US3728700A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alarm means for cobalt therapy machine
Assignee: Atomic Energy of Canada Ltd AECL
•
Filing: 1970-02-17
•
Granted: 1973-04-17
•
Expires: 1990-02-17
Abstract
Abstract An alarm means on a cobalt therapy machine of the type in which the patient rests on a stretcher and a moving rotating head of a cobalt irradiation device moves relative to the stretcher. Transducers measure changes in the forces on the stretcher, and so provide an alarm upon any interference between the moving parts and the stretcher by measuring the difference between an output signal and a reference signal.
Inventors
- 👤 F Duval
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:05
CPC Classifications
G; G21; G21K; G21K5/00; G21K5/10; A; A61; A61B; A61B6/00; A61B6/10; A61B6/102; A61N; A61N5/00; A61N5/01
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
198 words
A patient irradiation machine comprising; a. a table on which said patient is supported; b. a base on which said table is supported; c. transducer means arranged to ascertain the magnitude of a supporting force exerted between said table and said base; d. monitoring means having an input coupled to said transducer means and first and second outputs, said monitoring means further having first and second operating states; e. reference signal means for generating a reference signal of varying magnitude when said monitoring means is in its first operating state, said reference signal means being coupled between the first output and the input of said monitoring means, said monitoring means switching from its first to its second operating state when the magnitude of said reference signal corresponds to the ouTput of said transducer means; and f. alarm means coupled to the second output of said monitoring means, said alarm means being energized when said monitoring means is in its second operating state and the difference between the magnitude of said reference signal at the time said monitoring means switched from its first to its second operating state and the output of said transducer means exceeds a predetermined amount.
Claim 2
Dependent Claim
198 words
A patient irradiation machine comprising; a. a table on which said patient is supported; b. a base on which said table is supported; c. transducer means arranged to ascertain the magnitude of a supporting force exerted between said table and said base; d. monitoring means having an input coupled to said transducer means and first and second outputs, said monitoring means further having first and second operating states; e. reference signal means for generating a reference signal of varying magnitude when said monitoring means is in its first operating state, said reference signal means being coupled between the first output and the input of said monitoring means, said monitoring means switching from its first to its second operating state when the magnitude of said reference signal corresponds to the ouTput of said transducer means; and f. alarm means coupled to the second output of said monitoring means, said alarm means being energized when said monitoring means is in its second operating state and the difference between the magnitude of said reference signal at the time said monitoring means switched from its first to its second operating state and the output of said transducer means exceeds a predetermined amount.
Claim 3
Dependent Claim
173 words
A patient irradiating machine as defined by claim 1 wherein said moinitoring means comprises a. comparison means having its input coupled to the outputs of said transducer means and said reference signal means; b. detecting means having its input coupled to the output of said comparison means, said detecting means providing a first output when the output of said comparision means has a first predetermined value indicative of balance between the outputs of said transducer and reference signal means and a second output when the output of said comparison means has a second predetermined value indicative of a predetermined unbalance between the outputs of said transducer and reference signal means; and c. Switching means having first and second inputs coupled respectively to the first and second outputs of said detecting means, a first output coupled to said reference signal means and a second output coupled to said alarm means, the first or second output of said switching means being energized when said monitoring means is in its first or second operating stage respectively.
Claim 4
Dependent Claim
98 words
A patient irradiating machine as defined by claim 2 wherein the reference signal generated by said reference signal means varies cyclically between a higher magnitude and a lower magnitude and wherein said detecting means, when said monitoring means is in the first operating state, stops the cyclic variation in the reference signal when the output of said comparison means reaches said first predetermined value, said detecting means further, when said monitoring means are in the second operating state, initiating the cyclic variation in the reference signal when the output of said comparison means reaches said second predetermined value.
Claim 5
Dependent Claim
49 words
A patient irradiating machine as defined by claim 3 wherein said reference signal means comprises a counter, pulses being applied to said counter until said detecting means stops the cyclic variation in said reference signal and said monitoring means is switched from its first to its second operating state.
Claim 6
Dependent Claim
48 words
A patient irradiating machine as defined by claim 4 which further comprises a movable member; a motor coupled to said movable member to move said member relative to said table, energization of said motor changing said monitoring means from the first operating state to the second operating state.
Claim 7
Dependent Claim
42 words
A patient irradiating machine as defined by claim 5 which further comprises means for coupling a voltage to said alarm means and to said counter, said voltage deactivating said alarm means and permitting activation of said counter when said motor is deenergized.
Claim 8
Dependent Claim
52 words
A patient irradiating machine as defined by claim 4 wherein said reference signal means further comprises a ladder network coupled between the output of said counter and the input of said comparison means, said reference signal changing in a step-like manner in one direction between the higher magnitude and the lower magnitude.
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) | 1976-04-16 | 1976-10-16 | 1977-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-16 | 1980-10-16 | 1981-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-16 | 1984-10-16 | 1985-04-17 | $7700.00 | Window Closed / Lapsed |