Seizure sensing and detection using an implantable device

A method for detecting a neurological event by analyzing an electrical signal from a patient's brain with an implantable device, the method comprising the steps of:

• receiving the electrical signal with an electrode pair;
• processing the electrical signal with a detection subsystem, wherein the detection subsystem is adapted to identify at least one feature in the electrical signal and calculate at least one window parameter in the electrical signal;
• and
• causing the implantable device to perform an action in accordance with an indication from the detection subsystem;
• wherein the processing step comprises the steps of sampling the electrical signal to create a sampled digital signal, identifying a feature in the sampled digital signal with a wave morphology analysis unit, and calculating a window parameter in the sampled digital signal with a window analysis unit;
• and
• wherein the calculating step comprises the step of computing a line length function.

A method for detecting a neurological event by analyzing an electrical signal from a patient's brain with an implantable device, the method comprising the steps of:

• receiving the electrical signal with an electrode pair;
• processing the electrical signal with a detection subsystem, wherein the detection subsystem is adapted to identify at least one feature in the electrical signal and calculate at least one window parameter in the electrical signal;
• and
• causing the implantable device to perform an action in accordance with an indication from the detection subsystem;
• wherein the processing step comprises the steps of sampling the electrical signal to create a sampled digital signal, identifying a feature in the sampled digital signal with a wave morphology analysis unit, and calculating a window parameter in the sampled digital signal with a window analysis unit;
• and
• wherein the identifying step comprises the step of locating a half wave in the sampled digital signal, determining whether an amplitude of the half wave exceeds an amplitude threshold and whether a duration of the half wave exceeds a duration threshold, and if both thresholds are met, labeling the half wave as a qualified half wave, and if the half wave is a qualified half wave, storing a record representative of the qualified half wave.

An implantable device for detecting a neurological event by analyzing an electrical signal from a patient's brain, the device comprising:

• an implantable control module;
• a plurality of electrodes including at least one brain electrode;
• and
• a plurality of event detectors each adapted to analyze a signal from an electrode pair, wherein the electrode pair comprises two electrodes selected from the plurality of electrodes and including at least one brain electrode;
• wherein each event detector of the plurality of event detectors is programmable with respect to at least one detection parameter;
• and
• wherein each event detector of the plurality of event detectors is adapted to be selectively coupled to receive a signal from a corresponding electrode pair.

An implantable device for detecting a neurological event by analyzing an electrical signal from a patient's brain, the device comprising:

• a central processing unit;
• a detection subsystem comprising at least one electronics module and including a waveform analyzer having a window-based analysis unit adapted to analyze a line length function and an area function in the electrical signal, and a feature-based analysis unit adapted to analyze half waves in the electrical signal;
• and
• a power supply;
• wherein the detection subsystem includes a plurality of inputs and a plurality of detection channels;
• wherein the window-based analysis unit includes a plurality of window analysis units and the feature-based analysis unit includes a plurality of wave morphology analysis units;
• wherein the detection subsystem performs at least a portion of a detection task without the use of the central processing unit, thereby allowing the central processing unit to remain in a relatively inactive mode at least part of the time;
• wherein the central processing unit, the detection subsystem, and the power supply are enclosed within a housing and implanted in the patient;
• and
• wherein the neurological event comprises an epileptic seizure, an onset of an epileptic seizure, a precursor to an epileptic seizure, an episode of a movement disorder, an onset of an episode of a movement disorder, a precursor to an episode of a movement disorder, a migraine headache, an onset of a migraine headache, a precursor to a migraine headache, an episode of pain, an onset of an episode of pain, a precursor to an episode of pain, an episode of depression, an onset of an episode of depression, or a precursor to an episode of depression.

An implantable device for detecting a neurologcal event by analyzing an electrical signal from a patient's brain, the device comprising:

• an implantable control module;
• a central processing unit located within the control module;
• and
• a detection subsystem located within the control module and comprising a waveform analyzer having a window-based analysis unit and a feature-based analysis unit;
• wherein the window-based analysis unit comprises a line length function analysis tool.