Biological recording device and method for recording biological electrical activity
View Patent ↗A biological recording device used to monitor biological electrical activity and a method of recording neural signals. In a preferred embodiment, the biological recording device is a neural probe. The biological recording device includes a probe body with a probe shank and a recording platform that uses a delta (Δ) modulator and a delta sigma analog to digital converter (ΔΣ ADC). The Δ modulator and the ΔΣ ADC form a Δ-ΔΣ analog front end (AFE) architecture for processing biological electrical activity. A large dynamic range (DR) of neural signals, including local field potentials (LFPs) and action potentials (APs) for example, can be compressed and subsequently reconstructed.
1. A biological recording device, comprising:
a probe body having a probe shank;
a plurality of recording electrodes on the probe shank for monitoring a dynamic range of biological electrical activity, wherein one or more of the recording electrodes have an energy-area product between 4.84 fJ/C-s*mm 2 and 21.27 fJ/C-s*mm 2 , inclusive; and
a recording platform attached to the probe body for processing the biological electrical activity monitored by the plurality of recording electrodes, wherein the recording platform includes a delta (Δ) modulator and the dynamic range of the biological electrical activity is modulated by the Δ modulator.
2. The biological recording device of claim 1 , wherein the recording platform further comprises a delta sigma analog-to-digital converter (ΔΣ ADC) and the Δ modulator and the ΔΣ ADC comprise a Δ-ΔΣ analog front-end (AFE) architecture.
3. The biological recording device of claim 2 , wherein the dynamic range of the biological electrical activity is modulated by the Δ modulator before it is digitized by the ΔΣ ADC.
4. The biological recording device of claim 2 , wherein the Δ-ΔΣ AFE architecture is bonded on an interposer which interconnects the Δ-ΔΣ AFE architecture and the probe body.
5. The biological recording device of claim 2 , wherein the Δ-ΔΣ AFE architecture uses continuous time (CT) quantization.
6. The biological recording device of claim 2 , further comprising a capacitive coupling that includes a plurality of capacitors placed adjacent to the Δ-ΔΣ AFE architecture.
7. The biological recording device of claim 2 , further comprising a low-noise amplifier (LNA), a programmable gain amplifier (PGA), and a decimation filter, wherein the LNA, the PGA, the Δ modulator, the ΔΣ ADC and the decimation filter are connected in series.
8. The biological recording device of claim 1 , wherein each recording electrode monitors biological electrical activity and transmits a signal representative of the biological electrical activity via a channel to the recording platform.
9. The biological recording device of claim 8 , wherein a plurality of signals representative of the biological electrical activity are multiplexed in the digital domain.
10. The biological recording device of claim 1 , wherein the biological electrical activity is serialized into a single bit.
11. The biological recording device of claim 1 , further comprising a plurality of probe shanks that extend from the probe body.
12. The biological recording device of claim 11 , further comprising a plurality of recording platforms, each recording platform being attached to a respective one of a plurality of probe bodies.
13. A biological recording device, comprising:
a probe body having a probe shank;
a plurality of recording electrodes on the probe shank for monitoring biological electrical activity, wherein one or more of the recording electrodes have an energy-area product between 4.84 fJ/C-s*mm 2 and 21.27 fJ/C-s*mm 2 , inclusive; and
a recording platform attached to the probe body for processing the biological electrical activity monitored by the plurality of recording electrodes, wherein the recording platform includes a delta sigma analog to digital converter (ΔΣ ADC) to digitize the biological electrical activity.
14. A method of processing neural signals using the biological recording device of claim 13 , the method comprising the steps of:
acquiring a dynamic range for a plurality of neural signals;
compressing the dynamic range for the plurality of neural signals; and
quantizing the compressed dynamic range for the plurality of neural signals using the delta sigma analog to digital converter (ΔΣ ADC).
15. The method of claim 14 , further comprising the step of reconstructing the quantized dynamic range for the plurality of neural signals through sigma-modulated integration to obtain a retrieved dynamic range representing the plurality of neural signals.
16. The method of claim 14 , wherein the compressing step includes delta (Δ) modulating that takes a temporal difference of oversampled neural signals.
17. The method of claim 14 , wherein the quantizing step operates in continuous time (CT).
18. The method of claim 14 , wherein the plurality of neural signals includes local field potentials (LFPs) and action potentials (APs) that are monitored simultaneously.
19. A biological recording device, comprising:
a probe body having a probe shank;
a plurality of recording electrodes on the probe shank for monitoring a dynamic range of biological electrical activity; and
a recording platform attached to the probe body for processing the biological electrical activity monitored by the plurality of recording electrodes, wherein the recording platform includes a delta (Δ) modulator and a delta sigma analog-to-digital converter (ΔΣ ADC), wherein the Δmodulator is configured to modulate the dynamic range of the biological electrical activity before being digitized by the ΔΣ ADC.