APPARATUS AND METHOD FOR DELIVERING BENEFICIAL LIQUIDS AT STEADY RATE

摘要

An apparatus (1) for delivering a beneficial agent (2) is disclosed in one embodiment of the invention as including a water collection chamber. A water-transporting membrane (5) is provided to communicate with the water collection chamber (8). An extraction chamber receives water (9) through the water-transporting membrane (5), expanding the extraction chamber. A dispensing chamber, containing a beneficial agent (2), is configured to contract upon expanding the extraction chamber. This causes the dispensing chamber to expel the beneficial agent (2) through a subterranean delivery channel, such as a rigid hollow spike. In certain embodiments, a rate adjustment mechanism (6a, 6b) may control the rate that water (9) is received through the water-transporting membrane (5), thereby controlling the rate the beneficial agent (2) is expelled. The water-transporting membrane (5) has features that repel osmagent from passing through to the water collection chamber (8). The apparatus (1) features steady rate performance without refreshing the water chamber (8) and low temperature sensitivity.