Infusion device

Abstract

The present invention relates to an infusion device comprising a housing; a compartment inside said housing for positioning a medicament container, an infusion needle arranged to said housing, being connectable to said medicament container for delivering a dose of medicament, a piston plunger arranged in said housing capable of acting on said medicament container for delivering a dose of medicament, mechanical drive means capable of acting on said piston plunger for delivering a dose of medicament. The invention is characterised in that said piston plunger comprises a number of distinct segments being inter-connectable to each other for forming an elongated piston plunger.

1 . A medicament delivery device, comprising:
 a housing;   a cartridge retainer positioned within the housing and having a longitudinal axis;   a needle having a starting stationary position where the needle is completely within the housing and being in fluid communication with a medicament container positioned within the cartridge retainer so that a dose of medicament is delivered through the needle, where the needle is movably arranged within and relative to the housing, where the needle has a proximal end that moves from the starting stationary position to a second position that is extended to a position outside the housing, and where the movement of the needle from the starting stationary position to the second position defines an axis of movement; and   a piston plunger disposed within in the housing, where the piston plunger comprises movable segments that define a first portion and a second portion, where a pusher plate is positioned on the first portion such that the pusher plate extends into the medicament container during delivery of the dose of medicament, wherein the piston plunger moves parallel to the longitudinal axis of the cartridge retainer in a direction that is generally transverse to the axis of movement of the proximal end of the needle;   wherein the proximal end of the needle moves to the second position before delivery of the dose of the medicament begins.   
     
     
         2 . The medicament delivery device of  claim 1  further comprising a tube fixed to a distal end of the needle, where the needle hub moves in a direction generally transverse to the movement of the piston plunger. 
     
     
         3 . The medicament delivery device of  claim 1  further comprising tubing that is in fluid communication with the needle and the medicament within the medicament container when positioned within the cartridge retainer. 
     
     
         4 . The medicament delivery device of  claim 1 , where the needle when in the second position is locked relative to the housing to prevent movement in a distal direction. 
     
     
         5 . The medicament delivery device of  claim 1  further comprising a biasing member operatively associated with the housing to move the needle relative to the housing. 
     
     
         6 . The medicament delivery device of  claim 1  further comprises a driver operatively engaged with the piston plunger to move the piston plunger parallel to the longitudinal axis to deliver the dose of medicament. 
     
     
         7 . The medicament delivery device of  claim 6 , further comprising an injection speed control mechanism operatively connected to the driver. 
     
     
         8 . The medicament delivery device of  claim 1  further comprises an operation member that protrudes from the housing and is accessible to a user to activate the medical device. 
     
     
         9 . The medicament delivery device of  claim 1  wherein the proximal end of the needle is covered by a membrane when the needle is in the starting stationary position within the housing and the needle is in fluid communication with the medicament container prior to the needle moving relative to and exiting from the housing. 
     
     
         10 . The medicament delivery device of  claim 1  wherein a part of the housing is removable to allow user access to the cartridge retainer. 
     
     
         11 . The medicament delivery device of  claim 1  wherein the housing has a length at least equal to a length of the cartridge retainer as measured along the longitudinal axis. 
     
     
         12 . A medicament delivery device, comprising:
 a housing;   a cartridge retainer having a longitudinal axis and located within the housing;   an operation member that protrudes from the housing and is accessible to a user;   a needle having a proximal end and having a starting stationary position where the needle is completely within the housing such that the needle is in fluid communication with a medicament container positioned in the cartridge retainer prior to the needle moving relative to and exiting from the housing so that a dose of medicament is delivered through the needle, where the proximal end of the needle moves from the starting stationary position within the housing to a second position that is extended to a position outside the housing and where the movement of the needle from the first position to the second position defines an axis of movement;   a piston plunger comprising a stack of segments disposed within in the housing, where a first portion of the piston plunger extends into the medicament container during delivery of the medicament and a second portion of the piston plunger is operatively engaged with a driver that causes the first portion to move parallel to the longitudinal axis of the cartridge retainer in a direction that is generally transverse to the axis of movement of the proximal end of the needle; and   an injection speed control mechanism operatively controlling the driver and movement of the piston plunger,   wherein the proximal end of the needle moves to the second position before delivery of the dose of the medicament begins.   
     
     
         13 . The medicament delivery device of  claim 12 , where upon completion of the medicament delivery the needle moves distally from the second position to a third position where the needle is retracted to a position inside the housing to prevent unintentional needle sticks. 
     
     
         14 . The medicament delivery device of  claim 12  further comprising a window in the housing to allow a user to monitor medicament delivery progress. 
     
     
         15 . An medicament delivery device, comprising:
 a housing;   a compartment having a longitudinal axis and positioned inside the housing for holding a medicament container;   a needle connected to a flexible tube and movably arranged within the housing and in fluid communication with the medicament container through the flexible tube for delivering a dose of medicament, where the needle has a proximal end that moves from a first position within the housing to a second position that is extended to a position outside the housing, where the movement of the needle from the first position to the second position defines an axis of movement;   a piston plunger disposed in the housing for acting on the medicament container to deliver the dose of medicament, where a front portion of the piston plunger moves parallel to the longitudinal axis of the compartment in a direction that is transverse to the axis of movement of the proximal end of the needle and where the second portion of the piston plunger moves transverse to the longitudinal axis of the compartment; and   a driver operatively engaged with the second portion of the piston plunger to deliver the dose of medicament,   wherein when the medicament device is activated, the proximal end of the needle moves to the second position before delivering the dose of the medicament.   
     
     
         16 . The medicament delivery device of  claim 15 , wherein the piston plunger further comprises a stack of segments positioned inside and supported by a magazine. 
     
     
         17 . The medicament delivery device of  claim 15 , wherein the piston plunger has a generally rectangular cross-section. 
     
     
         18 . The medicament delivery device of  claim 15 , wherein the plunger piston further comprises a number of distinct separate segments that are successively interconnected during delivery of the dose of medicament. 
     
     
         19 . The medicament delivery device of  claim 15 , wherein an intersection of the first portion with the second portion defines a generally 90-degree angle. 
     
     
         20 . The medicament delivery device of  claim 15 , wherein the driver comprising a threaded drive nut that is threadedly engaged with the piston plunger such that rotation of the drive nut moves the first portion relative to the medicament container.