Methods and associated neural prosthetic devices for bridging brain areas to improve function
Methods for bridging brain sites between which there is substantially no effective communication, and associated neural prosthetic devices, are provided. A neural spike in a first neural site in a subject is detected, and a stimulus to a second neural site in the subject is delivered within a defined period of time after the detection of the neural spike, wherein there is substantially no effective communication between the first and second neural sites. The method forms an artificial bridge between the two neural sites, and establishes lasting communication between the two sites. The present disclosure provides, among other things, a neural prosthetic device comprising an integrated circuit that comprises a recording front-end comprising a plurality of recording channels; a processor unit; and a stimulus delivering back-end comprising a plurality of stimulation channels.
1. A method of using a neural prosthetic device, the neural prosthetic device comprising an integrated circuit that comprises a recording front-end which includes a plurality of recording channels, a stimulus delivering back-end which includes a plurality of stimulation channels, and a processor unit which includes a spike discriminator and decision circuitry, wherein the method comprises:
the processor unit detecting a first neural spike in at least a first channel of the plurality of recording channels at a first time value;
the processor unit detecting a second neural spike in at least a second channel of the plurality of recording channels at a second time value;
the processor unit comparing the first time value of the first neural spike from the first channel to the second time value of the second neural spike from the second channel; and
if the first time value and second time value meet a predetermined criterion, the processor unit causing a stimulus to be delivered in at least one of the plurality of stimulation channels within a defined period of time after the detection of the first and second neural spikes.
2. The method of claim 1 , wherein the spike discriminator identifies acceptable neural spikes by using a spike discrimination algorithm that utilizes adjustable, user-set parameters.
3. A neural prosthetic device comprising:
an integrated circuit that comprises:
a recording front-end comprising a plurality of recording channels;
a stimulus delivering back-end comprising a plurality of stimulation channels; and
a processor unit comprising a spike discriminator and decision circuitry, the processor unit configured to:
detect a first neural spike in at least a first channel of the plurality of recording channels at a first time value,
detect a second neural spike in at least a second channel of the plurality of recording channels at a second time value,
compare the first time value of the first neural spike from the first channel to the second time value of the second neural spike from the second channel, and
if the first time value and second time value meet a predetermined criterion, cause a stimulus to be delivered in at least one of the plurality of stimulation channels within a defined period of time after the detection of the first and second neural spikes.
4. The device of claim 3 , wherein the predetermined criterion comprises the first time value and second time value both occurring within a time window.
5. The device of claim 3 , wherein the recording front-end is configured to detect the first neural spike at a first neural site in a functional area of a cortex, and the stimulus delivering back-end is configured to deliver the stimulus at a second neural site in a different functional area of the cortex.
6. The device of claim 3 wherein the spike discriminator identifies acceptable neural spikes by using a spike discrimination algorithm.
7. The device of claim 6 wherein the spike discrimination algorithm utilizes adjustable, user-set parameters.
8. The device of claim 3 , wherein the spike discriminator includes a threshold level and a time-amplitude window.
9. The device of claim 3 , wherein the stimulus is an asymmetric biphasic electrical pulse.
10. The device of claim 3 , wherein the stimulus is a monophasic or biphasic electrical pulse.
11. The device of claim 3 , wherein the stimulus has an intensity of ≦10 mA.
12. The device of claim 3 further comprising a recording microelectrode having a plurality of recording sites operably connected to the plurality of recording channels of the recording front-end of the integrated circuit.
13. The device of claim 3 further comprising a stimulation microelectrode having a plurality of stimulation sites operably connected to the plurality of stimulation channels of the stimulus delivering back-end of the integrated circuit.
14. The device of claim 3 further comprising a power supply operably connected to the stimulus delivering back-end.
15. The device of claim 3 wherein the processor unit is a digital signal processor unit.
16. The device of claim 3 wherein the recording front-end further comprises a low-noise amplifier, a highpass filter, a secondary amplifier and an analog-to-digital converter.
17. The device of claim 3 wherein the stimulus delivering back-end further comprises a stimulator timing control, a signal level shifter, and a digital-to-analog converter.
18. The device of claim 3 further comprising a radio-frequency transmitter.
19. One or more hardware storage devices having stored thereon computer-executable instructions that are executable by an integrated circuit of a neural prosthetic device, the integrated circuit comprising:
a recording front-end comprising a plurality of recording channels;
a stimulus delivering back-end comprising a plurality of stimulation channels; and
a processor unit comprising a spike discriminator and decision circuitry, wherein the computer-executable instructions cause the processor unit to:
detect a first neural spike in at least a first channel of the plurality of recording channels at a first time value;
detect a second neural spike in at least a second channel of the plurality of recording channels at a second time value;
compare the first time value of the first neural spike from the first channel to the second time value of the second neural spike from the second channel; and
if the first time value and second time value meet a predetermined criterion, cause a stimulus to be delivered in at least one of the plurality of stimulation channels within a defined period of time after the detection of the first and second neural spikes.
20. The one or more hardware storage devices of claim 19 , wherein the stimulus has an intensity of ≦10 mA, and wherein the stimulus is an asymmetric biphasic electrical pulse.