Patent US3621838A successfully refreshed from Google Patents.
US3621838A
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Therapeutic spectacles
Assignee: NAT RES DEV
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Filing: 1970-03-26
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Granted: 1971-11-23
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Expires: 1990-03-26
Abstract
Abstract A THERAPEUTIC DEVICE FOR ALLEVIATING PHOTOSENSITIVE EPILEPSY COMPRISES A PAIR OF SPECTACLES OR THE LIKE IN COMBINATION WITH MEAN S FOR DETECTING FLICKERING ILUMINATIONS IN THE ADJACENT ENVIRONMENT AT A PREDETERMINED FREQUENCY TO WHICH THE INTENDED WEARER IS SINSITIVE, AND A SECONDARY SOURCE OF STEADY ILLUMINATION ARRANGED FOR ENERGISATION IN RESPONSE TO DETECTION OF SAID FLICKERING ILLUMINATIONS.
Inventors
- 👤 Graham Frederick Antho Harding
- 👤 Neville Drasdo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:01
CPC Classifications
A; A61; A61M; A61M21/00; A61H; A61H5/00; A61N; A61N5/00; A61N5/06; A61N5/0613; A61N5/0618; A61M2021/0005; A61M2021/0044; A61N2005/0635; A61N2005/0643; A61N2005/0645; A61N2005/0647; A61N2005/0648; A61N2005/065; A61N2005/0651; A61N2005/0652
Claims Analysis
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-22 | 1975-05-24 | 1975-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-22 | 1979-05-24 | 1979-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-22 | 1983-05-24 | 1983-11-23 | $7700.00 | Window Closed / Lapsed |