Method for automated detection of A-waves

• US 7,749,171 B2
• Filed: 03/09/2005
• Issued: 07/06/2010
• Est. Priority Date: 03/09/2004
• Status: Active Grant

• Current Assignee: Neurometrix, Inc.
• Original Assignee: Neurometrix, Inc.
• Inventors: Gozani, Shai N., Kong, Xuan
• Primary Examiner(s): Hindenburg; Max
• Assistant Examiner(s): TOWA, RENE T
• Application Number:
  US11/076,789
• Publication Number:
  US 20060020222A1
• Time in Patent Office: 1,945 Days
• Field of Search: 600/373, 600/378, 600544-546, 600/554
• US Class Current: 600/554
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61B 5/388 Nerve conduction study, e.g. detecting action potential of peripheral nerves

Abstract

In one form of the present invention, there is provided a method for detecting an A-wave, the method comprising:

• • applying a series of stimuli to a nerve;
  • recording a series of late responses;
  • creation of a feature space map from an ensemble of late responses;
  • identification of clusters within the feature space that represent A-wave components;
  • consolidation of A-wave components into a discrete collection of A-waves;
  • removal of false positive A-waves; and
  • extraction of A-wave characteristics.

In another form of the present invention, there is provided a system for detecting an A-wave comprising:

• • a stimulation electrode;
  • a stimulation circuit connected to the stimulation electrode for applying a series of stimuli to a nerve;
  • a detection electrode;
  • a detection circuit connected to the detection electrode; and
  • an analyzer connected to the detection electrode and adapted to detect an A-wave by:
    • recording a series of late responses detected by the detection circuit;
    • creation of a feature space map from an ensemble of late responses;
    • identification of clusters within the feature space map that represent A-wave components;
    • consolidation of A-wave components into a discrete collection of A-waves;
    • removal of false positive A-waves; and
    • extraction of A-wave characteristics.

Claims

1. A method for detecting an A-wave, the method comprising:

applying a series of stimuli to a nerve;

recording a series of evoked bioelectrical responses;

identifying one or more attributes in each of the responses;

utilizing each of the one or more attributes of each of the responses to create a new data set;

creating a search window that is smaller than the new data set;

searching the new data set for trends by;

sequentially applying the search window across the new data set; and

analyzing the search window by counting the number of data points contained within the search window at each separate, sequential search window position;

analyzing the new data set by;

registering a positive for an A-wave component if the number of data points contained within the search window at each separate, sequential search window position exceeds a predetermined threshold; and

registering a negative for an A-wave component if the number of data points contained within the search window at each separate, sequential search window position does not exceed a predetermined threshold; and

consolidating the A-wave components into a single A-wave.

2. A method according to claim 1 wherein the search window has an area such that the height of the search window is proportional to the amplitude location within the new data set.

3. A method according to claim 1 wherein the one or more attributes comprise the amplitude of local maxima and/or local minima.

4. A method according to claim 1 wherein the one or more attributes comprise the absolute value amplitude.

5. A method according to claim 1 wherein the one or more attributes comprise the second derivative of amplitude.