US3158803A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for monitoring magnetic field gradients
Assignee: Varian Medical Systems Inc
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Filing: 1962-02-21
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Granted: 1964-11-24
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Expires: 1982-02-21
Abstract
No abstract record available.
Inventors
- 👤 William E Bell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:27
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/24; G01R33/26; H; H03; H03L; H03L7/00; H03L7/26
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
136 words
APPARATUS FOR MONITORING MAGNETIC FIELD GRADIENTS COMPRISING: FIRST AND SECOND MAGNETIC RESONANCE OSCILLATORS HAVING FIRST AND SECOND SENSING SAMPLES RESPECTIVELY BEING DISPOSED IN SPACED-APART RELATION, EACH SAID OSCILLATOR BEING ADAPTED TO GENERATE AN OUTPUT FREQUENCY SIGNAL DEPENDENT UPON THE STRENGTH OF AN EXTERNAL MAGNETIC FIELD PASSING THROUGH EACH SAID SAMPLE; MEANS BILATERALLY COUPLING TOGETHER THE OUTPUT CIRCUITS OF SAID OSCILLATORS SO THAT EACH SAID OSCILLATOR OSCILLATES PHASE-LOCKED TO THE OTHER SAID OSCILLATOR AT A COMMON OUTPUT FREQUENCY WHEREBY A SIGNAL IS DERIVED IN VARIABLE ACCORDANCE WITH THE DIFFERENCE BETWEEN THE STRENGTH OF THE MAGNETIC FIELD PASSING THROUGH SAID FIRST SAMPLE AND THE STRENGTH OF THE MAGNETIC FLUID PASSING THROUGH SAID SECOND SAMPLE; AND MONITORING MEANS RESPONSIVE TO SAID DERIVED SIGNAL FOR MEASURING SAID DIFFERENCE BETWEEN THE STRENGTH OF SAID MAGNETIC FIELD EXISTING AT EACH SAID SAMPLE.
Claim 2
Dependent Claim
136 words
APPARATUS FOR MONITORING MAGNETIC FIELD GRADIENTS COMPRISING: FIRST AND SECOND MAGNETIC RESONANCE OSCILLATORS HAVING FIRST AND SECOND SENSING SAMPLES RESPECTIVELY BEING DISPOSED IN SPACED-APART RELATION, EACH SAID OSCILLATOR BEING ADAPTED TO GENERATE AN OUTPUT FREQUENCY SIGNAL DEPENDENT UPON THE STRENGTH OF AN EXTERNAL MAGNETIC FIELD PASSING THROUGH EACH SAID SAMPLE; MEANS BILATERALLY COUPLING TOGETHER THE OUTPUT CIRCUITS OF SAID OSCILLATORS SO THAT EACH SAID OSCILLATOR OSCILLATES PHASE-LOCKED TO THE OTHER SAID OSCILLATOR AT A COMMON OUTPUT FREQUENCY WHEREBY A SIGNAL IS DERIVED IN VARIABLE ACCORDANCE WITH THE DIFFERENCE BETWEEN THE STRENGTH OF THE MAGNETIC FIELD PASSING THROUGH SAID FIRST SAMPLE AND THE STRENGTH OF THE MAGNETIC FLUID PASSING THROUGH SAID SECOND SAMPLE; AND MONITORING MEANS RESPONSIVE TO SAID DERIVED SIGNAL FOR MEASURING SAID DIFFERENCE BETWEEN THE STRENGTH OF SAID MAGNETIC FIELD EXISTING AT EACH SAID SAMPLE.
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) | 1967-11-24 | 1968-05-25 | 1968-11-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-11-24 | 1972-05-25 | 1972-11-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-11-24 | 1976-05-25 | 1976-11-24 | $7700.00 | Window Closed / Lapsed |