US4737713A
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US
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Apparatus and method for processing an electrical signal and increasing a signal-to-noise ratio thereof
Assignee: Fonar Corp
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Filing: 1986-11-26
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Granted: 1988-04-12
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Expires: 2006-11-26
Abstract
Abstract An apparatus and method for processing a first electrical signal having a frequency interval I containing information, and increasing the signal-to-noise ratio thereof utilizes a mixer for shifting the frequencies of the first signal in the interval I to an interval I s . A plurality of filters, coupled in parallel, to the mixer pass, respectively, only frequencies in subintervals of I s , which are mutually disjoint. A second embodiment utilizes a plurality of mixers which shift, respectively, mutually disjoint subintervals of I such that their left end points are substantially equal. A plurality of filters, coupled, respectively, to the mixers, pass, respectively, only those frequencies in the shifted subintervals. Preferably, the frequency intervals passed by the filters in both embodiments are equal in bandwidth, and have no gaps therebetween.
Inventors
- 👤 Gordon T. Danby
- 👤 Jan V. Votruba
- 👤 Raymond V. Damadian
- 👤 Guo Ping Zhang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:54
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/32; G01R33/36; G01R33/3607; G01R33/44; G01R33/48; G01R33/54; G01R33/56
Claims Analysis
Total Claims: 46
Claim 1
Independent Claim
142 words
An apparatus for processing a first electrical signal, having a frequency interval I which extends from a first frequency to a second frequency containing information, and for increasing the signal-to-noise ratio thereof, comprising: means for providing said first signal; and means, for producing, in parallel, a plurality of signals S i , i=1, . . n, n being at least 2, S i being a signal substantially equal to a signal generated by filtering said first signal to eliminate substantially all frequencies thereof beyond an interval I i which extends from a first interval frequency I first-i to a second interval frequency I second-i , and shifting the frequencies within the filtered signal by a constant frequency f i which may be zero, where the intervals I i i=1, . . n are substantially contained in I, and are substantially mutually disjoint.
Claim 2
Independent Claim
142 words
An apparatus for processing a first electrical signal, having a frequency interval I which extends from a first frequency to a second frequency containing information, and for increasing the signal-to-noise ratio thereof, comprising: means for providing said first signal; and means, for producing, in parallel, a plurality of signals S i , i=1, . . n, n being at least 2, S i being a signal substantially equal to a signal generated by filtering said first signal to eliminate substantially all frequencies thereof beyond an interval I i which extends from a first interval frequency I first-i to a second interval frequency I second-i , and shifting the frequencies within the filtered signal by a constant frequency f i which may be zero, where the intervals I i i=1, . . n are substantially contained in I, and are substantially mutually disjoint.
Claim 3
Dependent Claim
109 words
The apparatus of claim 1, wherein said producing means comprises: means, coupled to said first signal providing means, for frequency shifting said first signal so that frequencies thereof in said interval I are shifted to an interval I s which extends from a new first frequency to a new second frequency; and a plurality of bandpass filters F i i=1, . . n, coupled in parallel to an output terminal of said shifting means, having, respectively, bandpass intervals I si which extend from a first bandpass interval frequency to a second bandpass interval frequency which are substantially contained in said I s , and which are substantially mutually disjoint.
Claim 4
Dependent Claim
35 words
The apparatus of claim 2, wherein said first signal providing means comprises an NMR scanner coil; and further comprising a plurality of analog-to-digital converters coupled, respectively, to said bandpass filters, for generating, respectively, digital signals.
Claim 5
Dependent Claim
36 words
The apparatus of claim 3, wherein each of said plurality of analog-to-digital converters is adapted for a sampling time substantially equal to 1/2L, where L is a bandwidth of a corresponding one of said bandpass filters.
Claim 6
Dependent Claim
31 words
The apparatus of claim 3 further comprising: a computer, coupled to each of said analog-to-digital converters, for generating images from, respectively, said digital signals, and combining said images into one image.
Claim 7
Dependent Claim
23 words
The apparatus of claim 5, further comprising means, coupled between said NMR scanner coil and said shifting means, for amplifying said first signal.
Claim 8
Dependent Claim
30 words
The apparatus of claim 2, wherein the frequency difference between the second bandpass interval frequency and the first bandpass interval frequency of I si is substantially constant for all i.
Claim 9
Dependent Claim
18 words
The apparatus of claim 2, wherein a union of the intervals I si is substantially I s .
Claim 10
Dependent Claim
104 words
The apparatus of claim 1, wherein said producing means comprises: a plurality of means M i i=1, . . n, coupled in parallel to said first signal providing means, for shifting frequencies of said first signal in, respectively, said intervals I i to, respectively, intervals I is , each of which intervals extends from a left end point frequency to a right end point frequency, said intervals having, respectively, left end point frequencies which are substantially equal; and a plurality of bandpass filters F i i=1, . . n, coupled to, respectively, said plurality of shifting means, having, respectively, bandpass intervals I is .
Claim 11
Dependent Claim
35 words
The apparatus of claim 9, wherein said first signal providing means comprises an NMR scanner coil; and further comprising a plurality of analog-to-digital converters coupled, respectively, to said bandpass filters, for generating, respectively, digital signals.
Claim 12
Dependent Claim
36 words
The apparatus of claim 10, wherein each of said plurality of analog-to-digital converters is adapted for a sampling time substantially equal to 1/2L, where L is a bandwidth of a corresponding one of said bandpass filters.
Claim 13
Dependent Claim
31 words
The apparatus of claim 10 further comprising a computer, coupled to each of said analog-to-digital converters, for generating images from, respectively, said digital signals, and combining said images into one image.
Claim 14
Dependent Claim
25 words
The apparatus of claim 12 further comprising means, coupled between said NMR scanner coil and said plurality of shifting means, for amplifying said first signal.
Claim 15
Dependent Claim
32 words
The apparatus of claim 9, wherein the frequency difference between the second interval frequency I second-i and the first interval frequency I first-i of I i is substantially constant for all i.
Claim 16
Dependent Claim
16 words
The apparatus of claim 9, wherein a union of the intervals I i is substantially I.
Claim 17
Dependent Claim
32 words
The apparatus of claim 1, wherein the frequency difference between the second interval frequency I second-i and the first interval frequency I first-i of I i is substantially constant for all i.
Claim 18
Dependent Claim
16 words
The apparatus of claim 1, wherein a union of the intervals I i is substantially I.
Claim 19
Dependent Claim
17 words
The apparatus of claim 16, wherein I=[a, b] and f i is substantially -a for all i.
Claim 20
Dependent Claim
41 words
The apparatus of claim 16, wherein f i i=1, . . n, is such that the frequency difference between the second interval frequency I second-i and the first interval frequency I first-i of S i is substantially identical for all i.
Claim 21
Dependent Claim
41 words
The apparatus of claim 1, wherein said first signal providing means comprises an NMR scanner coil; and further comprising a plurality of analog-to-digital converters, coupled to said producing means, for converting, respectively, said plurality of signals S i to digital signals.
Claim 22
Dependent Claim
31 words
The apparatus of claim 20 further comprising a computer, coupled to each of said analog-to-digital converters, for generating images from, respectively, said digital signals, and combining said images into one image.
Claim 23
Dependent Claim
23 words
The apparatus of claim 21 further comprising means, coupled between said NMR scanner coil and said producing means, for amplifying said first signal.
Claim 24
Independent Claim
137 words
A method of processing a first electrical signal having a frequency interval I which extends from a first frequency to a second frequency containing information, and of increasing the signal-to-noise ratio thereof, comprising: producing in parallel, from said first electrical signal, a plurality of signals S i i=1, . . n, n being at least 2, S i being a signal substantially equal to a signal generated by filtering said first signal to eliminate substantially all frequencies thereof beyond a frequency interval I i which extends from a first interval frequency I first-i to a second interval frequency I second-i , and shifting the frequencies within the filtered signal by a constant frequency f i which may be zero, where said intervals I i i=1, . . n are substantially contained in I, and substantially mutually disjoint.
Claim 25
Independent Claim
137 words
A method of processing a first electrical signal having a frequency interval I which extends from a first frequency to a second frequency containing information, and of increasing the signal-to-noise ratio thereof, comprising: producing in parallel, from said first electrical signal, a plurality of signals S i i=1, . . n, n being at least 2, S i being a signal substantially equal to a signal generated by filtering said first signal to eliminate substantially all frequencies thereof beyond a frequency interval I i which extends from a first interval frequency I first-i to a second interval frequency I second-i , and shifting the frequencies within the filtered signal by a constant frequency f i which may be zero, where said intervals I i i=1, . . n are substantially contained in I, and substantially mutually disjoint.
Claim 26
Dependent Claim
103 words
The method of claim 23, wherein said step of producing comprises: frequency shifting said first signal so that frequencies thereof in said interval I are shifted to an interval I s which extends from a new first frequency to a new second frequency; then filtering said shifted signal, in parallel through a plurality of bandpass filters F i i=1, . . n, having, respectively, bandpass intervals I si which extend from a first bandpass interval frequency to a second interval frequency, which are substantially contained in I si , and which are substantially mutually disjoint, to provide, respectively, a plurality of filtered signals.
Claim 27
Dependent Claim
41 words
A method of claim 24 further comprising: generating before the step of frequency shifting, said first signal in an NMR scanner coil; and converting, after the step of filtering, said plurality of filtered signals, respectively, to a plurality of digital signals.
Claim 28
Dependent Claim
37 words
The method of claim 25, wherein the step of converting comprises utilizing, for each of said filtered signals, a sampling time substantially equal to 1/2L, where L is a bandwidth of a corresponding one of said filters.
Claim 29
Dependent Claim
31 words
The method of claim 25 further comprising: generating, after the step of converting, a plurality of images from, respectively, said plurality of digital signals, and combining said images into one image.
Claim 30
Dependent Claim
25 words
The method of claim 27 further comprising: amplifying, between the steps of generating said first signal and frequency shifting said first signal, said first signal.
Claim 31
Dependent Claim
32 words
The method of claim 24 wherein the frequency difference between the second interval frequency I second-i and the first interval frequency I first-i of I si is substantially constant for all i.
Claim 32
Dependent Claim
18 words
The method of claim 24, wherein a union of the intervals I si is substantially I s .
Claim 33
Dependent Claim
103 words
The method of claim 23 wherein said step of producing comprises: frequency shifting said first signal to produce, in parallel, a plurality of shifted signals wherein frequencies of said first signal in, respectively, said intervals I i are shifted to, respectively, intervals I is , each of which intervals extends from a left end point frequency to a right end point frequency, said intervals having, respectively, left end point frequencies which are substantially equal; and filtering, in parallel, said shifted signals through, respectively, a plurality of bandpass filters having, respectively, bandpass intervals I is , to produce, respectively, a plurality of filtered signals.
Claim 34
Dependent Claim
41 words
The method of claim 31 further comprising: generating, before the step of frequency shifting, said first signal in an NMR scanner coil; and converting, after the step of filtering, said plurality of filtered signals, respectively, to a plurality of digital signals.
Claim 35
Dependent Claim
37 words
The method of claim 32, wherein the step of converting comprises utilizing, for each of said filtered signals, a sampling time substantially equal to 1/2L, where L is a bandwidth of a corresponding one of said filters.
Claim 36
Dependent Claim
31 words
The method of claim 32 further comprising: generating, after the step of converting, a plurality of images from, respectively, said plurality of digital signals, and combining said images into one image.
Claim 37
Dependent Claim
25 words
The method of claim 34 further comprising: amplifying, between the steps of generating said first signal and frequency shifting said first signal, said first signal.
Claim 38
Dependent Claim
32 words
The method of claim 31, wherein the frequency difference between the second interval frequency I second-i and the first interval frequency I first-i of I i is substantially constant for all i.
Claim 39
Dependent Claim
16 words
The method of claim 31, wherein a union of the intervals I i is substantially I.
Claim 40
Dependent Claim
42 words
The method of claim 23 further comprising: generating, before the step of producing, said first signal in an NMR scanner coil; and converting, after the step of producing, said plurality of signals S i , respectively, to a plurality of digital signals.
Claim 41
Dependent Claim
31 words
The method of claim 38 further comprising: generating, after the step of converting, a plurality of images from, respectively, said plurality of digital signals, and combining said images into one image.
Claim 42
Dependent Claim
28 words
The method of claim 39 further comprising: amplifying, between the steps of generating said first signal and producing said plurality of signals S i , said first signal.
Claim 43
Dependent Claim
32 words
The method of claim 23, wherein the frequency difference between the second interval frequency I second-i and the first interval frequency I first-i of I i is substantially constant for all i.
Claim 44
Dependent Claim
16 words
The method of claim 23, wherein a union of the intervals I i is substantially I.
Claim 45
Dependent Claim
17 words
The method of claim 41, wherein I=[a, b] and f i is substantially -a for all i.
Claim 46
Dependent Claim
27 words
The method of claim 41, wherein f i i=1, . . n is such that a frequency interval of S i is substantially identical for all i.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1991-04-12 | 1991-10-12 | 1992-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-12 | 1995-10-12 | 1996-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-12 | 1999-10-12 | 2000-04-12 | $7700.00 | Window Closed / Lapsed |