CN113749661A - Capacitive coupling PCB electrode structure for collecting human body bioelectricity signals - Google Patents
Capacitive coupling PCB electrode structure for collecting human body bioelectricity signals Download PDFInfo
- Publication number
- CN113749661A CN113749661A CN202111007796.XA CN202111007796A CN113749661A CN 113749661 A CN113749661 A CN 113749661A CN 202111007796 A CN202111007796 A CN 202111007796A CN 113749661 A CN113749661 A CN 113749661A
- Authority
- CN
- China
- Prior art keywords
- resistor
- capacitor
- insulating layer
- operational amplifier
- human body
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/24—Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
- A61B5/25—Bioelectric electrodes therefor
- A61B5/277—Capacitive electrodes
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/24—Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
- A61B5/30—Input circuits therefor
- A61B5/302—Input circuits therefor for capacitive or ionised electrodes, e.g. metal-oxide-semiconductor field-effect transistors [MOSFET]
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Heart & Thoracic Surgery (AREA)
- Molecular Biology (AREA)
- Biophysics (AREA)
- Pathology (AREA)
- Biomedical Technology (AREA)
- Veterinary Medicine (AREA)
- Medical Informatics (AREA)
- Physics & Mathematics (AREA)
- Surgery (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Measurement And Recording Of Electrical Phenomena And Electrical Characteristics Of The Living Body (AREA)
Abstract
The invention discloses a capacitive coupling PCB electrode structure for collecting human body bioelectricity signals, which adopts a lower insulating layer, an upper insulating layer and a two-stage alternating-current bootstrap buffer circuit, wherein the alternating-current bootstrap circuit leads positive feedback to the output end and the signal input end of an operational amplifier AMP1, so that the current flowing through a resistor R1 is close to 0, the operational amplifier AMP1 obtains input impedance with ultra-high T omega level, the resistor R2 and the resistor R1 form partial pressure on input signals, the gain multiple of a size control signal of the resistor R2 can be adjusted, a capacitor C1 can control the phase-frequency characteristic of the circuit, and the input signal with ultra-low frequency and the output signal of the operational amplifier AMP1 can be kept in phase by increasing the size of the capacitor C1. The capacitive coupling PCB electrode with ultrahigh input impedance can be used for coupling the bioelectricity signals by insulating objects such as air, hair and clothes, and the like, so that the comfort, portability and safety of bioelectricity signal acquisition are improved.
Description
Technical Field
The invention belongs to a capacitive coupling PCB electrode, and particularly relates to a capacitive coupling PCB electrode structure for collecting human body bioelectricity signals.
Background
Various bioelectric signals of the human body, such as Electrocardiogram (ECG), electroencephalogram (EEG), Electromyogram (EMG), Electrooculogram (EOG), etc., contain abundant information on the state of the human body's function, and have been widely used in the fields of medical clinical examination and scientific research. With the aid of modern medical instrument technology, it has become possible to utilize human body bioelectric signals in a non-invasive and relatively convenient manner for activities such as clinical physiological monitoring, assisted diagnosis, personal daily health management, and health big data services. With the rapid increase trend of chronic disease patients diagnosed in China year by year, modern medical treatment modes are gradually changed from hospital-centered distributed medical treatment to individual-centered distributed medical treatment and family-centered distributed medical treatment, so people hope to monitor various bioelectric signals of the people by means of more convenient and fast means, and the bioelectric signal acquisition device with more accuracy, comfort and operability is required.
The electrode is a key part of a bioelectricity signal acquisition device, and is divided into three categories of the existing wet electrode, the existing dry electrode and the existing capacitive coupling electrode according to the working principle. The wet electrode needs to be used with conductive adhesive, and the dry electrode needs to directly contact the metal electrode with the skin tightly. The two electrodes have the obvious defects of poor wearing comfort, conductive adhesive solidification, electrode falling, need of periodical replacement, skin damage caused by long-term wearing and the like in the using process. The capacitive coupling electrode does not need to be contacted with skin through a metal piece when in use, can be isolated from insulating objects such as air, hair, clothes and the like to couple a bioelectricity signal, and effectively avoids the defects, but the capacitive reactance between the electrode and the skin is very high due to the fact that the coupling capacitance between the electrode and the skin is only about 10pF, and the input impedance of an acquisition circuit on the existing capacitive coupling electrode is limited, so that the electrode does not have the capability of nondestructively capturing the bioelectricity signal and better anti-interference capability.
Disclosure of Invention
The invention aims to provide a capacitive coupling PCB electrode structure for collecting human body bioelectricity signals, so as to overcome the defects of the prior art.
In order to achieve the purpose, the invention adopts the following technical scheme:
a capacitive coupling PCB electrode structure for collecting human body bioelectricity signals comprises a lower insulating layer, an upper insulating layer and a two-stage alternating-current bootstrap buffer circuit, wherein a coupling electrode is arranged on the inner side of the lower insulating layer, a shielding ring is arranged on the outer ring of the coupling electrode, the outer side of the lower insulating layer is used for being attached to a human body, and a copper-clad shielding layer is arranged on the inner side of the upper insulating layer; the two-stage alternating-current bootstrap buffer circuit comprises an operational amplifier AMP1, an operational amplifier AMP2, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1 and a capacitor C2, wherein the inverting input end of the operational amplifier AMP1 is connected with one end of a capacitor C1, one end of the capacitor C2, the output end of the operational amplifier AMP1 and a shielding ring, the homodromous input end of the operational amplifier AMP1 is connected with the sum coupling electrode of the resistor R1, the other end of the resistor R1 is connected with one end of a resistor R2 and the other end of the capacitor C1, and the other end of the resistor R2 is connected with a copper-clad shielding layer and then connected with REF; the other end of the capacitor C2 is connected with one end of the resistor R3 and the same-direction input end of the operational amplifier AMP2, the other end of the resistor R3 is connected with the REF, the reverse-direction input end of the operational amplifier AMP2 is connected with one end of the resistor R4 as the output end, and the other end of the resistor R4 is connected with the output end of the operational amplifier AMP 2; the input impedance of the double-stage alternating-current bootstrap buffer circuit can reach T omega level.
Further, the lower insulating layer and the upper insulating layer are arranged on two sides of the outer side of the double-layer PCB substrate.
Furthermore, one side of the lower insulating layer, which is provided with the coupling electrode, and one side of the upper insulating layer, which is provided with the copper-coated shielding layer, are sealed through an insulating resin layer.
Furthermore, the PCB substrate is a double-layer thin plate with the thickness of 1.0mm and the diameter of 22 mm.
Further, the upper insulating layer and the lower insulating layer each have a thickness of 35 μm.
Further, the thickness of the coupling electrode and the shielding ring was 70 μm.
Furthermore, the difference between the inner diameter and the outer diameter of the shielding circular ring is 1 mm.
Furthermore, the thickness of the copper-clad shielding layer is 35 μm, and the copper-clad shielding layer is connected with a REF point of the double-stage alternating-current bootstrap buffer circuit.
Compared with the prior art, the invention has the following beneficial technical effects:
the invention discloses a capacitive coupling PCB electrode structure for collecting human body bioelectricity signals, which adopts a lower insulating layer, an upper insulating layer and a two-stage alternating-current bootstrap buffer circuit, wherein the alternating-current bootstrap circuit leads positive feedback to the output end and the signal input end of an operational amplifier AMP1, so that the current flowing through a resistor R1 is close to 0, and the operational amplifier AMP1 obtains ultrahigh input impedance of a T omega level. The resistor R2 and the resistor R1 form voltage division on the input signal, and the amplification or attenuation times of the signal can be controlled by adjusting the size of the resistor R2. The capacitor C1 can control the phase-frequency characteristic of the circuit, the low-frequency input signal and the ultra-low-frequency input signal can be kept in the same phase with the output signal of the operational amplifier AMP1 by increasing the size of the capacitor C1, the ultra-low-frequency signal synchronous phase transfer characteristic is achieved, the ultra-high input impedance capacitive coupling PCB electrode for collecting the bioelectricity signals is formed by the two-stage alternating-current bootstrap buffer circuit, the bioelectricity signals can be collected nondestructively, and the anti-interference capability is strong.
Drawings
FIG. 1 is a circuit diagram of the capacitively coupled PCB electrode of the present invention.
Fig. 2 is a schematic perspective view of the capacitively coupled PCB electrode of the present invention.
In the figure, 1, skin, 2, a barrier layer, 3, a lower insulating layer, 4, a shielding ring, 5, a coupling electrode, 6, an insulating resin layer, 7, a copper-coated shielding layer, 8, an upper insulating layer and 9, a double-stage alternating current bootstrap buffer circuit.
Detailed Description
The invention is described in further detail below with reference to the accompanying drawings:
as shown in fig. 1, a capacitive coupling PCB electrode structure for collecting human body bioelectricity signals comprises a lower insulating layer 3, an upper insulating layer 8 and a two-stage alternating-current bootstrap buffer circuit 9, wherein a coupling electrode 5 is arranged on the inner side of the lower insulating layer 3, a shielding ring 4 is arranged on the outer ring of the coupling electrode 5, the outer side of the lower insulating layer 3 is used for sticking a human body, and a copper-clad shielding layer 7 is arranged on the inner side of the upper insulating layer 8; the two-stage alternating-current bootstrap buffer circuit 9 comprises an operational amplifier AMP1, an operational amplifier AMP2, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1 and a capacitor C2, wherein the inverting input end of the operational amplifier AMP1 is connected with one end of a capacitor C1, one end of a capacitor C2, the output end of the operational amplifier AMP1 and the shielding ring 4, the homodromous input end of the operational amplifier AMP1 is connected with the coupling electrode 5 of the resistor R1, the other end of the resistor R1 is connected with one end of a resistor R2 and the other end of the capacitor C1, and the other end of the resistor R2 is connected with the copper-clad shielding layer 7 and then is connected with REF; the other end of the capacitor C2 is connected with one end of the resistor R3 and the same-direction input end of the operational amplifier AMP2, the other end of the resistor R3 is connected with the REF, the reverse-direction input end of the operational amplifier AMP2 is connected with one end of the resistor R4 as the output end, and the other end of the resistor R4 is connected with the output end of the operational amplifier AMP 2; the input impedance of the double-stage alternating-current bootstrap buffer circuit can reach T omega level.
As shown in fig. 1, the other side of the lower insulating layer 3 can be attached to the barrier layer 2 outside the human skin 1, and the barrier layer is a barrier layer formed with the human skin, such as clothes, hair and air, which can realize effective collection of various human body bioelectricity signals such as ECG, EEG, EMG and the like through insulating media such as clothes, hair and air.
The capacitive coupling PCB electrode structure for collecting the human body bioelectricity signals can stably collect the bioelectricity signals in a lossless manner, has strong anti-interference capability, can replace the traditional wet electrode and dry electrode used for collecting the human body bioelectricity signals in a general environment, and is suitable for long-time portable collection of the human body bioelectricity signals in special environments such as manned aerospace, deep sea manned diving, professional athletes and the like.
Specifically, the lower insulating layer 3 and the upper insulating layer 8 are both arranged on the outer side of the double-layer PCB substrate to form a double-layer PCB substrate structure; the side of the lower insulating layer 3 provided with the coupling electrode 5 and the side of the upper insulating layer 8 provided with the copper-clad shielding layer 7 are sealed by an insulating resin layer 6.
The PCB substrate is a double-layer thin plate, the thickness of the PCB substrate is 1.0mm, and the diameter of the PCB substrate is 22 mm. The lower layer of the PCB substrate consists of an insulating layer and a copper-clad layer, wherein the thickness of the insulating layer is 35 mu m, and the thickness of the copper-clad layer is 70 mu m;
wherein the copper-clad layer comprises a central coupling electrode and an external annular shielding ring, and the gap capacitance C between the coupling electrode and the scalpsCoupling bioelectrical signals, wherein the diameter of the coupling bioelectrical signals is 19mm, the difference between the inner diameter and the outer diameter of the copper shielding circular ring is 1mm, and an insulating resin filling material is arranged between the copper shielding circular ring and the coupling electrode; the upper layer of the PCB substrate is a copper-clad shielding layer 7 and an insulating layer, the thickness of the copper-clad shielding layer 7 is 35 mu m, the copper-clad shielding layer is connected with a REF point of a double-stage alternating-current bootstrap buffer circuit 9 and used for shielding noise of an upper-layer circuit, and the thickness of the insulating layer is 35 mu m.
The two-stage alternating-current bootstrap buffer circuit comprises an alternating-current bootstrap circuit and a following circuit; the two-stage ac bootstrap buffer circuit makes the current flowing through the resistor R1 approach 0 by introducing positive feedback at the output terminal and the signal input terminal of the operational amplifier AMP1, so that the operational amplifier AMP1 obtains an ultra-high input impedance of the level T Ω. The resistor R2 and the resistor R1 form voltage division on the input signal, and the amplification or attenuation times of the signal can be controlled by adjusting the size of the resistor R2. The capacitor C1 can control the phase frequency characteristic of the circuit, and the low frequency input signal and the ultra-low frequency input signal can keep the same phase with the output signal of the operational amplifier AMP1 by increasing the size of the capacitor C1. The capacitor C2 and the resistor R3 form a passive high-pass filter which filters out DC offset components in the output of the AMP 1. The operational amplifier AMP2 constitutes a signal follower. The operational amplifier AMP1 and the operational amplifier AMP2 are both powered by bipolarity, and the REF point of the power supply is connected with the copper-clad shielding layer of the PCB substrate.
The ultrahigh input impedance capacitive coupling PCB electrode for collecting the bioelectricity signals realizes ultrahigh input impedance of T omega level and a certain shielding function by utilizing the structural design of the PCB electrode and the structural design of an alternating-current bootstrap buffer circuit, so the electrode can collect the bioelectricity signals without damage and has stronger anti-interference capability, not only can replace the traditional wet electrode and dry electrode used for collecting the bioelectricity signals in general environment, but also is suitable for long-time portable collection of the bioelectricity signals in special environments such as manned aerospace, deep sea manned diving, professional training of athletes and the like, expands the collection scene of the bioelectricity signals of human bodies, and improves the collection efficiency of the bioelectricity signals of human bodies.
Claims (9)
1. A capacitive coupling PCB electrode structure for collecting human body bioelectricity signals is characterized by comprising a lower insulating layer (3), an upper insulating layer (8) and a two-stage alternating-current bootstrap buffer circuit (9), wherein the inner side of the lower insulating layer (3) is provided with a coupling electrode (5), the outer ring of the coupling electrode (5) is provided with a shielding ring (4), the outer side of the lower insulating layer (3) is used for sticking a human body, and the inner side of the upper insulating layer (8) is provided with a copper-coated shielding layer (7); the two-stage alternating-current bootstrap buffer circuit (9) comprises an operational amplifier AMP1, an operational amplifier AMP2, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1 and a capacitor C2, wherein the inverting input end of the operational amplifier AMP1 is connected with one end of a capacitor C1, one end of a capacitor C2, the output end of the operational amplifier AMP1 and a shielding ring (4), the homodromous input end of the operational amplifier AMP1 is connected with the coupling electrode (5) of the resistor R1, the other end of the resistor R1 is connected with one end of a resistor R2 and the other end of a capacitor C1, and the other end of the resistor R2 is connected with a copper-clad shielding layer (7) and then connected with REF; the other end of the capacitor C2 is connected with one end of the resistor R3 and the same-direction input end of the operational amplifier AMP2, the other end of the resistor R3 is connected with the REF, the reverse-direction input end of the operational amplifier AMP2 is connected with one end of the resistor R4 as the output end, and the other end of the resistor R4 is connected with the output end of the operational amplifier AMP 2; the input impedance of the double-stage alternating-current bootstrap buffer circuit can reach T omega level.
2. The capacitive coupling PCB electrode structure for human body bioelectrical signal collection according to claim 1, wherein the lower insulating layer (3) and the upper insulating layer (8) are disposed on both sides of the double-layer PCB substrate.
3. The capacitive coupling PCB electrode structure for human body bioelectrical signal acquisition as claimed in claim 2, wherein the side of the lower insulating layer (3) provided with the coupling electrode (5) and the side of the upper insulating layer (8) provided with the copper-coated shielding layer (7) are sealed by the insulating resin layer (6).
4. The capacitive coupling PCB electrode structure for human body bioelectrical signal acquisition of claim 2, wherein the PCB substrate has a thickness of 1.0mm and a diameter of 22 mm.
5. The capacitive coupling PCB electrode structure for human body bioelectrical signal acquisition as claimed in claim 1, wherein the upper insulating layer (8) and the lower insulating layer (3) are both 35 μm thick.
6. The PCB electrode structure for human body bioelectrical signal acquisition of claim 1, wherein the thickness of the coupling electrode (5) and the shielding ring (4) is 70 μm.
7. The PCB electrode structure for human body bioelectrical signal acquisition of claim 1 or 6, wherein the difference between the inner diameter and the outer diameter of the shielding ring (4) is 1 mm.
8. The PCB electrode structure for human body bioelectrical signal collection according to claim 1, wherein the copper-clad shielding layer (7) has a thickness of 35 μm and is connected to a REF point of the dual-stage AC bootstrap buffer circuit (9).
9. The PCB electrode structure of claim 1, wherein the operational amplifier AMP1 and AMP2 are connected to a bipolar power supply, the bipolar power supply comprises a capacitor C3 and a capacitor C4, one end of the capacitor C3 and one end of the capacitor C4 are connected and then connected to REF, the other end of the capacitor C3 is a positive electrode of the power supply, and the other end of the capacitor C4 is a negative electrode of the power supply.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111007796.XA CN113749661A (en) | 2021-08-30 | 2021-08-30 | Capacitive coupling PCB electrode structure for collecting human body bioelectricity signals |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111007796.XA CN113749661A (en) | 2021-08-30 | 2021-08-30 | Capacitive coupling PCB electrode structure for collecting human body bioelectricity signals |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113749661A true CN113749661A (en) | 2021-12-07 |
Family
ID=78791990
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111007796.XA Pending CN113749661A (en) | 2021-08-30 | 2021-08-30 | Capacitive coupling PCB electrode structure for collecting human body bioelectricity signals |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113749661A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114577377A (en) * | 2022-03-01 | 2022-06-03 | 山东大学 | Embedded surface leadless touch sensor and electronic equipment |
-
2021
- 2021-08-30 CN CN202111007796.XA patent/CN113749661A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114577377A (en) * | 2022-03-01 | 2022-06-03 | 山东大学 | Embedded surface leadless touch sensor and electronic equipment |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Majumder et al. | Noncontact wearable wireless ECG systems for long-term monitoring | |
| CN208799217U (en) | A kind of portable cardiac detection device and cardioelectric monitor system based on electronics epidermis | |
| US8427181B2 (en) | Floating front-end amplifier and one-wire measuring devices | |
| US8694084B2 (en) | Non-contact biopotential sensor | |
| US20070167848A1 (en) | Miniature wireless apparatus for collecting physiological signals | |
| CN105520730B (en) | Physiology signal acquires patch | |
| EP2298164A2 (en) | Cardiac monitoring circuit with adaptive sampling | |
| CN105361875A (en) | Wireless wearable electrocardiograph detection device with flexible skin electrode | |
| Dai et al. | A low-power and miniaturized electrocardiograph data collection system with smart textile electrodes for monitoring of cardiac function | |
| CN105769182A (en) | Electroencephalogram signal wireless collecting system | |
| CN106214147A (en) | A kind of wearable monitor device | |
| De Luca et al. | Pasteless electrode for clinical use | |
| CN113749661A (en) | Capacitive coupling PCB electrode structure for collecting human body bioelectricity signals | |
| WO2018129718A1 (en) | Device and method for use in detecting electrocardio signals | |
| CN101797152A (en) | Non-contact intelligent cardiac telemetry vest and operating method thereof | |
| CN215534445U (en) | Capacitive coupling PCB electrode structure for collecting human body bioelectricity signals | |
| CN113180676A (en) | Portable multi-lead electrocardiogram acquisition system and method based on capacitive coupling electrode | |
| Li et al. | Non-contact electrocardiogram measuring method based on capacitance coupling electrodes with ultra-high input impedance | |
| CN205215214U (en) | Flexible SMD bluetooth low energy electrocardio appearance | |
| Lee et al. | Low-power unobtrusive ECG sensor system for wireless power transfer | |
| Kim et al. | 32.1 A behind-the-ear patch-type mental healthcare integrated interface with 275-fold input impedance boosting and adaptive multimodal compensation capabilities | |
| Triwiyanto et al. | Recent technology and challenge in ECG data acquisition design: A review | |
| CN208511021U (en) | Sleep monitoring device based on Amplitude integrated electroencephalogram | |
| Xing et al. | A portable neuECG monitoring system for cardiac sympathetic nerve activity assessment | |
| CN209499724U (en) | A kind of portable mobile wireless ECG monitoring device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |