Body fluid sampling apparatus

• US 6,730,046 B1
• Filed: 03/27/2002
• Issued: 05/04/2004
• Est. Priority Date: 09/29/1999
• Status: Expired due to Fees

• Current Assignee: ARKRAY, Inc
• Original Assignee: ARKRAY, Inc
• Inventors: Hyodo, Hiroshi, Murakami, Atsushi, Hamamoto, Katsumi
• Primary Examiner(s): Hindenburg, Max F.
• Assistant Examiner(s): McCrosky, David J.
• Application Number:
  US10/089,296
• Time in Patent Office: 769 Days
• Field of Search: 600/573-584, 606/181-189
• US Class Current: 600/583
• CPC Class Codes: A61B 5/150022 for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/150099 by negative pressure, other than vacuum extraction into a syringe by pulling on the piston rod or into pre-evacuated tubes
• CPC Class Codes: A61B 5/150221 Valves
• 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 5/15113 Manually triggered, i.e. the triggering requires a deliberate action by the user such as pressing a drive button
• CPC Class Codes: A61B 5/15117 comprising biased elements, resilient elements or a spring, e.g. a helical spring, leaf spring, or elastic strap
• CPC Class Codes: A61B 5/15144 comprising driving means, e.g. a spring, for retracting the piercing unit into the housing

Abstract

A body fluid sampling apparatus (A), comprising a piston (11) provided in a tubular main case (10), a first plunger rod (12) extending into the piston (11) integrally with each other; a first spring (13) elastically energzing the piston (11) toward the upper end side, a second plunger rod (15) installed in the first plunger rod (12) through a second spring (14), a lancet mounted body (16) provided on the second plunger rod (15) and having a lancet (B) mounted therein, a third spring (17) elastically energizing the lancet mounted body (16) toward the upper end side, latch mechanisms (20, 30) suppressing the second plunger rod (15) and first plunger rod (12) when the first plunger rod (12) is moved to the lower end side by he push-down of the piston (11), and a release mechanism (40) for releasing the locked state of the first plunger rod (12) and the second plunger rod (15).

Claims

1. A body fluid sampler comprising:

a cylindrical main case having a first end provided with a first opening and a second end provided with a second opening;

a piston inserted in the main case to project from the first opening for movement within the main case airtightly with respect to an inner wall of the main case;

a first plunger rod extending integrally from the piston toward said second end;

a first elastic member for elastically urging the piston toward said first end;

a second plunger rod extending from the first plunger rod toward said second end for movement within the main case with a compressible second elastic member interposed between the first plunger rod and the second plunger rod;

a lancet mount associated with the second plunger rod adjacent to said second end for movement within the main case, the lancet mount being provided with a lancet oriented toward said second end;

a third elastic member for elastically urging the lancet mount toward said first end;

a latch mechanism which works, when the piston is pushed down for movement toward said second end together with the first plunger rod, for restricting movement of the second plunger rod toward said second end against a pushing force of the second elastic member and for restricting rebounding of the piston and first plunger rod which have been moved toward said second end while allowing the second elastic member to be compressed; and

a release mechanism for releasing the first plunger rod and second plunger rod which have been latched by the latch mechanism.

2. The body fluid sampler according to claim 1, wherein the latch mechanism includes:

a first and a second engagement members each of which has a stopper for stopping a corresponding one of the first and the second plunger rods;

a latching elastic member for elastically biasing each of the engagement members toward the corresponding one of the first and the second plunger rods; and

engagement portions respectively formed on the first and the second plunger rods, the engagement portions being spaced from each other by a distance which is larger than a distance between the stoppers when the plunger rods are held in an initial state;

the release mechanism including;

a release button for simultaneously releasing the stoppers from the corresponding engagement portions against an elastic biasing force of the latching elastic member.

3. The body fluid sampler according to claim 2, wherein the release button is provided with a push portion projecting from a predetermined portion of a side surface of the main case while keeping airtightness relative to the main case.

4. The body fluid sampler according to claim 1, wherein the main case is provided with a vacuum relief mechanism for relieving a vacuum state within the main case generated by pulling back the piston toward said first end.

5. The body fluid sampler according to claim 4, wherein the vacuum relief mechanism is provided with a vacuum relief button partially projecting from a predetermined portion of a side surface of the main case, the vacuum relief button being elastically urged in the projecting direction while keeping airtightness of the main case, the vacuum relief button being pushed against the elastic urging force for allowing air passage between inside and outside of the main case.

6. The body fluid sampler according to claim 1, wherein the piston has an outer circumferential wall provided with an O-ring for closely contacting the inner wall of the main case.