Amplifier with pulse coded output and remote signal reconstruction from the pulse output

A system comprising:

• a signal-conversion portion for generating a pulse train defined by a sequence of pulses generated at varying time intervals based upon a time-varying voltage signal, said signal-conversion portion having
• an amplifier for amplifying the time varying voltage signal, said amplifier providing an output voltage signal,
• a voltage-to-current converter, said converter converting said output voltage signal into a current signal, and
• an output stage including a current integrator for integrating said current signal to produce an integrated voltage, and an amplitude-to-time converter for generating said pulse train defined by the sequence of pulses generated at varying time intervals, wherein time intervals between the pulses vary based upon said time varying voltage signal such that said pulse train represents said time varying voltage signal;
• and
• a signal-reconstruction portion in communication with said signal-conversion portion for receiving said pulse train and reconstructing said time-varying voltage signal based upon said pulse train, said signal-reconstruction portion configured to generate a plurality of impulse functions based upon said pulse train, to determine a plurality of weights based upon recorded values of the time intervals between successive pulses, to generate a plurality of weighted impulse functions based upon the determined weights, to filter the weighted impulse functions using a low pass filter, and to sample an output of the low pass filter at a uniform rate to recover a reconstructed version of said time-varying voltage signal.

A system to produce asynchronous pulsed output suitable for use in bioinstrumentation, comprising:

• an integrate-and-fire asynchronous voltage-to-time (V/T) converter, said (V/T) converter converting a time-varying analog neural signal captured by an electrode into the asynchronous pulsed output, the V/T converter comprising:
• an integrator comprising a capacitor to integrate said time varying analog neural signal to produce an integrated voltage without sampling the time varying analog neural signal;
• and
• a comparator receiving as inputs said integrated voltage and a predetermined voltage to generate a pulse of the asynchronous pulse output upon determining that the integrated voltage reaches the predetermined voltage,
• wherein the asynchronous pulse train is defined by a sequence of pulses generated at varying time intervals, wherein time intervals between the pulses vary based upon said time varying analog neural signal such that said pulse train represents the time-varying analog neural signal as a set of non-uniform time instances such that the integrated voltage between any two adjacent non-uniform time instances of the time-varying voltage signal is approximately equal to a constant.