US5522391A
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US
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Delay generator for phased array ultrasound beamformer
Assignee: Koninklijke Philips NV
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Filing: 1994-08-09
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Granted: 1996-06-04
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Expires: 2014-08-09
Abstract
Abstract A delay generator for a beamformer in a phased array ultrasound imaging system is provided. The beamformer processes received signals from an array of transducer elements to form a receive beam. The beamformer includes a delay generator corresponding to each transducer element for delaying the received signal. The delay generator includes a delay unit and a delay controller. The delay is variable in response to a change delay signal supplied by the delay controller at discrete times during reception of ultrasound energy. According to one feature of the invention, the delay represents an exact solution, within the quantization error of the delay unit, to the delay equation for the delay at a given steering angle, transducer element and focal depth. According to another feature of the invention, the delay controller generates a change delay signal that steers the receive beam to a dynamically variable steering angle and dynamically focuses the receive beam during reception of ultrasound energy.
Inventors
- 👤 Raymond A. Beaudin
- 👤 Michael P. Anthony
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:51
CPC Classifications
G; G10; G10K; G10K11/00; G10K11/18; G10K11/26; G10K11/34; G10K11/341
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
237 words
In an ultrasound beamformer for processing received signals from an array of transducer elements, each providing a received signal, to form a receive beam, said beamformer comprising a delay generator corresponding to each transducer element for delaying the received signal and a combiner for combining the delayed signals to form said receive beam, each delay generator comprising: a delay unit for delaying the received signal by a quantized delay which is variable in response to a change delay signal, said delay unit comprising a circular memory having locations for storing discrete time values of said received signal, wherein the discrete time values of said received signal are written in successive locations in said memory; and a delay controller for generating said change delay signal at discrete times during reception of ultrasound energy, to steer said receive beam to a selected steering angle and to dynamically focus said receive beam, said change delay signal controlling reading of the discrete time values of said received signal from locations in said memory corresponding to said quantized delay, said delay controller comprising means responsive to an initial delay value for iteratively generating said change delay signal at each of said discrete times such that said quantized delay is an exact solution, within the quantization error of said delay unit, to the equation for said delay at a given steering angle, transducer element and focal depth at each of said discrete times.
Claim 2
Dependent Claim
237 words
In an ultrasound beamformer for processing received signals from an array of transducer elements, each providing a received signal, to form a receive beam, said beamformer comprising a delay generator corresponding to each transducer element for delaying the received signal and a combiner for combining the delayed signals to form said receive beam, each delay generator comprising: a delay unit for delaying the received signal by a quantized delay which is variable in response to a change delay signal, said delay unit comprising a circular memory having locations for storing discrete time values of said received signal, wherein the discrete time values of said received signal are written in successive locations in said memory; and a delay controller for generating said change delay signal at discrete times during reception of ultrasound energy, to steer said receive beam to a selected steering angle and to dynamically focus said receive beam, said change delay signal controlling reading of the discrete time values of said received signal from locations in said memory corresponding to said quantized delay, said delay controller comprising means responsive to an initial delay value for iteratively generating said change delay signal at each of said discrete times such that said quantized delay is an exact solution, within the quantization error of said delay unit, to the equation for said delay at a given steering angle, transducer element and focal depth at each of said discrete times.
Claim 3
Dependent Claim
43 words
A delay generator as defined in claim 1 wherein said delay controller includes means for generating said change delay signal in binary form such that an active state of said change delay signal causes said quantized delay to change by one delay quantum.
Claim 4
Dependent Claim
62 words
A delay generator as defined in claim 1 wherein said delay controller includes a plurality of registers for storing values representative of a delay curve for the selected steering angle and means for updating said registers at said discrete times during reception of ultrasound energy, said change delay signal being generated each time the values in said registers meet a predetermined condition.
Claim 5
Dependent Claim
75 words
A delay generator as defined in claim 3 wherein said registers include an A register, a B register and an N register, which are updated at said discrete times in accordance with the following rules: If N+A≧0: N←N+A A←A B←B+1; If N+A<0: N←N+B A←A+1 B←B+(2-2/k) where k is the ratio of the interval between said discrete update times and said delay quantum, and wherein the predetermined condition for generating said change delay signal is: N+A<0.
Claim 6
Dependent Claim
81 words
A delay generator as defined in claim 3 wherein said registers include an A register, a B register, and an N register, which are updated at said discrete times in accordance with the following rules: If N≧0: N←N+A A←A B←B+1; If N<0: N←N+B A←A+1 B←B+(2-2/k) where k is the ratio of the interval between said discrete update times and said delay quantum, and wherein the predetermined condition for generating said change delay signal is: [(N≧0) AND (N+A<0)] OR [(N<0) AND (N+B<0)].
Claim 7
Dependent Claim
30 words
A delay generator as defined in claim 3 further including means for placing said registers in a hold state until reception of ultrasound energy from a predetermined minimum image depth.
Claim 8
Dependent Claim
22 words
A delay generator as defined in claim 1 wherein said delay unit includes means for delaying digital representations of said received signals.
Claim 9
Dependent Claim
23 words
A delay generator as defined in claim 1 wherein said delay unit includes means for delaying continuous analog representations of said received signals.
Claim 10
Dependent Claim
23 words
A delay generator as defined in claim 1 wherein said delay unit includes means for delaying sampled analog representations of said received signals.
Claim 11
Dependent Claim
229 words
In an ultrasound beamformer for processing received signals from an array of transducer elements, each providing a received signal, to form a receive beam, said beamformer comprising a delay generator corresponding to each transducer element for delaying the received signal and a combiner for combining the delayed signals to form said receive beam, each delay generator comprising: a delay unit for delaying the received signal by a quantized delay which is variable in response to a change delay signal, said delay unit comprising a circular memory having locations for storing discrete time values of said received signal, wherein the discrete time values of said received signal are written in successive locations in said memory; and a delay controller for generating said change delay signal at discrete times during reception of ultrasound energy, to steer said receive beam to a dynamically variable steering angle and to dynamically focus said receive beam during reception of ultrasound energy, said change delay signal controlling reading of the discrete time values of said received signal from locations in said memory corresponding to said quantized delay, said delay controller comprising means responsive to an initial delay value for iteratively generating said change delay signal at each of said discrete times such that said quantized delay is an exact solution to the equation for said delay at a given steering angle, transducer element and focal depth.
Claim 12
Dependent Claim
229 words
In an ultrasound beamformer for processing received signals from an array of transducer elements, each providing a received signal, to form a receive beam, said beamformer comprising a delay generator corresponding to each transducer element for delaying the received signal and a combiner for combining the delayed signals to form said receive beam, each delay generator comprising: a delay unit for delaying the received signal by a quantized delay which is variable in response to a change delay signal, said delay unit comprising a circular memory having locations for storing discrete time values of said received signal, wherein the discrete time values of said received signal are written in successive locations in said memory; and a delay controller for generating said change delay signal at discrete times during reception of ultrasound energy, to steer said receive beam to a dynamically variable steering angle and to dynamically focus said receive beam during reception of ultrasound energy, said change delay signal controlling reading of the discrete time values of said received signal from locations in said memory corresponding to said quantized delay, said delay controller comprising means responsive to an initial delay value for iteratively generating said change delay signal at each of said discrete times such that said quantized delay is an exact solution to the equation for said delay at a given steering angle, transducer element and focal depth.
Claim 13
Dependent Claim
75 words
A delay generator as defined in claim 10 wherein said delay controller includes a plurality of registers for storing values representative of a delay curve for steering said receive beam to said dynamically variable steering angle and for dynamically focusing said receive beam, and means for incrementing said registers at said discrete times during reception of ultrasound energy, said change delay signal being generated each time the values in said registers meet a predetermined condition.
Claim 14
Dependent Claim
82 words
A delay generator as defined in claim 11 wherein said registers include an A register, a B register, an N register and a W register, which contain values A, B, N and W respectively, as follows: If N≧0: N←N+A+W A←A B←B+1; If N<0: N←N+B+W A←A+1 B←B+(2-2/k) where k is the ratio of the interval between said discrete update times and said delay quantum, and wherein the predetermined condition for generating said change delay signal is: [(N≧0) AND (N+A<0)] OR [(N<0) AND (N+B<0)].
Claim 15
Dependent Claim
56 words
A delay generator as defined in claim 12 wherein said delay controller receives delay coefficients that establish said required delay, said delay coefficients containing information representative of a selected steering angle Θ and deviations ΔΘ from said selected steering angle, said deviations ΔΘ being specified for a predetermined number of zones of a region being imaged.
Claim 16
Dependent Claim
36 words
A delay generator as defined in claim 13 wherein said delay controller includes means for causing said receive beam to have a specified deviation ΔΘ Z from the selected steering angle Θ in each zone Z.
Claim 17
Dependent Claim
22 words
A delay generator as defined in claim 10 wherein said delay unit includes means for delaying digital representations of said received signals.
Claim 18
Dependent Claim
23 words
A delay generator as defined in claim 10 wherein said delay unit includes means for delaying continuous analog representations of said received signals.
Claim 19
Dependent Claim
23 words
A delay generator as defined in claim 10 wherein said delay unit includes means for delaying sampled analog representations of said received signals.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-06-04 | 1999-12-04 | 2000-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-06-04 | 2003-12-04 | 2004-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-06-04 | 2007-12-04 | 2008-06-04 | $7700.00 | Window Closed / Lapsed |