housing 14 includes a reservoir 16 for holding a volume of infusion medium such as but not limited to a liquid medication to be administered to the patient housing 14 may also contain a drive mechanism 18 e g a pump a power source 13 and control electronics 20 pump 18 may be configured to receive infusion media from reservoir 16 via a pump inlet 22 inlet structure 22 may provide a closeable and sealable fluid flow path to the reservoir in the reservoir portion of the housing the inlet structure may include a port for receiving a needle through which fluid may be transferred to the imd for example to fill or re fill the reservoir of the device with the infusion media or a rinsing fluid as will be more fully discussed below in particular embodiments the inlet structure may be configured to re seal after a fill or re fill operation and to allow multiple re fill and re seal operations one example of an inlet structure is described in u s pat no 6 652 510 titled u201c implantable medical device and reservoir for same u201d which is incorporated by reference herein in its entirety and for everything it teaches and discloses however further embodiments may employ other suitable inlet structures including but not limited to those described in u s pat nos 5 514 103 and 5 176 644 each to srisathapat et al u s pat no 5 167 633 to mann et al u s pat no 4 697 622 to swift and u s pat no 4 573 994 to fischell et al also incorporated by reference representative examples of reservoir housing portions and reservoirs which may be employed in embodiments of the invention are described.