Drive Mechanism and Method of Use

• US 20090326459A1
• Filed: 06/30/2009
• Published: 12/31/2009
• Est. Priority Date: 06/30/2008
• Status: Abandoned Application

• Current Assignee: Animas Corporation (Johnson & Johnson)
• Original Assignee: Animas Corporation (Johnson & Johnson)
• Inventors: Shipway, Ian M., O'Connor, Sean
• Application Number:
  US12/494,546
• Publication Number:
  US 20090326459A1
• Time in Patent Office: Days
• US Class Current: 604/155
• CPC Class Codes: A61M 2005/16863 Occlusion detection
• CPC Class Codes: A61M 2005/3125 specific display means, e.g. to indicate dose setting
• CPC Class Codes: A61M 2005/31518 designed to reduce the overall size of an injection device, e.g. using flexible or pivotally connected chain-like rod members
• CPC Class Codes: A61M 2005/31588 electrically driven
• CPC Class Codes: A61M 2205/332 Force measuring means
• CPC Class Codes: A61M 2205/502 User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2205/8206 battery-operated
• CPC Class Codes: A61M 5/14244 adapted to be carried by the patient, e.g. portable on the body
• CPC Class Codes: A61M 5/14566 with a replaceable reservoir for receiving a piston rod of the pump
• CPC Class Codes: A61M 5/20 Automatic syringes, e.g. with automatically actuated piston rod, with automatic needle injection, filling automatically A61M5/142 , A61M5/46 take precedence; hypodermic projectiles F42B12/54
• CPC Class Codes: A61M 5/315 Pistons; Piston-rods; Guiding, blocking or restricting the movement of the rod or piston; Appliances on the rod for facilitating dosing ; Dosing mechanisms
• CPC Class Codes: A61M 5/31511 Piston or piston-rod constructions, e.g. connection of piston with piston-rod A61M5/5066 takes precedence
• CPC Class Codes: A61M 5/31515 Connection of piston with piston rod
• CPC Class Codes: A61M 5/31575 using scaling up or down transmissions, e.g. gearbox

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, at least a portion of the motor is also substantially contained within a cavity of the lead screw regardless of whether the piston is in the retracted or extended position. The configuration of the piston, the lead screw and the motor results in a more compact drug delivery device.

Claims

1. A drive mechanism for a medical device, comprising:

a piston having a cavity therein;

inner surface threads disposed on an internal surface of the piston;

a lead screw at least partially contained within the cavity;

external surface threads disposed on the lead screw for engaging the internal surface threads;

a motor having a drive shaft, the motor at least partially disposed within the lead screw, wherein the drive shaft engages the lead screw; and

a plunger in mechanical communication with the piston, for engaging a drug reservoir of a drug delivery device;

wherein, the motor and lead screw are coaxially aligned with the axis of travel of the plunger.