US3780290A
Expired / Lapsed
US
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Radiation camera motion correction system
Assignee: United States Atomic Energy Commission
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Filing: 1972-03-28
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Granted: 1973-12-18
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Expires: 1992-03-28
Abstract
Abstract The invention determines the ratio of the intensity of radiation received by a radiation camera from two separate portions of the object. A correction signal is developed to maintain this ratio at a substantially constant value and this correction signal is combined with the camera signal to correct for object motion.
Inventors
- 👤 P Hoffer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:50
CPC Classifications
G; G03; G03B; G03B42/00; G03B42/02; G01; G01T; G01T1/00; G01T1/16; G01T1/161; G01T1/164; G01T1/1641; G01T1/1642; G01T1/1648; A; A61; A61B; A61B6/00; A61B6/42; A61B6/4208; A61B6/4258
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
254 words
An object motion correction system for use with a radiation imaging device which includes radiation sensing means of a type which develops a first gamma signal and an unblanking signal in response to radiation received from the object being imaged, the first gamma signal consisting of a series of pulses with the amplitude of each pulse representing the magnitude of one dimension of the position in the object of the radiation event which developed the pulse, the radiation imaging device further having recording means for displaying each radiation event at its proper position to develop an image representing the distribution of radioactive material in the object, said object motion correction system including in combination, first input circuit means coupled to the radiation sensing means for receiving the first gamma signal and the unblanking signal, first gating means coupled to said first input circuit means and responsive to the first gamma signal and the unblanking signal to develop first input signals having an amplitude and polarity determined by the amplitude and polarity of the first gamma signal at the time of receipt of the unblanking signal, first integration means coupled to said gating means for integrating said first input signals to develop a first correction signal, first summing means coupled to said first integration means, said first input circuit means and the recording means, said first summing means acting to add the first gamma signal to said first correction signal to develop a corrected first gamma signal and apply the same to the recording means.
Claim 2
Dependent Claim
254 words
An object motion correction system for use with a radiation imaging device which includes radiation sensing means of a type which develops a first gamma signal and an unblanking signal in response to radiation received from the object being imaged, the first gamma signal consisting of a series of pulses with the amplitude of each pulse representing the magnitude of one dimension of the position in the object of the radiation event which developed the pulse, the radiation imaging device further having recording means for displaying each radiation event at its proper position to develop an image representing the distribution of radioactive material in the object, said object motion correction system including in combination, first input circuit means coupled to the radiation sensing means for receiving the first gamma signal and the unblanking signal, first gating means coupled to said first input circuit means and responsive to the first gamma signal and the unblanking signal to develop first input signals having an amplitude and polarity determined by the amplitude and polarity of the first gamma signal at the time of receipt of the unblanking signal, first integration means coupled to said gating means for integrating said first input signals to develop a first correction signal, first summing means coupled to said first integration means, said first input circuit means and the recording means, said first summing means acting to add the first gamma signal to said first correction signal to develop a corrected first gamma signal and apply the same to the recording means.
Claim 3
Dependent Claim
161 words
The object motion correction system of claim 1 wherein: the first gamma signal pulses developed from radiation from one portion of the object have a positive polarity and the first gamma signal pulses developed from radiation from the remaining portion of the object have a negative polarity, said first input circuit means including first and second comparator circuits each receiving the first gamma pulses, said first comparator being responsive to the positive polarity first gamma pulses to develop first trigger pulses therefrom and said second comparator being responsive to the negative polarity first gamma pulses to develop second trigger pulses therefrom, said first gating means being coupled to said first and second comparators, said first gating means being responsive to the unblanking signal and said first trigger signal to develop said first input signal of a first amplitude and further being responsive to the unblanking signal and said second trigger signal to develop said first input signal of a second amplitude.
Claim 4
Dependent Claim
48 words
The object motion correction system of claim 1 and further including, amplitude level shifting means coupling said first gating means to said first integration means, said amplitude level shifting means acting to change said first and second amplitudes of said first and second trigger signals to desired levels.
Claim 5
Dependent Claim
71 words
The object motion correction system of claim 1, wherein said first gating means includes storage means responsive to the unblanking pulse to store a reference signal representing the amplitude of the first gamma signal present at the time of the unblanking pulse for the period of time between unblanking pulses, said storage means being coupled to said integration means for integration of said reference signals to develop said first correction signal.
Claim 6
Dependent Claim
210 words
The object motion correction system of claim 1 wherein the radiation sensing means further develops a second gamma signal in addition to the first gamma signal, the second gamma signal consisting of a series of pulses with the amplitude of each pulse representing the magnitude of a second dimension of the position in the object of the radiation event which developed the pulse, said object motion correction system further including, second input circuit means coupled to the radiation sensing means for receiving the second gamma signal and the unblanking signal, second gating means coupled to said second input circuit and responsive to the second gamma signal and the unblanking signal to develop second input signals having an amplitude and polarity determined by the amplitude and polarity of the second gamma signal at the time of receipt of the unblanking signal, second integration means coupled to said second gating means for integrating said second input signals to develop a second correction signal, second summing means coupled to said second integration means, said second input circuit means and the recording means, said second summing means acting to add the second gamma signal to said second correction signal to develop a corrected second gamma signal and apply the same to the recording means.
Claim 7
Independent Claim
131 words
A method of correcting for object motion in a radiation imaging system which develops a gamma signal and an unblanking signal in response to radiation from the object being imaged, the gamma signal consisting of a series of pulses, with the amplitude of each pulse representing the magnitude of one dimension of the position in the object of the radiation event which developed the pulse, including the steps of: a. developing input signals having an amplitude and polarity determined by the amplitude and polarity of the gamma signal at the time of receipt of each unblanking signal; b. integrating said input signals over a predetermined time period to develop a correction signal; and c. adding said correction signal to the gamma signal to develop a gamma signal corrected for object motion.
Claim 8
Independent Claim
131 words
A method of correcting for object motion in a radiation imaging system which develops a gamma signal and an unblanking signal in response to radiation from the object being imaged, the gamma signal consisting of a series of pulses, with the amplitude of each pulse representing the magnitude of one dimension of the position in the object of the radiation event which developed the pulse, including the steps of: a. developing input signals having an amplitude and polarity determined by the amplitude and polarity of the gamma signal at the time of receipt of each unblanking signal; b. integrating said input signals over a predetermined time period to develop a correction signal; and c. adding said correction signal to the gamma signal to develop a gamma signal corrected for object motion.
Claim 9
Dependent Claim
38 words
The method of correcting for object motion of claim 6 wherein, the input signals have a fixed amplitude, a polarity determined by the polarity of the gamma signals and a period equal to the period between unblanking pulses.
Claim 10
Dependent Claim
45 words
The method of correcting for object motion of claim 6 wherein, the input signals have a polarity determined by the polarity of the gamma signal, an amplitude proportional to the amplitude of the gamma signal and a period equal to the period between unblanking pulses.
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) | 1976-12-17 | 1977-06-18 | 1977-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-17 | 1981-06-18 | 1981-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-17 | 1985-06-18 | 1985-12-18 | $7700.00 | Window Closed / Lapsed |