Systems, devices and methods using phase-amplitude coupling measures in implantable medical devices

Inventors

ARCOT DESAI, Sharanya • Tcheng, Thomas K. • Archer, Stephen T.

Assignees

Neuropace Inc

Abstract

A sensor of an implantable medical device senses electrical activity of the brain. A data analyzer of the device monitors an electrographic signal corresponding to the electrical activity of the sensed brain signal, and processes the brain signal to obtain a measure of phase-amplitude coupling. For a selected portion of the electrographic signal, the data analyzer detects first features and second features of the electrographic signal. The first features represent oscillations in a low frequency range, while the second features represent oscillations in a frequency range higher than the low frequency range. For example, the low frequency range may correspond to theta frequency and the higher frequency range may correspond to gamma frequency. The data analyzer determines a measure of phase-amplitude coupling between oscillations in the low frequency range and oscillations in the higher frequency range based on occurrences of second features which coincide with first features.

Core Innovation

The invention relates to an implantable medical device with at least one sensor configured to be implanted in or on a brain of a patient to sense electrical activity of the brain. The device includes a processor coupled to the sensor and configured to derive a phase-amplitude coupling index based on one or more measures of phase-amplitude coupling computed from the sensed electrical activity, and to evaluate the phase-amplitude coupling index relative to a phase-amplitude coupling index criterion to determine if the patient is, or may soon be, in a state of abnormal neural activity.

When the patient is determined to be in a state of abnormal neural activity, the device delivers neuromodulation therapy. The therapy includes stimulating a first area of the brain using a first stimulation waveform comprising electrical stimulation pulses delivered at a low frequency within a low frequency range, and delivering the low-frequency stimulation pulses in synchrony or near-synchrony with fiducial points of a low-frequency filtered brain signal.

The therapy further includes stimulating a second area of the brain using a second stimulation waveform comprising electrical stimulation pulses delivered at a high frequency greater than the low frequency, and delivering the high-frequency stimulation pulses in synchrony or near-synchrony with fiducial points of a high-frequency filtered brain signal. Dependent refinements configure the neuromodulation therapy to modulate subsequent phase-amplitude coupling measures either by increasing or decreasing them.

Claims Coverage

The partial content provided includes two independent claims. Both independent claims share a common core of deriving and evaluating a phase-amplitude coupling index to determine abnormal neural activity, and delivering neuromodulation therapy using synchrony or near-synchrony with fiducial points derived from low- and high-frequency bandpass filtered brain signals.

Across the two independent claims, the inventive coverage centers on computing and criterion-evaluating a phase-amplitude coupling index from sensed brain electrical activity and using that determination to trigger neuromodulation therapy. The therapy is implemented as dual-area stimulation with distinct low- and high-frequency pulse waveforms, where each waveform’s pulses are delivered in synchrony or near-synchrony with fiducial points of the corresponding low- and high-frequency bandpass filtered brain signals.

Stated Advantages

Documented Applications