Abstract: The present disclosure provides a system for processing biological signals. The system may comprise a sensing module comprising one or more sensors for detecting at least one of a biological parameter of a subject and one or more biological signals of the subject, and an additional sensor for detecting ambient conditions associated with a surrounding environment of the subject. The system may comprise a signal processing module in communication with the sensing module, wherein the processing module is configured to aggregate and process data obtained using the one or more sensors to compute one or more markers for the subject. The system may comprise an output device optimization module in communication with the signal processing module and one or more output devices, wherein the output device optimization module is configured to control the output devices using the one or more computed markers and data obtained using the additional sensor.

Abstract: A neuromodulator may output stimuli that causes a user to fall asleep faster than the user would in the absence of the stimuli. Alternatively, the stimuli may modify a sleep state or behavior associated with a sleep state, or may cause or hinder a transition from a waking state to a sleep state or from a sleep state to another sleep state. The neuromodulator may take electroencephalography measurements. Based on these measurements, the neuromodulator may detect, in real time, instantaneous amplitude and instantaneous phase of an endogenous brain signal. The neuromodulator may output stimulation that is, or that causes sensations which are, phase-locked with the endogenous brain signal. In the course of calculating instantaneous phase and amplitude, the neuromodulator may perform an endpoint-corrected Hilbert transform. The stimuli may comprise auditory, visual, electrical, magnetic, vibrotactile or haptic stimuli.

Abstract: A neuromodulator accurately measures—in real time and over a range of frequencies—the instantaneous phase and amplitude of a natural signal. For example, the natural signal may be an electrical signal produced by neural tissue, or a motion such as a muscle tremor. The neuromodulator generates signals that are precisely timed relative to the phase of the natural signal. For example, the neuromodulator may generate an exogenous signal that is phase-locked with the natural signal. Or, for example, the neuromodulator may generate an exogenous signal that comprises short bursts which occur only during a narrow phase range of each period of an oscillating natural signal. The neuromodulator corrects distortions due to Gibbs phenomenon. In some cases, the neuromodulator does so by applying a causal filter to a discrete Fourier transform in the frequency domain, prior to taking an inverse discrete Fourier transform.