Infusion pumps and methods and delivery devices and methods with same

Abstract

A delivery device includes a durable housing portion and a separable disposable portion that selectively engage and disengage from each other. The disposable housing portion secures to the patient-user and may be disposed of after it has been in use for a prescribed period. Components that normally come into contact with a patient-user or with an infusion medium, including a pump device, are supported by the disposable housing portion for disposal after the prescribed use, while the durable housing portion supports other components such as electronics for controlling delivery of the infusion medium from the reservoir and a drive device and drive linkage.

1 . A delivery device for delivering an infusion medium to a user, the device comprising:
 a first housing portion adapted to be secured to a user;   a second housing portion configured to be selectively engaged with and disengaged from the first housing portion, the second housing portion having an enclosed interior volume;   a drive shaft supported by the second housing portion, for movement in a first direction and in a second direction opposite to the first direction;   a drive device operatively connected to the drive shaft, to selectively move the drive shaft in the first direction; and   a pump device supported by the first housing portion, the pump device comprising:
 a piston chamber having an interior including a fluid portion having a variable volume for containing an infusion medium; 
 an inlet port in fluid flow communication with the interior volume of the piston chamber, the inlet port configured for connection with a reservoir, for fluid flow communication with the reservoir; 
 an outlet port in fluid flow communication with interior volume of the piston chamber; 
 a push plate supported for back-and-forth movement in a first direction and in a second direction opposite to the first direction, the push plate being arranged in a position for operative engagement with the drive shaft for movement of the push plate in the first direction as the drive shaft is moved in the first direction, and for allowing movement of the push plate in the second direction as the drive shaft is moved in the second direction, when the first housing portion and the second housing portion are engaged with each other; 
 a piston head moveable within the piston chamber between a retracted position and an active position to vary the volume of the fluid portion of the piston chamber, the piston head being operatively coupled in a fixed relation to the push plate, for movement from the retracted position to the active position with movement of the push plate in the first direction; 
 wherein, when the piston chamber contains infusion fluid, the volume of the fluid portion of the piston chamber is reduced as the piston head is moved from the retracted position to the active position to provide a pressure within the piston chamber to force the infusion fluid from the fluid portion of the piston chamber and through the outlet port; 
 wherein, the volume of the fluid portion of the piston chamber is increased as the piston head is moved from the retracted position to the active position to provide a pressure within the piston chamber to draw infusion fluid into the fluid portion of the piston chamber, through the inlet port, when the inlet port is connected in fluid flow communication with a reservoir. 
   
     
     
         2 . A delivery device according to  claim 1 , further comprising a bias member operatively coupled to the push plate, for imparting a bias force on the push plate in the second direction sufficient to move the push plate in the second direction as the drive shaft is moved in the second direction, when the first housing portion and the second housing portion are engaged with each other. 
     
     
         3 . A delivery device according to  claim 1 , further comprising a reservoir having an interior volume for containing an infusion medium and a conduit connecting the interior volume of the reservoir in fluid flow communication with the inlet port of the pump device. 
     
     
         4 . A delivery device according to  claim 3 , wherein the reservoir is supported by the first housing portion. 
     
     
         5 . A delivery device according to  claim 1 , wherein the push plate is coupled to the piston head by a piston rod, the piston chamber is open to a channel section through which the piston rod extends, and a seal is provided to inhibit fluid from passing through the channel section. 
     
     
         6 . A delivery device according to  claim 1 , wherein:
 the first housing portion comprises a housing structure having an interior volume in which the pump device is located,   the housing structure of the first housing portion includes a wall having an opening;   the push plate has a surface that is positioned to be acted upon by the drive shaft, through the opening in the wall of the housing structure of the first housing portion, when the first housing portion and the second housing portion are engaged with each other.   
     
     
         7 . A delivery device according to  claim 6 , wherein:
 the second housing portion comprises a housing structure having an interior volume in which the drive device is located,   the housing structure of the second housing portion includes a wall having an opening;   the drive shaft extends through the opening in the wall of the second housing portion.   
     
     
         8 . A delivery device according to  claim 7 , wherein:
 the drive shaft has an end that is positioned external to the second housing portion for engaging the surface of the push plate, when the first housing portion and the second housing portion are engaged with each other.   
     
     
         9 . A delivery device according to  claim 1 , wherein one of the second housing portion and the first housing portion has at least one flexible pawl and the other of the second housing portion and the first housing portion has at least one receptacle having a shape for receiving the at least one flexible pawl, when the first housing portion and the second housing portion are engaged with each other. 
     
     
         10 . A delivery device according to  claim 9 , wherein each flexible pawl includes a first stop surface and each receptacle includes a second stop surface and wherein the first stop surface engages the second stop surface, upon the pawl being received within the receptacle. 
     
     
         11 . A delivery device according to  claim 1 , further comprising electrical control circuitry contained in the second housing-portion, wherein the electrical control circuitry controls the drive device for delivery of the infusion medium from the reservoir to the user when the second housing portion and the first housing portion are engaged. 
     
     
         12 . A delivery device according to  claim 1 , wherein the first housing portion comprises a base portion having a bottom surface and an adhesive material on the bottom surface for securing the first housing portion to the skin of the user. 
     
     
         13 . A delivery device according to  claim 1 , wherein the first housing portion comprises a base portion having a bottom surface securable to the skin of the user, the delivery device further comprising an injection site at which a hollow needle or cannula may be inserted into a user's skin when the bottom surface of the base portion is secured to the user's skin, and a conduit coupling the injection site in fluid flow communication with the outlet port of the pump device. 
     
     
         14 . A delivery device according to  claim 13 , further comprising a one-way valve within the conduit. 
     
     
         15 . A delivery device according to  claim 1 , further comprising a conduit coupled to the inlet port of the pump device, and a one-way valve within the conduit. 
     
     
         16 . A pump device for conveying a fluidic medium, the pump device comprising:
 a piston chamber having an interior including a fluid portion having a variable volume for containing a fluidic medium;   an inlet port in fluid flow communication with the interior volume of the piston chamber, the inlet port configured for connection with a source of fluidic medium, for receiving fluid medium from the source into the interior volume of the piston chamber;   an outlet port in fluid flow communication with interior volume of the piston chamber;   a push plate supported for back-and-forth movement in a first direction and in a second direction opposite to the first direction, the push plate being arranged in a position for operative engagement with a drive shaft for movement of the push plate in the first direction as the drive shaft is moved in the first direction, and for allowing movement of the push plate in the second direction as the drive shaft is moved in the second direction;   a piston head moveable within the piston chamber between a retracted position and an active position to vary the volume of the fluid portion of the piston chamber, the piston head being operatively coupled in a fixed relation to the push plate, for movement from the retracted position to the active position with movement of the push plate in the first direction;   wherein, when the piston chamber contains infusion fluid, the volume of the fluid portion of the piston chamber is reduced as the piston head is moved from the retracted position to the active position to provide a pressure within the piston chamber to force the infusion fluid from the fluid portion of the piston chamber and through the outlet port;   wherein, the volume of the fluid portion of the piston chamber is increased as the piston head is moved from the retracted position to the active position to provide a pressure within the piston chamber to draw a fluidic medium into the fluid portion of the piston chamber, through the inlet port, when the inlet port is connected in fluid flow communication with the source of fluidic medium.   
     
     
         17 . A pump device according to  claim 16 , further comprising a bias member operatively coupled to the push plate, for imparting a bias force on the push plate in the second direction sufficient to move the push plate in the second direction as the drive shaft is moved in the second direction. 
     
     
         18 . A pump device according to  claim 16 , wherein the push plate is coupled to the piston head by a piston rod, the piston chamber is open to a channel section through which the piston rod extends, and a seal is provided to inhibit fluid from passing through the channel section. 
     
     
         19 . A method of making a pump device for conveying a fluidic medium, the method comprising:
 providing a piston chamber having an interior including a fluid portion having a variable volume for containing a fluidic medium;   providing an inlet port in fluid flow communication with the interior volume of the piston chamber, and configuring the inlet port for connection with a source of fluidic medium, for receiving fluid medium from the source into the interior volume of the piston chamber;   providing an outlet port in fluid flow communication with interior volume of the piston chamber;   supporting a push plate for back-and-forth movement in a first direction and in a second direction opposite to the first direction, and arranging the push plate in a position for operative engagement with a drive shaft for movement of the push plate in the first direction as the drive shaft is moved in the first direction, and for allowing movement of the push plate in the second direction as the drive shaft is moved in the second direction;   supporting a piston head for movement within the piston chamber between a retracted position and an active position to vary the volume of the fluid portion of the piston chamber, and operatively coupling the piston head in a fixed relation to the push plate, for movement from the retracted position to the active position with movement of the push plate in the first direction;   wherein, when the piston chamber contains infusion fluid, the volume of the fluid portion of the piston chamber is reduced as the piston head is moved from the retracted position to the active position to provide a pressure within the piston chamber to force the infusion fluid from the fluid portion of the piston chamber and through the outlet port;   wherein, the volume of the fluid portion of the piston chamber is increased as the piston head is moved from the retracted position to the active position to provide a pressure within the piston chamber to draw a fluidic medium into the fluid portion of the piston chamber, through the inlet port, when the inlet port is connected in fluid flow communication with the source of fluidic medium.   
     
     
         20 . A method according to  claim 19 , further comprising operatively coupling a bias member to the push plate, for imparting a bias force on the push plate in the second direction sufficient to move the push plate in the second direction as the drive shaft is moved in the second direction. 
     
     
         21 . A method according to  claim 19 , further comprising operatively coupling the push plate to the piston head by a piston rod, wherein the piston chamber is open to a channel section through which the piston rod extends, and a seal is provided to inhibit fluid from passing through the channel section.