Dry electrodes are soft and easy to make multiple electrode contact points. They have little effect on the skin and can be worn for a long time. They are usually used on smart wearable devices, but their contact impedance is high, and users with dry skin need a larger input impedance; wet electrodes have low contact impedance, and users with dry skin do not need special processing to collect good signals at the acquisition end, but wet electrodes are usually harder and not suitable for making many electrode contact points. At the same time, wet electrodes are less comfortable to wear than dry electrodes, and skin allergic reactions may occur after long-term wearing. Currently, wet electrodes are usually used on Holter.
[0003] In the prior art, the application scenarios of dry electrodes and wet electrodes are usually separate. However, for some specific patients, ECG collection in multiple application scenarios is sometimes required. For example, in the daily monitoring of postoperative patients, wearable devices are used to connect dry electrodes for ECG monitoring, but wet electrodes may be required to collect ECG signals regularly according to doctor's orders, and the electrodes need to be replaced in time for collection. In the prior art, due to the different application scenarios of dry and wet electrodes, the technical solution of switching between dry and wet electrodes is not considered in the internal circuit design of wearable devices. At this time, it is usually necessary to replace the equipment, such as using Holter to connect wet electrodes for collection or using smart wearable devices for dry electrodes for collection. The user experience is not good and the replacement operation is cumbersome. Utility Model Content
[0004] The purpose of the utility model is to overcome the deficiencies of the prior art and provide a dry-wet electrode switching circuit and a wearable device to solve the technical problem of complicated switching of dry-wet electrode devices in the prior art.
[0005] In order to solve the above technical problems, the utility model adopts the following technical solutions:
[0006] A dry-wet electrode switching circuit includes a collection chip, a collection electrode, and a collection circuit. In addition, it also includes an interface input end, wherein the interface input end includes a dry electrode interface input end and a wet electrode interface input end connected in parallel, and the interface input end is connected to an access detection branch for detecting whether the collection electrode is connected;
[0007] The interface input end is also connected to a dry and wet electrode detection branch, the dry and wet electrode detection branch is connected to an ADC, the dry electrode interface input end is grounded, and the wet electrode interface input end is connected to a resistor;
[0008] When the ADC acquisition signal is not 0 after the electrode is connected, the acquisition circuit switches to the wet electrode acquisition circuit; when the ADC acquisition signal is 0, the acquisition circuit switches to the dry electrode acquisition circuit.
[0009] Furthermore, the acquisition circuit and the acquisition electrode simultaneously realize the acquisition of ECG signals and respiratory signals. In the wet electrode acquisition circuit, ECG acquisition and respiratory acquisition share the same acquisition electrode; in the dry electrode acquisition circuit, ECG acquisition and respiratory acquisition are acquired through different acquisition electrodes.
[0010] Furthermore, the wet electrode acquisition circuit uses AFE_RESP3 and AFE_RESP4 electrodes for the acquisition of respiratory signals and electrocardiogram signals;
[0011] The respiratory signal is driven to send electrical signals through the RESP3 and RESP4 pins of the acquisition chip, and the ECG3 and ECG4 pins are driven to collect them back;
[0012] The ECG signal is driven by the ECG3 and ECG4 pins of the acquisition chip to collect the ECG signal.
[0013] Furthermore, in the dry electrode acquisition circuit, the respiratory signal is acquired through the AFE_RESP3 and AFE_RESP4 electrodes;
[0014] The respiratory signal is driven to send electrical signals through the RESP3 and RESP4 pins of the acquisition chip, and the ECG3 and ECG4 pins are driven to collect them back;
[0015] The ECG signal is collected through the AFE_ECGN and AFE_ECGP electrodes, and the ECG signal is collected by driving the ECGN and ECGP pins of the acquisition chip.
[0016] Furthermore, a differential amplifier is provided at the input end of the dry electrode acquisition circuit to increase the input impedance.
[0017] On the other hand, the utility model provides a wearable device, the wearable device is provided with an electrode connection point for connecting to a base of a collection electrode, characterized in that: the wearable device is equipped with a dry-wet electrode switching circuit as described above;
[0018] The wearable device is also provided with a prompt light.
[0019] Furthermore, the wearable device is a heart rate sticker, a heart rate belt, or an electrocardiogram shirt.
[0020] The beneficial effects of the utility model are:
[0021] A dry-wet electrode switching circuit is provided, which is mounted on a wearable device. When the application scenario of the electrode changes, the electrode can be directly replaced and the wearable device can continue to be worn without additional operation or replacement of the wearable device. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.
[0023] Figure 1 It is a circuit diagram of the dry-wet electrode identification switching part in the dry-wet electrode switching circuit of the utility model;
[0024] Figure 2 It is a schematic diagram of a dry-wet electrode acquisition circuit in a dry-wet electrode switching circuit of the utility model;
[0025] Figure 3 This is a reference schematic diagram of the acquisition chip in the dry-wet electrode switching circuit of the utility model;
[0026] Figure 4 Schematic diagram of a heart rate sticker in a wearable device in an embodiment of the present utility model. DETAILED DESCRIPTION
[0027] Unless otherwise defined, all technical and scientific terms used in this document have the same meaning as commonly understood by technicians in the technical field of the present invention; the terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. For example, the directions or positions indicated by terms such as "length", "width", "up", "down", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", and "outside" are based on the directions or positions shown in the drawings, which are only for the convenience of description and cannot be understood as limitations on the present technical solution.
[0028] The terms "including" and "having" and any variations thereof in the specification and claims of the present utility model and the above-mentioned drawings are intended to cover non-exclusive inclusions; the terms "first", "second", etc. in the specification and claims of the present utility model or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. "Multiple" means two or more, unless otherwise clearly and specifically defined.
[0029] In the specification and claims of the utility model and the above-mentioned drawings, when an element is referred to as being "fixed on" or "mounted on" or "disposed on" or "connected to" another element, it may be directly or indirectly located on the other element. For example, when an element is referred to as being "connected to" another element, it may be directly or indirectly connected to the other element.
[0030] In addition, the reference to "embodiment" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present invention. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments. Example
[0031] Dry and wet electrode switching circuit
[0032] In the first aspect, the present embodiment provides a dry-wet electrode switching circuit and a wearable device, including a collection chip, a collection electrode and a collection circuit. The collection chip can use the existing chip for collecting physiological signals such as electrocardiogram and respiration. Further, Figure 1 As shown, the dry-wet electrode switching circuit also includes an interface input end, and the interface input end includes a parallel dry electrode interface input end and a wet electrode interface input end. The interface input end is connected to an access detection branch for detecting whether the collection electrode is connected. The interface input end is composed of a parallel dry electrode interface input end and a wet electrode interface input end. When the interface input end is connected to an electrode (dry electrode or wet electrode), the KEY of the access detection branch is used to determine whether the electrode is successfully connected. For possible scenarios in the embodiment, when no electrode is connected, the wearable device prompts that the electrode is not connected; when the electrode is connected but the electrode contact is abnormal, the wearable device prompts that the electrode is not connected; when the electrode is connected normally, the wearable device prompts that the electrode is connected. As an optional embodiment, the prompt of the wearable device can be in a variety of ways, such as vibration, flashing lights, voice broadcast, screen text display, and other ways.
[0033] Further, such as Figure 1As shown, the interface input end is also connected in parallel with a dry-wet electrode detection branch, the dry-wet electrode detection branch is connected to an ADC, the dry electrode interface input end is grounded, the wet electrode interface input end is connected to a resistor, and the dry electrode interface input end and the wet electrode interface input end are rectified by a diode; when the dry electrode interface input end is connected to the dry electrode, since the dry electrode interface input end is grounded, the value collected by the ADC is 0 at this time; when the wet electrode interface input end is connected to the wet electrode, since the wet electrode interface input end is connected to the resistor (not shown in the figure), the value collected by the ADC is not 0 at this time; by judging the value of the ADC, it is judged whether the wearable device is externally connected to a dry electrode or a wet electrode at this time, and further, when it is determined that the wearable device is externally connected to a dry electrode at this time, the acquisition circuit switches to the dry electrode acquisition circuit, and when it is determined that the wearable device is externally connected to a wet electrode at this time, the acquisition circuit switches to the wet electrode acquisition circuit.
[0034] Some of the current wearable devices have the function of collecting multiple physiological signals. As an optional embodiment, the dry-wet electrode switching circuit can simultaneously collect ECG signals and respiratory signals. Specifically, in the wet electrode collection circuit, ECG collection and respiratory collection share the same collection electrode; in the dry electrode collection circuit, ECG collection and respiratory collection are collected through different collection electrodes.
[0035] like Figure 2 The figure shows the acquisition circuit of dry and wet electrodes. Figure 3 This is a schematic diagram of the acquisition chip;
[0036] As an optional embodiment, in the wet electrode acquisition circuit, the acquisition of respiratory signals and electrocardiogram signals share the AFE_RESP3 and AFE_RESP4 electrodes, and the electrocardiogram signals are acquired through the ECG3 and ECG4 pins. Since the respiratory signal is calculated by sending an impedance wave to the human body to be tested and then collecting the collected signal, in this embodiment, the respiratory signal is driven by the RESP3 and RESP4 pins of the acquisition chip to send an electrical signal, and the ECG3 and ECG4 pins drive the collected signal.
[0037] As an optional embodiment, the dry electrode acquisition circuit collects the respiratory signal through the AFE_RESP3 and AFE_RESP4 electrodes;
[0038] The respiratory signal is driven to send electrical signals through the RESP3 and RESP4 pins of the acquisition chip, and the ECG3 and ECG4 pins are driven to collect them back;
[0039] Since the contact effect of dry electrodes is not as good as that of wet electrodes, in order to better collect ECG signals, it is usually necessary to increase the input impedance at the input end of the acquisition circuit. After increasing the input impedance, respiratory acquisition and ECG acquisition still share the same acquisition electrode, which will make the impedance of the ECG acquisition branch unable to be effectively improved. Therefore, in the dry electrode acquisition circuit, ECG signals are collected through another set of electrodes.
[0040] Specifically, the ECG signal is collected through the AFE_ECGN and AFE_ECGP electrodes, and the ECG signal is collected by driving the ECGN and ECGP pins of the acquisition chip.
[0041] As an optional embodiment, a differential amplifier is provided at the input end of the dry electrode acquisition circuit to increase the input impedance.
[0042] In the specific implementation, firstly, it is judged whether the electrode is connected normally by the user to be tested pressing the button KEY, and the type of electrode connected at this time is judged according to the ADC acquisition value. If the ADC acquisition value is 0, the electrode connected at this time is a dry electrode. If the ADC acquisition value is not 0, the electrode connected at this time is a wet electrode. When the dry electrode is connected, the acquisition circuit automatically switches to the dry electrode acquisition circuit, and the respiratory signal of the dry electrode acquisition circuit is driven to send electrical signals through the RESP3 and RESP4 pins of the acquisition chip, and the ECG3 and ECG4 pins are driven to collect. The electrocardiogram signal is collected through the AFE_ECGN and AFE_ECGP electrodes, and the electrocardiogram signal is driven to collect through the ECGN and ECGP pins of the acquisition chip; after replacing the wet electrode, the ADC acquisition value is set to 0, and the acquisition circuit automatically switches to the wet electrode acquisition circuit, and the acquisition of the respiratory signal and the electrocardiogram signal shares the AFE_RESP3 and AFE_RESP4 electrodes, and the respiratory signal is driven to send electrical signals through the RESP3 and RESP4 pins of the acquisition chip, and the ECG3 and ECG4 pins are driven to collect the signal; the electrocardiogram signal is driven to collect through the ECG3 and ECG4 pins.
[0043] Wearable devices
[0044] On the other hand, this embodiment provides a wearable device, such as Figure 4 The figure shows a wearable device - a heart rate patch, which is provided with an electrode connection point for connecting and replacing the collection electrode, and a reminder light is also provided on the wearable device;
[0045] More specifically, the wearable device is equipped with a dry-wet electrode switching circuit as described in the above embodiment.
[0046] In specific implementation, after the wearable device is connected to any electrode, the prompt light turns green to indicate a normal connection, and the prompt light turns off to indicate that the electrode is not connected normally. After the connection, the above-mentioned dry-wet electrode switching circuit determines whether the current connection is a wet electrode or a dry electrode, and further starts the corresponding electrode acquisition circuit. If the electrode needs to be replaced, press the button KEY again. After the electrode is connected, the circuit switches to the acquisition circuit of the replaced electrode.
[0047] As an optional embodiment, the wearable device may be in various forms such as a heart rate sticker, a heart rate belt, and an electrocardiogram shirt.
[0048] The above embodiments are preferred implementation schemes of the present invention. In addition, the present invention can also be implemented in other ways. Any obvious replacement without departing from the concept of the present technical solution is within the protection scope of the present invention.
Claims
1. A dry-wet electrode switching circuit, comprising a collection chip, a collection electrode, and a collection circuit, characterized in that: It also includes an interface input end, the interface input end includes a dry electrode interface input end and a wet electrode interface input end connected in parallel, and the interface input end is connected to an access detection branch for detecting whether the collection electrode is connected; The interface input end is also connected to a dry and wet electrode detection branch, the dry and wet electrode detection branch is connected to an ADC, the dry electrode interface input end is grounded, and the wet electrode interface input end is connected to a resistor; When the ADC acquisition signal is not 0 after the electrode is connected, the acquisition circuit switches to the wet electrode acquisition circuit; when the ADC acquisition signal is 0, the acquisition circuit switches to the dry electrode acquisition circuit.
2. The dry-wet electrode switching circuit according to claim 1, characterized in that: The acquisition circuit and the acquisition electrode simultaneously realize the acquisition of ECG signals and respiratory signals. In the wet electrode acquisition circuit, ECG acquisition and respiratory acquisition share the same acquisition electrode; in the dry electrode acquisition circuit, ECG acquisition and respiratory acquisition are acquired through different acquisition electrodes.
3. The dry-wet electrode switching circuit according to claim 2, characterized in that: The wet electrode acquisition circuit uses AFE_RESP3 and AFE_RESP4 electrodes for respiratory signal and ECG signal acquisition; The respiratory signal is driven to send electrical signals through the RESP3 and RESP4 pins of the acquisition chip, and the ECG3 and ECG4 pins are driven to collect them back; The ECG signal is driven by the ECG3 and ECG4 pins of the acquisition chip to collect the ECG signal.
4. The dry-wet electrode switching circuit according to claim 2, characterized in that: The dry electrode acquisition circuit collects the respiratory signal through the AFE_RESP3 and AFE_RESP4 electrodes; The respiratory signal is driven to send electrical signals through the RESP3 and RESP4 pins of the acquisition chip, and the ECG3 and ECG4 pins are driven to collect them back; The ECG signal is collected through the AFE_ECGN and AFE_ECGP electrodes, and the ECG signal is collected by driving the ECGN and ECGP pins of the acquisition chip.
5. The dry-wet electrode switching circuit according to claim 1, characterized in that: A differential amplifier is arranged at the input end of the dry electrode acquisition circuit to improve the input impedance.
6. A wearable device, the wearable device having an electrode connection point for connecting to a base of a collection electrode, characterized in that: The wearable device is equipped with a dry-wet electrode switching circuit as described in any one of claims 1 to 5; The wearable device is also provided with a prompt light.
7. A wearable device according to claim 6, characterized in that: The wearable device is a heart rate sticker, a heart rate belt, and an electrocardiogram shirt.