US5299174A
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Automatic clutter elimination
Assignee: Diasonics Inc
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Filing: 1993-01-26
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Granted: 1994-03-29
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Expires: 2013-01-26
Abstract
Abstract An apparatus and method for clutter elimination from signals which digitizes a signal to generate n samples of the signals. M basis functions (such as various levels of filters) are fit to the n samples. An i+1 basis function of the m basis functions is iteratively subtracted from each of the n samples, and the difference is stored in an i difference signal until the i+1 difference signal is less than a threshold. In various embodiments, the threshold may be an absolute noise floor (R O min ) preset by a manufacturer or a user. In other embodiments, the threshold may be based upon an absolute or relative predictor error of the signal once the basis function (filter) has been removed. The i difference signal may be used for performing a frequency estimate of the signal.
Inventors
- 👤 Steven F. Forestieri
- 👤 Ray S. Spratt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:43
CPC Classifications
G; G01; G01S; G01S15/00; G01S15/88; G01S15/89; G01S15/8906; G01S15/8979; G01S15/8981; G01S15/02; G01S15/50; G01S15/58; G06; G06F; G06F17/00; G06F17/10; G06F17/17; Y; Y10; Y10S; Y10S367/00; Y10S367/901
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
81 words
A method for automatic clutter elimination from signals comprising the following steps: a. digitizing a signal to generate n samples; b. fitting m basis functions to said n samples; c. iteratively subtracting an i+1 basis function of each of said m basis functions from said n samples and storing the difference in an i+1 difference signal until said i+1 difference signal is less than a threshold; and d. using said i difference signal for performing a frequency estimate of said signal.
Claim 2
Independent Claim
81 words
A method for automatic clutter elimination from signals comprising the following steps: a. digitizing a signal to generate n samples; b. fitting m basis functions to said n samples; c. iteratively subtracting an i+1 basis function of each of said m basis functions from said n samples and storing the difference in an i+1 difference signal until said i+1 difference signal is less than a threshold; and d. using said i difference signal for performing a frequency estimate of said signal.
Claim 3
Dependent Claim
12 words
The method of claim 1 wherein said threshold comprises a user-settable threshold.
Claim 4
Dependent Claim
13 words
The method of claim 1 wherein said threshold comprises a minimum noise value.
Claim 5
Dependent Claim
12 words
The method of claim 1 wherein said threshold comprises a prediction value.
Claim 6
Dependent Claim
14 words
The method of claim 4 wherein said prediction value comprises a relative prediction value.
Claim 7
Dependent Claim
14 words
The method of claim 4 wherein said prediction value comprises an absolute prediction value.
Claim 8
Independent Claim
105 words
A method for automatic clutter elimination from signals comprising the following steps: a. digitizing a signal to generate n samples; b. determining m filtering functions to remove clutter from said n samples, each i+1 filtering function of said m filtering functions removing additional clutter from said n samples than an i filtering function; c. iteratively subtracting an i+1 filtering function of each of said m filtering functions from said n samples and storing the difference in an i difference signal until said i+1 difference signal is less than a threshold; and d. using said i difference signal for performing a frequency estimate of said signal.
Claim 9
Independent Claim
105 words
A method for automatic clutter elimination from signals comprising the following steps: a. digitizing a signal to generate n samples; b. determining m filtering functions to remove clutter from said n samples, each i+1 filtering function of said m filtering functions removing additional clutter from said n samples than an i filtering function; c. iteratively subtracting an i+1 filtering function of each of said m filtering functions from said n samples and storing the difference in an i difference signal until said i+1 difference signal is less than a threshold; and d. using said i difference signal for performing a frequency estimate of said signal.
Claim 10
Dependent Claim
23 words
The method of claim 7 wherein said signal is a ultrasonic echo signal of a color sample volume in a subject under examination.
Claim 11
Dependent Claim
19 words
The method of claim 7 which is repeated for each signal in a portion of a subject under examination.
Claim 12
Dependent Claim
30 words
The method of claim 7 wherein said steps are repeated for each signal of an area under examination in a subject to generate a plurality of pixels for a frame.
Claim 13
Independent Claim
132 words
A method of clutter elimination from signals comprising the following steps: a. digitizing a plurality of signals to generate n samples of each of said plurality of signals; b. for each of said plurality of signals, determining m filtering functions to remove clutter from said n samples of each of said plurality of signals, each of said m filtering functions removing additional clutter from said n samples; c. for each said plurality of signals, iteratively subtracting an i+1 filtering function of each of said m filtering functions from said n samples and storing the difference in an i difference signal until said i+1 difference signal is less than a threshold; and d. for each of said plurality of signals, using said i difference signal for performing a frequency estimate of said signal.
Claim 14
Independent Claim
132 words
A method of clutter elimination from signals comprising the following steps: a. digitizing a plurality of signals to generate n samples of each of said plurality of signals; b. for each of said plurality of signals, determining m filtering functions to remove clutter from said n samples of each of said plurality of signals, each of said m filtering functions removing additional clutter from said n samples; c. for each said plurality of signals, iteratively subtracting an i+1 filtering function of each of said m filtering functions from said n samples and storing the difference in an i difference signal until said i+1 difference signal is less than a threshold; and d. for each of said plurality of signals, using said i difference signal for performing a frequency estimate of said signal.
Claim 15
Dependent Claim
22 words
The method of claim 11 wherein said plurality of signals comprises ultrasonic echo reflections from a region in a subject under examination.
Claim 16
Dependent Claim
20 words
The method of claim 12 wherein said plurality of signals comprise color sample volumes (CSV's) in said subject under examination.
Claim 17
Dependent Claim
12 words
The method of claim 11 wherein said threshold comprises a user-settable threshold.
Claim 18
Dependent Claim
13 words
The method of claim 11 wherein said threshold comprises a minimum noise value.
Claim 19
Dependent Claim
12 words
The method of claim 11 wherein said threshold comprises a prediction value.
Claim 20
Dependent Claim
14 words
The method of claim 16 wherein said prediction value comprises a relative prediction value.
Claim 21
Dependent Claim
14 words
The method of claim 16 wherein said prediction value comprises an absolute prediction value.
Claim 22
Independent Claim
133 words
An apparatus for filtering signals comprising: a. means for digitizing a plurality of signals to generate n samples of each of said plurality of signals; b. means for determining from each of said plurality of signals, m filtering functions to remove clutter from said n samples of each of said plurality of signals, each of said m filtering functions removing additional clutter from said n samples; c. means for iteratively subtracting an i+1 filtering function of each of said m filtering functions from said n samples for each of said plurality of signals, and storing the difference in an i+1 difference signal until said i+1 difference signal is less than a threshold; and d. means for using said i difference signal for performing a frequency estimate of each of said plurality of signals.
Claim 23
Independent Claim
133 words
An apparatus for filtering signals comprising: a. means for digitizing a plurality of signals to generate n samples of each of said plurality of signals; b. means for determining from each of said plurality of signals, m filtering functions to remove clutter from said n samples of each of said plurality of signals, each of said m filtering functions removing additional clutter from said n samples; c. means for iteratively subtracting an i+1 filtering function of each of said m filtering functions from said n samples for each of said plurality of signals, and storing the difference in an i+1 difference signal until said i+1 difference signal is less than a threshold; and d. means for using said i difference signal for performing a frequency estimate of each of said plurality of signals.
Claim 24
Independent Claim
100 words
A method of clutter elimination from signals comprising the following steps: a. digitizing a signal to generate a digitized of said signal; b. determining m filtering functions to remove clutter from said digitized signal, each of said m filtering functions removing additional clutter from said digitized signal; c. iteratively subtracting an i+1 filtering function of each of said m filtering functions from said digitized signal and storing the difference in an i+1 difference signal until said i+1 difference signal is less than a threshold; and d. using said i difference signal for performing a frequency estimate of said digitized signal.
Claim 25
Independent Claim
100 words
A method of clutter elimination from signals comprising the following steps: a. digitizing a signal to generate a digitized of said signal; b. determining m filtering functions to remove clutter from said digitized signal, each of said m filtering functions removing additional clutter from said digitized signal; c. iteratively subtracting an i+1 filtering function of each of said m filtering functions from said digitized signal and storing the difference in an i+1 difference signal until said i+1 difference signal is less than a threshold; and d. using said i difference signal for performing a frequency estimate of said digitized signal.
Claim 26
Independent Claim
88 words
A method of clutter elimination from a signal comprising the following steps: a. determining m filtering functions to remove clutter from said signal, each of said m filtering functions removing additional clutter from said signal than a previous m filtering function; b. iteratively subtracting an i+1 filtering function of each of said m filtering functions from said signal to generate a difference and storing said difference in an i+1 difference signal until said i+1 difference signal is less than a threshold; and c. using said i difference signal.
Claim 27
Independent Claim
88 words
A method of clutter elimination from a signal comprising the following steps: a. determining m filtering functions to remove clutter from said signal, each of said m filtering functions removing additional clutter from said signal than a previous m filtering function; b. iteratively subtracting an i+1 filtering function of each of said m filtering functions from said signal to generate a difference and storing said difference in an i+1 difference signal until said i+1 difference signal is less than a threshold; and c. using said i difference signal.
Claim 28
Dependent Claim
17 words
The method of claim 21 wherein said signal comprises a zero order lag product R 0 .
Claim 29
Dependent Claim
14 words
The method of claim 22 wherein said difference signal comprises R 0 i .
Claim 30
Dependent Claim
13 words
The method of claim 23 wherein said threshold comprises R 0 min .
Claim 31
Dependent Claim
31 words
The method of claim 24 further comprising the step of determining whether a discrimination factor α is greater than ##EQU3## and if so, then setting said signal to zero and terminating.
Claim 32
Dependent Claim
17 words
The method of claim 23 wherein said signal comprises a first order lag product R 1 .
Claim 33
Dependent Claim
49 words
The method of claim 23 wherein said step of determining whether said i difference signal is less than a threshold comprises determining whether an absolute predictor error αp e i+1 is greater than p e i wherein p e i =R 0 i (1-c 0 i ) and ##EQU4##
Claim 34
Dependent Claim
45 words
The method of claim 23 wherein said step of determining whether said i difference signal is less than a threshold comprises determining whether a relative predicator error αp e i+1 is less than αp e i wherein p e i =1-c 0 i and ##EQU5##
Claim 35
Dependent Claim
23 words
The method of claim 21 wherein said step of using said i difference signal comprises performing a frequency estimate of said i signal.
Claim 36
Independent Claim
53 words
A method of clutter elimination from a signal R 0 comprising the following steps: a. iteratively determining a filtered signal R 0 i+1 of said signal R 0 until said filtered signal R 0 i+1 is less than a threshold R 0 min ; and b. using said R 0 i difference signal.
Claim 37
Independent Claim
53 words
A method of clutter elimination from a signal R 0 comprising the following steps: a. iteratively determining a filtered signal R 0 i+1 of said signal R 0 until said filtered signal R 0 i+1 is less than a threshold R 0 min ; and b. using said R 0 i difference signal.
Claim 38
Dependent Claim
35 words
The method of claim 30 further comprising the step of determining whether a discrimination factor α is greater than ##EQU6## and if so, then setting said filtered signal R 0 i to zero and terminating.
Claim 39
Independent Claim
75 words
A method of clutter elimination from a signal comprising lag products R 0 and R 1 comprising the following steps: a. iteratively determining a filtered signal comprising R 0 i and R 1 i of said signal until an absolute predictor error αp e i+1 of said filtered signal is greater than p e i wherein p e i =R 0 i (1-c 0 i ) and ##EQU7## b. using said i filtered difference signal.
Claim 40
Independent Claim
75 words
A method of clutter elimination from a signal comprising lag products R 0 and R 1 comprising the following steps: a. iteratively determining a filtered signal comprising R 0 i and R 1 i of said signal until an absolute predictor error αp e i+1 of said filtered signal is greater than p e i wherein p e i =R 0 i (1-c 0 i ) and ##EQU7## b. using said i filtered difference signal.
Claim 41
Independent Claim
70 words
A method of clutter elimination from a signal comprising lag products R 0 and R 1 comprising the following steps: a. iteratively determining a filtered signal R 0 i and R 1 i of said signal until a relative predictor error αp e i+1 of said filtered signal is greater than p e i wherein p e i =1-c 0 i and ##EQU8## b. using said i filtered difference signal.
Claim 42
Independent Claim
70 words
A method of clutter elimination from a signal comprising lag products R 0 and R 1 comprising the following steps: a. iteratively determining a filtered signal R 0 i and R 1 i of said signal until a relative predictor error αp e i+1 of said filtered signal is greater than p e i wherein p e i =1-c 0 i and ##EQU8## b. using said i filtered difference signal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-03-28 | 1997-09-27 | 1998-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-03-28 | 2001-09-27 | 2002-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-03-28 | 2005-09-27 | 2006-03-29 | $7700.00 | Window Closed / Lapsed |