Blood sampling instrument

Abstract

A blood sampling instrument for drawing a few drops of blood from a finger or the like is provided wherein the sampling device consists primarily of a tubular member which conceals all of the working parts and which has a flange thereon so that it can be easily held by a patient and pressed against a finger while releasing a trigger mechanism to actuate a plunger within the instrument.

We claim.]. .Iadd.What is claimed is.Iaddend.: 
     
       1. A blood sampling instrument designed to be hand held by an operator and being adapted to prick a finger or the like of a patient to draw a few drops of blood, said instrument having a distal end toward a patient and a proximal end toward an operator, comprising in combination: .[.(a).]. a tubular member having a hollow nosepiece at the distal end with an aperture at the terminal end thereof and a spring chamber at the proximal end,   .[.(b).]. an annular collar having a shoulder at the proximal end thereof and an annular flange immediately behind said nosepiece at the distal end of said collar,   .[.(c).]. a hollow sleeve surrounding said spring chamber,   .[.(d).]. a plunger mounted for reciprocation within said tubular member,   .[.(e).]. a shoulder within said tubular member, a main spring mounted within said spring chamber, said shoulder engaging said spring and biasing said plunger toward said nosepiece,   .[.(f).]. a socket and a needle mounted therein on the distal end of said plunger,   .[.(g).]. an aperture on the side of said tubular member, a finger on said plunger to engage said aperture and hold said plunger when said plunger is drawn away from said nosepiece,   .[.(h).]. a trigger button extending from said collar and having means to engage the finger on said plunger,   .[.(i).]. plunger cocking means on said sleeve to pull said plunger away from said nosepiece and engage said finger whereby   .[.(j).]. the nosepiece of said instrument can be pressed against a finger by exerting pressure on said flange while pressing said trigger to release said plunger and cause said needle to be driven out of said nosepiece.   
     
     
       2. The instrument of claim 1 having mounting means on said tubular member for said sleeve whereby said sleeve can be retracted to lie against said shoulder after a cocking operation permitting said sleeve to remain stationary when said plunger is released and protecting the plunger from contact with the holding hand. 
     
     
       3. The instrument of claim 2 having a projection on said sleeve and a mating notch in the tubular member to provide a click stop when said sleeve is fully retracted to give an audible and tactile indication that the sleeve is retracted and to restrain the sleeve against easy sliding movement. 
     
     
       4. The instrument of claim 1 having a bounce back spring on the proximal end of said plunger whereby said needle is drawn back into the nosepiece after initially extending beyond the nosepiece. 
     
     
       5. The instrument of claim 1 having detachable mounting means on said tubular member for said nosepiece whereby nosepieces of different lengths can be mounted on said tubular member. .Iadd.6. A lancet designed to be hand-held by an operator to prick a finger or the like comprising in combination: a plunger assembly;   means including a two-part assembly for housing said plunger assembly and comprising a tubular member and a tubular sleeve, one received within the other for relative sliding and reciprocating movement;   said plunger assembly including a trigger mechanism reciprocably movable within said two-part assembly;   a nosepiece detachably mounted to one end of said tubular member;   a needle assembly detachably mounted to one end of said plunger assembly and housed within said nosepiece;   a spring mounted within said two-part assembly and seated within said tubular member for biasing said plunger assembly toward said nosepiece;   said trigger mechanism having a detent engageable with said tubular member when said plunger assembly occupies a position of retraction against said spring; and   means formed on said plunger assembly and contained within said tubular sleeve limiting movement of said plunger assembly relative to said tubular sleeve;   whereby axial movement of said tubular sleeve in one direction relative to said tubular member moves said plunger assembly against the bias of said spring into a cocked position, said sleeve thereafter being axially moved in the opposite direction relative to said plunger assembly into a position for releasing said detent, and   whereby subsequent operation of said detent releases it from engagement with said tubular member allowing said spring to move said plunger assembly and thrust said needle assembly through said nosepiece. .Iaddend.   
     
     
        .Iadd.7.  The lancet of claim 6 and further comprising a trigger button for engaging said detent, and an annular collar mounted to said tubular member and defining a recess for retaining said trigger button, said collar also providing a stop that is engaged by said tubular sleeve in its position for releasing said detent. .Iaddend. .Iadd.8. The lancet of claim 6 and further comprising a flange mounted on the end of said tubular member adjacent said nosepiece. .Iaddend. .Iadd.9. The lancet of claim 6 and further comprising a bounce back spring interposed between said plunger assembly and said tubular sleeve, whereby said needle assembly is withdrawn into said nosepiece after being extended therethrough following 
     
     
        release of said detent. .Iaddend. .Iadd.10.  A blood sampling instrument designed to be hand-held by an operator to prick a finger or the like, said instrument comprising in combination: a tubular member having a spring chamber at one end and a trigger chamber at its other end,   a tubular sleeve sidably mounted over and along the one end of said tubular member,   a hollow nosepiece detachably mounted on the other end of said tubular member,   first means formed on said tubular member and said tubular sleeve for limiting relative axial movement therebetween,   a plunger assembly mounted within and housed by said tubular member and tubular sleeve, said assembly including a resilient trigger finger having a detent,   second means formed on said tubular sleeve and plunger assembly that allows limited relative axial movement therebetween,   said first and second means interacting to allow retraction of said plunger assembly as said tubular sleeve is moved along said tubular member away from said nosepiece,   third means formed in said tubular member for engaging said detent and retaining said plunger assembly in a cocked position,   a trigger button mounted on said tubular member for releasing said detent from engagement with said third means,   a spring mounted within the spring chamber of said tubular member, one end of said spring being seated in said chamber, the other end engaged with said plunger assembly biasing said plunger assembly in the direction of said nosepiece,   and a needle assembly detachably mounted to the end of said plunger assembly and housed in said nosepiece,   whereby said plunger assembly is housed within said tubular member and tubular sleeve and is set to a cocked position by their relative reciprocation, said plunger assembly and needle assembly being driven in the direction of said nosepiece upon release of said detent. .Iaddend.