John Howard Gordon,Ashok V. Joshi,Truman Wold,Sai Bhavaraju
申请号：
US13281282
公开号：
US08240260B2
申请日:
2011.10.25
申请国别(地区):
US
年份:
2012
代理人:
摘要：
An apparatus for delivering a beneficial agent is disclosed in one embodiment of the invention as including a water collection chamber. A water-transporting membrane is provided to communicate with the water collection chamber. An extraction chamber receives water through the water-transporting membrane, expanding the extraction chamber. A dispensing chamber, containing a beneficial agent, is configured to contract upon expanding the extraction chamber. This causes the dispensing chamber to expel the beneficial agent through a subterranean delivery channel, such as a rigid hollow spike. In certain embodiments, a rate adjustment mechanism may control the rate that water is received through the water-transporting membrane, thereby controlling the rate the beneficial agent is expelled. The water-transporting membrane has features that repel osmagent from passing through to the water collection chamber. The apparatus features steady rate performance without refreshing the water chamber and low temperature sensitivity.
