GAS DRIVEN DRUG DELIVERY DEVICE

摘要

A subcutaneous drug delivery device (10) comprises a housing having an internal reservoir (12) in communication with a drug delivery needle (21) vi a a fluid path (23). An expandable chamber (14) disposed adjacent to the reservoir (12) forces drug from the reservoir (12) to the needle (21) when supplied with a gas. A flow regulating chamber (24-26), in communication wit h the fluid path, is capable of volumetric changes in response to temperature and/or pressure changes. An increase in the volume of the flow regulating chamber (24-26) increases flow resistance to the needle (21) and thereby counteracts the corresponding increase in delivery rate resulting from the expansion of the expandable chamber (14) due to the same volumetric changes in response to temperature and/or pressure.