Biopotential Waveform Data Fusion Analysis and Classification Method

• US 20080208072A1
• Filed: 02/26/2007
• Published: 08/28/2008
• Est. Priority Date: 08/30/2004
• Status: Abandoned Application

• Current Assignee: Neuronetrix Solutions, Inc., Neuronetrix Solutions LLC
• Original Assignee: Neuronetrix Solutions LLC
• Inventors: Fadem, Kalford C., Gupta, Lalitmore
• Application Number:
  US11/678,658
• Publication Number:
  US 20080208072A1
• Time in Patent Office: Days
• US Class Current: 600/544
• CPC Class Codes: A61B 5/291 for electroencephalography [EEG]
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/377 using evoked responses
• CPC Class Codes: A61B 5/378 Visual stimuli
• CPC Class Codes: A61B 5/38 Acoustic or auditory stimuli
• CPC Class Codes: A61B 5/4088 Diagnosing of monitoring cognitive diseases, e.g. Alzheimer, prion diseases or dementia
• CPC Class Codes: A61B 5/6803 Head-worn items, e.g. helmets, masks, headphones or goggles
• CPC Class Codes: A61B 5/726 using Wavelet transforms
• CPC Class Codes: A61B 5/7267 involving training the classification device
• CPC Class Codes: G16H 50/70 for mining of medical data, e.g. analysing previous cases of other patients

Abstract

Biopotential waveforms such as ERPs, EEGs, ECGs, or EMGs are classified accurately by dynamically fusing classification information from multiple electrodes, tests, or other data sources. These different data sources or “channels” are ranked at different time instants according to their respective univariate classification accuracies. Channel rankings are determined during training phase in which classification accuracy of each channel at each time-instant is determined. Classifiers are simple univariate classifiers which only require univariate parameter estimation. Using classification information, a rule is formulated to dynamically select different channels at different time-instants during the testing phase. Independent decisions of selected channels at different time instants are fused into a decision fusion vector. The resulting decision fusion vector is optimally classified using a discrete Bayes classifier. Finally, the dynamic decision fusion system provides high classification accuracies, is quite flexible in operation, and overcomes major limitations of classifiers applied currently in biopotential waveform studies and clinical applications.

Claims

1. An apparatus for classifying an unknown multi-channel biopotential signal, comprising:

a memory operatively configured to access a biopotential dataset produced by detecting a respective biopotential signal from a plurality of biopotential channels received from the patient and containing a program; and

a controller in communication with the memory and operatively configured to execute the program comprising;

determining a classification accuracy ranking for each biopotential channel at each time instant,

selecting a subset of the biopotential channels for a selected time instant having the highest classification accuracy,

classifying independently the selected subset of biopotential channels for the selected time instant,

fusing the resulting independent classifications into a single decision fusion vector for the selected time instant, and

classifying the single decision fusion vector using a discrete Bayes classifier.

2. The apparatus of claim 1, wherein the controller is further operatively configured to execute a program that selects the subset of the biopotential channels by reordering the biopotential dataset according to the classification accuracy ranking and selecting a subset based on a predetermined number of top channels.

3. The apparatus of claim 1, where the controller is further operatively configured to execute a program further comprising determining a time instant in reference to a stimulus imparted to the patient.

4. The apparatus of claim 1, where the controller is further operatively configured to execute a program further comprising determining a time instant by pattern matching against a characteristic heart beat waveform.