TELESCOPING PISTON DRIVE FOR MEDICAL INFUSION DEVICE
First Claim
1. A medicament infusion device, comprising:
- a housing having an interior surface, the interior surface of the housing being at least partially threaded;
a cavity within the housing configured to receive a cartridge, the cartridge having a reservoir for holding a medicament, a plunger for expelling the medicament from the reservoir, and an outlet port at a distal end of the housing;
a drive mechanism disposed at a proximal end of the housing;
a drive shaft in cooperation with the drive mechanism;
a compound lead screw, the compound lead screw being essentially cylindrical and having at least a portion having a first diameter and at least a portion having a second diameter, wherein each of the portion having the first diameter and the portion having the second diameter are threaded, and the second diameter is greater than the first diameter;
a piston having at least one threaded surface; and
at least one keyway, whereinthe at least one keyway is configured to permit lateral motion of one of the compound lead screw or piston without permitting rotational motion.
5 Assignments
0 Petitions
Accused Products
Abstract
Described is a drive mechanism for a drug infusion pump. In one embodiment, an in-line drive mechanism is provided that includes a motor operatively coupled to a lead screw, which is configured to engage a piston. The piston includes a cavity to receive the motor and the lead screw such that the lead screw and at least a portion of the motor are substantially contained within the piston cavity when the piston is in a retracted position. In one embodiment, the motor rotates a drive shaft is configured to turn a mechanism comprising a piston, a lead screw, and a housing that cooperate to extend telescopically to drive a plunger into a medicament cartridge, thereby expelling fluid.
10 Citations
9 Claims
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1. A medicament infusion device, comprising:
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a housing having an interior surface, the interior surface of the housing being at least partially threaded; a cavity within the housing configured to receive a cartridge, the cartridge having a reservoir for holding a medicament, a plunger for expelling the medicament from the reservoir, and an outlet port at a distal end of the housing; a drive mechanism disposed at a proximal end of the housing; a drive shaft in cooperation with the drive mechanism; a compound lead screw, the compound lead screw being essentially cylindrical and having at least a portion having a first diameter and at least a portion having a second diameter, wherein each of the portion having the first diameter and the portion having the second diameter are threaded, and the second diameter is greater than the first diameter; a piston having at least one threaded surface; and at least one keyway, wherein the at least one keyway is configured to permit lateral motion of one of the compound lead screw or piston without permitting rotational motion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification