Neural sensing system with optical data communication

Abstract

A neural implant system (100) includes an internal unit (102) implanted in the user's body (10) and includes: a cranial implant (110) unit responsive to user-generated neural impulses; a fiber optic cable (120) coupled to the internal unit (102) that receives the neural optical signal; an optical data transmission unit (130) that receives the optical signal and generates an enhanced optical signal. An optical window (636), implanted in the dermal tissue adjacent to the optical data transmission unit (130) allows the enhanced optical signal to be transmitted. An external unit (140) adjacent to the optical window (636) includes an optical sensor (714) responsive to the enhanced optical signal. An electronic circuit (716) converts the enhanced optical signal into an electronic signal.

Description

NEURAL SENSING SYSTEM WITH OPTICAL DATA COMMUNICATIONBACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to neural implant systems and, more specifically, to a neural implant system with wireless data transfer.

[0003] 2. Description of the Related Art

[0004] Neural implant systems can be used to sense neural impulses generated by an individual’s brain. Many existing neural implant systems involve a neural implant that has been implanted at a selected site of the individual’s brain and that is responsive to neural impulses generated by the individual’s brain. A wire is used to transmit electrical impulses from the implant to an external device. Such a wire typically passes through the individual’s skin and connects to the external device. Because the wire passes through the skin, the opening through which it passes can become infected. Also, force placed on the wire can cause movements in the implant, which can disrupt the sensing of neural impulses.

[0005] Implant systems employing an internal implanted radio frequency (RF) transmitter to transmit data to an external RF receiver have been tried. However, for some applications the bandwidth of the RF signal is too limited.

[0006] Many exiting neural data transmission units include an exterior portion placed on the user’s skull. This can result in embarrassment to the user.

[0007] Therefore, there is a need for a high bandwidth neural implant system that does not require the passage of a wire through the user’s skin.

[0008] These and other aspects of the invention will become apparent from the following description of the preferred embodiments taken in conjunction with the following drawings. As would be obvious to one skilled in the art, many variations andmodifications of the invention may be effected without departing from the spirit and scope of the novel concepts of the disclosure.SUMMARY OF THE INVENTION

[0009] The disadvantages of the prior art are overcome by the present invention which, in one aspect, is a neural implant system for use with a user having a body with dermal tissue, that includes an internal unit implanted internally in the body of the user. The internal unit includes a cranial implant unit that is responsive to neural impulses generated by the user. The internal unit also includes a fiber optic cable coupled to the internal unit so as to receive the neural optical signal. The internal unit also includes an optical data transmission unit that receives the optical signal from the fiber optic cable and that generates an enhanced optical signal representative thereof. An optical window is implanted in the dermal tissue of the user and is disposed adjacently to the optical data transmission unit. The optical window allows the enhanced optical signal to be transmitted thereto. An external unit is external to the body of the user and is adjacent to the optical window. The external unit includes an optical sensor that is responsive to the enhanced optical signal. The external unit includes an electronic circuit that converts the enhanced optical signal into an electronic signal representative thereof.

[0010] In another aspect, the invention is a neural implant processing system for use with a user having a body with dermal tissue, that includes a neural electrode array implanted in neural tissue of the user. The neural electrode implant array is responsive to neural impulses generated by the user. A recording amplifier / digitizer receives analog electrical impulses from the neural electrode array and digitizes the analog electrical impulses into a digital electronic signal and then amplifies the digital electronic signal. An electro-optic modulator generates a neural optical digital signal corresponding to the electronic digital signal. A micro-optic beam splitter and fiber collimator transmits the neural optical digital signal. A fiber optic cable receives the neural optical digital signal from the fiber collimator. A downlink opto-electric photo diode converts the neural optical signal from the fiber optic cable into a corresponding electrical data signal. A digital logic circuit prepares the electrical data signal for transmission. A transdermal light emitting diode array is responsive to the electrical data signal from the digital logic circuit and generates an enhanced optical signal representative of the electrical data signal. An opticalwindow is implanted in the dermal tissue of the user and is disposed adjacently to the optical data transmission unit. The optical window allows the enhanced optical signal to be transmitted thereto. An external unit is external to the body of the user and is adjacent to the optical window. The external unit includes an optical sensor that is responsive to the enhanced optical signal. The external unit includes an electronic circuit that converts the enhanced optical signal into an electronic signal representative thereof. A photovoltaic electro-optical vertical-cavity surface-emitting laser (VCSEL) transmits a power signal to the optical fiber cable. A control channel electro-optical VCSEL transmits optical control information to the optical fiber cable.

[0011] In yet another aspect, the invention is a method of transmitting neural impulse data from a user having a brain and a body to a remote device, in which neural impulses generated in the brain of the user are sensed with a neural electrode array that has been implanted in the brain of the user. The neural impulses are converted into an optical signal. The optical signal is transmitted to an internal optical data transmission unit that has been implanted in the body of the user adjacent to dermal tissue. The optical signal is received through a window implanted in the dermal tissue with an external unit. The optical signal is converted into an electronic data signal in the external unit. The electronic data signal is processed in the external unit so as to generate useful information.BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS

[0012] FIG. 1 is a schematic diagram of a neural implant system with optical data transmission implanted in a user.

[0013] FIG. 2 is a schematic diagram of a neural implant unit with optical signal generation.

[0014] FIG. 3 is a schematic diagram of an optical signal transmission unit.

[0015] FIG. 4 is a schematic diagram of an internal portion of a neural implant system implanted in a user.

[0016] FIG. 5 is a block diagram showing one embodiment of a cranial implant system.

[0017] FIG. 6 is a block diagram showing one embodiment of an internal chestmounted optical data transmission unit.

[0018] FIG. 7 is a block diagram showing one embodiment of an external unit.DETAILED DESCRIPTION OF THE INVENTION

[0019] A preferred embodiment of the invention is now described in detail. Referring to the drawings, like numbers indicate like parts throughout the views. Unless otherwise specifically indicated in the disclosure that follows, the drawings are not necessarily drawn to scale. The present disclosure should in no way be limited to the exemplary implementations and techniques illustrated in the drawings and described below. As used in the description herein and throughout the claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise: the meaning of “a,” “an,” and “the” includes plural reference, the meaning of “in” includes “in” and “on.”

[0020] U.S. Patent Nos. 7187967, 7275035, 9474488, and 10,575,750 is incorporated herein by reference for the purpose of disclosing neural implants and methods of making neurotrophic electrodes. U.S. Patent Application No. 18 / 384,628 discloses embodiments of cone electrode arrays and is incorporated herein by reference.

[0021] As shown in FIGS. 1 - 2, one embodiment of a neural implant system 100 includes an internal unit 102 and an external unit 104. The internal unit 102 is implanted internally in the neural tissue of a user 10 and includes a cranial implant unit 110 (that can include a cone electrode array) and is coupled to an optical data transmission unit 130 via a broadband optical fiber cable 120 that is implanted in the user’s body, which carries a neural optical signal and which passes from the neural implant unit 110 implanted, for example, behind the clavicle into the user’s 10 chest 12. In other embodiments, the optical data transmission unit 130 can be placed at other positions of the user’s body. Typically, such positions would be those that can be covered by the user’s clothing. The external unit104 includes an external unit 140 that receives optical data from the optical data transmission unit 130 through the user’s skin 12 and transmits the data either by wire or wirelessly to a remote unit 142, such as a computer, a tablet or a smartphone, etc., for further analysis. For example, analytical results could be used by a clinician to help formulate a treatment plan. The results could also be employed in research. Data transmission can be accomplished using a reflectance modulation scheme such as a Bragg Grating or an LCD. The optical data transmission unit 130 receives the optical information from the neural implant unit 110 via the broadband optical fiber 120 and rebroadcasts an optical signal through the tissue.

[0022] As shown in FIG. 3, the cranial implant unit 110 includes a neural implant 112, or array thereof, that has at least one electrode (such as a neurotrophic electrode) that senses neural impulses generated by the user’s 10 brain and that is implanted at a selected site of the user’s 10 brain, and an electronics / optical unit 114 that amplifies the neural impulses sensed by the neural implant 112 and that generates optical signals corresponding to the neural impulses.

[0023] As shown in FIG. 4, the optical data transmission unit 130 receives the optical signals from the neural implant unit 110 via the broadband optical fiber 120 and generates an optical signal that has a wavelength and amplitude that allows it to be passed through the user’s 10 dermal tissue 12. The optical data transmission unit 130 includes an optical transmission device 132 that generates the optical signal. The optical data transmission unit 130 also includes a first magnetic coupler, which includes at least one magnet 134 having a first polarity.

[0024] Also, as shown in FIG. 4, the external unit 140 includes an optical sensor 146 and a second magnetic coupler, which includes at least one magnet 144 having a second polarity that is opposite from the first polarity. Thus, when the second magnet coupler is placed opposite from the first magnet coupler, the magnet(s) 134 of the first polarity will be attracted to the magnet(s) 144 of the second polarity so as to hold the optical data transmission unit 130 in alignment with the external unit 140 so that the optical sensor 146 receives a maximum amount of optical energy from the optical transmission device 132. When data is received by the external 140, it can be analyzed and processed by the remote unit 142.

[0025] As shown in greater detail in FIG. 5, the cranial implant unit 110 includes a hermetic enclosure 500 in which is sealed an optical transmission unit 502 that includes the necessary electronic components that are coupled to one or more neural electrodes 512 (which in one embodiment can include a cone electrode array). The hermetic enclosure 500 typically includes a biocompatible polymer to protect its contents. While any one of several types of neural electrodes may be used, this embodiment employs arrays of cone electrodes. A recording amplifier / digitizer 522 receives analog electrical impulses from the neural electrodes 512 and then digitizes them and amplifies the resulting digital signal. A digital timing circuit 524 provides a clock signal for the generation of a continuous electrical digital signal. An electro-optic modulator 526 generates an optical digital signal corresponding to the electrical digital signal and a micro-optic beam splitter and fiber collimator 528 sends the optical digital signal to the optical fiber cable 120.

[0026] The optical fiber cable 120 can be bidirectional and receive a power signal and data from the external unit 140. An uplink opto-electronic device 530, such as a photo diode, can receive data signals from micro-optic beam splitter and fiber collimator 528 for various uses such as control and neural stimulation. A photovoltaic opto-electronic power converter 532 can receive an optical power signal via the optical fiber cable 120 and convert it to electricity, which is used to power the electronics in the cranial implant unit 110

[0027] As shown in FIG. 6, a second hermetic enclosure 600 houses the optical data transmission unit 130. The optical data transmission unit 130 includes a micro-optic beam splitter and fiber collimator 610 for bidirectional optical data communication and power transmission with the optical fiber cable 120. It transmits received optical data signals to a downlink opto-electric photo diode 614, which converts a received optical signal into a corresponding electrical signal. A digital logic circuit 618 prepares the resulting electrical signal for transmission and a transdermal light emitting diode array 620 generates an enhanced optical signal 650, which can carry data, through the a transmission window 636 having micro-lenses used to distribute the optical signal through the user’s dermal tissue 12. Data transmission can be accomplished using a reflectance modulation scheme such as a Bragg grating or an LCD.

[0028] The optical data transmission unit 130 can also receive an optical power signal through the patient’s dermal tissue 12. Upon receiving a power signal, a power inductioncircuit 632 converts part of the power signal into electricity used to power a battery / power supply unit 630, which can include a storage battery. A control channel circuit 634 controls the operations of unit 130.

[0029] A photovoltaic electro-optical vertical-cavity surface-emitting laser (VCSEL) 612 can transmit a power signal to the optical fiber cable 120 and a control channel electro- optical VCSEL 616 can transmit optical control information to the optical fiber cable 120.

[0030] As shown in FIG. 7, the external unit 140 includes an enclosure 700 housing electronic circuits that communicate with the enhanced optical signal 650 through the dermal tissue 12 via an optical window 710. When an optical data signal is received, a beam collimator 712 directs it to a downlink opto-electronic wideband photodiode 714, which converts the optical signal into an electronic signal. A digital logic circuit 716 converts the electronic signal to a format that can be used by a processor 718 for further processing and analysis. A wireless communications circuit 720 (such as a Bluetooth low energy device or other type of wireless local area network device) communicates between the processor 718 and the remote device 142. A battery 724 stores energy to power a power supply 722 used to power the external unit 140. An induction coil drive 720 can be used to recharge the battery 724 wirelessly. A control channel uplink circuit 710 can be used to condition digital and power signals for optical transmission through the dermal tissue 12.

[0031] A typical embodiment includes a full duplex optical link to allow synchronization and control from unit 130 back up into unit 110. There is a need to synchronize the data collection process. With a full duplex power over fiber link the invention can employ existing commercially available recording integrated circuits in unit 110. A synchronous system simplifies the downlink and signal recovery in unit 130.

[0032] The invention avoids embarrassment for the user by placing the optical data transmission unit 130 in a location such that the receiver unit 140 can be covered by clothing, such as adjacent to the user’s 10 chest. This removes the stigma of having visible wires attached to the user’s head.

[0033] Although specific advantages have been enumerated above, various embodiments may include some, none, or all of the enumerated advantages. Othertechnical advantages may become readily apparent to one of ordinary skill in the art after review of the following figures and description. It is understood that, although exemplary embodiments are illustrated in the figures and described below, the principles of the present disclosure may be implemented using any number of techniques, whether currently known or not. Modifications, additions, or omissions may be made to the systems, apparatuses, and methods described herein without departing from the scope of the invention. The components of the systems and apparatuses may be integrated or separated. The operations of the systems and apparatuses disclosed herein may be performed by more, fewer, or other components and the methods described may include more, fewer, or other steps. Additionally, steps may be performed in any suitable order. As used in this document, “each” refers to each member of a set or each member of a subset of a set. It is intended that the claims and claim elements recited below do not invoke 35 U.S.C. §112(f) unless the words “means for” or “step for” are explicitly used in the particular claim. The abovedescribed embodiments, while including the preferred embodiment and the best mode of the invention known to the inventor at the time of filing, are given as illustrative examples only. It will be readily appreciated that many deviations may be made from the specific embodiments disclosed in this specification without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is to be determined by the claims below rather than being limited to the specifically described embodiments above.

Claims

CLAIMSWhat is claimed is:

1. A neural implant system for use with a user having a body with dermal tissue, comprising: a. an internal unit implanted internally in the body of the user, the internal unit including a cranial implant unit that is responsive to neural impulses generated by the user, the internal unit also including a fiber optic cable coupled to the internal unit so as to receive the neural optical signal, the internal unit also including an optical data transmission unit that receives the optical signal from the fiber optic cable and that generates an enhanced optical signal representative thereof; b. an optical window implanted in the dermal tissue of the user that is disposed adjacently to the optical data transmission unit and that allows the enhanced optical signal to be transmitted thereto; and c. an external unit that is external to the body of the user and is adjacent to the optical window, the external unit including an optical sensor that is responsive to the enhanced optical signal, the external unit including an electronic circuit that converts the enhanced optical signal into an electronic signal representative thereof.

2. The neural implant system of Claim 1, wherein the cranial implant unit comprises a cone electrode array.

3. The neural implant system of Claim 1, wherein the user has a clavicle and wherein the optical data transmission unit is implanted in the body of the user adjacent to the clavicle.

4. The neural implant system of Claim 2, wherein the cranial implant unit comprises: a. a recording amplifier / digitizer that is configured to receive analog electrical impulses from the cone electrode array and to digitize the analog electrical impulses into a digital electronic signal and then amplify the digital electronic signal;b. an electro-optic modulator that generates a neural optical digital signal corresponding to the electronic digital signal; and c. a micro-optic beam splitter and fiber collimator that transmits the neural optical digital signal to the fiber optic cable.

5. The neural implant system of Claim 2, wherein the cranial implant unit comprises a hermetic enclosure that envelopes all components in the cranial implant unit.

6. The neural implant system of Claim 1, wherein the optical data transmission unit comprises: a. a downlink opto-electric photo diode that converts the neural optical signal into a corresponding electrical data signal; b. a digital logic circuit that prepares the electrical data signal for transmission; and c. a transdermal light emitting diode array, that is responsive to the electrical data signal from the digital logic circuit, that generates an enhanced optical signal representative of the electrical data signal through the a transmission window.

7. The neural implant system of Claim 6, wherein the optical data transmission unit further comprises: a. a photovoltaic electro-optical vertical-cavity surface-emitting laser (VCSEL) that transmits a power signal to the optical fiber cable; and b. a control channel electro-optical VCSEL that transmits optical control information to the optical fiber cable.

8. The neural implant system of Claim 6, wherein the optical data transmission unit further comprises a hermetic enclosure enveloping all components in the optical data transmission unit.

9. The neural implant system of Claim 1, wherein the external unit comprises: a. a beam collimator that directs the enhanced optical signal; b. a downlink opto-electronic wideband photodiode that converts the optical signal into an electronic signal;c. a digital logic circuit that converts the electronic signal into a usable format signal; and d. a processor that receives the usable format signal and that processes usable format signal to provide analytical results.

10. The neural implant system of Claim 9, wherein the external unit comprises a local area network wireless communications circuit that communicates data from the processor to a remote device.

11. The neural implant system of Claim 1, wherein the optical data transmission unit includes a DC power supply and a power induction circuit that supplies electrical power to the DC power supply and wherein the external unit includes an induction coil drive that generates an inductive power signal that is received by power induction circuit, which converts the inductive power signal in an electrical signal supplied to the DC power supply.

12. A neural implant processing system for use with a user having a body with dermal tissue, comprising: a. a neural electrode array implanted in neural tissue of the user, wherein the neural electrode implant array is responsive to neural impulses generated by the user; b. a recording amplifier / digitizer that receives analog electrical impulses from the neural electrode array and digitizes the analog electrical impulses into a digital electronic signal and then amplifies the digital electronic signal; c. an electro-optic modulator that generates a neural optical digital signal corresponding to the electronic digital signal; d. a micro-optic beam splitter and fiber collimator that transmits the neural optical digital signal; e. a fiber optic cable that receives the neural optical digital signal from the fiber collimator; f. a downlink opto-electric photo diode that converts the neural optical signal from the fiber optic cable into a corresponding electrical data signal; g. a digital logic circuit that prepares the electrical data signal for transmission;h. a transdermal light emitting diode array, that is responsive to the electrical data signal from the digital logic circuit, that generates an enhanced optical signal representative of the electrical data signal; i. an optical window implanted in the dermal tissue of the user that is disposed adjacently to the optical data transmission unit and that allows the enhanced optical signal to be transmitted thereto; j . an external unit that is external to the body of the user and is adjacent to the optical window, the external unit including an optical sensor that is responsive to the enhanced optical signal, the external unit including an electronic circuit that converts the enhanced optical signal into an electronic signal representative thereof; k. a photovoltaic electro-optical vertical-cavity surface-emitting laser (VCSEL) that transmits a power signal to the optical fiber cable; and l. a control channel electro-optical VCSEL that transmits optical control information to the optical fiber cable.

13. The neural implant processing system of Claim 12, wherein the neural electrode array comprises a cone electrode array.

14. The neural implant processing system of Claim 12, wherein the user has a clavicle and wherein the optical data transmission unit is implanted in the body of the user adjacent to the clavicle.

15. The neural implant processing system of Claim 12, further comprising an external unit that includes: a. a beam collimator that directs the enhanced optical signal; b. a downlink opto-electronic wideband photodiode that converts the optical signal into an electronic signal; c. a digital logic circuit that converts the electronic signal into a usable format signal; and d. a processor that receives the usable format signal and that processes usable format signal to provide analytical results.

16. The neural implant processing system of Claim 15, further comprising a local area network wireless communications circuit that communicates data from the processor to a remote device.

17. The neural implant processing system of Claim 15, further comprising a DC power supply and a power induction circuit that supplies electrical power to the DC power supply and further comprising an induction coil drive that generates an inductive power signal that is received by power induction circuit, which converts the inductive power signal in an electrical signal supplied to the DC power supply.

18. A method of transmitting neural impulse data from a user having a brain and a body to a remote device, comprising the steps of: a. sensing neural impulses generated in the brain of the user with a neural electrode array that has been implanted in the brain of the user; b. converting the neural impulses into an optical signal; c. transmitting the optical signal to an internal optical data transmission unit that has been implanted in the body of the user adjacent to dermal tissue; d. receiving the optical signal through a window implanted in the dermal tissue with an external unit; e. converting the optical signal into an electronic data signal in the external unit; f. processing the electronic data signal in the external unit so as to generate useful information.

19. The method of Claim 18, further comprising the step of transmitting the useful information wirelessly to a remote unit.

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