Implantable neural interface
A neural interface arrangement has multiple probes for subdural implantation into or onto a human brain. Each probe has at least one sensing electrode, a coil for receiving power via inductive coupling, signal processing circuitry coupled to the electrode(s), and a transmitter for wirelessly transmitting data signals arising from the electrode(s). An array of coils is implanted above the dura beneath the skull, for inductively coupling with the coil of each probe, and for transmitting power to the probes. A primary coil is connected to the coil array, for inductively coupling with an external transmitter device, and for receiving power from the external transmitter device. In use, the primary coil is operable to receive power from the external transmitter device by inductive coupling and to cause the coil array to transmit power to the probes by inductive coupling, and the probes wirelessly transmit data signals arising from the electrodes.
1 . A probe for subdural implantation into a human brain, the probe comprising a head, a plurality of sensing electrodes, a coil for receiving power via inductive coupling, signal processing circuitry coupled to the sensing electrode, and a wireless transmitter for wirelessly transmitting data-carrying signals;
wherein the coil is located in the head of the probe;
wherein the probe is of drawing-pin-like form, having either
a rigid shank on which the sensing electrodes are located, or
a non-rigid shank made up of a plurality of flexible and/or soft insulated wires, each wire being connected to a respective sensing electrode;
wherein the sensing electrodes are a plurality of discrete independent sensing electrodes; and
wherein the plurality of discrete independent sensing electrodes are located at different depth positions along the shank.
2 . The probe according to claim 1 , further comprising a reference electrode.
3 . The probe according to claim 1 , wherein the signal processing circuitry is in the form of a complementary metal-oxide semiconductor system on a chip.
4 . The probe according to claim 1 , wherein the signal processing circuitry includes a power management module and a communication module.
5 . The probe according to claim 4 , wherein the communication module includes downlink circuitry and uplink circuitry;
wherein the downlink circuitry is connected to configuration and control circuitry, for configuring and controlling the operation of the probe;
wherein the uplink circuitry is connected to processing and encoding circuitry, to process and encode signals arising from the electrode(s).
6 . The probe according to claim 1 , wherein the output of the or each sensing electrode is supplied to a respective low noise amplifier.
7 . The probe according to claim 6 , further comprising a reference electrode, wherein the output of the reference electrode is also supplied to the or each low noise amplifier, such that the or each low noise amplifier subtracts the reference electrode signal from the respective sensing electrode signal.
8 . The probe according to claim 6 , wherein the output of each low noise amplifier is provided to a multiplexer and buffer.
9 . The probe according to claim 8 , wherein the output of the multiplexer and buffer is provided to an analogue-to-digital converter, the output of which is then provided to the processing and encoding circuitry.
10 . The probe according to claim 1 , wherein the electrode(s) are coupled to the signal processing circuitry by means of one or more through-silicon-vias, or by means of conductors that are tunnelled within inter metal dielectrics, or by means of an interposer layer.
11 . The probe according to claim 1 , wherein the coil comprises a millimetre-scale coil.
12 . The probe according to claim 1 , wherein the electrode(s) are spring-biased into an extended position, with means for holding the electrode(s) in a retracted position prior to implantation.
13 . The probe according to claim 1 , wherein the wireless transmitter comprises the probe's coil, or a second coil, with which the probe is operable to transmit data-carrying signals arising from the sensing electrode(s) by inductive coupling.
14 . The probe according to claim 1 , wherein the wireless transmitter is operable to transmit data-carrying signals directly to an external receiver device.
15 . The probe according to claim 4 , wherein the power management module includes rectification circuitry and regulation circuitry.
16 . The probe according to claim 8 , wherein the output of each low noise amplifier is provided to the multiplexer and buffer via a bandpass filter.
17 . The probe according to claim 10 , wherein the signal processing circuitry is provided within micropackaging.