Distal movement limiting assembly for finger stick device

• US 5,397,334 A
• Filed: 01/11/1994
• Issued: 03/14/1995
• Est. Priority Date: 01/11/1994
• Status: Expired due to Term

• Current Assignee: Sherwood Services AG
• Original Assignee: Sherwood Medical Company (Medtronic Plc)
• Inventors: Ranford, Alan B., Schenk, Robert W., Ray, Shawn C.
• Primary Examiner(s): HINDENBURG, MAX F
• Application Number:
  US08/180,169
• Time in Patent Office: 427 Days
• Field of Search: 128/760, 128/770, 606/181, 606/182, 604/192, 604/194, 604/198
• US Class Current: 606/182
• CPC Class Codes: A61B 5/1411 by percutaneous method, e.g. by lancet
• CPC Class Codes: A61B 5/150022 for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/150412 Pointed piercing elements, e.g. needles, lancets for piercing the skin blade-like piercing elements A61B5/150442
• CPC Class Codes: A61B 5/150549 Protectors removed by rotational movement, e.g. torsion or screwing
• 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 5/15113 Manually triggered, i.e. the triggering requires a deliberate action by the user such as pressing a drive button
• CPC Class Codes: A61B 5/15128 comprising 2D- or 3D-shaped elements, e.g. cams, curved guide rails or threads comprising tooth-shaped elements A61B5/15132
• CPC Class Codes: A61B 5/15142 Devices intended for single use, i.e. disposable

Abstract

An assembly for preventing movement of a sharp lancet tip out of a lancet device of the type having a linearly movable and retractable lancet tip is disclosed. The lancet device has a patient contacting or distal end and an opposed proximal end. The lancet device has a lancet that is substantially encased in an elongated molded plastic lancet body. The lancet has a sharp tip that extends beyond the end of the lancet and is enclosed in a removable cap. The distal end of the lancet has a pair of retainer arms that extend away from the lancet body on opposite sides of the lancet body parallel to the axis of the lancet body. The distal end of the retainer arms extend slightly beyond the distal end of the lancet body and are curved toward the axis of the lancet body to contact the outer surface of the cap. Each retainer arm has a stop, located near the distal end of the retainer arms. The distal end of the lancet body fits in a chamber in the lancet device. The chamber has a pair of retainer arm supports located along opposite sides of the inner surfaces of the chamber. These retainer arm supports jut away from the inner surfaces at an obtuse angle. The retainer arm supports abut the corresponding stops along the distal surface of the stops.

Claims

1. A safety device for selectively preventing movement of a sharp lancet tip out of a lancet device of the type having a linearly movable and retractable lancet tip, the lancet tip substantially enclosed in a lancet body having a proximal and a distal end and a central axis, the sharp lancet tip extending distally from the lancet body, the lancet body also having a removable cap surrounding the lancet tip, the cap having an outer surface, the lancet device having a case having a patient contacting distal end and an opposed proximal end, the case having a chamber at its distal end, the chamber open to the distal end of the case, the chamber containing the lancet, the lancet device having an assembly for linearly and consecutively moving the sharp tip out of the distal end of the case and then back into the distal end of the case along the central axis of the lancet, the safety device comprising:

the distal end of the lancet body having a pair of retainer arms that extend away from the lancet body on opposite sides of the lancet body parallel to the central axis of the lancet body, the distal end of the retainer arms extending slightly beyond the distal end of the lancet body and directed toward the central axis of the lancet body, each retainer arm having a stop located near the distal end of the retainer arms that extends from each of the retainer arms away from the central axis of the lancet body, the retainer arms contacting the outer surface of the cap;

the chamber having a pair of retainer arm supports located along the inner surfaces of the chamber on opposite sides of the chamber, the retainer arm supports jutting away from the inner surfaces at an obtuse angle as viewed by moving distally along the inner surfaces of the chamber, the stops abutting the corresponding retainer arm supports along the distal surface of the stops when the lancet body is in its most proximal position within the chamber;

whereby, with the cap in place around the distal tip of the lancet, any force applied to the lancet body by the lancet device to move the lancet body distally causes the stops to contact the retainer arm supports, where, because the retainer arm supports are angled, as the stops are pressured to move distally, contact between the stops and the retainer arm supports deflects the stops toward the axis of the lancet body where the distal ends of the retainer arms contact the outer surface of the cap so that the stops cannot move clear of contact with the retainer arm supports thereby preventing the retainer arms, and consequently the lancet body, from moving distally; and

,

whereby, after the cap is removed so that the lancet device may be used to produce a drop of blood from a patient and the lancet device puts pressure on the lancet body to move the lancet body distally, distal pressure on the lancet body is transferred to the retainer arms and to the stops so that as the stops are pressured to move distally, contact between the retainer arm supports and the stops again causes the stops to deflect toward the axis of the lancet body, but because the distal ends of the retainer arms do not contact the outer surface of the cap, the retainer arms may move toward the axis of the lancet body to a position clear of the retainer arm supports thereby allowing the retainer arms, and consequently the lancet body, to move distally so that the distal tip of the lancet may move beyond the distal end of the device.

2. A safety device for selectively preventing movement of a sharp lancet tip out of a lancet device of the type having a linearly movable and retractable lancet tip, the lancet tip substantially enclosed in a lancet body having a proximal and a distal end and a central axis, the sharp lancet tip extending distally from the lancet body, the lancet body also having a cap surrounding the lancet tip, the cap having an outer surface, the lancet device having a case having a patient contacting distal end and an opposed proximal end, the case having a chamber at its distal end, the chamber open to the distal end of the case, the chamber containing the lancet, the lancet device having an assembly for linearly and consecutively moving the sharp tip out of the distal end of the case and then back into the distal end of the case along the central axis of the lancet, the safety device comprising:

a lancet body having a proximal and a distal end and a central axis, the lancet body having a sharp lancet tip extending distally from the lancet body, the lancet body, the distal end of the lancet body having a pair of retainer arms that extend away from the lancet body on opposite sides of the lancet body parallel to the central axis of the lancet body, the distal end of the retainer arms extending slightly beyond the distal end of the lancet body and directed toward the central axis of the lancet body, each retainer arm having a stop located near the distal end of the retainer arms that extends from each of the retainer arms away from the central axis of the lancet body;

a removable cap surrounding the lancet tip, the cap having an outer surface wherein the retainer arms contact the outer surface of the cap when the cap surrounds the lancet tip;

a case having a patient contacting distal end and an opposed proximal end, the case having a chamber at its distal end, the chamber open to the distal end of the case, the chamber containing the lancet body, the chamber having a pair of retainer arm supports located along the inner surfaces of the chamber on opposite sides of the chamber, the retainer arm supports jutting away from the inner surfaces at an obtuse angle as viewed by moving distally along the inner surfaces of the chamber, the stops abutting the corresponding retainer arm supports along the distal surface of the stops when the lancet body is in its most proximal position within the chamber;

means for linearly and consecutively moving the sharp lancet tip out of the distal end of the case and then back into the distal end of the case along the central axis of the lancet body;

whereby, with the cap in place around the distal tip of the lancet, any force applied to the lancet body by the lancet device to move the lancet body distally causes the stops to contact the retainer arm supports, where, because the retainer arm supports are angled, as the stops are pressured to move distally, contact between the stops and the retainer arm supports deflects the stops toward the axis of the lancet body where the distal ends of the retainer arms contact the outer surface of the cap so that the stops cannot move clear of contact with the retainer arm supports thereby preventing the retainer arms, and consequently the lancet body, from moving distally; and

,

whereby, after the cap is removed so that the lancet device may be used to produce a drop of blood from a patient and the lancet device puts pressure on the lancet body to move the lancet body distally, distal pressure on the lancet body is transferred to the retainer arms and to the stops so that as the stops are pressured to move distally, contact between the retainer arm supports and the stops again causes the stops to deflect toward the axis of the lancet body, but because the distal ends of the retainer arms do not contact the outer surface of the cap, the retainer arms may move toward the axis of the lancet body to a position clear of the retainer arm supports thereby allowing the retainer arms, and consequently the lancet body, to move distally so that the distal tip of the lancet may move beyond the distal end of the device.

3. The device of claim 2 wherein the case includes a lower section and an opposed congruent upper section.

4. The device of claim 3 wherein the lower section is locked into contact with the upper section thereby forming the case and the chamber.

5. The device of claim 4 wherein the lower section in locked into contact with the upper section by mating of lock holes in the lower section and corresponding lock tabs that extend away from the upper section, or vice versa.

6. The device of claim 3 wherein the lower section and upper section are each substantially concave shaped;

and,

wherein the lower section and the upper section are joined together to form a substantially hollow case.

7. The device of claim 3 wherein the lower section and the upper section each have a generally planar outer edge that extends around the outer periphery of the lower section and upper section, respectively.

8. The device of claim 3 wherein the lower section includes a lower section recess formed in the interior of the lower section that extends from the distal end of the lower section proximally, the lower section recess having a distal end, and

wherein the upper section includes an upper section recess formed in the interior of the upper section that extends from the distal end of the upper section proximally, the upper section recess having a distal end;

whereby lower section recess and the upper section recess form the chamber when the lower section and the upper section are joined together.

9. The device of claim 8 wherein the lower section recess and the upper section recess are both half cylindrical and open at their respective distal ends and wherein the lower section recess and the upper section recess are aligned to form a cylindrical chamber that is open at the distal end of the device.

10. The device of claim 8 wherein the central axis of the lower section recess is aligned with the planar outer edge of the lower section, and

wherein the central axis of the upper section recess is aligned with the planar outer edge of the upper section.

11. The device of claim 8 wherein the lower and upper section recesses also each have an elongated recess slot that extends into the lower and upper section, respectively, from the outer edges of the lower and upper section recesses, respectively, and wherein the axes of the recess slots are aligned with the axes of the lower and upper section recesses, respectively.

12. The device of claim 8 wherein the lower and upper sections also each have an elongated positioning slot located proximal to the lower and upper section recesses, respectively, an]wherein the axis of the positioning slots are aligned with of lower and upper section recesses, respectively.