The Prometra® drug delivery system is a valve gated pump. Instead of rollers and plastic tubing, it uses valves to isolate a titanium dosing chamber from the reservoir and catheter. This results in two principle effects: better control over dosing reliability and longer battery life. Separating the dosing chamber from the reservoir prevents the increase in pressure in the reservoir at refill, decrease in pressure over the weeks as drug is emptied from the reservoir, and from having an impact on the amount of drug delivered. With this design, temperature and pressure effects, like getting into a hot tub or traveling by plane are minimized.
Additionally, decreasing the number of moving parts from a long list of complex gears, rotors, and pliable tubing to just the two valves results in a nearly 50% increase in service life.