Controlled delivery drive mechanisms for drug delivery pumps

Abstract

A controlled delivery drive mechanism includes a drive housing, a piston, and a biasing member initially retained in an energized state and is configured to bear upon an interface surface of the piston. The piston is configured to translate a plunger seal and a barrel. A tether is connected between the piston and the winch drum to restrain the free expansion of the biasing member and the free axial translation of the piston upon which the biasing member bears upon. The drive mechanism may further include a gear assembly and an escapement regulating mechanism configured to control the rotation of the gear assembly to release the tether from the winch drum. The metering of the tether by the escapement regulating mechanism controls the rate or profile of drug delivery to a user.

1 . (canceled) 
     
     
         2 . A controlled delivery drive mechanism, comprising:
 a drive housing;   a piston having an interface surface;   at least one biasing member initially retained in an energized state and configured to bear upon the interface surface of piston;   a tether connected at one end to the piston and at another end to a winch drum, the tether configured to restrain expansion of the at least one biasing member;   a status reader configured to recognize one or more status triggers incrementally spaced on tether; and   an escapement regulating mechanism configured to meter release of the tether by the winch drum, wherein metered release of the tether provides for controlled expansion of the at least one biasing member.   
     
     
         3 . The controlled delivery drive mechanism of  claim 2 , further comprising:
 a drug container having a plunger seal located within a barrel, wherein the piston is configured to axially translate the plunger seal within the barrel.   
     
     
         4 . The controlled delivery drive mechanism of  claim 3 , wherein the drug container contains a drug fluid within a drug chamber of barrel. 
     
     
         5 . The controlled delivery drive mechanism of  claim 2 , wherein the metering of tether by escapement regulating mechanism controls a rate or profile of drug delivery to a user. 
     
     
         6 . The controlled delivery drive mechanism of  claim 2 , wherein the escapement regulating mechanism comprises a gear train having one or more gears, wherein rotation of at least one gear of the gear train is coupled to rotation of the winch drum. 
     
     
         7 . The controlled delivery drive mechanism of  claim 6 , wherein the escapement regulating mechanism further comprises a lever and an escape wheel configured to engage with the gear train and meter rotational movement of the gear train. 
     
     
         8 . The controlled delivery drive mechanism of  claim 7 , wherein the escape wheel is a compound gear including escape teeth at a large diameter escape gear and a small diameter escape gear configured to engage with the gear train. 
     
     
         9 . The controlled delivery drive mechanism of  claim 7 , wherein the lever has pins and a prong, the prong configured to moveably engage a post and an impulse pin of a balance wheel, the balance wheel configured to engage with and oscillate around a post in combination with a hair spring. 
     
     
         10 . The controlled delivery drive mechanism of  claim 9  further comprising an actuator that at least partially controls oscillation of the balance wheel. 
     
     
         11 . The controlled delivery drive mechanism of  claim 10 , wherein the actuator is a mechanical actuator, an electrical actuator, or an electromechanical actuator. 
     
     
         12 . The controlled delivery drive mechanism of  claim 7 , wherein gear train comprises a winch gear rotationally coupled to winch drum and configured to engage at least one compound gear, the at least one compound gear configured to engage directly or indirectly with the escape wheel, the at least one compound gear thereby coupling rotation of the escape wheel to rotation of the winch drum. 
     
     
         13 . The controlled delivery drive mechanism of  claim 2 , wherein the status reader is an optical status reader and the one or more status triggers are optical status triggers. 
     
     
         14 . The controlled delivery drive mechanism of  claim 2 , wherein the status reader is an electromechanical status reader and the one or more status triggers are electromechanical status triggers. 
     
     
         15 . A drug delivery pump comprising:
 a housing;   an insertion mechanism;   a fluid pathway connection;   a power and control system; and   a controlled delivery drive mechanism comprising:
 a drive housing; 
 a piston having an interface surface; 
 at least one biasing member initially retained in an energized state and configured to bear upon the interface surface of piston; 
 a tether connected at one end to the piston and at another end to a winch drum, the tether configured to restrain expansion of the at least one biasing member; 
 a status reader configured to recognize one or more status triggers incrementally spaced on tether; and 
 an escapement regulating mechanism configured to meter release of the tether by the winch drum, wherein metered release of the tether provides for controlled expansion of the at least one biasing member; 
   wherein the power and control system is configured to receive one or more inputs to meter the release of tether by the winch drum and permit axial translation of the piston by the biasing member.   
     
     
         16 . The drug delivery pump of  claim 15 , wherein the one or more inputs are received from an activation mechanism configured to be acted upon by a user. 
     
     
         17 . The drug delivery pump of  claim 15 , wherein the power and control system is configured to receive one or more inputs to adjust an amount of restraint provided by the tether and winch drum on the axial translation of the piston to start, stop or pause operation of the drive mechanism. 
     
     
         18 . The drug delivery pump of  claim 17 , wherein the power and control system is configured to receive one or more inputs to adjust an amount of restraint provided by the tether and winch drum on the axial translation of the piston to change a dose volume or a delivery rate for delivery to a user. 
     
     
         19 . A method of assembling a drug delivery pump, comprising:
 attaching to an assembly platform or a housing a controlled delivery drive mechanism comprising:
 a drive housing, 
 a piston having an interface surface, 
 at least one biasing member initially retained in an energized state and configured to bear upon the interface surface of piston; 
 a tether connected at one end to the piston and at another end to a winch drum, the tether configured to restrain expansion of the at least one biasing member, and 
 an escapement regulating mechanism configured to meter release of the tether by the winch drum, wherein metered release of the tether provides for controlled expansion of the at least one biasing member; and 
   attaching an insertion mechanism, a fluid pathway connection, and a power and control system to the assembly platform or housing.   
     
     
         20 . The method of  claim 19  further comprising:
 attaching to the assembly platform to or inserting into the housing a drug container.