摘要 |
<p>An infusion pump has a removable reservoir including a piston (13) and drive member (12). The drive member is an internally threaded elongated portion of the piston. A motor rotates a short drive screw (14), which engages the threads of the drive member to displace the piston in the reservoir (11). In one embodiment the piston (13) is attached to the drive member (12) by a severable central stem (131) which breaks away to allow engagement with the drive screw. With the stem severed, the piston (13) cannot be retracted, or the reservoir (11) refilled. Other safety features are shown for locking the displaced piston (13) in the reservoir (11). A digital metering system has a safety circuit to prevent dangerous failure modes of the rotation sensor and motor drive systems.</p> |