THE FEASIBILITY OF A CROSS-COUPLED ADAPTIVE CANCELLER FOR REAL-TIME SIGNAL EXTRACTION

Period of Performance: 01/01/1991 - 12/31/1991

$250K

Phase 2 SBIR

Recipient Firm

Perinatronics Medical Systems, Inc.
PERINATRONICS MEDICAL SYSTEMS, 1703 PEARTREE LN
Crofton, MD 21114
Principal Investigator

Abstract

THIS RESEARCH FOCUSES ITS ATTENTION ON THE STUDY OF A CROSS-COUPLED ADAPTIVE NOISE CANCELLATION ALGORITHM THAT IS SUITABLE FOR APPLICATIONS IN WHICH THE PRIMARY AND NOISE INPUTS MAY BE CLOSELY SPACED, THUS A PURE NOISE REFERENCE ISNOT AVAILABLE FOR EFFECTIVE NOISE CANCELLATION FROM THE PRIMARY SIGNAL. THE STRUCTURE OF THIS NEW ALGORITHM IS BASED ON TWO LEAST-MEAN SQUARED (LMS) DELAY LINE CANCELLERS WITH CROSS-COUPLED FEEDBACK. THE OVERALL OBJECTIVE IS TO DETERMINE THE FEASIBILITY OF THIS NOVEL CROSS-COUPLED ADAPTIVE ALGORITHM TO IMPROVE THE SIGNAL-TO-NOISE RATIO OF DATA COMPOSED OF RECURRING PULSES IN NOISE FOR SYSTEMS IN WHICH A PURE NOISE REFERENCE INPUT CANNOT BE FOUND, I.E., INTHE PROBLEM OF EXTRACTING THE FETAL ELECTROCARDIOGRAPHIC (FECG) SIGNALS EMBEDDED IN MUSCLE NOISE RECORDED FROM THE PREGNANT MATERNAL ABDOMEN. THE RESEARCHERS HOPE TO SHOW THAT THIS LMS CROSS-COUPLED CANCELLER ALGORITHM, WHICH DOES NOT REQUIRE A PURE NOISE REFERENCE INPUT, EFFECTIVELY CANCELS MATERNAL MUSCLE NOISE FROM RECORDED FETAL ECG DATA WITHOUT DISTORTION OF THE FECG SIGNAL, THUS, PROVIDING AN ENHANCED FETAL SIGNAL FOR SUBSEQUENT ANALYSIS OR DETECTION. THE EVALUATION OF THIS CROSS-COUPLED CANCELLATION ALGORITHM FOR THE REAL-TIME CANCELLATION OF MUSCLE NOISE FROM THE FECGSIGNAL IS THE EXPECTED RESULT OF THIS RESEARCH. SUCCESSFUL APPLICATION OF THIS ALGORITHM TO THIS FETAL ELECTROCARDIOGRAPHY PROBLEM WOULD SUGGEST OTHER APPLICATIONSTO PROBLEMS IN ELECTRICAL AND BIOMEDICAL SIGNAL PROCESSING, SINCE MANY PROBLEMS OF NOISE CANCELLATION ARE DIFFICULT TO SOLVE DUE TO THE LACK OF A PURE NOISE SIGNAL.