A photoelectric neural interface device

Abstract

The present invention discloses a photoelectric combined neural interface device, which belongs to the field of bioelectrode technology and can solve the problems of difficult wiring and complex structure of traditional neural interface devices. The neural interface device includes: a substrate, on which a plurality of conductive through-holes are provided; a plurality of microelectrodes, which are provided on the front of the substrate; the microelectrodes correspond one-to-one with the conductive through-holes, and the microelectrodes are used to collect electrophysiological signals; a plurality of optical modulators, which are provided on the back of the substrate; the conductive through-holes are used to transmit electrophysiological signals to the optical modulators, and the optical modulators are used to modulate the electrophysiological signals into optical signals; a bidirectional optical unit, which is provided on the back of the substrate, is used to provide light waves for modulation to each optical modulator, collect the modulated optical signals of each optical modulator, and then output the signals. The present invention is used for neural interface devices.

Description

Technical Field

[0001] The present invention relates to a photoelectric combined neural interface device, belonging to the technical field of bioelectrodes. Background Art

[0002] Brain science has long been a hot topic in modern scientific research, exploring how the human brain generates, transmits, and processes information. Brain-computer interface devices, as one type of neural electrode, serve as a channel between the brain and external devices. They can record and stimulate brain nerves, providing the potential for analyzing electrical signals in the cerebral cortex. Applying this technology in the medical field could improve the ability of severely disabled patients to communicate with the outside world or control their external environment. Furthermore, brain-computer interfaces can help observe the activity of neural signals in response to external stimuli, providing relevant data for further medical research.

[0003] Traditional neural interface devices are based on pure electrical connections, and generally export signals through wires (i.e., passive devices) or transmit signals after being amplified by the device (i.e., active devices); neural interface devices based on pure electrical connections usually require a large number of connecting wires to export electrical signals, which makes the wiring of traditional neural interface devices more difficult and the structure more complex. Summary of the Invention

[0004] The present invention provides a photoelectric combined neural interface device, which can solve the problems of difficult wiring and complex structure of traditional neural interface devices.

[0005] The present invention provides a photoelectric combined neural interface device, comprising:

[0006] a substrate having a plurality of conductive through holes disposed thereon;

[0007] A plurality of microelectrodes are provided on the front surface of the substrate; the microelectrodes correspond one-to-one to the conductive through holes, and the microelectrodes are used to collect electrophysiological signals;

[0008] A plurality of optical modulators are provided on the back side of the substrate; the conductive through holes are used to transmit the electrophysiological signals to the optical modulators, and the optical modulators are used to modulate the electrophysiological signals into optical signals;

[0009] The bidirectional optical unit is arranged on the back side of the substrate, and is used to provide a modulated light wave to each of the optical modulators, collect the modulated optical signal of each of the optical modulators, and then output the signal.

[0010] Optionally, also include:

[0011] a plurality of amplifying units, disposed on the substrate, the amplifying units corresponding one to one with the microelectrodes, and configured to amplify the electrophysiological signals;

[0012] a power supply unit, configured to supply power to the amplifying unit;

[0013] The conductive via is used to transmit the amplified electrophysiological signal to the optical modulator.

[0014] Optionally, the power supply unit includes a light receiving window and a photodiode;

[0015] The light receiving window is provided on the substrate and corresponds to the position of the photodiode, and is used to receive the illumination light provided by the bidirectional light unit;

[0016] The photodiode is arranged on the front surface of the substrate and connected to the amplifying unit, and is used for providing electric energy to the amplifying unit under the irradiation of the irradiation light.

[0017] Optionally, each of the optical modulators receives an electrophysiological signal conducted by one of the conductive vias as a single-ended input signal, or simultaneously receives electrophysiological signals conducted by any two of the conductive vias as differential input signals.

[0018] Optionally, the bidirectional optical unit includes:

[0019] An optical bidirectional interface, provided at the edge of the substrate, for coupling external light waves into the waveguide subunit and for outputting modulated optical signals;

[0020] The waveguide subunit is connected to the optical bidirectional interface and is used to disperse the light wave and transmit it to each of the optical modulators, and couple the modulated optical signal of each optical modulator and transmit it to the optical bidirectional interface.

[0021] Optionally, the waveguide subunit includes: a first waveguide, a plurality of second waveguides, a plurality of third waveguides, an optical splitter connected between the plurality of second waveguides and the first waveguide, and a coupler connected between the plurality of third waveguides and the first waveguide;

[0022] The first waveguide is used to receive the light wave coupled by the optical bidirectional interface and transmit the light wave to the optical splitter, and is also used to transmit the modulated optical signal coupled by the coupler to the optical bidirectional interface;

[0023] The second waveguide is used to transmit the light waves dispersed by the optical splitter to each of the optical modulators;

[0024] The third waveguide is used to transmit the modulated optical signal of the optical modulator to the coupler.

[0025] Optionally, the amplifying unit is further configured to perform filtering processing on the electrophysiological signal.

[0026] Optionally, a plurality of the microelectrode arrays are arranged on the substrate.

[0027] Optionally, the optical modulator is an electro-optical modulator or a thermo-optical modulator.

[0028] The beneficial effects that the present invention can produce include:

[0029] (1) The optoelectronic neural interface device provided by the present invention can avoid electromagnetic interference and electromagnetic crosstalk between channels during transmission by modulating the electrophysiological signals collected by microelectrodes into optical signals through electro-optical conversion. At the same time, it can rationally utilize optical signal multiplexing, such as wavelength division multiplexing and time division multiplexing, to realize the input and output of optical signals through a single optical fiber, which can greatly reduce the number and difficulty of wiring.

[0030] (2) The optoelectronic neural interface device provided by the present invention can obtain a high-quality signal (i.e., a high signal-to-noise ratio signal) by locally amplifying the electrophysiological signal. After the electrophysiological signal is amplified by the electrical chip, it is modulated to the modulator of the optical chip integrated with the electrical chip, thus avoiding the fan-out problem of the signal line. Furthermore, the present invention can utilize optoelectronic materials such as photodiodes to power the electrical chip, thereby achieving single-fiber access, thereby further reducing the number and difficulty of wiring. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of the front structure of a neural interface device provided by an embodiment of the present invention;

[0032] Figure 2 Schematic diagram of the back structure of the neural interface device provided by the embodiment of the present invention Figure 1 ;

[0033] Figure 3 Schematic diagram of the back structure of the neural interface device provided by the embodiment of the present invention Figure 2 .

[0034] List of parts and reference numerals:

[0035] 11. Substrate; 12. Conductive through-hole; 13. Microelectrode; 14. Optical modulator; 15. Amplification unit; 16. Photodiode; 17. Light-receiving window; 18. Optical bidirectional interface; 19. First waveguide; 20. Second waveguide; 21. Third waveguide; 22. Fourth waveguide. DETAILED DESCRIPTION

[0036] The present invention is described in detail below with reference to the embodiments, but the present invention is not limited to these embodiments.

[0037] The embodiment of the present invention provides a photoelectric combined neural interface device, such as Figures 1 to 3 Shown, including:

[0038] a substrate 11 having a plurality of conductive through holes 12 disposed thereon;

[0039] A plurality of microelectrodes 13 are provided on the front surface of the substrate 11 ; the microelectrodes 13 correspond one-to-one to the conductive through-holes 12 , and the microelectrodes 13 are used to collect electrophysiological signals; wherein the plurality of microelectrodes 13 can be arranged in an array on the substrate 11 .

[0040] A plurality of optical modulators 14 are provided on the back side of the substrate 11 ; the conductive vias 12 are used to transmit the electrophysiological signals to the optical modulators 14 , and the optical modulators 14 are used to modulate the electrophysiological signals into optical signals.

[0041] Furthermore, the neural interface device further includes:

[0042] A plurality of amplifying units 15 are provided on the substrate 11. The amplifying units 15 correspond one-to-one to the microelectrodes 13 and are used to amplify electrophysiological signals. The conductive through-holes 12 are used to transmit the amplified electrophysiological signals to the optical modulator 14. In practical applications, the amplifying units 15 can also be used to filter the electrophysiological signals. The present invention does not limit the specific location of the amplifying units 15, and those skilled in the art can set them according to actual conditions. For example, the amplifying units 15 can be provided on the front side of the substrate 11, or in the area between the front and back sides of the substrate 11. During the process, the amplifying units 15 can be made into a multi-layer thin film structure.

[0043] In the embodiment of the present invention, the neural interface device further includes: a power supply unit, configured to supply power to the amplification unit 15 .

[0044] Specifically, the power supply unit may include:

[0045] A photodiode 16 is provided on the front surface of the substrate 11 and connected to the amplifying unit 15;

[0046] The light receiving window 17 is provided on the substrate 11 and corresponds to the position of the photodiode 16;

[0047] The bidirectional light unit is also used to provide irradiation light to the light receiving window 17;

[0048] The photodiode 16 is used to provide electric energy to the amplifying unit 15 under the illumination of the illumination light.

[0049] refer to Figure 1As shown, the front surface of substrate 11 is the interface between the electrical chip and neural tissue. It is composed of an array of microelectrodes 13, which are used to sense and transmit electrophysiological signals. An amplifier unit 15 (i.e., an amplifier circuit) is fabricated near each microelectrode 13 to amplify the sensed electrophysiological signal. A filter circuit can also be added at this step to filter the electrophysiological signal to improve the signal-to-noise ratio. The amplified signal is transmitted through conductive vias 12 to the bottom of the electrical chip (i.e., the back surface of substrate 11).

[0050] The bidirectional optical unit is provided on the back side of the substrate 11 and is used to provide a modulated light wave to each optical modulator 14 and collect the modulated light signal of each optical modulator 14 and then output the signal.

[0051] Specifically, the bidirectional optical unit includes:

[0052] An optical bidirectional interface 18 is provided at the edge of the substrate 11;

[0053] The waveguide subunit is connected to the optical bidirectional interface 18. The optical bidirectional interface 18 is used to couple external light waves into the waveguide subunit. The waveguide subunit disperses the light waves and transmits them to each optical modulator 14. It also couples the modulated optical signals from each optical modulator 14 and transmits them to the optical bidirectional interface 18. The optical bidirectional interface 18 is also used to output the coupled modulated optical signals. The external light waves are the light waves used for modulation.

[0054] The waveguide subunit may include: a first waveguide 19, a plurality of second waveguides 20, and a plurality of third waveguides 21; an optical splitter is connected between the plurality of second waveguides 20 and the first waveguide 19, and a coupler is connected between the plurality of third waveguides 21 and the first waveguide 19;

[0055] The external light waves are coupled to the first waveguide 19 via the optical bidirectional interface 18. The light waves in the first waveguide 19 are dispersed into multiple second waveguides 20 via the optical splitter. The second waveguides 20 provide modulated light waves to the optical modulator 14. The modulated optical signal of the optical modulator 14 is transmitted to the coupler via the third waveguide 21, coupled to the first waveguide 19 via the coupler, and then output via the optical bidirectional interface 18.

[0056] In practical applications, the waveguide subunit of the bidirectional optical unit may further include a fourth waveguide 22 . After the light waves in the first waveguide 19 are dispersed by the optical splitter, a portion enters the fourth waveguide 22 and is transmitted by the fourth waveguide 22 to the light receiving window 17 to illuminate the photodiode 16 .

[0057] refer to Figure 2As shown, the back of the substrate 11 is the optical chip. Light energy is coupled into the first waveguide 19 of the optical chip via an optical bidirectional interface 18 (i.e., an IO interface), and then split by an optical splitter into different functional modules. A portion of the light is used for power supply and is transmitted to the optical output port. A grating coupler or other device is used to align the light with the light receiving window 17 of the photodiode 16 on the electronic chip for emission. Another portion of the light is dispersed into an array of optical modulators 14. Using methods such as time division multiplexing, space division multiplexing, and wavelength division multiplexing, the optical signal is dispersed to each optical modulator 14. The optical modulator 14 modulates the electrophysiological signal into an optical signal, which is then integrated into the signal collection optical path formed by the third waveguide 21 and the coupler and returned to the optical bidirectional interface 18. The electrophysiological signal used for modulation is connected to the optical chip via the conductive via 12 of the electronic chip. Finally, the sensed electrophysiological signal is obtained by performing processing on the transmitted optical signal, such as photoelectric conversion and filtering.

[0058] In the embodiment of the present invention, each optical modulator 14 receives an electrophysiological signal transmitted by one conductive via 12 as a single-ended input signal, or simultaneously receives electrophysiological signals transmitted by any two conductive vias 12 as differential input signals. The two conductive vias 12 may be adjacent or non-adjacent, and this is not limited in the embodiment of the present invention.

[0059] Specifically, depending on the configuration of the optical modulator 14, there are two modes: differential input and single-ended input. In the differential input configuration, two microelectrodes 13 form a pair, collecting one signal at a time. In the single-ended input configuration, one or more common ground electrodes are shared by multiple microelectrodes 13, and these single-ended microelectrodes 13 can each collect one signal at a time.

[0060] refer to Figure 3 As shown, for differential signals, every two conductive vias 12 correspond to one optical modulator 14 ( Figure 3 If a single-ended connection is used, all optical modulators 14 need to share a common ground and be connected by wires distributed on the optical chip ( Figure 3 (see figure on the middle right).

[0061] The connections between the neural interface devices and the outside world are divided into two categories: signal and power supply. For signal lines, both incoming and outgoing signals are light, so optical fiber connections can be used. Power supply can be implemented in several different ways:

[0062] (1) The wires are directly connected to the electrical chip.

[0063] (2) The wires are connected to the optical chip and then transferred from the optical chip (wires can be prepared on the optical chip) to the electrical chip.

[0064] (3) A light source (such as a laser or LED) is integrated on the optical chip, and optoelectronic materials such as a photodiode 16 are integrated on the electrical chip. Wires are connected to the optical chip to function as a light source. The light source illuminates the corresponding area of ​​the electrical chip to generate electrical energy to power the electrical chip.

[0065] (4) Light is directed directly to the electronic chip via an optical fiber (either a separate optical fiber or the same signal optical fiber), or is relayed via an optical chip to the photoelectric conversion region of the electronic chip (i.e., the region where the photodiode 16 is located), thereby providing energy to the electronic chip. During relaying, the direction of the light can be changed using a grating coupler or other method.

[0066] In the present invention, any one of the above four methods may be used to power the amplifier in the electronic chip, and the embodiment of the present invention does not limit this.

[0067] In embodiments of the present invention, the optical modulator 14 may be an electro-optic modulator or a thermo-optic modulator. The present invention imposes no restrictions on the material or structure of the optical modulator 14. For example, the optical modulator 14 may be made of lithium niobate, silicon nitride, silicon, or the like, and may have a structure such as a ring modulator or a Mach-Zehnder modulator. In the present invention, multiple optical modulators 14 of the same type or different types may be fabricated on the substrate 11 to form an array. The array of optical modulators 14 may be stacked together into a single device using flip-chip or other advanced packaging methods.

[0068] The principles of the present invention can be simply summarized as an electrical front end plus optical transmission. The electrical front end comprises an array of microelectrodes 13, a preamplifier for electrical signals fabricated on the array's substrate 11, and the amplifier's input connected to the microelectrodes 13. The output is provided with an interface (PAD) for subsequent connections. All amplifiers can be powered by a single power supply or multiple power supplies. This power can be provided by an external power source via electrical conductors, or by fabricating on-chip optoelectronic materials (such as photodiodes 16) and irradiating them with light to power the amplifier front end.

[0069] Signal transmission is handled by the optical modulator array 14, which modulates electrical signals into optical signals. A bidirectional optical unit containing a multiplexing structure and optical waveguide is fabricated within the optical modulator array 14 to enable the transmission and multiplexing of optical signals.

[0070] The present invention modulates the electrophysiological signals collected by the microelectrode 13 into optical signals through electro-optical conversion, thereby avoiding electromagnetic interference and electromagnetic crosstalk between channels during transmission; at the same time, it rationally utilizes optical signal multiplexing, such as wavelength division multiplexing, time division multiplexing, etc., to realize the input and output of optical signals through a single optical fiber, which can greatly reduce the number and difficulty of wiring.

[0071] Furthermore, the present invention achieves higher-quality signals (i.e., high signal-to-noise ratio) by locally amplifying electrophysiological signals. After being amplified by the electrical chip, the electrophysiological signals are modulated onto a modulator on an optical chip integrated with the electrical chip, thus avoiding the fan-out problem of signal lines. Furthermore, the present invention utilizes optoelectronic materials such as photodiodes 16 to power the electrical chip, thereby enabling single-fiber access, further reducing the number and difficulty of wiring connections.

[0072] With the development of technology, in the future, the optical chip part and the electrical chip part can be directly made on the same surface of the substrate 11 by stacking.

[0073] The above descriptions are merely a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application discloses the preferred embodiments as above, they are not intended to limit the present application. Any technical personnel familiar with the present profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A photoelectric neural interface device, characterized in that: include: a substrate having a plurality of conductive through holes disposed thereon; a plurality of microelectrodes disposed on the front surface of the substrate; The microelectrodes correspond to the conductive through holes one by one, and the microelectrodes are used to collect electrophysiological signals; a plurality of light modulators, disposed on the back side of the substrate; The conductive through hole is used to conduct the electrophysiological signal to the optical modulator, and the optical modulator is used to modulate the electrophysiological signal into an optical signal; a bidirectional optical unit, disposed on the back side of the substrate, for providing a modulated light wave to each of the optical modulators, collecting the modulated optical signal from each of the optical modulators, and then outputting the signal; The bidirectional optical unit comprises: An optical bidirectional interface, provided at the edge of the substrate, for coupling external light waves into the waveguide subunit and for outputting modulated optical signals; a waveguide subunit connected to the optical bidirectional interface, configured to disperse the light wave and transmit it to each of the optical modulators, and couple the modulated optical signal of each optical modulator and transmit it to the optical bidirectional interface; The waveguide subunit includes a first waveguide, a plurality of second waveguides, a plurality of third waveguides, an optical splitter connected between the plurality of second waveguides and the first waveguide, and a coupler connected between the plurality of third waveguides and the first waveguide.

2. The neural interface device according to claim 1, wherein Also includes: a plurality of amplifying units, disposed on the substrate, the amplifying units corresponding one to one with the microelectrodes, and configured to amplify the electrophysiological signals; a power supply unit, configured to supply power to the amplifying unit; The conductive via is used to transmit the amplified electrophysiological signal to the optical modulator.

3. The neural interface device according to claim 2, wherein: The power supply unit includes a light receiving window and a photodiode; The light receiving window is provided on the substrate and corresponds to the position of the photodiode, and is used to receive the illumination light provided by the bidirectional light unit; The photodiode is arranged on the front surface of the substrate and connected to the amplifying unit, and is used for providing electric energy to the amplifying unit under the irradiation of the irradiation light.

4. The neural interface device according to claim 1, wherein Each of the optical modulators receives the electrophysiological signal conducted by one of the conductive vias as a single-ended input signal, or simultaneously receives the electrophysiological signals conducted by any two of the conductive vias as differential input signals.

5. The neural interface device according to claim 1, wherein The first waveguide is used to receive the light wave coupled by the optical bidirectional interface and transmit the light wave to the optical splitter, and is also used to transmit the modulated optical signal coupled by the coupler to the optical bidirectional interface; The second waveguide is used to transmit the light waves dispersed by the optical splitter to each of the optical modulators; The third waveguide is used to transmit the modulated optical signal of the optical modulator to the coupler.

6. The neural interface device according to claim 2, wherein: The amplifying unit is further configured to perform filtering processing on the electrophysiological signal.

7. The neural interface device according to claim 1, wherein A plurality of microelectrode arrays are arranged on the substrate.

8. The neural interface device according to claim 1, wherein The optical modulator is an electro-optical modulator or a thermo-optical modulator.

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