Needle free hypodermic injector and ampule for intradermal, subcutaneous and intramuscular injection

Abstract

A needle free hypodermic injector comprising a hand manipulatable elongate housing, an impact impulse injection mechanism within the housing, a suction generating means within the housing and cooperable with the impact impulse injection mechanism, a safety interlock mechanism, at least one medicament containing ampule cooperable with the impact impulse injection mechanism and the suction generating means and having a jet orifice through which medicament is injectable through a skin surface in response to an impulse placed on the medicament by the impact impulse injection mechanism, and means to receive and hold the ampule on the injector in registration with the impact impulse injection mechanism and in communication with the suction generating means; whereby the injector is adapted to expel the medicament from the ampule in a jet stream of sufficient velocity to penetrate skin tissue held against the orifice by the suction generating means and to deposit the medicament intradermally, subcutaneously or intramuscularly based on the position and angle of the jet orifice.

1 . A needle free hypodermic injector comprising: 
 a hand manipulatable elongated housing,    an impact impulse injection mechanism within said housing,    a suction generating means within said housing and cooperable with said impact impulse injection mechanism,    a safety interlock mechanism,    at least one medicament containing ampule cooperable with said impact impulse injection mechanism and said suction generating means and having at least one jet orifice through which medicament is injectable through a skin surface in response to an impulse placed on said medicament by said impact impulse injection mechanism, and    means to receive and hold said ampule on said injector in registration with said impact impulse injection mechanism and in communication with said suction generating means,    whereby said injector is adapted to expel said medicament from said ampule in a jet stream of sufficient velocity to penetrate skin tissue held against said orifice by said suction generating means and to deposit said medicament intradermally, subcutaneously or intramuscularly based on the position and angle of said jet orifice and the force provided by said impact impulse injection mechanism.    
   
   
       2 . The needle free hypodermic injector of  claim 1  wherein said ampule comprises an elongated body having a forward end, a rearward end, a substantially planar upper surface and a lower surface having a downward offset between said forward end and said rearward end, said offset providing a forward facing step face, a horizontally disposed bore within said body extending from the rearward end of said body to a point substantially adjacent to said step face, said bore being open at said rearward end and having a sealing plunger disposed therein, said bore further having at least one jet orifice extending through said step face, whereby said bore is capable of holding a quantity of medicament injectable through a skin surface held against said orifice in response to said plunger being driven forward in said bore by said impact impulse injection mechanism.  
   
   
       3 . The needle free hypodermic injector of  claim 2  wherein said ampule further comprises at least one suction port extending vertically through said body from said upper surface to said lower surface at a point forward of said step face, said suction port being in fluid communication with said suction generating means whereby a suction generated by said suction generating means is applicable to said skin surface through said port whereby said skin surface is drawn against said lower surface of said ampule and said jet orifice prior to injection of said medicament.  
   
   
       4 . The needle free hypodermic injector of  claim 3  wherein said impact impulse injection mechanism comprises: 
 a drive rod linearly reciprocatable within said housing between a cocked position and an injection position and having a forward portion adapted to project from said housing into said ampule bore to contact and drive said plunger upon movement of said drive rod from said cocked position to said injection position,    a compressible drive spring concentrically disposed along a rear portion of said drive rod between a stationary abutment and a projection substantially midway along said drive rod,    a releasable latch mechanism adapted to engage said projection and hold said drive rod in said cocked position with said spring compressed, and    a cocking mechanism adapted to draw said drive rod rearward to said cocked position,    whereby actuating said cocking mechanism draws said drive rod rearward in said housing compressing said drive spring between said stationary abutment and said projection and positioning said drive rod such that said latch mechanism engages said projection thereby holding said drive rod in said cocked position ready for injection and releasing said latch mechanism allows said spring to decompress thereby driving said drive rod forward to engage said plunger in said ampule and drive said plunger against said medicament whereby said medicament is forced through said orifice and injected into said skin surface.    
   
   
       5 . The needle free hypodermic injector of  claim 4  wherein said suction generating means comprises a reciprocating piston disposed in a cylinder in said housing, said piston being mechanically connected to said cocking mechanism whereby said piston is moved in said cylinder concurrently with cocking of said drive rod thereby creating a suction behind said piston, and means providing fluid communication between said cylinder and said ampule whereby said suction is conveyed from said cylinder to said ampule suction port.  
   
   
       6 . The needle free hypodermic injector of  claim 5  wherein said safety interlock mechanism comprises a reciprocating rod responsive to said suction and adapted to engage said latch mechanism in response to incomplete suction applied through said ampule suction port to said skin surface, whereby said latch mechanism is prevented from operating to release said drive rod and drive spring from said cocked position in the absence of secure contact of said ampule with said skin surface.  
   
   
       7 . The needle free hypodermic injector of  claim 3  further comprising a concave depression in said lower surface of said ampule surrounding and concentric with said suction port, whereby a suction generated by said suction generating means is applicable to said skin surface through said port whereby said skin surface is drawn against said lower surface of said ampule into said depression and against said jet orifice prior to injection of said medicament.  
   
   
       8 . The needle free hypodermic injector of  claim 7  wherein said jet orifice is located in said step face adjacent to an upper edge thereof and horizontally along a centerline of said bore whereby said ampule is adapted for intradermal injection of medicament.  
   
   
       9 . The needle free hypodermic injector of  claim 7  wherein said jet orifice is located in said step face at a downward angle relative to a centerline of said bore whereby said ampule is adapted for subcutaneous or intramuscular injection of medicament.  
   
   
       10 . The needle free hypodermic injector of  claim 2  wherein said ampule further comprises two suction ports laterally spaced on opposite sides of a center line of said ampule and extending vertically through said body from said upper surface to said lower surface at a point forward of said step face, said suction ports being in fluid communication with said suction generating means, said ampule further comprising a concave depression in said lower surface encompassing the lower ends of said suction ports, whereby a suction generated by said suction generating means is applicable to said skin surface through said ports whereby said skin surface is drawn against said lower surface of said ampule into said depression and against said jet orifice prior to injection of said medicament.  
   
   
       11 . A needle free hypodermic injector comprising an injector assembly and at least one medicament containing ampule removably attachable to said injector assembly, said injector assembly comprising an elongated hand manipulatable housing, said housing comprising: 
 a main body portion containing a mechanical impact impulse means comprising a drive rod linearly reciprocatable within said housing between a cocked position and an injection position, a compressible drive spring linearly concentric about a rear portion of said drive rod, said spring being confined between a stationary abutment within said housing and a projection substantially midway along said drive rod whereby rearward displacement of said drive rod compresses said spring, a latch mechanism cooperating with said projection to releasably hold said drive rod in a cocked position wherein said spring is compressed, a release means to release said latch mechanism when injection is desired, and a cocking means cooperating with said drive rod and operable to draw said drive rod in a rearward direction to said cocked position thereby compressing said spring and engaging said latch mechanism;    a forward nose portion adapted to removably receive said at least one ampule and having detent means to releasably secure said ampule to said injector assembly when said impact impulse mechanism is in said cocked position, said at least one ampule comprising a body having a forward end and a rearward end, a substantially planar upper surface and a stepped lower surface having a forward facing step face therein, said body having formed therein behind said step face a horizontally disposed substantially cylindrical medicament chamber open at said rearward end and narrowing to at least one jet orifice in said step face, said chamber being sized and positioned to receive a forward end of said drive rod when said ampule is secured to said injector assembly and said latch mechanism is released, said chamber further containing a sealing plunger providing a means to retain medicament in said chamber, said plunger adapted to be engaged by said drive rod upon release of said latch mechanism, whereby said drive rod drives said plunger forward within said chamber forcing said medicament under pressure through said jet orifice for injection into a skin surface held against said ampule.    
   
   
       12 . The needle free hypodermic injector of  claim 11  further comprising at least one suction port vertically disposed through said ampule body forward of said jet orifice, a suction generating means disposed in said main body portion of said housing and suction conduits within said housing and said nose portion providing fluid communication between said suction generating means and said at least one suction port whereby suction generated by said suction generating means is conveyed to said at least one suction port of said ampule, said suction serving to draw said skin surface against said ampule and said orifice prior to injection.  
   
   
       13 . The needle free hypodermic injector of  claim 12  wherein said suction generating means comprises a piston reciprocatable within a cylinder in said housing, said piston being connected to and operable by said cocking means to generate said suction.  
   
   
       14 . The needle free hypodermic injector of  claim 13  further comprising a suction operated interlock adapted to lock said latch mechanism against inadvertent operation in response to insufficient suction applied to said skin surface, said interlock comprising a piston operating within a cylinder adjacent to said suction generating means and fluidly connected thereto by said suction conduits, said piston having a locking rod projecting longitudinally therefrom, said locking rod having an end remote from said piston adapted to engage said latch mechanism when said interlock is in said locked position and to disengage from said latch mechanism when sufficient suction is applied to the skin through said ampule thereby permitting release of said drive rod and spring from said cocked position whereby said drive rod moves forward to engage and drive said plunger within said ampule chamber.  
   
   
       15 . The needle free hypodermic injector of  claim 14  wherein said cocking means comprises a handle pivoted to said housing, a slide frame within said housing mechanically connected to said handle so as to reciprocate within said housing upon pivoting of said handle, a drive rod latch attached to said slide frame and adapted to engage said drive rod when said handle is pivoted away from said housing and to draw said drive rod rearward against the force of said compression drive spring when said handle is pivoted toward said housing, said drive rod latch being biased to disengage from said drive rod upon engagement of said latch mechanism, and a mechanical link between said slide frame and said piston of said suction generating means whereby said piston is moved within said cylinder when said handle is pivoted and generates a suction at said ampule when said handle is pivoted toward said housing.  
   
   
       16 . The needle free hypodermic injector of  claim 14  wherein said cocking means comprises a pneumatically operated piston within said housing, a source of compressed air, air conduits, a trigger operated valve, a slide frame within said housing mechanically connected to said pneumatically operated piston so as to reciprocate within said housing upon actuation of said piston, a drive rod latch attached to said slide frame and adapted to engage said drive rod when said pneumatically operated piston is driven in a first direction and to draw said drive rod rearward against the force of said compression drive spring when said pneumatically operated piston is driven in a second direction, said drive rod latch being biased to disengage from said drive rod upon engagement of said latch mechanism, and a mechanical link between said slide frame and said piston of said suction generating means whereby said suction piston is moved within said suction piston cylinder when said pneumatically operated piston is actuated and generates a suction at said ampule when said pneumatically operated piston is driven in said second direction.  
   
   
       17 . The needle free hypodermic injector of  claim 13  further comprising a concave depression in said lower surface of said ampule surrounding and concentric with said suction port, whereby a suction generated by said suction generating means is applicable to said skin surface through said port whereby said skin surface is drawn against said lower surface of said ampule into said depression and against said jet orifice prior to injection of said medicament.  
   
   
       18 . The needle free hypodermic injector of  claim 17  wherein said jet orifice is located in said step face adjacent to an upper edge thereof and horizontally along a centerline of said bore whereby said ampule is adapted for intradermal injection of medicament.  
   
   
       19 . The needle free hypodermic injector of  claim 17  wherein said jet orifice is located in said step face at a downward angle relative to a centerline of said bore whereby said ampule is adapted for subcutaneous or intramuscular injection of medicament.  
   
   
       20 . The needle free hypodermic injector of  claim 11  wherein said ampule further comprises two suction ports laterally spaced on opposite sides of a center line of said ampule and extending vertically through said body from said upper surface to said lower surface at a point forward of said step face, said suction ports being in fluid communication with said suction generating means, said ampule further comprising a concave depression in said lower surface encompassing the lower ends of said suction ports, whereby a suction generated by said suction generating means is applicable to said skin surface through said ports whereby said skin surface is drawn against said lower surface of said ampule into said depression and against said jet orifice prior to injection of said medicament.  
   
   
       21 . The needle free hypodermic injector of  claim 14  wherein said at least one ampule comprises a multiple ampule assembly comprising a plurality of identical ampules arranged about and parallel to a center shaft in a cylindrical assembly, said cylindrical assembly being rotatable about said shaft for sequential registration of each ampule in said assembly with said drive rod and said suction conduits, said forward nose portion of said housing having a socket into which said center shaft is received, said socket and said shaft having cooperating detent means to removably secure said multiple ampule assembly to said injector housing, and said nose portion having detent means cooperable with said ampules to ensure accurate regisration of each of said ampules in turn with said drive rod and said suction conduits.  
   
   
       22 . The needle free hypodermic injector of  claim 14  wherein said at least one ampule further comprises a filling port disposed in said upper surface of said body, said filling port comprising a conduit providing fluid communication with the forward end of said chamber and a self sealing plug within said conduit adapted to receive a needle or probe of a filling syringe for injecting medicament into said chamber, said ampule further comprising a removable plug temporarily closing said jet orifice during filling and removable protective seals over said filing port, said removable plug and said open rearward end of said chamber.  
   
   
       23 . The needle free hypodermic injector of  claim 14  wherein said cocking means comprises an electrically actuated solenoid within said housing, a source of electrical power, electrical circuits, a trigger operated switch, a slide frame within said housing mechanically connected to said solenoid so as to reciprocate within said housing upon actuation of said solenoid, a drive rod latch attached to said slide frame and adapted to engage said drive rod when said solenoid is actuated in a first direction and to draw said drive rod rearward against the force of said compression drive spring when said solenoid is actuated in a second direction, said drive rod latch being biased to disengage from said drive rod upon engagement of said latch mechanism, and a mechanical link between said slide frame and said piston of said suction generating means whereby said suction piston is moved within said suction piston cylinder when said solenoid is actuated and generates a suction at said ampule when said pneumatically operated piston is driven in said second direction.  
   
   
       24 . The needle free hypodermic injector of  claim 14  wherein said drive rod is divided into two sections, a rear section with said compression drive spring concentric thereabout and a forward section adapted to enter said ampule, and a shock absorbing means uniting said front and rear sections, whereby said shock absorbing means operates to absorb the initial impact shock of release of said drive spring whereby the impulse of said drive rod against said ampule plunger is smooth and constant.  
   
   
       25 . The needle free hypodermic injector of  claim 4  wherein said drive rod is divided into two sections, a rear section with said compression drive spring concentric thereabout and a forward section adapted to enter said ampule, and a shock absorbing means uniting said front and rear sections, whereby said shock absorbing means operates to absorb the initial impact shock of release of said drive spring whereby the impulse of said drive rod against said ampule plunger is smooth and constant.  
   
   
       26 . The needle free hypodermic injector of  claim 3  wherein said impact impulse injection mechanism comprises: 
 a drive rod linearly reciprocatable within said housing between a cocked position and an injection position and having a forward portion adapted to project from said housing into said ampule bore to contact and drive said plunger upon movement of said drive rod from said cocked position to said injection position,    a pneumatic means reciprocating said drive rod between said cocked position and said injection position, and    a manually operated valve means actuating said pneumatic means,    whereby a first actuation of said pneumatic means draws said drive rod rearward in said housing allowing attachment of an ampule to said injector and a second actuation of said pneumatic means drives said drive rod forward to engage said plunger in said ampule and drive said plunger against said medicament whereby said medicament is forced through said orifice and injected into said skin surface.    
   
   
       27 . The needle free hypodermic injector of  claim 3  wherein said impact impulse injection mechanism comprises: 
 a drive rod linearly reciprocatable within said housing between a cocked position and an injection position and having a forward portion adapted to project from said housing into said ampule bore to contact and drive said plunger upon movement of said drive rod from said cocked position to said injection position,    a solenoid means reciprocating said drive rod between said cocked position and said injection position, and    a manually operated switch means actuating said solenoid means,    whereby a first actuation of said solenoid means draws said drive rod rearward in said housing allowing attachment of an ampule to said injector and a second actuation of said solenoid means drives said drive rod forward to engage said plunger in said ampule and drive said plunger against said medicament whereby said medicament is forced through said orifice and injected into said skin surface.    
   
   
       28 . The needle free hypodermic injector of  claim 6  wherein said cocking mechanism comprises a pneumatically actuated piston, a slide frame within said housing mechanically connected to said pneumatically actuated piston so as to reciprocate within said housing upon pneumatic actuation of said pneumatically actuated piston, valve means directing pneumatic fluid to said pneumatically actuated piston, a drive rod latch attached to said slide frame and adapted to engage said drive rod upon actuation of said piston, said drive rod latch being biased to disengage from said drive rod upon engagement of said releasable latch mechanism, and a mechanical link between said pneumatically actuated piston and said suction generating means whereby said suction generating means is actuated when said pneumatically actuated piston is actuated.  
   
   
       29 . The needle free hypodermic injector of  claim 6  wherein said cocking mechanism comprises an electrically actuated push-pull solenoid having a reciprocating core, a slide frame within said housing mechanically connected to said reciprocating core so as to reciprocate within said housing upon actuation of said solenoid, an electrical power source, switch means connecting said electrical power source and said solenoid operable to actuate said solenoid, a drive rod latch attached to said slide frame and adapted to engage said drive rod upon actuation of said solenoid, said drive rod latch being biased to disengage from said drive rod upon engagement of said releasable latch mechanism, and a mechanical link between said solenoid and said suction generating means whereby said suction generating means is actuated when said solenoid is actuated.