Neural interface electrical circuit for bidirectional signal transmission

Abstract

The present invention relates to a neural interface electric circuit for bidirectional signal transmission, which includes at least one electrode for collecting neural signals and receiving excitation signals. In the present invention, the neural interface electric circuit can transmit signals bidirectionally, and can collect neural signals through the electrodes, while receiving excitation signals through the electrodes, so that the purpose of research and therapeutic intervention can be achieved through the excitation signals.

Description

[Technical field]

[0001] The present invention relates to the field of interface electrical circuits, and in particular to neural interface electrical circuits for bidirectional signal transmission. [Background technology]

[0002] Microelectrodes can record action potentials, and most of the devices used for long-term nerve recording are microelectrode arrays made of rigid metals or semiconductors. Since the amplitude of the action potential is usually small, in the uV order, conventional nerve electrode interface readout circuits often first amplify the signal to the mV order using a pre-amplifier, and then sample and read it out using an ADC. However, in the medical application field, there is not only a demand for research and analysis of the output nerve signal, but in the future, there will also be a demand for research and intervention of the input stimulation signal. For such expected applications, the field is required to invent an interface electrical circuit for bidirectional signal transmission that can support the output of the nerve electrode signal and the input of excitation. Summary of the Invention [Problem to be solved by the invention]

[0003] The present invention relates to a neural interface electrical circuit for bidirectional signal transmission, which can overcome at least some of the drawbacks of the prior art. [Means for solving the problem]

[0004] The technical solution of the present invention is realized by providing a neural interface electrical circuit for bidirectional signal transmission, the neural interface electrical circuit including at least one electrode used for collecting neural signals and receiving excitation signals.

[0005] In one preferred embodiment, the device includes at least one collection input channel and at least one excitation output channel, said collection input channel and said excitation output channel sharing the same said electrode.

[0006] In one preferred embodiment, the acquisition input channel includes a first strobe switch connected to a control module, and the control module controls the on / off of the first strobe switch.

[0007] In one preferred embodiment, the sampling input channel further includes a filter and an amplifier, the electrode being connected to an input terminal of the filter, an output terminal of the filter being connected to an input terminal of the amplifier, and an output terminal of the amplifier being connected to an input terminal of the first strobe switch.

[0008] In one preferred embodiment, the neural interface electrical circuit further comprises an operational amplifier, the output terminal of the sampling input channel being connected to a non-inverting input terminal of the operational amplifier.

[0009] In one preferred embodiment, the neural interface electrical circuit further includes a sampling capacitor, one end of which is grounded and the other end of which is connected to the non-inverting input terminal of the operational amplifier.

[0010] In one preferred embodiment, the output terminal of the operational amplifier is connected to an AD conversion unit.

[0011] In one preferred embodiment, the excitation output channel includes a second strobe switch connected to a control module, the control module controlling the on / off of the second strobe switch.

[0012] In one preferred embodiment, the excitation output channel is further provided with gain scheduling and filtering noise reduction processing circuitry.

[0013] In one preferred embodiment, when there are multiple electrodes, some of the electrodes are used to collect neural signals and some of the electrodes are used to receive excitation signals.

[0014] The present invention has at least the following beneficial effects: The present invention provides a neural interface electric circuit for bidirectional signal transmission, which includes at least one electrode for collecting neural signals and receiving excitation signals. In the present invention, the neural interface electric circuit can transmit signals bidirectionally, can collect neural signals through the electrodes, and can receive excitation signals through the electrodes, and can achieve the purpose of research and therapeutic intervention through the excitation signals.

[0015] Furthermore, the present invention provides a plurality of sampling input channels and a plurality of excitation output channels, the input terminals of the plurality of sampling input channels are connected to a plurality of electrodes in a one-to-one correspondence, a first strobe switch is connected in series to each sampling input channel, the plurality of excitation output channels are connected to a plurality of sampling input channels in a one-to-one correspondence, the output terminals of the plurality of excitation output channels are connected to a plurality of electrodes in a one-to-one correspondence, the input terminals of each excitation output channel are connected to an external stimulation source, a second strobe switch is connected in series to each excitation output channel, the first strobe switch and the second strobe switch are connected to a control module, and the control module controls the on / off of the first strobe switch and the second strobe switch. By adopting the above-mentioned scheme, the neuroelectric signal can be collected by controlling the conduction of the first strobe switch, and the excitation input can be performed by controlling the conduction of the second strobe switch. The present invention allows the front-end electrode to sample and amplify the output, and at the same time, when the output channel is disconnected, the electrode can selectively receive an external stimulation signal. A signal with an appropriate amplitude can be input by gain scaling for the external stimulus signal, and filtering noise removal processing can be performed on the signal.

[0016] In order to more clearly describe the technical solutions in the embodiments of the present invention or the prior art, the following will briefly describe the accompanying drawings required for the description of the embodiments or the prior art. It is clear that the accompanying drawings in the following description are only some embodiments of the present invention, and those skilled in the art can obtain other accompanying drawings based on these accompanying drawings without creative labor. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a schematic diagram of an interface electrical circuit for bidirectional signal transmission capable of supporting neural electrode signal output and excitation input provided by one embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram of a single multi-channel sampling unit provided by one embodiment of the present invention. [Diagram 3] FIG. 2 is a schematic diagram of an output unit provided by one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] In the following, the technical solutions in the embodiments of the present invention will be clearly and completely described in combination with the accompanying drawings in the embodiments of the present invention. It is clear that the described embodiments are only some of the embodiments of the present invention, not all of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments that a person skilled in the art can obtain without performing creative work fall within the scope of protection of the present invention.

[0019] In the present description, unless otherwise limited, "plurality" and "several" mean two or more than two.

[0020] Example 1 This embodiment provides a neural interface electrical circuit for bidirectional signal transmission, the neural interface electrical circuit includes at least one electrode used for collecting neural signals and receiving excitation signals, where the electrode is an electrode solder bump on the neural interface electrical circuit, the solder bump is used for connecting to an electrode point implanted on a neural cell to obtain the neural signals collected by the electrode point, and also used for outputting a stimulation signal to the electrode point to stimulate the neural cell.

[0021] In a preferred embodiment, the neural interface electrical circuitry includes at least one collection input channel and at least one excitation output channel sharing the same electrode, where the collection input channel is used to transmit signals collected by the electrode to a back-end circuit, and the excitation output channel is used to receive and transmit excitation signals to the electrode.

[0022] In one specific application scenario, the neural interface electrical circuitry includes at least one sampling unit, each of which includes at least one acquisition input channel and at least one excitation output channel.

[0023] In this embodiment, the collection input channel includes a first strobe switch connected to a control module, and the collection input channel is selectively made conductive by controlling the on / off of the first strobe switch by the control module.

[0024] Furthermore, the sampling input channel further includes a filter and an amplifier, the electrode being connected to an input terminal of the filter, an output terminal of the filter being connected to an input terminal of the amplifier, and an output terminal of the amplifier being connected to an input terminal of the first strobe switch.

[0025] The neural interface electrical circuit further includes an operational amplifier, the output terminal of the sampling input channel being connected to a non-inverting input terminal of the operational amplifier, and the neural interface electrical circuit further includes a sampling capacitor, one end of which is grounded and the other end of which is connected to the non-inverting input terminal of the operational amplifier.

[0026] In practical application, the output terminal of the operational amplifier is connected to an AD conversion unit, which is used to convert an analog signal into a digital signal.

[0027] The excitation output channel includes a second strobe switch connected to the control module, and the control module controls the second strobe switch to be on or off to selectively conduct the excitation output channel.

[0028] In a preferred embodiment, the excitation output channel is further provided with gain scheduling and filtering de-noising processing circuitry for performing upscaling or downscaling on the excitation signal and for performing filtering and de-noising on the excitation signal.

[0029] In the above embodiment, the same electrode simultaneously has the acquisition function and the excitation output function, and the electrode achieves these two functions by operating in a time-division multiplexed manner.

[0030] In a preferred embodiment, when there are a plurality of electrodes, some of the electrodes are used to collect neural signals, and some of the electrodes are used to receive excitation signals. That is, the same electrode has only one of the collection function or the excitation output function. Specifically, when an electrode is used to collect neural signals, the electrode is connected to the collection input channel, and when an electrode is used to receive excitation signals, the electrode is connected to the excitation output channel.

[0031] Example 2 As shown in FIG. 1 to FIG. 3, the present invention discloses a neural interface electric circuit for bidirectional signal transmission, the neural interface electric circuit includes a control module, at least one sampling unit, and an output unit, the sampling unit is connected to the control module, the sampling unit includes at least one sampling input channel and at least one excitation output channel, the input terminals of the sampling unit (i.e., the input terminals of the sampling input channels) are connected to the electrodes in one-to-one correspondence, a first strobe switch is connected in series to each sampling input channel, the excitation output channels are in one-to-one correspondence to the sampling input channels, the output terminals of the excitation output channels are connected to the electrodes in one-to-one correspondence, the input terminals of each excitation output channel are connected to an external stimulation source, a second strobe switch is connected in series to each excitation output channel, the first strobe switch and the second strobe switch are connected to the control module, and the control module controls the on / off of the first strobe switch and the second strobe switch.

[0032] The control module of the present invention is used to execute data processing and output control. The control module of the present invention may be an MCU, but is not limited to an MCU. The first and second strobe switches of the present invention may be multiplexer switches MUX, or of course relay switches or the like.

[0033] In one embodiment, for a large array of thousands to tens of thousands of neural electrodes, m sampling units are stacked, each sampling unit is connected to n electrodes, and the total number of electrodes is m*n. As shown in FIG. 2, if the single-point sampling frequency of the neural electrodes is designed to be 20K Hz, the n electrodes of each sampling unit sample the neural electric signal, then filter and amplify it, and the first strobe switches S1-Sn of each sampling unit are turned on sequentially to sample at a sampling frequency of 20KHz, and the signal obtained by sampling is converted into AD to obtain the final digital data, which is the sampling process of one multi-channel sampling unit. By adopting the above-mentioned sampling method, the present invention solves the technical problem that the sampling speed is too high when the conventional method is applied to an electrode array of tens of thousands of points, which makes it difficult to design and easily distorts the signal.

[0034] In one embodiment, the neural interface electrical circuit includes a sampling capacitor, the output terminal of the sampling input channel is connected to one terminal of the sampling capacitor, and the other terminal of the sampling capacitor is grounded.

[0035] In one embodiment, the neural interface electrical circuit further includes an operational amplifier, the output terminal of the sampling input channel is connected to one terminal of a sampling capacitor and a non-inverting input terminal of an operational amplifier, the inverting input terminal of the operational amplifier is connected to an output terminal of the operational amplifier, and the output terminal of the operational amplifier is connected to an AD conversion module. The sampling circuit of the present invention is not limited to the above-mentioned embodiment, and any sampling circuit that meets the sampling requirements of the present invention can be used in the present invention.

[0036] In addition, each sampling input channel is further provided with a first signal processing unit, and the first signal processing unit of each sampling input channel and the strobe switch are connected in series. The first signal processing unit of this embodiment is located before the strobe switch. Of course, the first signal processing unit may be located after the strobe switch.

[0037] Furthermore, the first signal processing unit includes a filter circuit and an amplifier circuit, and the filter circuit is connected in series with the amplifier circuit. The filter circuit in this embodiment is located before the amplifier circuit. Of course, the filter circuit may be located after the amplifier circuit.

[0038] Furthermore, a second signal processing unit is further provided for each excitation output channel, and the second signal processing unit of each excitation output channel is connected in series with a second strobe switch.

[0039] In addition, the second signal processing unit includes a gain scheduling and filtering noise elimination processing circuit. The gain scheduling and filtering noise elimination processing circuit of the present invention can adopt a conventional stimulation signal processing circuit, and the description is omitted here.

[0040] Example 3 In contrast to the first embodiment in which a first signal processing unit is connected in series to each sampling input channel of each sampling unit, in this embodiment, only one first signal processing unit is provided in each sampling unit, and specifically, the following proposal may be adopted.

[0041] Each sampling unit further includes a first signal processing unit, which is located between the output terminal of the sampling input channel and the sampling circuit, and is connected in series with the sampling circuit. Other technical features of this embodiment are the same as those of the first embodiment.

[0042] Example 4 In this embodiment, an output unit is provided between the output terminal of each sampling unit of the sampling unit and the control module. The structure of the output unit is as shown in FIG. 3, the output unit includes a parallel-serial conversion module and a plurality of sampling output channels, the output terminals of the plurality of sampling output channels are connected to the output terminals of the plurality of sampling units in one-to-one correspondence, and the output terminals of the plurality of sampling output channels are connected to the output terminals of the parallel-serial conversion module. Enter the output terminal of the parallel-serial conversion module is connected to a control module; a third strobe switch is connected in series to each sampling output channel, and the third strobe switch is controlled to be turned on and off by the control module.

[0043] As the third strobe switch of the present invention, a multiplexer switch MUX may be adopted, and of course a relay switch or the like may also be adopted.

[0044] In one embodiment, the output terminals of a plurality of acquisition input channels are connected in one-to-one correspondence to a plurality of input terminals of an AD conversion module, and the plurality of output terminals of the AD conversion module are connected in one-to-one correspondence to the input terminals of a plurality of sampling output channels.

[0045] For a large array of thousands to tens of thousands of neural electrodes, the present invention divides the electric circuit into m sampling units each including n electrodes, and each sampling unit has n sampling input channels, with the total number of electrodes=m*n. During sampling, the neuroelectric signals are collected by m*n electrodes, and the strobe switches S1-Sn of each sampling unit are sequentially turned on to perform sampling via the sampling input channels, and the signals obtained by sampling are AD converted to obtain final digital data. The m sampling units operate simultaneously to output m data, and the on / off state of the third strobe switch of each sampling output channel is controlled to realize selectable and switchable output of each data, and the parallel-serial conversion module performs parallel-serial conversion on the output data. In this way, the reduction of the data output speed and the reduction of the overall power consumption can be simultaneously realized.

[0046] The interface electrical circuit for bidirectional signal transmission of the present invention, which can support the input of neural electrode signals and the output of excitation, can be applied to, but is not limited to, the fields of cranial nerves, optic nerves, and motor nerves. The front-end electrode can sample and amplify the output, and at the same time, when the output is cut off, the single-point electrode can selectively receive an external stimulation signal. The gain scaling of the external stimulation signal can input a signal with an appropriate amplitude, and the signal can be filtered to remove noise.

[0047] The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the scope of the spirit and principle of the present application should be included within the protection scope of the present invention.

Claims

1. A neural interface electrical circuit for bidirectional signal transmission, comprising: a plurality of electrodes used to collect neural signals and receive excitation signals derived from an external stimulus; a plurality of sampling units each including a plurality of collection input channels and a plurality of excitation output channels in one-to-one correspondence, the corresponding collection input channels and excitation output channels sharing the same electrodes, the collection input channels including a first strobe switch connected to a control module, the control module being used to selectively make the collection input channels conductive by controlling the on / off of the first strobe switch, the excitation output channels including a second strobe switch connected to the control module, the control module being used to selectively make the excitation output channels conductive by controlling the on / off of the second strobe switch, the excitation output channels further including a gain scheduling and filtering noise reduction processing circuit; a first signal processing unit provided for each acquisition input channel, the first signal processing unit including a filter circuit and an amplifier circuit connected in series; an operational amplifier having a non-inverting input terminal connected to an output terminal of the acquisition input channel, an operational amplifier inverting input terminal connected to an output terminal of the operational amplifier, and an output terminal of the operational amplifier connected to an AD conversion unit; a sampling capacitor having one end grounded and the other end connected to the non-inverting input terminal of the operational amplifier; an output unit including a parallel-serial conversion module and a plurality of sampling output channels, the output terminals of the plurality of sampling output channels being connected to the output terminals of the plurality of sampling units in one-to-one correspondence, the output terminals of the plurality of sampling output channels being connected to the input terminals of the parallel-serial conversion module, the output terminals of the parallel-serial conversion module being connected to a control module, a third strobe switch being connected in series to each sampling output channel, and the control module being used to control the on / off of the third strobe switch; m sampling units are stacked, each sampling unit is connected to n electrodes, the total number of electrodes is m*n; during sampling, neuroelectric signals are collected by the m*n electrodes, the first strobe switches S1-Sn of each sampling unit are turned on sequentially to perform sampling through the collection input channel, and the signal obtained by sampling is AD converted to obtain final digital data; the m sampling units operate simultaneously to output m pieces of data; the on / off state of the third strobe switch of each sampling output channel is controlled to realize selectable and switchable output of each piece of data; and the parallel-serial conversion module performs parallel-serial conversion on the output data. A neural interface electrical circuit comprising:

2. A first signal processing unit for each acquisition input channel and a first strobe switch are connected in series.

2. The neural interface electrical circuit of claim 1.

3. Some of the electrodes are used to collect neural signals and some of the electrodes are used to receive excitation signals.

2. The neural interface electrical circuit of claim 1.

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