Human body coupled communication and common mode rejection parallel fusion circuit and data acquisition system

Abstract

The application discloses a human body coupling communication and common mode suppression parallel fusion circuit and a data acquisition system, and the circuit comprises a first amplifier connected with a physiological signal sensing electrode and used for amplifying and processing a physiological signal collected by the physiological signal sensing electrode; a common mode signal extraction module connected with the physiological signal sensing electrode and used for extracting a common mode interference signal; and a signal coupling module connected with the common mode signal extraction module and an input electrode respectively and used for outputting the common mode interference signal through the input electrode in reverse and receiving a transmission signal transmitted by a transmitter, coupling the transmission signal with the common mode interference suppression signal, and outputting the coupled signal through the input electrode. The application outputs the received transmission signal and the common mode interference suppression signal after superposition in the time domain, so that two paths of the transmission signal and the common mode interference suppression signal are combined into one path, and thus transmission path leakage of the transmission signal from the common mode interference suppression signal can be avoided.

Description

Technical Field

[0001] This invention relates to the field of integrated circuit design technology, and in particular to a parallel fusion circuit and data acquisition system for human body coupling communication and common-mode suppression. Background Technology

[0002] For telemedicine, real-time and low-noise acquisition of human physiological data is essential, making continuous sensing and wireless data transmission crucial. Currently, wearable devices can monitor human physiological signals in real time and transmit them wirelessly. While radio frequency (RF) communication exhibits good path loss in air, its path loss (especially in non-line-of-sight transmission) is significant in body surface transmission applications due to factors such as human shielding and antenna distortion. Compared to RF communication, capacitive human-coupled wireless communication mechanisms have attracted widespread attention. This mechanism utilizes the human body as a signal transmission medium, coupling electric field signals to the body surface via capacitive coupling and forming a loop through parasitic capacitance to ground, thereby enabling communication between devices. Due to its superior body surface path loss and its non-line-of-sight transmission capability, Body-Coupled Communication (BCC) can significantly improve energy efficiency and reduce output power consumption, making it suitable for energy-constrained wearable devices. Because ExG sensors use a dual-electrode differential structure to acquire physiological data (such as ECG heartbeat signals and EEG electroencephalograms), common-mode interference suppression is crucial. Power line interference is a primary common-mode interference signal to consider. It originates from household AC power systems, generating 50Hz AC signals that couple to the human body through various objects in the environment, causing common-mode interference. Furthermore, the amplitude of the signals acquired by ExG sensors is relatively small, making it easy for power line interference to saturate the ExG signal, resulting in the inability to acquire the desired signal. Therefore, strong suppression of power line interference is necessary.

[0003] Existing power frequency interference suppression methods include Right-LegDrive (RLD) using a reference electrode, Active Lead Bias (ALB), and Input Common-mode Current Drain (ICCD). While these methods can suppress power frequency interference to some extent, when wireless sensor nodes employ low-power, high-efficiency human body coupling communication mechanisms, these methods all cause leakage current in the high-frequency signal output by the transmitter through the common-mode interference suppression point, leading to a decrease in the transmitted signal strength and a degradation in the performance of human body coupling communication.

[0004] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a parallel fusion circuit and data acquisition system for human body coupling communication and common mode suppression, so as to avoid the problem of reduced transmission signal strength caused by transmission signal leakage while suppressing common mode interference signals.

[0006] The technical solution of the present invention is as follows:

[0007] In a first aspect, the present invention provides a parallel fusion circuit for human body coupling communication and common-mode suppression, comprising:

[0008] A first amplifier is connected to a physiological signal sensing electrode, and the first amplifier is used to amplify the physiological signals collected by the physiological signal sensing electrode.

[0009] A common-mode signal extraction module is connected to the physiological signal sensing electrode, and the common-mode signal extraction module is used to extract common-mode interference signals;

[0010] The signal coupling module is connected to the common-mode signal extraction module and the input electrode, respectively. The signal coupling module is used to invert the common-mode interference signal and output it through the input electrode, and to receive the transmitted signal output by the transmitter, and to couple the transmitted signal with the common-mode interference suppression signal and output it through the input electrode.

[0011] In a further embodiment of the present invention, the signal coupling module includes a signal amplification unit, a driving unit, and a signal coupling unit;

[0012] The signal amplification unit is connected to the common-mode signal extraction module and the driving unit respectively. The signal amplification unit is used to amplify the common-mode interference signal and output it to the driving unit.

[0013] The driving unit is connected to the signal coupling unit, and the driving unit is used to invert the common-mode interference signal and output it to the signal coupling unit.

[0014] The signal coupling unit is connected to the input electrode. The signal coupling unit is used to output the common-mode interference suppression signal to the input electrode, and to couple the common-mode interference suppression signal with the transmitted signal and then output it to the input electrode.

[0015] In a further embodiment of the present invention, the driving unit includes a low-current driving unit and a plurality of high-current driving units stacked together.

[0016] The low-current drive unit is connected to the signal amplification unit, and the low-current drive unit is used to reverse the common-mode interference signal.

[0017] The high-current drive unit is connected to the low-current drive unit, and the high-current drive unit is used to turn on when the signal coupling unit receives the transmitted signal.

[0018] In a further embodiment of the present invention, the low-current drive unit includes a first MOS transistor, a second MOS transistor, a third MOS transistor, and a fourth MOS transistor;

[0019] The source of the first MOS transistor is connected to a first current, the drain of the first MOS transistor is connected to the drain of the second MOS transistor, and the gate of the first MOS transistor is connected to the output terminal of the signal amplification unit.

[0020] The source of the second MOS transistor is connected to the source of the third MOS transistor, and the gate of the second MOS transistor is connected to the first power supply voltage;

[0021] The drain of the third MOS transistor is connected to the drain of the fourth MOS transistor, and the gate of the third MOS transistor is connected to the second power supply voltage.

[0022] The source of the fourth MOS transistor is grounded, and the gate of the fourth MOS transistor is connected to the output terminal of the signal amplification unit.

[0023] The common terminal of the drains of the first MOS transistor and the second MOS transistor is connected to the first input terminal of the signal coupling unit; the common terminal of the drains of the third MOS transistor and the fourth MOS transistor is connected to the second input terminal of the signal coupling unit.

[0024] In a further embodiment of the present invention, the high-current drive unit includes: a fifth MOS transistor, a sixth MOS transistor, a seventh MOS transistor, and an eighth MOS transistor;

[0025] The source of the fifth MOS transistor is connected to a second current, the drain of the fifth MOS transistor is connected to the drain of the sixth MOS transistor, and the gate of the sixth MOS transistor is connected to the output terminal of the signal amplification unit.

[0026] The source of the sixth MOS transistor is connected to the source of the seventh MOS transistor, and the gate of the seventh MOS transistor is connected to the output enable signal.

[0027] The drain of the seventh MOS transistor is connected to the drain of the eighth MOS transistor, and the gate of the seventh MOS transistor is connected to the output enable signal.

[0028] The source of the eighth MOS transistor is grounded, and the gate of the eighth MOS transistor is connected to the output terminal of the signal amplification unit.

[0029] The common terminal of the drains of the fifth MOS transistor and the sixth MOS transistor is connected to the first input terminal of the signal coupling unit; the common terminal of the drains of the seventh MOS transistor and the eighth MOS transistor is connected to the second input terminal of the signal coupling unit.

[0030] In a further embodiment of the present invention, the signal coupling unit includes a ninth MOS transistor and a tenth MOS transistor;

[0031] The source of the ninth MOS transistor is connected to the common terminal of the drains of the first MOS transistor and the second MOS transistor, as well as the common terminal of the drains of the fifth MOS transistor and the sixth MOS transistor. The drain of the ninth MOS transistor is connected to the drain of the tenth MOS transistor.

[0032] The source of the tenth MOS transistor is connected to the common terminal of the drains of the third and fourth MOS transistors, and the common terminal of the drains of the seventh and eighth MOS transistors.

[0033] The common terminal of the gates of the ninth MOS transistor and the tenth MOS transistor is connected to the transmit signal;

[0034] The common terminal of the drains of the ninth MOS transistor and the tenth MOS transistor is connected to the input electrode.

[0035] In a further embodiment of the present invention, the physiological signal sensing electrode is a dual-electrode differential structure; the common-mode signal extraction module includes a second amplifier, a first resistor, a third amplifier, and a second resistor; the input terminal of the second amplifier is connected to the physiological signal sensing electrode, and the output terminal of the second amplifier is connected to the first resistor; the input terminal of the third amplifier is connected to the physiological signal sensing electrode, and the output terminal of the third amplifier is connected to the second resistor; the common terminal of the first resistor and the second resistor is connected to the input terminal of the signal coupling module.

[0036] In a further embodiment of the present invention, the signal amplification unit includes a fourth amplifier, the input terminal of which is connected to the output terminal of the common-mode signal extraction module, and the output terminal of which is connected to the input terminal of the driving unit.

[0037] In a further embodiment of the present invention, at least three sets of high-current drive units are provided.

[0038] Secondly, the present invention also provides a data acquisition system, including a transmitter and a receiver, wherein the receiver includes the parallel fusion circuit for human body coupling communication and common mode suppression as described above.

[0039] This invention provides a parallel fusion circuit and data acquisition system for human body coupled communication and common-mode suppression. The circuit includes: a first amplifier connected to a physiological signal sensing electrode, used to amplify the physiological signals acquired by the physiological signal sensing electrode; a common-mode signal extraction module connected to the physiological signal sensing electrode, used to extract common-mode interference signals; and a signal coupling module connected to both the common-mode signal extraction module and an input electrode, used to invert the common-mode interference signal and output it through the input electrode, and to receive a transmitted signal from a transmitter, coupling the transmitted signal with a common-mode interference suppression signal and outputting it through the input electrode. After extracting the common-mode interference signal, this invention uses the signal coupling module to superimpose the received transmitted signal and the common-mode interference suppression signal in the time domain before outputting the result. This merges the two paths of the transmitted signal and the common-mode interference suppression signal into a single path, thereby preventing leakage of the transmitted signal from the transmission path of the common-mode interference suppression signal, thus improving the strength of the transmitted signal and ultimately enhancing the performance of human body coupled communication. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0041] Figure 1 This is a block diagram illustrating the principle of the parallel fusion circuit for human body coupling communication and common-mode suppression in this invention.

[0042] Figure 2 This is a circuit diagram of a parallel fusion circuit for human body coupling communication and common-mode suppression in one embodiment of the present invention.

[0043] Figure 3 This is a circuit diagram of a parallel fusion circuit for human body coupling communication and common-mode suppression with three configurable current paths, according to one embodiment of the present invention.

[0044] The labels in the attached diagram are as follows: 100, first amplifier; 200, common-mode signal extraction module; 210, second amplifier; 220, third amplifier; 300, signal coupling module; 310, signal amplification unit; 311, fourth amplifier; 320, drive unit; 321, low-current drive unit; 322, high-current drive unit; 330, signal coupling unit; 400, transmitter. Detailed Implementation

[0045] This invention provides a parallel fusion circuit for human body coupling communication and common-mode suppression, as well as a data acquisition system. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0046] In the implementation methods and claims, unless otherwise specified in the text, the terms "a," "an," "the," and "the" may also include plural forms. If the embodiments of the present invention involve descriptions of "first," "second," etc., such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0047] It should be further understood that the term "comprising" as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when an element is referred to as "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements present. Furthermore, "connected" or "coupled" as used herein can include wireless connections or wireless coupling. The term "and / or" as used herein includes all or any of the units and all combinations thereof of one or more associatedly listed items.

[0048] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0049] Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0050] The inventors discovered that in human body coupled communication, because ExG sensors use a dual-electrode differential structure to acquire physiological data, common-mode interference suppression is crucial. Power frequency interference is the primary common-mode interference signal that needs to be considered. Common power frequency interference suppression methods include: active noise cancellation using right-leg drive (RLD) technology with a reference electrode. Specifically, this involves introducing a known bias voltage at the amplifier input to compensate for DC bias caused by poor contact between the electrode and the skin or electrode misalignment. RLD amplifiers are typically configured as integrators, adjusting their output voltage to make the inverting input voltage the same as the voltage applied to the non-inverting input, ensuring a constant common-mode voltage. Active Lead Bias (ALB) technology improves the common-mode rejection ratio (CMRR) by introducing a known bias voltage at the amplifier's input to compensate for DC bias caused by poor contact between the electrodes and skin or electrode misalignment. Input Common-mode Current Drain (ICCD) technology refers to the current flowing from the input (usually the two input pins) to ground or power supply to maintain a stable common-mode voltage, minimizing common-mode interference (CMI) fluctuations.

[0051] However, when wireless sensing nodes employ low-power, high-efficiency human body coupling communication mechanisms, the aforementioned power frequency interference suppression methods all cause leakage of the high-frequency signal (MHz level) output by the transmitter through the common-mode interference suppression circuit, resulting in a significant reduction in output signal strength and a substantial weakening of human body coupling communication performance. The specific leakage path is as follows: the human body coupling communication transmitter output signal is coupled to the human body via electrodes, then coupled to the physiological signal sensing electrodes via the human body, and finally leaks to ground through the low-impedance displacement current path of the common-mode interference suppression circuit. Currently, there is no effective solution to this challenge. Existing solutions mitigate this problem by using PCB parasitic inductance to couple the output signal to electrical ground, but this solution requires driving a low-impedance ground path, resulting in high power consumption. Another viewpoint suggests that the presence of a ground-coupled circuit (RLD) affects the signal strength of the common-mode interference suppression (BCC), therefore proposing to remove the common-mode interference suppression path formed by the RLD and utilize the parasitic capacitance between the human body and circuit ground for CMI suppression. However, the CMI suppression capability increases with the increase of parasitic capacitance, while the BCC TX output swing decreases with the increase of parasitic capacitance. This leads to the need to make a trade-off between the CMI suppression capability and the BCC TX output swing.

[0052] To address the aforementioned technical problems, this invention provides a parallel fusion circuit for human body coupled communication and common-mode suppression, as well as a data acquisition system. When simultaneously performing BCC TX transmission and ExG sensing, after extracting the common-mode interference signal, the common-mode interference suppression signal is superimposed on the transmitted signal in the time domain. This allows the two paths of BCC TX and RLD to be merged into one path, transmitting the superimposed signal. This avoids leakage of the BCC signal from the RLD path, increases the strength of the transmitted signal, and ultimately improves the performance of human body coupled communication. Compared to existing solutions, this reduces power consumption and does not require reducing the output swing of BCC TX.

[0053] Please also refer to Figures 1 to 3 The present invention provides a preferred embodiment of a parallel fusion circuit for human body coupling communication and common mode suppression and a data acquisition system.

[0054] In some embodiments, such as Figure 1 As shown, this invention provides a parallel fusion circuit for human body coupled communication and common-mode suppression, comprising: a first amplifier 100, a common-mode signal extraction module 200, and a signal coupling module 300. The first amplifier 100 is connected to a physiological signal sensing electrode and is used to amplify the physiological signals collected by the physiological signal sensing electrode. The common-mode signal extraction module 200 is connected to the physiological signal sensing electrode and is used to extract common-mode interference signals. The signal coupling module 300 is connected to both the common-mode signal extraction module 200 and an input electrode. The signal coupling module 300 is used to invert the common-mode interference signal and output it through the input electrode, and to receive the transmitted signal output by the transmitter 400, couple the transmitted signal with a common-mode interference suppression signal, and output it through the input electrode.

[0055] In this embodiment, the first amplifier 100, the common-mode signal extraction module 200, and the signal coupling module 300 are part of the receiver. The receiver has three electrodes: a physiological signal sensing electrode and an input electrode. The physiological signal sensing electrode is a pair of dual-electrode differential structures, namely electrode Vi+ and electrode Vi-. The physiological signal sensing electrode is responsible for collecting physiological signals from the human body, while the input electrode is responsible for inputting the common-mode interference suppression signal or the signal superimposed with the common-mode interference suppression signal to the human body.

[0056] During detection, the first amplifier 100 amplifies the physiological signal collected by the physiological signal sensing electrode and outputs it to the subsequent circuit for further processing to complete the monitoring of human physiological data. In this process, the common-mode signal processing module can extract the common-mode interference signal, such as power frequency interference signal, from the two signal lines of the physiological signal sensing electrode, and output it to the signal coupling module 300 after preliminary amplification. If signal transmission is not required, the signal coupling module 300 can simply invert the common-mode interference signal and output it to the input electrode, which then inputs it to the human body to cancel out the common-mode interference signal in the body, thus achieving common-mode signal suppression. When simultaneous transmission of the signal is required, the signal coupling module 300 inverts the common-mode interference signal extracted by the common-mode signal extraction module 200 and further modulates the output transmission signal V by the modulator of the transmitter 400. TX With common-mode interference suppression signal V RLD The signal is superimposed and coupled in the time domain before output. Thus, when BCC TX transmission and ExG sensing are performed simultaneously, after extracting the common-mode interference signal, the common-mode interference suppression signal is superimposed on the transmitted signal in the time domain. This allows the two paths of BCC TX and RLD to be merged into one path, transmitting the superimposed signal. This avoids BCC signal leakage from the RLD path, increases the strength of the transmitted signal, and ultimately improves the performance of human body coupled communication. Compared to existing solutions, this reduces power consumption and does not require reducing the output swing of BCC TX.

[0057] In some embodiments, such as Figure 2 As shown, the common-mode signal extraction module 200 includes a second amplifier 210, a first resistor R1, a third amplifier 220, and a second resistor R2; the input terminal of the second amplifier 210 is connected to the physiological signal sensing electrode, and the output terminal of the second amplifier 210 is connected to the first resistor R1; the input terminal of the third amplifier 220 is connected to the physiological signal sensing electrode, and the output terminal of the third amplifier 220 is connected to the second resistor R2; the common terminal of the first resistor R1 and the second resistor R2 is connected to the input terminal of the signal coupling module 300.

[0058] In this embodiment, the common-mode interference signal is extracted by the second amplifier 210 and the third amplifier 220, and after primary amplification of the common-mode interference signal, it is output to the signal coupling module 300.

[0059] In some embodiments, such as Figure 2As shown, the signal coupling module 300 includes a signal amplification unit 310, a driving unit 320, and a signal coupling unit 330. The signal amplification unit 310 is connected to both the common-mode signal extraction module 200 and the driving unit 320. The signal amplification unit 310 amplifies the common-mode interference signal and outputs it to the driving unit 320. The driving unit 320 is connected to the signal coupling unit 330. The driving unit 320 inverts the common-mode interference signal and outputs it to the signal coupling unit 330. The signal coupling unit 330 is connected to the input electrode V. O The signal coupling unit 330 is used to output a common-mode interference suppression signal to the input electrode V. O And used to suppress common-mode interference signal V RLD With the transmitted signal V TX After coupling, the output is sent to the input electrode.

[0060] In this embodiment, as Figure 2 As shown, the signal amplification unit 310 includes a fourth amplifier 311. The input terminal of the fourth amplifier 311 is connected to the output terminal of the common-mode signal extraction module 200, and the output terminal of the fourth amplifier 311 is connected to the input terminal of the driving unit 320. The fourth amplifier 311 can perform a second-stage amplification of the acquired common-mode interference signal and output it to the driving unit 320. After the driving unit 320 receives the common-mode interference signal, it can perform reverse processing on the common-mode interference signal to obtain a common-mode interference suppression signal V that can cancel out the common-mode interference signal in the human body. RLD When only common-mode signal suppression is performed, the signal coupling unit 330 can convert the common-mode interference suppression signal V... RLD Transmitted to the input electrode V O via the input electrode V O The common-mode interference suppression signal V RLD The signal is input into the human body to suppress common-mode signals. When signal transmission is required, the signal coupling unit 330 superimposes the transmitted signal and the common-mode interference suppression signal in the time domain and outputs the result to the input electrode, which then inputs the superimposed signal into the human body.

[0061] In some embodiments, such as Figure 2As shown, the driving unit 320 includes a low-current driving unit 321 and a plurality of stacked high-current driving units 322; the low-current driving unit 321 is connected to the signal amplification unit 310, and the low-current driving unit 321 is used to reverse the common-mode interference signal; the high-current driving unit 322 is connected to the low-current driving unit 321, and the high-current driving unit 322 is used to input the transmitted signal V into the signal coupling unit 330. TX It will be turned on at that time.

[0062] In this embodiment, there are two current paths, namely a low current path and a high current path, wherein the low current path is connected to a first current I. L The low-current drive unit 321 provides the high-current path, which is provided by the second current I. H The high-current drive unit 322 provides the second current I H Greater than the first current I L When only common-mode signal suppression is performed, the low-current path is activated, and the low-current drive unit 321 operates. When a transmit signal needs to be transmitted, both the high-current and low-current paths are activated simultaneously, and the low-current drive unit 321 and the high-current drive unit 322 operate simultaneously to increase the drive strength. Furthermore, this allows the drive stage path of the RLD circuit to be merged with the transmission drive path of the transmit signal, achieving structural reuse of the RLD drive stage and the BCC transmission drive stage, reducing circuit area overhead, and thus lowering costs.

[0063] In some embodiments, such as Figure 2 As shown, the low-current drive unit 321 includes a first MOSFET M1, a second MOSFET M2, a third MOSFET M3, and a fourth MOSFET M4. The source of the first MOSFET M1 is connected to a first current I. L The drain of the first MOSFET M1 is connected to the drain of the second MOSFET M2, and the gate of the first MOSFET M1 is connected to the output terminal of the signal amplification unit 310. The source of the second MOSFET M2 is connected to the source of the third MOSFET M3, and the gate of the second MOSFET M2 is connected to the first power supply voltage VDD. The drain of the third MOSFET M3 is connected to the drain of the fourth MOSFET M4, and the gate of the third MOSFET M3 is connected to the second power supply voltage VSS. The source of the fourth MOSFET M4 is grounded, and the gate of the fourth MOSFET M4 is connected to the output terminal of the signal amplification unit 310. The common terminal of the drains of the first MOSFET M1 and the second MOSFET M2 is connected to the first input terminal of the signal coupling unit 330. The common terminal of the drains of the third MOSFET M3 and the fourth MOSFET M4 is connected to the second input terminal of the signal coupling unit 330.

[0064] Further, the signal coupling unit 330 includes a ninth MOS transistor M9 and a tenth MOS transistor M10; the source of the ninth MOS transistor M9 is connected to the common terminal of the drains of the first MOS transistor M1 and the second MOS transistor M2, and the common terminal of the drains of the fifth MOS transistor M5 and the sixth MOS transistor M6; the drain of the ninth MOS transistor M9 is connected to the drain of the tenth MOS transistor M10; the source of the tenth MOS transistor M10 is connected to the common terminal of the drains of the third MOS transistor M3 and the fourth MOS transistor M4, and the common terminal of the drains of the seventh MOS transistor M7 and the eighth MOS transistor M8; the common terminal of the gates of the ninth MOS transistor M9 and the tenth MOS transistor M10 is connected to the transmit signal; the common terminal of the drains of the ninth MOS transistor M9 and the tenth MOS transistor M10 is connected to the input electrode V. O connect.

[0065] In this embodiment, the first MOSFET M1 and the second MOSFET M2 form a first inverter, and the third MOSFET M3 and the fourth MOSFET M4 form a second inverter. The source of the first MOSFET M1 is connected to a first current I. L The ninth MOS transistor M9 and the tenth MOS transistor M10 constitute the third inverter.

[0066] The fourth amplifier 311 amplifies the common-mode interference signal and outputs it to the gates of the first MOS transistor M1 and the fourth MOS transistor M4. After inversion, it generates two common-mode interference suppression signals: a first common-mode interference suppression signal Vvirt and a second common-mode interference suppression signal Gvirt. The two common-mode interference suppression signals have the same amplitude and frequency, but different DC voltages. The first common-mode interference suppression signal Vvirt is used as a high-level signal of the third inverter and is input to the source of the ninth MOS transistor. The second common-mode interference suppression signal Gvirt is used as a low-level signal of the third inverter and is input to the source of the tenth MOS transistor M10. If the input signal of the third inverter is a periodic signal, it can achieve the effect of swinging between the first common-mode interference suppression signal Vvirt and the second common-mode interference suppression signal Gvirt. In other words, if the transmitted signal is a periodic signal, it can be coupled with the common-mode interference suppression signal. After coupling and superposition, it is input into the human body through the input electrode, thereby realizing the common-mode interference suppression function of RLD while transmitting TX data through the human body, and without the current leakage of the traditional structure.

[0067] In some embodiments, the signal coupling unit 330 may also use a comparator to provide rail-to-rail voltage to perform time-domain superposition.

[0068] In some embodiments, such as Figure 2 As shown, the high-current drive unit 322 includes: a fifth MOSFET M5, a sixth MOSFET M6, a seventh MOSFET M7, and an eighth MOSFET M8; the source of the fifth MOSFET M5 is connected to a second current I. H The drain of the fifth MOSFET M5 is connected to the drain of the sixth MOSFET M6, and the gate of the sixth MOSFET M6 is connected to the output terminal of the signal amplification unit 310; the source of the sixth MOSFET M6 is connected to the source of the seventh MOSFET M7, and the gate of the seventh MOSFET M7 is connected to the output enable signal; the drain of the seventh MOSFET M7 is connected to the drain of the eighth MOSFET M8, and the gate of the seventh MOSFET M7 is connected to the output enable signal; the source of the eighth MOSFET M8 is grounded, and the gate of the eighth MOSFET M8 is connected to the output terminal of the signal amplification unit 310; the common terminal of the drains of the fifth MOSFET M5 and the sixth MOSFET M6 is connected to the first input terminal of the signal coupling unit 330; the common terminal of the drains of the seventh MOSFET M7 and the eighth MOSFET M8 is connected to the second input terminal of the signal coupling unit 330.

[0069] In this embodiment, when transmitting a signal, a strong drive is required because the transmitted signal is a high-frequency signal. However, when only common-mode signal suppression is needed, a strong drive is not required. In other words, the high-current drive unit 322 only operates when transmitting a signal. When only common-mode signal suppression is needed, the input of the third inverter is not connected to the transmitted signal V. TX When the input is 0, only the ninth MOS transistor M9 (PMOS transistor) is turned on, and the first common-mode interference suppression signal Vvirt is input to the human body for common-mode signal suppression. When signal transmission is required, the gates of the sixth MOS transistor M6 and the seventh MOS transistor M7 are connected to output enable signals EN. TX That is, output enable signal EN TX When the signal is high, the high-current drive unit 322 is activated to increase the drive strength. This allows for dynamic adjustment of the drive current in both common-mode signal suppression and transmission signal transmission modes. Specifically, when transmission signal transmission is not required, the high-current drive unit 322 remains inactive, effectively reducing overall power consumption.

[0070] In some embodiments, such as Figure 3As shown, the high-current drive unit 322 can be configured in multiple groups, such as 3 groups, 5 groups, 7 groups, etc., which can adapt to a wider range of transmitted signal strengths and make the dynamic adjustment range of the drive capability broader. In one implementation, the number of high-current drive units 322 can be set to 3 groups.

[0071] In some embodiments, the present invention also provides a data acquisition system, namely a human physiological data acquisition system, which includes a transmitter and a receiver. The receiver includes the parallel fusion circuit for human body coupling communication and common-mode suppression as described above. The transmitter includes a modulator, etc., and the transmitted signal is modulated and output to the signal coupling module. Specific details are as described in the embodiment of the parallel fusion circuit for human body coupling communication and common-mode suppression, and will not be repeated here.

[0072] In summary, the parallel fusion circuit and data acquisition system for human body coupling communication and common-mode suppression provided by this invention have the following beneficial effects:

[0073] When performing BCC TX transmission and ExG sensing simultaneously, after extracting the common-mode interference signal, the common-mode interference suppression signal is superimposed on the transmitted signal in the time domain. This allows the two paths of BCC TX and RLD to be merged into one path, transmitting the superimposed signal. This avoids the leakage of BCC signal from the RLD path, which can improve the strength of the transmitted signal and ultimately improve the performance of human body coupling communication. Compared with the existing solution, it reduces power consumption and does not require reducing the output swing of BCC TX.

[0074] The drive current can be dynamically adjusted in two modes: common-mode signal suppression and transmission signal transmission. That is, when transmission signal transmission is not required, the high-current drive unit does not work, thereby effectively reducing the overall power consumption.

[0075] Multiple sets of the high-current drive unit can be configured, which can adapt to a wider range of transmitted signal strengths and make the dynamic adjustment of drive capability more extensive.

[0076] The structure of the RLD driver stage and the BCC transmission driver stage is reused, reducing circuit area overhead and thus reducing costs.

[0077] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A parallel fusion circuit for human body coupling communication and common-mode suppression, characterized in that, include: A first amplifier is connected to a physiological signal sensing electrode, and the first amplifier is used to amplify the physiological signals collected by the physiological signal sensing electrode. A common-mode signal extraction module is connected to the physiological signal sensing electrode, and the common-mode signal extraction module is used to extract common-mode interference signals; The signal coupling module is connected to the common-mode signal extraction module and the input electrode, respectively. The signal coupling module is used to invert the common-mode interference signal and output it through the input electrode, and to receive the transmitted signal output by the transmitter, and to couple the transmitted signal with the common-mode interference suppression signal and output it through the input electrode.

2. The parallel fusion circuit for human body coupling communication and common-mode suppression according to claim 1, characterized in that, The signal coupling module includes a signal amplification unit, a driving unit, and a signal coupling unit; The signal amplification unit is connected to the common-mode signal extraction module and the driving unit respectively. The signal amplification unit is used to amplify the common-mode interference signal and output it to the driving unit. The driving unit is connected to the signal coupling unit, and the driving unit is used to invert the common-mode interference signal and output it to the signal coupling unit. The signal coupling unit is connected to the input electrode. The signal coupling unit is used to output the common-mode interference suppression signal to the input electrode, and to couple the common-mode interference suppression signal with the transmitted signal and then output it to the input electrode.

3. The parallel fusion circuit for human body coupling communication and common-mode suppression according to claim 2, characterized in that, The driving unit includes a low-current driving unit and a plurality of high-current driving units stacked together. The low-current drive unit is connected to the signal amplification unit, and the low-current drive unit is used to reverse the common-mode interference signal. The high-current drive unit is connected to the low-current drive unit, and the high-current drive unit is used to turn on when the signal coupling unit receives the transmitted signal.

4. The parallel fusion circuit for human body coupling communication and common-mode suppression according to claim 3, characterized in that, The low-current drive unit includes a first MOSFET, a second MOSFET, a third MOSFET, and a fourth MOSFET; The source of the first MOS transistor is connected to a first current, the drain of the first MOS transistor is connected to the drain of the second MOS transistor, and the gate of the first MOS transistor is connected to the output terminal of the signal amplification unit. The source of the second MOS transistor is connected to the source of the third MOS transistor, and the gate of the second MOS transistor is connected to the first power supply voltage; The drain of the third MOS transistor is connected to the drain of the fourth MOS transistor, and the gate of the third MOS transistor is connected to the second power supply voltage. The source of the fourth MOS transistor is grounded, and the gate of the fourth MOS transistor is connected to the output terminal of the signal amplification unit. The common terminal of the drains of the first MOS transistor and the second MOS transistor is connected to the first input terminal of the signal coupling unit; the common terminal of the drains of the third MOS transistor and the fourth MOS transistor is connected to the second input terminal of the signal coupling unit.

5. The parallel fusion circuit for human body coupling communication and common-mode suppression according to claim 4, characterized in that, The high-current drive unit includes: a fifth MOSFET, a sixth MOSFET, a seventh MOSFET, and an eighth MOSFET; The source of the fifth MOS transistor is connected to a second current, the drain of the fifth MOS transistor is connected to the drain of the sixth MOS transistor, and the gate of the sixth MOS transistor is connected to the output terminal of the signal amplification unit. The source of the sixth MOS transistor is connected to the source of the seventh MOS transistor, and the gate of the seventh MOS transistor is connected to the output enable signal. The drain of the seventh MOS transistor is connected to the drain of the eighth MOS transistor, and the gate of the seventh MOS transistor is connected to the output enable signal. The source of the eighth MOS transistor is grounded, and the gate of the eighth MOS transistor is connected to the output terminal of the signal amplification unit. The common terminal of the drains of the fifth MOS transistor and the sixth MOS transistor is connected to the first input terminal of the signal coupling unit; the common terminal of the drains of the seventh MOS transistor and the eighth MOS transistor is connected to the second input terminal of the signal coupling unit.

6. The parallel fusion circuit for human body coupling communication and common-mode suppression according to claim 5, characterized in that, The signal coupling unit includes a ninth MOS transistor and a tenth MOS transistor; The source of the ninth MOS transistor is connected to the common terminal of the drains of the first MOS transistor and the second MOS transistor, as well as the common terminal of the drains of the fifth MOS transistor and the sixth MOS transistor. The drain of the ninth MOS transistor is connected to the drain of the tenth MOS transistor. The source of the tenth MOS transistor is connected to the common terminal of the drains of the third and fourth MOS transistors, and the common terminal of the drains of the seventh and eighth MOS transistors. The common terminal of the gates of the ninth MOS transistor and the tenth MOS transistor is connected to the transmit signal; The common terminal of the drains of the ninth MOS transistor and the tenth MOS transistor is connected to the input electrode.

7. The parallel fusion circuit for human body coupling communication and common-mode suppression according to claim 1, characterized in that, The physiological signal sensing electrode has a dual-electrode differential structure; the common-mode signal extraction module includes a second amplifier, a first resistor, a third amplifier, and a second resistor; the input terminal of the second amplifier is connected to the physiological signal sensing electrode, and the output terminal of the second amplifier is connected to the first resistor; the input terminal of the third amplifier is connected to the physiological signal sensing electrode, and the output terminal of the third amplifier is connected to the second resistor; the common terminal of the first resistor and the second resistor is connected to the input terminal of the signal coupling module.

8. The parallel fusion circuit for human body coupling communication and common-mode suppression according to claim 2, characterized in that, The signal amplification unit includes a fourth amplifier, the input of which is connected to the output of the common-mode signal extraction module, and the output of which is connected to the input of the driving unit.

9. The parallel fusion circuit for human body coupling communication and common-mode suppression according to claim 3, characterized in that, The high-current drive unit is provided in at least 3 sets.

10. A data acquisition system, comprising a transmitter and a receiver, characterized in that, The receiver includes the parallel fusion circuit for human body coupling communication and common mode suppression as described in any one of claims 1-9.

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