Overfill protection systems for implantable drug delivery devices
US6228050A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 30, 1999 |
| Grant date | May 8, 2001 |
| Priority date | — |
| Expiry date | Apr 30, 2019 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61M2209/045
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
The displacement of refill valves in an implantable drug delivery device is reduced to permit the housings of a drug delivery device to remain compact in size while permitting reservoirs of increased depth to be used. In a preferred embodiment, a collapsible link is provided as a telescoping member incorporating a coil spring. As the valve is pulled into contact with its seat, a detectable pressure increase is sensed in the refill device. In accordance with the invention, as the drug supply contained in the reservoir depletes, the reservoir surface moves towards a collapsed position, compressing the coil spring and eventually contacting the valve stem, thereby lifting the valve from its seat. By virtue of telescoping link, the valve stem length and therefore the valve travel may be reduced as compared to prior art devices, thus eliminating the need for increased housing depth when deeper reservoirs are used. The collapsible link may be comprised of a second spring combined with a telescoping link. The second spring is situated on a side of the valve opposite the telescoping link, thereby providing a downward force on the valve and valve stem. As an other alternative, the invention …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.