Fast wavelet estimation of weak bio-signals using novel algorithms for generating multiple additional data frames
AssigneeEverest Biomedical Instruments Co.
InventorsElvir Causevic, Eldar Causevic, Mladen Victor Wickerhauser
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Abstract
A method and apparatus for de-noising weak bio-signals having a relatively low signal to noise ratio utilizes an iterative process of wavelet de-noising a data set comprised of a new set of frames of wavelet coefficients partially generated through a cyclic shift algorithm. The method preferably operates on a data set having 2N frames, and the iteration is performed N−1 times. The resultant wavelet coefficients are then linearly averaged and an inverse discrete wavelet transform is performed to arrive at the de-noised original signal. The method is preferably carried out in a digital processor.
Claims45
A signal de-noiser, said signal de-noiser comprising a processor configured to process a plurality of 2N frames of sampled data comprising the signal, said processor being further configured to
- (a) perform a discrete wavelet transform operation on each of said sampled data frames to thereby create a corresponding frame of wavelet coefficients;
- (b) iteratively (i) construct a plurality of frames of wavelet coefficients;
- and (ii) de-noise each constructed plurality of frames of wavelet coefficients;
- (d) combine the final plurality of frames of wavelet coefficients into a final frame of wavelet coefficients;
- and
- (e) inverse discrete wavelet transform said final frame of wavelet coefficients.
A method of de-noising a signal by using a processor, said signal comprising a plurality of 2N frames of sampled data, the method comprising the steps of:
- (a) performing a discrete wavelet transform operation on each of said sampled data frames to thereby create a corresponding frame of wavelet coefficients;
- (b) iteratively (i) constructing a plurality of frames of wavelet coefficients;
- and (ii) de-noising each constructed plurality of frames of wavelet coefficients;
- (d) combining the final plurality of frames of wavelet coefficients into a final frame of wavelet coefficients;
- and
- (e) inverse discrete wavelet transforming said final frame of wavelet coefficients.
A signal processor for de-noising an input signal, said signal processor including a memory for storing said input signal as an array A1 of a plurality of component frames, and a processor configured to:
- (a) perform a wavelet transform on each of said component frames to thereby create a corresponding array of wavelet coefficients;
- (b) iteratively for at least one repetition (i) combine multiple numbers of said wavelet coefficients into a plurality of resultant wavelet coefficients forming an array A2 of wavelet coefficients, each of said resultant wavelet coefficients being formed from a different combination of wavelet coefficients determined from the original set of wavelet coefficients or the previous iteration, as appropriate;
- and (ii) wavelet de-noising each resultant wavelet coefficient of array A2;
- and
- (c) combine the resultant wavelet coefficients resulting from the last iteration to form a combined resultant wavelet coefficient.
A signal processor for de-noising an input signal, said signal processor including a memory for storing said input signal as a plurality of component frames, and a processor configured to:
- (a) separately perform a wavelet de-noising operation on each of said component frames to produce a first plurality of de-noised frames;
- (b) re-order the component frames and perform a wavelet de-noising operation on each of said frames to produce a second plurality of de-noised frames;
- and
- (b) combine the first and second pluralities of resultant de-noised frames to form a combined frame of resultant de-noised wavelet coefficients.
A method for de-noising an input signal using a signal processor, said signal processor including a memory for storing said input signal as an array A1 of a plurality of component frames, said method comprising the steps of:
- (a) performing a wavelet transform on each of said component frames to thereby create a corresponding array of wavelet coefficients;
- (b) iteratively for at least one repetition (i) combining multiple numbers of said wavelet coefficients into a plurality of resultant wavelet coefficients forming an array A2 of wavelet coefficients, each of said resultant wavelet coefficients being formed from a different combination of wavelet coefficients determined from the original set of wavelet coefficients or the previous iteration, as appropriate;
- and (ii) wavelet de-noising each resultant wavelet coefficient of array A2;
- and
- (c) combining the resultant wavelet coefficients resulting from the last iteration to form a frame of combined resultant wavelet coefficients.
A method for de-noising an input signal using a signal processor, said signal processor including a memory for storing said input signal as a plurality of component frames, the method comprising the steps of:
- (a) separately performing a wavelet de-noising operation on each of said component frames to produce a first plurality of de-noised frames;
- (b) re-ordering the component frames and performing a wavelet de-noising operation on each of said frames to produce a second plurality of de-noised frames;
- and
- (b) combining the first and second pluralities of resultant de-noised frames to form a combined frame of resultant de-noised wavelet coefficients.
Dependencies are inferred from the claim text.