A biopotential signal synchronous acquisition system with equally divided waiting time slots and acquisition circuit control method

Abstract

A biopotential signal synchronous acquisition system and acquisition circuit control method that evenly divides waiting time slots, the system includes a trigger pulse generator, first and second timing control logics, and first and second biopotential signal acquisition circuits. A controller generates a trigger pulse signal sequence with equal intervals, and the trigger timing control logic sends the required interface command sequence to each biopotential signal acquisition circuit in parallel, controlling it to complete a sequential sampling of all channels in the circuit and additional functions, and the above process is repeated. The interfaces and functions of each acquisition circuit can be different, and the time to send a command does not have to be the same. If the total time to send a command is less than the trigger pulse period, changing the channel sampling frequency only requires changing the frequency of the sampling trigger pulse signal. The present invention provides a synchronous control method and system for controlling multiple biopotential signal acquisition circuits with different interfaces, number of channels, sampling times and additional functions to sample at the required sampling frequency, and is also suitable for multi-channel biopotential signal acquisition circuits with time-division multiplexing sampling of a single analog-to-digital converter.

Description

Technical Field

[0001] The invention belongs to the technical field of biopotential signal acquisition, and relates to a biopotential signal synchronous acquisition system for equally-dividing waiting time slots and an acquisition circuit control method. Background Art

[0002] The electrophysiological signals generated by human cells or tissues are the main way for the nervous system to communicate. They contain a wealth of information about physiology, disease, and mental state. The recording of bioelectric signals can be used to effectively monitor the state of the human body and is also the basis for building a human-computer interaction highway. Common recordings of biopotential signals include direct recording of neuronal action potentials in the cerebral cortex; local field potential signals (LFP) recorded from the brain or cerebral blood vessels; electroencephalograms (ECoG) measured from the surface of the cerebral cortex; electroencephalograms (EEG) measured from the scalp; electromyographic signals (EMG) measured from within or near the muscles, and electrocardiograms (ECG) measured from the heart or near the heart.

[0003] The biopotential signal acquisition system usually includes a biopotential signal collector and special software running on a computer. The biopotential signal collector generally includes electrodes, electrode interfaces, signal amplifiers, analog-to-digital converters (ADCs), microcontrollers, data communication interfaces, etc. In brain science related research, it is often necessary to apply electrical stimulation to the cerebral cortex to obtain induced EEG signals, so an EEG signal acquisition system with electrical stimulation function has emerged. In order to obtain EEG signals from multiple brain regions more comprehensively, or to more finely distinguish the areas of cerebral cortical activity, it is necessary to increase the number of electrode channels of the EEG acquisition system, and the number of channels can be as high as 1000 or more. Increasing the number of channels will multiply the number of EEG signal amplifiers and analog-to-digital converters, and proportionally increase the system volume. With the advancement of integrated circuit technology, it is possible to integrate multi-channel EEG signal amplifiers, analog-to-digital converters and other parts into a dedicated EEG acquisition circuit, or to integrate multi-channel EEG signal amplifiers, analog-to-digital converters, and electrical stimulation circuits into a dedicated EEG acquisition circuit with electrical stimulation function. The application of multi-channel EEG acquisition circuits has greatly improved the integration of multi-channel EEG acquisition systems.

[0004] Biopotential signal acquisition circuits with different interface timings generally use different interface clock frequencies, different communication timings, different numbers of acquisition channels, different single-channel sampling times, and different additional functions, while existing biopotential signal collectors only use the same type of biopotential signal acquisition circuits, such as a biopotential signal collector that has multiple biopotential signal acquisition circuits with only acquisition functions and a microcontroller. The number of channels of this biopotential signal collector can be as high as more than 1,000, but it cannot perform electrical stimulation. In addition, there are also biopotential signal collectors with electrical stimulation functions that have multiple biopotential signal acquisition circuits with electrical stimulation functions and circuits such as microcontrollers, but the number of channels of this biopotential signal collector is small, generally only more than 100. In order to meet the application requirements of both being able to perform electrical stimulation and having enough acquisition channels, the biopotential signal acquisition circuit with electrical stimulation function and the biopotential signal acquisition circuit with only acquisition function can be integrated into a biopotential signal acquisition system. However, the interface timings of a biopotential signal acquisition circuit with an electrical stimulation function and a biopotential signal acquisition circuit with only an acquisition function are generally different. The biopotential signal acquisition circuits with different interface timings have different interfaces, different commands, and different external clock frequencies. How to enable the biopotential signal acquisition circuits with different interface timings to perform synchronous sampling at the same sampling frequency while taking into account the electrical stimulation function has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a biopotential signal synchronous acquisition system and an acquisition circuit control method for equally dividing waiting time slots.

[0006] The technical solution adopted by the present invention is:

[0007] A biopotential signal synchronous acquisition system with equally divided waiting time slots, the acquisition system comprises a trigger pulse generator, a first timing control logic, a second timing control logic, n first biopotential signal acquisition circuits, and m second biopotential signal acquisition circuits, where n and m are natural numbers.

[0008] The first biopotential signal acquisition circuit and the second biopotential signal acquisition circuit have different interface timings; the first biopotential signal acquisition circuit is connected to the first timing control logic through the first interface, and the first biopotential signal acquisition circuit completes one acquisition of all channels thereon and completes one first additional function, which is called one first action; the second biopotential signal acquisition circuit is connected to the second timing control logic through the second interface, and the second biopotential signal acquisition circuit completes one acquisition of all channels thereon and completes one second additional function, which is called one second action. Biopotential signal acquisition circuits with different interface timings finally maintain synchronous acquisition.

[0009] The trigger pulse generator is used to generate a first sampling trigger pulse and a second sampling trigger pulse, and the first timing control logic is used to send a first interface command to the first biopotential signal acquisition circuit to perform a first action under the triggering of the first sampling trigger pulse. The second timing control logic is used to send a second interface command to the second biopotential signal acquisition circuit to perform a second action under the triggering of the second sampling trigger pulse.

[0010] The biopotential signal synchronous acquisition system that equally shares the waiting time slots completes continuous acquisition by continuously completing a first action through the first biopotential signal acquisition circuit, and completes continuous acquisition by continuously completing a second action through the second biopotential signal acquisition circuit.

[0011] Furthermore, the different interface timing biopotential signal acquisition circuits finally maintain synchronous acquisition based on the following method: each time the n first biopotential signal acquisition circuits perform the first action, the start time of each execution of the second action by the m second biopotential signal acquisition circuits is exactly the same, and the end time of each action is before the start time of the next action, that is, the end time is before the first trigger pulse of the next action. The time interval Ts between the start time of one action and the start time of the next action is always fixed and is the reciprocal of the required sampling frequency fs. The biopotential signal sampling data obtained in each action is output after the start time of the action and before the start time of the next action.

[0012] A synchronous control method for a biopotential signal acquisition circuit with equally divided waiting time slots is implemented based on the above-mentioned biopotential signal synchronous acquisition system with equally divided waiting time slots, and includes the following steps:

[0013] (1) According to the required sampling frequency, the period Ts of one action of each biopotential signal acquisition circuit is set (Ts is the reciprocal of the required sampling frequency fs, i.e., Ts=1 / fs). According to the required function, the number of first interface commands required for the first biopotential signal acquisition circuit to complete one first action is set to x, and the number of second interface commands required for the second biopotential signal acquisition circuit to complete the second action is set to y.

[0014] (2) The trigger pulse generator generates a first sampling trigger pulse and a second sampling trigger pulse continuously and at the same time interval. The time interval Ts1 of the first sampling trigger pulse satisfies Ts1=Ts / x, and the time interval Ts2 of the second sampling trigger pulse satisfies Ts2=Ts / y.

[0015] (3) The first sampling trigger pulse triggers the first timing control logic to send x first interface commands in parallel to the n first biopotential signal acquisition circuits, and the first timing control logic sends a first interface command at each first sampling trigger pulse; the second sampling trigger pulse triggers the second timing control logic to send y second interface commands in parallel to the m second biopotential signal acquisition circuits, and the second timing control logic sends a second interface command at each second sampling trigger pulse.

[0016] (4) The n first biopotential signal acquisition circuits continuously complete the first action under the control of the first interface command; the m second biopotential signal acquisition circuits continuously complete the second action under the control of the second interface command.

[0017] Furthermore, in step (1), the first additional function includes an electrical stimulation function.

[0018] Furthermore, in step (1), the first interface command includes a first sampling command for controlling each channel of the first biopotential signal acquisition circuit, and the second interface command includes a second sampling command for controlling each channel of the second biopotential signal acquisition circuit.

[0019] Furthermore, in step (1), the first interface command also includes a first additional command for controlling the first biopotential signal acquisition circuit to perform a first additional function, and the second interface command also includes a second additional command for controlling the second biopotential signal acquisition circuit to perform a second additional function.

[0020] Furthermore, in step (1), the first additional command includes a command for controlling the first biopotential signal acquisition circuit to generate channel electrical stimulation.

[0021] Furthermore, in step (3), the time for the first timing control logic to send each of the first interface commands is the same and is T1, and the time for the second timing control logic to send each of the second interface commands is the same and is T2, and Ts1>T1, Ts2>T2 are satisfied. That is, for any biopotential signal acquisition circuit in the biopotential signal synchronous acquisition system that evenly divides the waiting time slots, the interface commands received sequentially are equally spaced. That is, when sending interface commands to each biopotential signal acquisition circuit, there is a waiting time slot between each interface command, and the waiting time slot is evenly divided according to the required sampling period (the inverse of the sampling frequency) and the number of interface commands.

[0022] Furthermore, in step (4), the start time of each of the first actions completed by the n first biopotential signal acquisition circuits and the start time of each of the second actions completed by the m second biopotential signal acquisition circuits are exactly the same, and the end time is within the cycle of the last trigger pulse of each action, that is, the end time of each action is before the start time of the next action. And for the series of first sampling trigger pulses corresponding to each of the first actions completed by the n first biopotential signal acquisition circuits and the series of second sampling trigger pulses corresponding to each of the second actions completed by the m second biopotential signal acquisition circuits, the first pulses of the two series of sampling trigger pulses are completely synchronized. That is, the first biopotential signal acquisition circuit and the second biopotential signal acquisition circuit always maintain the same sampling frequency for synchronous sampling.

[0023] The beneficial effects of the technical solution provided by the present invention are:

[0024] The present invention realizes synchronous control of biopotential signal acquisition circuits with different interface clock frequencies, different interface command formats, different acquisition channel numbers, different single-channel sampling times and different additional functions requiring an external clock. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of a biopotential signal synchronous acquisition system with equally divided waiting time slots provided by the present invention (not including all functional modules);

[0026] Figure 2 A timing diagram of a sampling trigger pulse signal and an interface command sequence provided by the present invention. DETAILED DESCRIPTION

[0027] The technical solution of the present invention will be further described below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0028] The embodiment of the present invention provides a biopotential signal synchronous acquisition system for equally dividing waiting time slots and an acquisition circuit control method.

[0029] Figure 1 A schematic diagram of a biopotential signal synchronous acquisition system for equally dividing waiting time slots provided by an embodiment of the present invention. The biopotential signal synchronous acquisition system includes a controller, a first subsystem and a second subsystem.

[0030] The first subsystem includes n first biopotential signal acquisition circuits (n is a natural number), that is, the first subsystem includes first biopotential signal acquisition circuits 1 to first biopotential signal acquisition circuits n. In addition, the first subsystem also includes a first timing control logic. The n first biopotential acquisition circuits are connected to the first timing control logic of the first subsystem through their own dedicated digital communication interfaces (SPI interface, Serial Peripheral Interface is used in this embodiment). The first timing control logic is used to send a first interface command to all first biopotential signal acquisition circuits at the same time after receiving the first sampling trigger pulse signal generated by the trigger pulse generator in the controller, and return the sampling data to the controller after receiving the sampling data output by each first biopotential signal acquisition circuit. The first interface command includes a first sampling command and a first additional command. Further, each first biopotential signal acquisition circuit has a plurality of first electrode interfaces, and the first electrode interface is used to connect biological electrodes. Each first electrode interface has a first additional function in addition to the acquisition function. In this embodiment, the first additional function of the first electrode interface is an electrical stimulation function. Therefore, the first subsystem has the functions of electrical stimulation and acquisition, and the first subsystem is also called the electrical stimulation and acquisition subsystem. Correspondingly, the first timing control logic is also called the electrical stimulation and acquisition circuit timing control logic. Figure 2 , the timing of the first interface command is shown in the figure, exemplary, the first sampling command is in front, and the first additional command is in the back. The first sampling command includes all the first electrode interface sampling commands arranged in sequence, that is, the first sampling command includes the first first electrode interface sampling command ( Figure 2 The channel ch0 sampling command in the control unit controls the second first electrode interface to perform the sampling action. Figure 2 The first additional command includes an electrical stimulation command. The specific electrical stimulation command for each first biopotential acquisition circuit can be dynamically generated by the controller according to the electrical stimulation waveform sequence data. The first timing control logic reads the electrical stimulation parameter command before issuing the electrical stimulation command, and sends it to each first biopotential signal acquisition circuit respectively. In addition to the electrical stimulation command, the first additional command may also include other additional commands, such as clear limit state command, read register command and other idle commands that do not affect the working state. See more Figure 2, the first additional command includes an electrical stimulation command and an idle command. Exemplarily, the first additional command operates each first biopotential signal acquisition circuit. For the first biopotential signal acquisition circuit that needs to generate electrical stimulation, the corresponding command is an electrical stimulation command, and for the first biopotential signal acquisition circuit that does not need to generate electrical stimulation, the corresponding command is an idle command. In this way, it can be ensured that the number of first interface commands required for n first biopotential signal acquisition circuits to complete a first action remains consistent.

[0031] Similarly, the second subsystem includes m second biopotential signal acquisition circuits (m is a natural number). That is, the second subsystem includes second biopotential signal acquisition circuit 1 to second biopotential signal acquisition circuit m, and the number of biopotential signal acquisition circuits of the entire acquisition system is n+m. In addition, the second subsystem also includes a second timing control logic. The m second biopotential acquisition circuits are connected to the second timing control logic of the second subsystem through their own dedicated digital communication interfaces (SPI interface is used in this embodiment). The second timing control logic is used to send a second interface command to all second biopotential signal acquisition circuits at the same time after receiving the second sampling trigger pulse signal generated by the trigger pulse generator in the controller, and return the sampling data to the controller after receiving the sampling data output by each second biopotential signal acquisition circuit. The second interface command sequence includes a second sampling command and a second additional command. Further, each second biopotential signal acquisition circuit includes a plurality of second electrode interfaces, and the second electrode interface is used to connect a biological electrode. In addition to the acquisition function, each second electrode interface may also have a second additional function, and the first additional function and the second additional function are not necessarily the same. In this embodiment, the second electrode interface has a collection function but not an electrical stimulation function. Therefore, the second subsystem has a collection function but not an electrical stimulation function, and the second subsystem is also called a single collection subsystem. Accordingly, the second timing control logic is also called a single collection circuit timing control logic. In this embodiment, see Figure 2 , the second interface command is shown in the figure. The second sampling command includes all the second electrode interface sampling commands arranged in sequence, that is, the second sampling command includes the first second electrode interface sampling command ( Figure 2 The channel ch0 sampling command in the control unit controls the second second electrode interface to perform the sampling action. Figure 2 The second additional command includes an idle command, such as a register read operation, to obtain the collection result of the pipelined biopotential signal collection circuit used in this embodiment in the idle command time slot.

[0032] The number of electrode interfaces in the biopotential signal acquisition circuit in each subsystem is not limited. For example, in the present embodiment, each first biopotential signal acquisition circuit in the electrical stimulation and acquisition subsystem includes 16 electrode interfaces, and each second biopotential signal acquisition circuit in the single acquisition subsystem includes 32 electrode interfaces. In the present embodiment, the number of electrode interfaces in the second biopotential signal acquisition circuit is exactly twice the number of electrode interfaces in the first biopotential signal acquisition circuit, so the second electrode interface sampling command is followed by an appropriate number of second additional commands, so that the number of second interface commands required for the second biopotential signal acquisition circuit to complete the second action is set to twice the number of first interface commands required for the first biopotential signal acquisition circuit to complete the first action, so that the frequency of the second sampling pulse is exactly twice the frequency of the first sampling pulse, and the trigger pulse generator is more concise.

[0033] The present invention has no particular restrictions on the types of controller, first timing control logic, and second timing control logic, as long as they can realize the timing required by the digital interface. The controller, the first timing control logic, and the second timing control logic can be hardware that performs logical operations in physical form, for example, a single-chip microcomputer, a microprocessor, a programmable logic controller (PLC, Programmable Logic Controller) or a field programmable gate array (FPGA, Field-Programmable Gate Array), or a software program, functional module, function, object library (Object Libraries) or dynamic link library (Dynamic-Link Libraries) that implements the above functions based on hardware. In this embodiment, the controller and the first timing control logic, the second timing control logic, etc. are all implemented using FPGA. In this embodiment, the controller, the first timing control logic, and the second timing control logic are integrated together to form a component; in an alternative embodiment, the controller, the first timing control logic, and the second timing control logic are all independent components.

[0034] Each biopotential signal acquisition circuit in the biopotential signal acquisition system works synchronously in parallel under the control of the controller and the timing control logic of each subsystem. All biopotential signal acquisition circuits receive interface commands under the control of their own timing control logic, perform sampling actions on each electrode interface or perform additional actions (for example, a biopotential signal acquisition circuit with an electrical stimulation function controls some electrode interfaces to perform electrical stimulation actions). All biopotential signal acquisition circuits in the same subsystem always receive the interface command sequence of the controller in complete synchronization. The interface command sequences of each biopotential acquisition circuit in the same subsystem may be the same or different; the interface command sequences of each biopotential acquisition circuit between different subsystems are at least partially different.

[0035] Figure 2 A timing diagram of a sampling trigger pulse signal and an interface command sequence provided by an embodiment of the present invention. The trigger pulse generator in the controller is used to generate a sampling trigger pulse signal sequence with a frequency that is a multiple of a specified sampling frequency, continuous, and with the same time interval. The frequency of the first sampling trigger pulse generated is fs1=fs×x, where fs is the specified sampling frequency, and x is the number of first interface commands required for the first biopotential signal acquisition circuit to complete a first action; the frequency of the second sampling trigger pulse generated is fs2=fs×y. Where fs is the specified sampling frequency, and y is the number of second interface commands required for the second biopotential signal acquisition circuit to complete a second action.

[0036] When the trigger pulse generator generates the first first sampling trigger pulse signal, the first timing control logic in the first subsystem is triggered to send the respective first first interface commands to all the first biopotential signal acquisition circuits, thereby driving all the corresponding first biopotential signal acquisition circuits to synchronously perform actions according to the first interface command; when the trigger pulse generator generates the second first sampling trigger pulse signal, the first timing control logic in the first subsystem is triggered to send the respective second first interface commands to all the first biopotential signal acquisition circuits, thereby driving all the corresponding first biopotential signal acquisition circuits to synchronously perform actions according to the first interface command; sequentially, when the trigger pulse generator generates the xth first sampling trigger pulse signal, the first timing control logic in the first subsystem is triggered to send the respective xth first interface commands to all the first biopotential signal acquisition circuits, thereby driving all the corresponding first biopotential signal acquisition circuits to synchronously perform actions according to the first interface command, and this action ends before the next first sampling pulse signal is generated. At this point, all the first biopotential signal acquisition circuits have completed a first action, that is, a sampling of all electrode interfaces on the first biopotential signal acquisition circuit and other additional functions are completed.

[0037] When the trigger pulse generator generates the first second sampling trigger pulse signal, the first timing control logic in the second subsystem is triggered to send the first second interface command to all the second biopotential signal acquisition circuits, thereby driving all the corresponding second biopotential signal acquisition circuits to synchronously perform actions according to the second interface command. When the trigger pulse generator generates the second second sampling trigger pulse signal, the first timing control logic in the second subsystem is triggered to send the second second interface command to all the second biopotential signal acquisition circuits, thereby driving all the corresponding second biopotential signal acquisition circuits to synchronously perform actions according to the second interface command. When the trigger pulse generator generates the yth second sampling trigger pulse signal, the second timing control logic in the second subsystem is triggered to send the yth first interface command to all the second biopotential signal acquisition circuits, thereby driving all the corresponding second biopotential signal acquisition circuits to synchronously perform actions according to the second interface command, and this action ends before the next second sampling pulse signal is generated. At this point, all the second biopotential signal acquisition circuits have completed a second action, that is, a sampling of all electrode interfaces on the second biopotential signal acquisition circuit and other additional functions are completed.

[0038] The first first sampling trigger pulse signal in the first action is completely synchronized with the first second sampling trigger pulse signal in the corresponding second action. In this embodiment, in order to simplify the description, the first interface command sequences corresponding to all first biopotential signal acquisition circuits in the first subsystem are the same, and the second interface command sequences corresponding to the second biopotential signal acquisition circuits in the second subsystem are the same.

[0039] In the biopotential signal acquisition system, continuous acquisition is completed by continuously completing the first action by the first biopotential signal acquisition circuit and continuously completing the second action by the second biopotential signal acquisition circuit. The biopotential signal sampling data obtained in each action is outputted between the start time of this action and the start time of the next action.

[0040] Specifically, for the electrical stimulation and acquisition subsystem, the first interface command sequence in a first action cycle includes a first sampling command and a first additional command for controlling each electrode interface in the first biopotential signal acquisition circuit to perform a sampling action; wherein the first additional command includes an electrical stimulation command for controlling the first electrode interface to perform an electrical stimulation action and other additional commands. In the above-mentioned first action cycle, the first timing control logic first sends the first sampling command of each electrode interface to each first biopotential signal acquisition circuit in sequence at the same time. If the electrode interface is required to perform an electrical stimulation action, the first timing control logic continues to send the electrical stimulation command after the first sampling command. If the electrode interface is not required to perform an electrical stimulation action, the first timing control logic can send other first additional commands after the first sampling command. The electrical stimulation command is not limited to being sent after the first sampling command, but can also be inserted before the first sampling command or sent between the first sampling commands. However, based on the principle of completing the important task (biopotential signal sampling) first, it is most appropriate to arrange the electrical stimulation command after the first sampling command. Furthermore, the first biopotential signal acquisition circuit used in this embodiment executes commands in a pipeline mode. After a certain (first) first sampling command is sent, the sampling and quantization actions specified by the first first sampling command are completed when the next (second) first sampling command enters, and the sampling result of the first first sampling command is output when the third first sampling command enters. Therefore, after sending the last first sampling command, at least two more first additional commands need to be sent to obtain the sampling results corresponding to the last two first sampling commands. Therefore, preferably, this embodiment places the electrical stimulation command as the first additional command after the first sampling command, which can be used for the electrical stimulation function and can obtain the sampling results at the same time. If no electrical stimulation action is required, other additional function commands are placed in the electrical stimulation command position.

[0041] For a single acquisition subsystem, the second interface command sequence in a second action cycle includes a second sampling command and a second additional command for controlling each electrode interface in the second biopotential signal acquisition circuit to perform a sampling action. In the above-mentioned second action cycle, the second timing control logic first sends the second sampling command of each electrode interface to each second biopotential signal acquisition circuit in sequence at the same time, and then sends the second additional command. Similarly, based on the principle of completing the important task (biopotential signal sampling) first, it is most appropriate to arrange the second additional command after the second sampling command. Similarly, the second biopotential signal acquisition circuit of this embodiment also uses a pipeline mode to execute commands. Therefore, it is preferred to place the second additional command after all the second sampling commands, taking into account both the acquisition of sampling data and the execution of additional functions, saving command time slots.

[0042] For all biopotential signal acquisition circuits in the biopotential signal acquisition system, their internal sampling actions or electrical stimulation actions and command result outputs are all driven synchronously by the interface clock. The interface clock frequency remains unchanged, so the time used to execute a command remains fixed. Different sampling frequencies only result in different waiting times after each command.

[0043] like Figure 2 As shown, the time interval (i.e., sampling period) of the first trigger pulse signal generated by the trigger pulse generator is Ts1, and the time interval (i.e., sampling period) of the second trigger pulse signal generated is Ts2. In the same subsystem, the biopotential signal acquisition circuit using the same interface timing, the time required for the first timing control logic to send each of the first interface commands is the same and is T1, and the time required for the second timing control logic to send each of the second interface commands is the same and is T2. As long as Ts1>T1 and Ts2>T2 are ensured, the biopotential signal acquisition system can achieve synchronous sampling without losing the sampling of any channel.

[0044] The present invention provides a synchronous control method and acquisition system for controlling multiple biopotential signal acquisition circuits with different interfaces, number of channels, sampling time and additional functions to sample at a required sampling frequency; it is also applicable to multi-channel biopotential signal acquisition circuits with time-division multiplexing sampling of a single analog-to-digital converter. The control method is as follows: a controller generates a trigger pulse signal sequence with equal intervals, and the trigger pulse frequency is a specific multiple of the required sampling frequency, which is used to trigger the timing control logic to send the required interface command sequence to each biopotential signal acquisition circuit in parallel, and control it to complete a sequential sampling of all channels in the circuit and complete the additional functions, and the above work flow is repeated. The interfaces and functions of each biopotential signal acquisition circuit can be different, and the time for sending the command does not have to be the same. If the total time for sending the interface command is less than the trigger pulse period, changing the channel sampling frequency only requires changing the frequency of the sampling trigger pulse signal.

[0045] The above-described embodiments merely express the implementation methods of the present invention, but they cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A synchronous control method for a biopotential signal acquisition circuit that evenly divides waiting time slots, characterized in that: The synchronous control method is implemented based on a biopotential signal synchronous acquisition system, which includes a trigger pulse generator, a first timing control logic, a second timing control logic, n first biopotential signal acquisition circuits, and m second biopotential signal acquisition circuits, where n and m are natural numbers; The first biopotential signal acquisition circuit and the second biopotential signal acquisition circuit have different interface timings; the first biopotential signal acquisition circuit is connected to the first timing control logic via the first interface, and the first biopotential signal acquisition circuit completes one acquisition of all channels thereon and completes one first additional function, which is called one first action; the second biopotential signal acquisition circuit is connected to the second timing control logic via the second interface, and the second biopotential signal acquisition circuit completes one acquisition of all channels thereon and completes one second additional function, which is called one second action; biopotential signal acquisition circuits with different interface timings always maintain synchronous acquisition; The trigger pulse generator is used to generate a first sampling trigger pulse and a second sampling trigger pulse, and the first timing control logic is used to send a first interface command to the first biopotential signal acquisition circuit to execute a first action under the triggering of the first sampling trigger pulse; The second timing control logic, under the triggering of the second sampling trigger pulse, sends a second interface command to the second biopotential signal acquisition circuit to execute a second action; The biopotential signal synchronous acquisition system that evenly shares the waiting time slots completes continuous acquisition by continuously completing a first action through the first biopotential signal acquisition circuit, and completes continuous acquisition by continuously completing a second action through the second biopotential signal acquisition circuit; The synchronous control method comprises the following steps: (1) according to the required sampling frequency, the period Ts of one action of each biopotential signal acquisition circuit is set, where Ts is the reciprocal of the required sampling frequency fs, that is, Ts=1 / fs; according to the required function, the number of first interface commands required for the first biopotential signal acquisition circuit to complete one first action is set to x, and the number of second interface commands required for the second biopotential signal acquisition circuit to complete the second action is set to y; (2) The trigger pulse generator continuously generates a first sampling trigger pulse and a second sampling trigger pulse at the same time interval, wherein the time interval Ts1 of the first sampling trigger pulse satisfies Ts1=Ts / x, and the time interval Ts2 of the second sampling trigger pulse satisfies Ts2=Ts / y; (3) The first sampling trigger pulse triggers the first timing control logic to send x first interface commands to n first biopotential signal acquisition circuits in parallel, and the first timing control logic sends one first interface command for each first sampling trigger pulse; the second sampling trigger pulse triggers the second timing control logic to send y second interface commands to m second biopotential signal acquisition circuits in parallel, and the second timing control logic sends one second interface command for each second sampling trigger pulse; (4) The n first biopotential signal acquisition circuits continuously complete the first action under the control of the first interface command; the m second biopotential signal acquisition circuits continuously complete the second action under the control of the second interface command.

2. The synchronous control method of the biopotential signal acquisition circuit with equally divided waiting time slots according to claim 1 is characterized in that: In step (1), the first additional function includes an electrical stimulation function.

3. The synchronous control method of the biopotential signal acquisition circuit with equally divided waiting time slots according to claim 1 is characterized in that: In step (1), the first interface command includes a first sampling command for controlling each channel of the first biopotential signal acquisition circuit, and the second interface command includes a second sampling command for controlling each channel of the second biopotential signal acquisition circuit.

4. The synchronous control method of the biopotential signal acquisition circuit with equally divided waiting time slots according to claim 3 is characterized in that: In step (1), the first interface command also includes a first additional command for controlling the first biopotential signal acquisition circuit to perform a first additional function, and the second interface command also includes a second additional command for controlling the second biopotential signal acquisition circuit to perform a second additional function.

5. The synchronous control method of the biopotential signal acquisition circuit with equally divided waiting time slots according to claim 4 is characterized in that: In step (1), the first additional command includes a command for controlling the first biopotential signal acquisition circuit to generate channel electrical stimulation.

6. The synchronous control method of the biopotential signal acquisition circuit with equally divided waiting time slots according to claim 1 is characterized in that: In step (3), the time for the first timing control logic to send each of the first interface commands is the same and is T1, and the time for the second timing control logic to send each of the second interface commands is the same and is T2, and satisfies Ts1>T1, Ts2>T2; that is, for any biopotential signal acquisition circuit in the biopotential signal synchronization acquisition system that evenly divides the waiting time slots, the interface commands received sequentially are equally spaced; that is, when sending interface commands to each biopotential signal acquisition circuit, there is a waiting time slot between each interface command, and the waiting time slot is evenly divided according to the required sampling period and the number of interface commands.

7. The synchronous control method of the biopotential signal acquisition circuit with equally divided waiting time slots according to claim 1 is characterized in that: In step (4), the start time of each of the first actions completed by the n first biopotential signal acquisition circuits and the start time of each of the second actions completed by the m second biopotential signal acquisition circuits are exactly the same, and the end time is within the period of the last trigger pulse of each action, that is, the end time of each action is before the start time of the next action; and for the series of first sampling trigger pulses corresponding to each of the first actions completed by the n first biopotential signal acquisition circuits and the series of second sampling trigger pulses corresponding to each of the second actions completed by the m second biopotential signal acquisition circuits, the first pulses of the two series of sampling trigger pulses are completely synchronized; that is, the first biopotential signal acquisition circuit and the second biopotential signal acquisition circuit always maintain the same sampling frequency for synchronous sampling.

8. The synchronous control method of the biopotential signal acquisition circuit with equally divided waiting time slots according to claim 1 is characterized in that: The different interface timing biopotential signal acquisition circuits always maintain synchronous acquisition based on the following method: Each time the n first biopotential signal acquisition circuits execute the first action, the start time of each execution of the second action by the m second biopotential signal acquisition circuits is exactly the same, the end time of the first action or the second action is before the start time of the next action, that is, the end time is before the first trigger pulse of the next action; the time interval Ts between the start time of the first action or the second action and the start time of the next action is always fixed; the biopotential signal sampling data obtained by the first action or the second action is output after the start time of the action and before the start time of the next action.

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