Blood lancing device

• US 4,712,548 A
• Filed: 12/19/1985
• Issued: 12/15/1987
• Est. Priority Date: 04/23/1980
• Status: Expired due to Term

• Current Assignee: Hans Enstrom
• Original Assignee: Hans Enstrom
• Inventors: Enstrom, Hans
• Primary Examiner(s): Yasko, John D.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US06/810,924
• Time in Patent Office: 726 Days
• Field of Search: 128/314, 128/315, 128/329 A, 128/329 R, 128/305, 128/753, 128/754, 128/763, 128/770, 30/346.55, 30/346, 30/366, 30/357
• US Class Current: 606/181
• CPC Class Codes: A61B 17/32093 for skin incisions
• CPC Class Codes: A61B 5/150022 for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/150282 for piercing elements, e.g. blade, lancet, canula, needle
• CPC Class Codes: A61B 5/150435 Specific design of proximal end
• CPC Class Codes: A61B 5/150541 Breakable protectors, e.g. caps, shields or sleeves, i.e. protectors separated destructively, e.g. by breaking a connecting area
• CPC Class Codes: A61B 5/150618 Integrally moulded protectors, e.g. protectors simultaneously moulded together with a further component, e.g. a hub, of the piercing element
• CPC Class Codes: A61B 5/150717 manually removed
• CPC Class Codes: A61B 5/15113 Manually triggered, i.e. the triggering requires a deliberate action by the user such as pressing a drive button
• CPC Class Codes: A61B 5/1513 comprising linear sliding guides comprising tooth-shaped elements A61B5/15132
• CPC Class Codes: A61B 5/15142 Devices intended for single use, i.e. disposable

Abstract

A plunger having an oblong body with a front end and a rear end and a lancet having a cutting edge projecting axially from said body at the front end is insertable in a cylinder having an oblong hollow body with a front end, a rear end and an axial hole. The plunger of such a length and the lancet is so arranged that it protrudes a predetermined distance out of the cylinder at the front end when the plunger is inserted thereby defining an operative cutting position. The plunger and cylinder have first engaging stop means arranged after partial insertion of the plunger, to temporarily prevent continued insertion at a predetermined initial position. The arresting function of the stop means is overcome by applying pressure on the plunger thereby pushing it the remaining distance into the cylinder from the initial position to the operative position. The lancet has a single cutting edge extending transversely to the axis of the lancet and a pair of identical inclined surfaces uniformly disposed about the cutting edge.

Claims

1. A disposable miniature lancing device for obtaining a drop of blood by cutting the skin without passing through the body of the patient comprising a cylinder and a plunger, at least said cylinder being formed of a material distendable under force applied thereto, said plunger being insertable at its front end into said cylinder, said plunger and said cylinder having a slight clearance enabling said plunger to be freely slidable within said cylinder, sadi plunger having a radially extending flange at its rear end engageable with the rear end of said cylinder for limiting passage of said plunger throguh said cylinder and defining the full insertion of said plunger in said cylinder, a lancet integrally formed with said plunger and having a cutting edge projecting axially from said front end of said plunger, said plunger, cylinder and lancet being so formed that said lancet protrudes from the front end of said cylinder a predetermined distance when said plunger is fully inserted within said cylinder, said cutting edge extending transversely to said plunger in a longitudinal plane passing through the central axis of said lancet and having a pair of identical inclined surfaces extending on either side of said longitudinal plane freom said cutting edge and forming uniform angles with the central plane.

2. The lancing device according to claim 1 wherein the inclined surfaes encompass an angle of between 15 to 20 degrees.

3. The lancing device according to claim 2 wherein each inclined surface has a length of between 0.5 to 1.5 mm.

4. A lancing device according to claim 2 wherein each inclined surface are concavely formed.

5. The lancing device according to claim 1 wherein said cutting edge extends at an angle to the central axis of said lancet.

6. The lancing device according to claim 5 wherein the cutting edge extends at an angle of 75 degrees.

7. The lancing means according to claim 1 wherein said lancet is provided with a chordal recess set back from said cutting edge and encased in said plunger.

8. The lancing device according to claim 1 wherein the outer surface of said plunger has a radially outwardly protruding peripheral ridge spaced from the rear end thereof and the inner surface of said cylinder has at least one radial projection extending inwardly from the wall adjacent the rear end thereof, said peripheral ridge and projection cooperating to form detent means for restricting the freely slidable movement of said plunger at a predetermined location within said cylinder, said location being less than the full insertion of said plunger so that said lancet remains within said cylinder spaced from the front end thereof, said restriction being overcome by application of an axial force on said plunger at said rear end thereof, said axial force causing said cylinder to distend and the peripheral ridge to pass axially over said projection without fracture of said ridge or projection, said plunger being thereafter freely movable through said cylinder into the fully inserted position.

9. The lancing device according to claim 8, wherein said plunger and cylinder are molded as a unit, said plunger being integrally connected at its forward end to portion of said cylinder, so as to be easily severable said connection being thin and easily frangible permitting severance of said plunger from said cylinder and exposure of the tip of said lancet.

10. The lancing device according to claim 8 wherein the cylinder is formed with a radially exterior flange forming a finger-grip for the user.

11. The lancing device according to claim 8 wherein the cylinder has a slit at said rear end to enable the entrance of the hole to expand upon said application of pressure on the plunger.

12. The lancing device according to claim 8 wherein said lancet protrudes from the front end of said plunger, when fully inserted in said cylinder between 0.5-2 mm.

13. The lancing device according to claim 8 when the entrance to said cylinder at its rear end has radially inward stop means restricting the movement of said plunger, and said plunger is provided with a circumferential protrusion located axially between the peripheral ridge and the front end of the plunger, said circumferential protrusion having a diameter less than that of said peripheral ridge but greater than that of the entrance to said cylinder at the rear end.

14. In a lancing device for obtaining a drop of blood, a needle comprising a solid shank having a cutting edge at one end, said cutting edge extending transversely to said shank in a longitudinal plane passing through the central axis of said lancet and said shank having a pair of identical concave surfaces inclined downwardly on either side of said longitudinal plane from said cutting edge and forming uniform angles with the central plane.

15. The lancing device according to claim 14 wherein the incline of said concave surfaces encompass an angle of between 15 to 20 degrees with the longitudinal plane.

16. The lancing device according to claim 15 wherein each concave surfce has a length of between 0.5 to 1.5 mm.

17. The lancing device according to claim 14 wherein said cutting edge extends at an angle to the central axis of said lancet.

18. The lancing device according to claim 17 wherein the cutting edge extends at an angle of 75 degrees.

19. The lancing means according to claim 14 wherein said lancet is provided with a chordal recess set back from said cutting edge.