Self-driven hypodermic injector
US4340048A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 28, 1981 |
| Grant date | Jul 20, 1982 |
| Priority date | — |
| Expiry date | Mar 28, 2001 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61M5/145
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A self-driven hypodermic injector that injects an injectable pharmaceutical composition at a constant baseline rate and may be manipulated to supplement the baseline rate with one or more pulses of the composition. The injector consists of a tubular housing with one fixed basal end wall that carries a hollow small gauge needle and one axially moveable end wall; an axially slideable water imbibing assembly mounted transversely in the housing lumen that divides the lumen into a pharmaceutical composition-containing compartment contiguous to the basal end wall and a water-containing compartment. In operation the subassembly imbibes water from the water-containing compartment and expands into the pharmaceutical-containing compartment to displace the pharmaceutical therefrom at the baseline rate. Pulses are effected by depressing the axially moveable end wall which in turn slides the subassembly toward the fixed end wall thereby exerting pressure on the pharmaceutical composition and increasing the injection rate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.