Compact, power-efficient architectures using microvalves and microsensors, for intrathecal, insulin, and other drug delivery systems.

This paper describes a valve-regulated architecture, for intrathecal, insulin and other drug delivery systems, that offers high performance and volume efficiency through the use of micromachined components. Multi-drug protocols can be accommodated by using a valve manifold to modulate and mix drug flows from individual reservoirs. A piezoelectrically-actuated silicon microvalve with embedded pressure sensors is used to regulate dosing by throttling flow from a mechanically-pressurized reservoir. A preliminary prototype system is demonstrated with two reservoirs, pressure sensors, and a control circuit board within a 130cm(3) metal casing. Different control modes of the programmable system have been evaluated to mimic clinical applications. Bolus and continuous flow deliveries have been demonstrated. A wide range of delivery rates can be achieved by adjusting the parameters of the manifold valves or reservoir springs. The capability to compensate for changes in delivery pressure has been experimentally verified. The pressure profiles can also be used to detect catheter occlusions and disconnects. The benefits of this architecture compared with alternative options are reviewed.