Method and apparatus for monitoring the autonomic nervous system
OwnerLyle Aaron Margulies, David B. Harrell +1inventors
InventorsLyle Aaron Margulies, David B. Harrell, Michael Riggins
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Abstract
An apparatus and method for detection and monitoring of autonomic nervous system (ANS) activity in humans, primarily in the field of sleep research. The present invention discloses a portable, simple, and cost-effective electronic device containing hardware and software that permits real-time monitoring of a pulsatile blood volume waveform obtained through use of a photoplethysmographic (optical volume detecting) probe, thereby allowing signal conditioning, waveform slope analysis, display, recording, and output of pulse transitional slope data representative of activity in the ANS.
Claims16
An apparatus for monitoring human autonomic nervous system activity using pulsatile blood volume waveform signals, said apparatus comprising:
- a photoplethysmographic probe having a light emitting element and an opposing light detecting element, and having an output signal indicating changes in blood volume on at least one alpha andrenergic receptor site of a human body;
- a processor element, responsive to said output signal indicating changes in blood volume, said processor element defining a time interval for calculation of slope of blood volume waveform continuously and in real time and reducing said waveform signals to a slope value within said time interval;
- said processor element containing an algorithm for normalization of the slope value;
- said processor element containing an artifact rejection algorithm for eliminating from further processing slope values less than one;
- and
- amplifier and filter circuitry for rendering output signals representative of said slope values.
A method for identification of human autonomic nervous system activity, the method comprising the steps of:
- disposing a photoplethysmographic probe proximate to a single alpha andrenergic receptor site of a human body part;
- obtaining an electrical signal from said probe representative of pulsatile blood volume within said body part;
- deriving a pulsatile blood volume waveform as a function of amplitude and time;
- defining a time interval for calculation of a slope of the pulsatile blood volume waveform;
- applying an algorithm that continuously provides real-time calculation of the slope along said waveform within said time interval;
- dividing peak amplitude values by a time constant and eliminating slope values less than 1, whereby artifact elimination is achieved;
- normalizing slope values;
- and providing information representative of slope values, whereby autonomie nervous system activity is monitored.
Dependencies are inferred from the claim text.