A configurable active electrode and signal acquisition system

Abstract

The present invention relates to a configurable active electrode and signal acquisition system, comprising: a first electrode, a first active electrode processing device corresponding to the first electrode, and a first signal lead wire; the first electrode is used to be placed on the surface of the object to be measured during signal acquisition to obtain a first induction signal; the first active electrode processing device collects the first induction signal obtained by the first electrode, and outputs a first acquisition signal after amplifying and preprocessing the first induction signal; the first signal lead wire receives the first acquisition signal and transmits the first acquisition signal to the signal acquisition device; the first signal lead wire is a shielded lead wire; the power supply signal of the first active electrode processing device is a system power supply signal, and the grounding signal of the first active electrode processing device is a system grounding signal. The present invention can improve the transmission signal-to-noise ratio of weak signals, can adapt to the acquisition requirements of different signals, and can have signal shielding and anti-interference capabilities while realizing global system power supply.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and more particularly to a configurable active electrode and a signal acquisition system. Background Art

[0002] The weak bioelectric signals on the surface of the skin reflect the real-time physiological state of the human body and play an extremely important role in health monitoring, disease diagnosis and treatment, and sports health. High-precision, portable bioelectric signal monitoring equipment combined with the use scenarios of smart wearable devices has broad application prospects. Because the bioelectric signal is very weak and the sensing collection is carried out for the human body, the interference of human daily activities and environmental noise bring great challenges to signal collection. Therefore, to obtain accurate bioelectric signals, a precise amplifier system must be used, and good collection conditions are required, such as using wet electrodes with conductive glue, the skin needs to be cleaned before collection, the collection cable needs to use shielded lead wires, and the human body needs to be in a lying or resting state in order to obtain a higher first collection signal quality. Therefore, wet electrodes are widely used in current high-precision bioelectric signal acquisition equipment. However, this electrode has obvious disadvantages: on the one hand, the skin and electrodes need to be pre-treated before measurement, the skin's stratum corneum needs to be cleaned, and conductive paste needs to be applied to make the electrode fully contact with the skin, which is inconvenient to use. On the other hand, the wet electrode itself has conductive glue, and the skin will feel uncomfortable after a period of use, which is not suitable for long-term monitoring.

[0003] The use of traditional wet electrodes and the requirements for daily human actions greatly limit the application of devices in wearable scenarios. The research and development of new electrodes and wires is mainly to overcome the shortcomings of traditional wet electrodes, that is, the electrodes can be more convenient to use and do not require additional pretreatment, and the typical representative is active electrodes.

[0004] In terms of the design of active electrodes and cables, the main method is to embed the amplifier chip in the traditional electrode shell, and use traditional shielded lead wires for signal transmission. Specific implementation schemes include: (1) The amplifier used in the electrode is generally a unit gain operational amplifier, and the amplifier circuit usually uses a conventional operational amplifier. This design can provide higher input impedance and low output impedance, and realize the function of impedance conversion. (2) The amplifier used in the electrode is a feedback operational amplifier structure based on the "virtual ground". This "virtual ground" solves the common ground problem of different wire electrodes in the system. (3) The noise shielding of the active electrode is achieved by stacking three PCBs, in which the upper and lower PCB boards provide shielding, and the middle PCB board circuit provides the function of impedance conversion. (4) In the existing active electrode structure, in the power supply scheme using an operational amplifier, the electrode circuit board generally adopts an independent power supply method, that is, local power supply requires a battery embedded in the active electrode.

[0005] For the active electrode in (1) above, although the integrated unity gain buffer can obtain a lower impedance characteristic through impedance conversion, the unity gain amplifier has no signal amplification function. The signal-to-noise ratio of the signal transmitted in the lead wire after the unit gain amplifier is relatively low, especially when the signal environment noise interference is large and the wire transmission distance is long. The "virtual ground" feedback active amplifier structure in (2) above makes the circuit design complicated and the stability of the circuit is difficult to ensure. In addition, each electrode in the multiple electrode application uses a "virtual ground" structure, which is not easy to ensure that the signal acquisition of each electrode point is on the same common ground plane, which easily causes the collected signal distortion and instability. The active electrode with a stacked structure of multiple PCB circuit boards in the upper, middle and lower parts in (3) above makes the active electrode larger and heavier, which is inconvenient to use. The power supply method of the active electrode structure described in (4) above adopts independent local power supply. On the one hand, the power supply uses button batteries or lithium batteries, which increases the volume of the electrode. On the other hand, the signal is attenuated or there is no output due to low battery power or no power during use, which is not easy to troubleshoot. Furthermore, the replacement or charging of the battery during subsequent use also brings inconvenience to use. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a configurable active electrode and a signal acquisition system in view of the above-mentioned defects of the prior art.

[0007] The technical solution adopted by the present invention to solve the technical problem is: constructing a configurable active electrode and signal acquisition system, including: a first electrode, a first active electrode processing device corresponding to the first electrode, and a first signal lead wire;

[0008] The first electrode is used to be placed on the surface of the object to be measured during signal collection to obtain a first sensing signal;

[0009] The first active electrode processing device collects a first sensing signal acquired by the first electrode, amplifies and pre-processes the first sensing signal, and then outputs a first collected signal;

[0010] The first signal lead wire receives the first acquisition signal and transmits the first acquisition signal to a signal acquisition device;

[0011] The first signal lead wire is a shielded lead wire; the power supply signal of the first active electrode processing device is a system power supply signal, and the ground signal of the first active electrode processing device is a system ground signal.

[0012] The configurable active electrode and signal acquisition system of the present invention further includes: a second electrode, a second active electrode processing device arranged corresponding to the second electrode, and a second signal lead wire;

[0013] The second electrode is used to be placed on the surface of the object to be measured during signal collection to obtain a second sensing signal;

[0014] The second active electrode processing device collects the second sensing signal obtained by the second electrode, amplifies and pre-processes the second sensing signal, and then outputs a second collected signal;

[0015] The second signal lead wire receives the second acquisition signal and transmits the second acquisition signal to a signal acquisition device;

[0016] The second signal lead wire is a shielded lead wire; the power supply signal of the second active electrode processing device is a system power supply signal, and the ground signal of the second active electrode processing device is a system ground signal.

[0017] The configurable active electrode and signal acquisition system of the present invention further includes: the signal acquisition device;

[0018] The first end of the first signal lead wire is connected to the first active electrode processing device, and the second end of the first signal lead wire is connected to the first input end of the signal acquisition device;

[0019] The first end of the second signal lead wire is connected to the second active electrode processing device, and the second end of the second signal lead wire is connected to the second input end of the signal acquisition device;

[0020] The signal acquisition device is used to receive the first acquisition signal and the second acquisition signal respectively, and process the first acquisition signal and the second acquisition signal respectively to output a first bioelectric signal and a second bioelectric signal respectively.

[0021] The configurable active electrode and signal acquisition system of the present invention further includes: a reference electrode;

[0022] The reference electrode is connected to the signal acquisition device via a cable, and is used to receive a reference voltage generated by the signal acquisition device during signal acquisition, and output the reference voltage to the surface of the object under test.

[0023] In the configurable active electrode and signal acquisition system of the present invention, the first active electrode processing device and the second active electrode processing device both include: a pre-input buffer and a post-programmable gain amplifier;

[0024] The positive input terminal of the pre-input buffer receives the first sensing signal or the second sensing signal, the negative input terminal of the pre-input buffer is connected to its output terminal, the power supply terminal of the pre-input buffer is connected to a reference power supply, the output terminal of the pre-input buffer is connected to the input terminal of the post-programmable gain amplifier, the output terminal of the post-programmable gain amplifier is connected to the first terminal of the first signal lead wire or the first terminal of the second signal lead wire, the power supply terminal of the post-programmable gain amplifier is connected to the reference power supply, and the ground terminal of the post-programmable gain amplifier is connected to a reference ground;

[0025] The reference power supply is a system power supply, and the reference ground is a system ground.

[0026] In the configurable active electrode and signal acquisition system described in the present invention, the pre-input buffer is an operational amplifier with high input impedance and low offset voltage.

[0027] In the configurable active electrode and signal acquisition system of the present invention, the post-programmable gain amplifier comprises: a low noise amplifier and a feedback loop;

[0028] The positive input end of the low noise amplifier is connected to the output end of the front input buffer as the input end of the post programmable gain amplifier, and the output end of the low noise amplifier is connected to the first end of the first signal lead wire or the first end of the second signal lead wire as the output end of the post programmable gain amplifier;

[0029] The first end of the feedback loop is connected to the negative input end of the low noise amplifier, the second end of the feedback loop is connected to the output end of the low noise amplifier, and the third end of the feedback loop is connected to the reference ground; the third end of the feedback loop is the ground end of the post-programmable gain amplifier.

[0030] In the configurable active electrode and signal acquisition system of the present invention, the feedback loop includes: a feedback resistor and a variable resistor group;

[0031] The first end of the variable resistor group is connected to the negative input end of the low noise amplifier and the first end of the feedback resistor, the second end of the variable resistor group is connected to the reference ground, and the second end of the feedback resistor is connected to the output end of the low noise amplifier; the control end of the variable resistor group is connected to the external control circuit;

[0032] The connection end between the first end of the variable resistor group and the feedback resistor is the first end of the feedback loop, the second end of the feedback resistor is the second end of the feedback loop, and the second end of the variable resistor group is the third end of the feedback loop.

[0033] In the configurable active electrode and signal acquisition system of the present invention, the variable resistor group includes: a plurality of input resistor branches arranged in parallel;

[0034] The input resistance branch includes: a sub-resistance, and an access switch connected in series with the sub-resistance; a control end of the access switch is connected to the external control circuit.

[0035] In the configurable active electrode and signal acquisition system described in the present invention, the first signal lead wire and the second signal lead wire are two-core wires, the outer layer of the two-core wires is a conductive wrapping layer, and the conductive wrapping layer is connected to the reference ground.

[0036] The configurable active electrode and signal acquisition system implementing the present invention has the following beneficial effects: comprising: a first electrode, a first active electrode processing device corresponding to the first electrode, and a first signal lead wire; the first electrode is used to be placed on the surface of the object to be measured during signal acquisition to obtain a first sensing signal; the first active electrode processing device acquires the first sensing signal acquired by the first electrode, and outputs a first acquisition signal after amplifying and preprocessing the first sensing signal; the first signal lead wire receives the first acquisition signal and transmits the first acquisition signal to the signal acquisition device; the first signal lead wire is a shielded lead wire; the power supply signal of the first active electrode processing device is a system power supply signal, and the grounding signal of the first active electrode processing device is a system grounding signal. The present invention can improve the transmission signal-to-noise ratio of weak signals, can adapt to the acquisition requirements of different signals, and can have signal shielding and anti-interference capabilities while realizing global system power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0038] Figure 1 It is a principle block diagram of a configurable active electrode and a signal acquisition system provided by an embodiment of the present invention;

[0039] Figure 2 is a circuit diagram of a configurable active electrode and a signal acquisition system provided by an embodiment of the present invention;

[0040] Figure 3 is a circuit diagram of a first active electrode processing device and a second active electrode processing device of the present invention;

[0041] Figure 4 1 is a circuit diagram of the variable resistor group of the present invention. DETAILED DESCRIPTION

[0042] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0043] The configurable active electrode and signal acquisition system provided by the embodiment of the present invention has an impedance conversion function and a certain amplification capability, which can improve the transmission signal-to-noise ratio of weak signals. At the same time, the embedded amplifier circuit has a configurable amplification factor, which can adapt to the acquisition requirements of different signals. In addition, the active electrode and signal acquisition system of the present invention can have the ability of signal shielding and anti-interference while realizing global system power supply, and has a wide range of adaptability.

[0044] Specifically, refer to Figure 1 , which is a circuit diagram of an optional embodiment of the configurable active electrode and signal acquisition system provided by the present invention.

[0045] like Figure 1 As shown, the configurable active electrode and signal acquisition system includes: a first electrode 11 , a first active electrode processing device 12 arranged corresponding to the first electrode 11 , and a first signal lead wire 13 .

[0046] The first electrode 11 is used to be placed on the surface of the object to be measured during signal acquisition to obtain a first sensing signal. The first active electrode processing device 12 collects the first sensing signal obtained by the first electrode 11, amplifies and pre-processes the first sensing signal, and outputs a first acquisition signal. The first signal lead wire 13 receives the first acquisition signal and transmits the first acquisition signal to the signal acquisition device 30. The first signal lead wire 13 is a shielded lead wire. Optionally, in an embodiment of the present invention, the object to be measured can be a biological body, such as a human being.

[0047] The power supply signal of the first active electrode processing device 12 is a system power supply signal, and the grounding signal of the first active electrode processing device 12 is a system grounding signal. By adopting the system power supply signal for power supply, the system global power supply can be realized.

[0048] Specifically, by contacting the first electrode 11 with human skin, a corresponding sensing signal can be obtained. After being amplified and pre-processed by the first active electrode processing device 12, the sensing signal obtains a certain signal-to-noise ratio, and then is transmitted to the signal acquisition device 30 through the shielded first signal lead line 13 to complete the high-precision acquisition of the entire signal.

[0049] Furthermore, if Figure 1 As shown, in some embodiments, the configurable active electrode and signal acquisition system further includes: a second electrode 21 , a second active electrode processing device 22 arranged corresponding to the second electrode 21 , and a second signal lead wire 23 .

[0050] The second electrode 21 is used to be placed on the surface of the object to be measured during signal acquisition to obtain a second sensing signal. The second active electrode processing device 22 collects the second sensing signal obtained by the second electrode 21, amplifies and pre-processes the second sensing signal, and outputs a second acquisition signal. The second signal lead wire 23 receives the second acquisition signal and transmits the second acquisition signal to the signal acquisition device 30. The second signal lead wire 23 is a shielded lead wire; the power supply signal of the second active electrode processing device 22 is a system power supply signal, and the grounding signal of the second active electrode processing device 22 is a system grounding signal.

[0051] Figure 1 , wherein the signal acquisition of two channels is shown, wherein the two channels are independent of each other. In practical applications, multiple channels can be set according to actual needs.

[0052] Furthermore, if Figure 1 As shown, the configurable active electrode and signal acquisition system also includes: a signal acquisition device 30.

[0053] The first end of the first signal lead wire 13 is connected to the first active electrode processing device 12, and the second end of the first signal lead wire 13 is connected to the first input end of the signal acquisition device 30; the first end of the second signal lead wire 23 is connected to the second active electrode processing device 22, and the second end of the second signal lead wire 23 is connected to the second input end of the signal acquisition device 30; the signal acquisition device 30 is used to receive the first acquisition signal and the second acquisition signal respectively, and process the first acquisition signal and the second acquisition signal respectively to output the first bioelectric signal and the second bioelectric signal respectively.

[0054] Furthermore, the configurable active electrode and signal acquisition system also includes: a reference electrode 31 .

[0055] The reference electrode 31 is connected to the signal acquisition device 30 via a cable, and is used to receive the reference voltage generated by the signal acquisition device 30 during signal acquisition, and output the reference voltage to the surface of the object under test.

[0056] Optionally, in an embodiment of the present invention, the signal acquisition device 30 includes an amplifier circuit, a bandpass filter circuit, an analog-to-digital converter, a microprocessor, and a reference electrode 31 circuit for generating a reference voltage.

[0057] refer to Figure 2 and Figure 3 The first active electrode processing device 12 and the second active electrode processing device 22 both include: a pre-input buffer and a post-programmable gain amplifier.

[0058] The positive input terminal of the pre-input buffer receives the first sensing signal or the second sensing signal, the negative input terminal of the pre-input buffer is connected to its output terminal, the power supply terminal of the pre-input buffer is connected to the reference power supply, the output terminal of the pre-input buffer is connected to the input terminal of the post-programmable gain amplifier, the output terminal of the post-programmable gain amplifier is connected to the first end of the first signal lead line 13 or the first end of the second signal lead line 23, the power supply terminal of the post-programmable gain amplifier is connected to the reference power supply, and the ground terminal of the post-programmable gain amplifier is connected to the reference ground; the reference power supply is the system power supply, and the reference ground is the system ground.

[0059] like Figure 3 As shown, Vi is the electrode output signal, Vo is the output signal of the post-programmable gain amplifier, AGND is the system ground, and AVDD is the system power supply.

[0060] Optionally, the pre-input buffer is a high input impedance, low offset voltage operational amplifier (such as Figure 3 in A1).

[0061] Optionally, the post-programmable gain amplifier includes: a low noise amplifier A2 and a feedback loop. Figure 3 As shown, the pre-input buffer is an operational amplifier with high input impedance and low offset voltage, and its output is connected to the negative input terminal to form a buffer structure with a closed-loop amplification position of 1.

[0062] Specifically, the positive input terminal of the low noise amplifier A2 is connected to the output terminal of the front input buffer as the input terminal of the post programmable gain amplifier, and the output terminal of the low noise amplifier A2 is connected to the first end of the first signal lead line 13 or the first end of the second signal lead line 23 as the output terminal of the post programmable gain amplifier; the first end of the feedback loop is connected to the negative input terminal of the low noise amplifier A2, the second end of the feedback loop is connected to the output terminal of the low noise amplifier A2, and the third end of the feedback loop is connected to the reference ground; the third end of the feedback loop is the ground terminal of the post programmable gain amplifier.

[0063] The feedback loop includes: a feedback resistor Rf and a variable resistor group Rs.

[0064] A first end of the variable resistor group Rs is connected to the negative input end of the low noise amplifier A2 and the first end of the feedback resistor Rf, a second end of the variable resistor group Rs is connected to the reference ground, and a second end of the feedback resistor Rf is connected to the output end of the low noise amplifier A2; a control end of the variable resistor group Rs is connected to an external control circuit; a connection end between the first end of the variable resistor group Rs and the feedback resistor Rf is a first end of a feedback loop, a second end of the feedback resistor Rf is a second end of the feedback loop, and a second end of the variable resistor group Rs is a third end of the feedback loop.

[0065] like Figure 3As shown, the post-programmable gain amplifier selects a low-noise amplifier A2 with a certain output driving capability and low noise to form a negative feedback structure with a resistor network, wherein the resistance of the feedback path is realized by the feedback resistor Rf, and the resistance from the negative input node to the reference ground is realized by the variable resistor group Rs.

[0066] The embodiment of the present invention performs impedance conversion through a unit pre-input buffer to obtain a lower impedance input while also having a signal isolation function. Moreover, the signal passing through the buffer is amplified by a post-programmable gain amplifier, and the signal can obtain a higher signal-to-noise ratio and dynamic range.

[0067] The embodiment of the present invention can support the use of dry electrodes whose electrode materials are metal or fabric due to its high input impedance. At the same time, the programmable gain can select different amplification factors for different input signals to obtain a suitable dynamic range. While protecting higher signal accuracy, it can be suitable for signal transmission over longer wires.

[0068] like Figure 3 As shown, the post-programmable gain amplifier adopts a closed-loop feedback structure, in which the resistance value of the feedback circuit is fixed, and the variable resistor group Rs can be realized by a resistor array network with different resistance values, and different resistance values ​​can be selected by an external switch control circuit to achieve different system amplification factors. Among them, the closed-loop gain of the system can be expressed as:

[0069]

[0070] In some embodiments, such as Figure 4 As shown, the variable resistor group Rs includes: a plurality of input resistor branches arranged in parallel. The input resistor branch includes: a sub-resistor and an access switch connected in series with the sub-resistor; the control end of the access switch is connected to an external control circuit.

[0071] That is Figure 4 As shown, the variable resistor group Rs may include n input resistor branches, wherein the first input resistor branch includes: a first sub-resistor and a first switch; the first input resistor branch includes: a second sub-resistor and a second switch; the third input resistor branch includes: a third sub-resistor and a third switch; ...; the nth input resistor branch includes: an nth sub-resistor and an nth switch. Therefore, different sub-resistors can be connected by controlling the opening or closing of the first switch, the second switch, the third switch, ..., and the nth switch to obtain different resistance values.

[0072] Furthermore, in an embodiment of the present invention, the power supply of the first active electrode processing device 12 and the second active electrode processing device 22 can be achieved through the first signal lead wire 13 and the second signal lead wire 23, respectively. Specifically, the first signal lead wire 13 and the second signal lead wire 23 are both two-core wires. The outer layer of the two-core wire is a conductive wrapping layer, and the conductive wrapping layer is connected to the reference ground. Among them, the two-core wire in the middle of the cable includes a signal line and a power supply (AVDD), and the outer layer of the two-core wire is a conductive wrapping layer, which can be directly connected to the reference ground (AGND). Therefore, when the plug of the wire is connected to the signal acquisition device 30 again, it will automatically connect to the AVDD and AGND of the system to complete the power supply of the active electrode processing device.

[0073] The configurable active electrode and signal acquisition system of the embodiment of the present invention can, on the one hand, ensure that the active electrodes that are relatively far away and independent of each other have the same reference ground and reference power supply, ensuring that the amplitude of the signal is not affected by the different reference power supplies when passing through the active electrode. On the other hand, the lead wire wrapping layer can shield the signal wire inside the wire while realizing power supply, thereby enhancing the anti-interference ability of the signal in the lead wire. Furthermore, compared with the traditional independent power supply mode, this power supply method does not require an independent battery to be built in the active electrode, so it is smaller in size and lighter in weight. At the same time, it will not cause the problem of misjudgment due to the inability to collect signals due to low or no power in the built-in battery of the active electrode.

[0074] The signal input electrode adopts an active electrode, and the reference electrode 31 does not need to use an active electrode.

[0075] The active electrode amplifier circuit and signal acquisition system of the present invention have simple structures and are easy to implement. They can be implemented by using separate components or by using an integrated circuit chip design solution.

[0076] The active electrode processing device of the present invention forms a unit gain buffer by selecting an operational amplifier with high input impedance and low offset voltage, has high input impedance, and can support the use of other new dry electrodes such as metal electrodes and conductive fabric electrodes. The configurable gain structure in the active electrode has flexible amplification factor setting and selection, which can effectively enhance the anti-interference ability of the electrode and the lead wire to transmit weak electrical signals and alleviate the signal attenuation problem caused by long wire transmission, thereby improving the acquisition accuracy and fidelity of weak signals. Different amplification factors can also be set for weak signals of different amplitudes, and the active electrodes based on this are more flexible to use and have a wider range of applications. In addition, the active electrode processing device of the present invention and the signal acquisition device 30 at the back end use the same power supply and ground for acquisition, so the active electrode structure does not need to be powered by a built-in independent battery, and is easy to be embedded in the active electrode structure, further reducing the complexity, weight and volume of the active electrode. At the same time, powering the device through the cable can not only solve the problem of power supply but also provide a shielding effect for signal transmission, thereby enhancing the anti-interference ability of the signal during transmission.

[0077] The configurable active electrode and signal acquisition system of the embodiment of the present invention can be applied to the field of weak electrical signal sensing, including the weak bioelectric signal acquisition for health information monitoring, and the high-precision sensing acquisition of other weak electrical signals in the Internet of Things sensor system.

[0078] In some other embodiments, the adjustable gain of the post-programmable gain amplifier may also be achieved by changing the resistance value of the feedback resistor Rf, and generally can be achieved by using an integrated operational amplifier with adjustable gain.

[0079] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0080] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0081] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0082] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot limit the scope of protection of the present invention. All equivalent changes and modifications made to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A signal acquisition system, characterized in that: include: A first electrode, a first active electrode processing device corresponding to the first electrode, and a first signal lead wire; further comprising: a second electrode, a second active electrode processing device corresponding to the second electrode, a second signal lead wire, a signal acquisition device, and a reference electrode; the first active electrode processing device and the second active electrode processing device both comprise: a front input buffer and a post programmable gain amplifier; The first electrode is used to be placed on the surface of the object to be measured during signal collection to obtain a first sensing signal; The first active electrode processing device collects a first sensing signal acquired by the first electrode, amplifies and pre-processes the first sensing signal, and then outputs a first collected signal; The first signal lead wire receives the first acquisition signal and transmits the first acquisition signal to a signal acquisition device; The first signal lead wire is a shielded lead wire; the power supply signal of the first active electrode processing device is a system power supply signal, and the ground signal of the first active electrode processing device is a system ground signal; The second electrode is used to be placed on the surface of the object to be measured during signal acquisition to obtain a second sensing signal; the second active electrode processing device acquires the second sensing signal acquired by the second electrode, amplifies and pre-processes the second sensing signal, and then outputs a second acquisition signal; the second signal lead wire receives the second acquisition signal and transmits the second acquisition signal to the signal acquisition device; the second signal lead wire is a shielded lead wire; the power supply signal of the second active electrode processing device is a system power supply signal, and the ground signal of the second active electrode processing device is a system ground signal; The first end of the first signal lead wire is connected to the first active electrode processing device, and the second end of the first signal lead wire is connected to the first input end of the signal acquisition device; the first end of the second signal lead wire is connected to the second active electrode processing device, and the second end of the second signal lead wire is connected to the second input end of the signal acquisition device; the signal acquisition device is used to receive the first acquisition signal and the second acquisition signal respectively, and process the first acquisition signal and the second acquisition signal respectively to output a first bioelectric signal and a second bioelectric signal respectively; The reference electrode is connected to the signal acquisition device via a cable, and is used to receive a reference voltage generated by the signal acquisition device during signal acquisition, and output the reference voltage to the surface of the object under test.

2. The signal acquisition system according to claim 1, characterized in that: The positive input terminal of the pre-input buffer receives the first sensing signal or the second sensing signal, the negative input terminal of the pre-input buffer is connected to its output terminal, the power supply terminal of the pre-input buffer is connected to a reference power supply, the output terminal of the pre-input buffer is connected to the input terminal of the post-programmable gain amplifier, the output terminal of the post-programmable gain amplifier is connected to the first terminal of the first signal lead wire or the first terminal of the second signal lead wire, the power supply terminal of the post-programmable gain amplifier is connected to the reference power supply, and the ground terminal of the post-programmable gain amplifier is connected to a reference ground; The reference power supply is a system power supply, and the reference ground is a system ground.

3. The signal acquisition system according to claim 2, characterized in that: The pre-input buffer is an operational amplifier with high input impedance and low offset voltage.

4. The signal acquisition system according to claim 2, characterized in that: The post-programmable gain amplifier comprises: a low noise amplifier and a feedback loop; The positive input end of the low noise amplifier is connected to the output end of the front input buffer as the input end of the post programmable gain amplifier, and the output end of the low noise amplifier is connected to the first end of the first signal lead wire or the first end of the second signal lead wire as the output end of the post programmable gain amplifier; The first end of the feedback loop is connected to the negative input end of the low noise amplifier, the second end of the feedback loop is connected to the output end of the low noise amplifier, and the third end of the feedback loop is connected to the reference ground; the third end of the feedback loop is the ground end of the post-programmable gain amplifier.

5. The signal acquisition system according to claim 4, characterized in that: The feedback loop includes: a feedback resistor and a variable resistor group; The first end of the variable resistor group is connected to the negative input end of the low noise amplifier and the first end of the feedback resistor, the second end of the variable resistor group is connected to the reference ground, and the second end of the feedback resistor is connected to the output end of the low noise amplifier; the control end of the variable resistor group is connected to the external control circuit; The connection end between the first end of the variable resistor group and the feedback resistor is the first end of the feedback loop, the second end of the feedback resistor is the second end of the feedback loop, and the second end of the variable resistor group is the third end of the feedback loop.

6. The signal acquisition system according to claim 5, characterized in that: The variable resistor group includes: a plurality of input resistor branches arranged in parallel; The input resistance branch includes: a sub-resistance, and an access switch connected in series with the sub-resistance; a control end of the access switch is connected to the external control circuit.

7. The signal acquisition system according to claim 1, characterized in that: The first signal lead wire and the second signal lead wire are two-core wires, the outer layers of the two-core wires are conductive wrapping layers, and the conductive wrapping layers are connected to a reference ground.

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