Methods for Optimizing Evoked Potential Baseline Reference Value in an Intraoperative Neurophysiological Monitoring Environment
AssigneeCadwell Laboratories, Inc.
InventorsJulia Aina Caviness, Michael Batdorf, Joseph Callahan Myers, John A. Cadwell
Life of this patent
Estimating the term…
Abstract
A method of determining an optimized stimulus intensity required to obtain an evoked potential (EP) response from a patient in a surgical intraoperative neurophysiological monitoring environment includes determining an initial stimulus current, determining an initial count to determine a predefined signal-to-noise ratio (SNR) threshold, and using a search algorithm for automatically generating an optimized/baseline stimulus intensity and average count required to elicit a maximal EP response from the patient based on the initial stimulus current and the initial count.
Claims20
A computer-implemented method for determining an initial stimulus intensity and averaging count that elicit an evoked potential (EP) response amplitude from a patient within a region of a stimulus response curve as input to a later second stage, the method comprising:
- determining a baseline noise level by acquiring neurological data for one or more selected peripheral nerves of the patient, wherein the neurological data is generated in an absence of applied peripheral electrical stimulation;
- computing, based on the baseline noise level, an initial count representing a function of a number of stimulus trials;
- stimulating said one or more peripheral nerves of the patient over the initial count using an initial stimulation current, wherein the initial stimulation current is selected from within a region of a stimulus-response curve;
- acquiring EP response data over the initial count and determining an EP response amplitude associated with the initial stimulation current;
- and
- determining whether the EP response amplitude is indicative of a valid EP response amplitude within the region,
- wherein, if a valid EP response amplitude is not obtained, incrementally increasing at least one of the initial count or the initial stimulation current and iterating the steps of acquiring EP response data and determining whether the EP response amplitude is indicative of a valid EP response amplitude within the region, and
- wherein, if either a valid EP response amplitude is obtained or when predefined limits on increasing the initial count or the stimulation current are reached, terminating the method.
A system for determining a stimulus intensity and averaging count that elicit a maximal evoked potential (EP) response amplitude from a patient, the system comprising:
- an EP stimulus optimizer comprising at least one stimulating electrode positioned in proximity to a peripheral nerve of the patient and one or more electrodes positioned on the patient's head in proximity to the sensory cortex;
- a computing device in data communication with the EP stimulus optimizer and comprising at least one processor and a non-volatile memory for storing a plurality of instructions of programmatic code which, when executed, configure the processor to:
- acquire neurological data, for the peripheral nerve of the patient, in the absence of peripheral stimulation to determine a baseline noise level;
- compute, based on the baseline noise level, an initial count representing a function of a number of stimulus trials;
- stimulate the peripheral nerve of the patient over the initial count using an initial stimulation current, wherein the initial stimulation current is selected from within a region of a modeled stimulus-response curve;
- acquire EP response data over the initial count and determine an EP response amplitude associated with the initial stimulation current;
- and
- determine whether the EP response amplitude is indicative of a valid EP response amplitude within the region,
- wherein, if a valid EP response amplitude is not obtained then incrementally increase at least one of the initial count or the stimulation current and iterate the steps of acquiring EP response data and of determining if the EP response data is indicative of a valid EP response amplitude within the region, and
- wherein, if either a valid EP response amplitude is obtained or predefined limits are reached on increasing the initial count or the stimulation current, terminate the execution of the plurality of instructions of programmatic code.
Dependencies are inferred from the claim text.