Suction-type blood sampler

• US 5,666,966 A
• Filed: 06/02/1995
• Issued: 09/16/1997
• Est. Priority Date: 06/24/1994
• Status: Expired due to Term

• Current Assignee: Nissho Corporation (Nitto Denko Corporation)
• Original Assignee: Nissho Corporation (Nitto Denko Corporation)
• Inventors: Nakagami, Hiroyuki, Horie, Masao, Takatera, Masayuki, Kishigami, Yoshikazu
• Primary Examiner(s): Rimell, Sam
• Assistant Examiner(s): WINGOOD, PAMELA LYNN
• Application Number:
  US08/459,962
• Time in Patent Office: 837 Days
• Field of Search: 128/763, 128/765, 128/770, 606/181, 606/182, 604/131
• US Class Current: 600/573
• 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 5/150213 Venting means
• 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 5/15111 Semi-automatically triggered, e.g. at the end of the cocking procedure, for instance by biasing the main drive spring or when reaching sufficient contact pressure, the piercing device is automatically triggered without any deliberate action by the user
• 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 5/15194 fully automatically retracted, i.e. the retraction does not require a deliberate action by the user, e.g. by terminating the contact with the patient's skin

Abstract

A suction-type blood sampler has a housing (1), a lancet unit (2) having a rod (4) extending backward from the lancet unit, and a plunger (3) connected to the rod in the housing and having a seal (7) attached to a forward end of the plunger. The seal is in sliding airtight contact with an inner periphery of the housing. The lancet unit consists of a lancet body (11) having a forwardly extending needle (12) and held by a lancet retainer (18) which is in sliding contact with the inner periphery. The blood sampler further has first, second and third springs (8, 9, 10) placed between the lancet unit and the plunger. The second spring urges the lancet unit to project the needle forwards, and the third spring tends to retract it. The first spring acts to reduce air pressure in the housing when the plunger is released. The blood sampler also has an air sealing means (32) disposed in the plunger so as to exhaust air and inhibit ambient air from entering the housing, so that the skin is pierced sharply and quickly, and by introducing ambient air into the evacuated housing, just a required amount of blood can be taken accurately and without any fear that the blood will scatter when the open end of the housing is removed from the skin.

Claims

1. A suction-type blood sampler comprising:

a housing, the housing having an open frontal end and an open rearward end;

a lancet unit accommodated in a front region of the housing, the lancet unit comprising a lancet body fixed to a lancet retainer, the lancet body having a needle extending forward toward the frontal end of the housing and the lancet retainer being in sliding contact with the inner peripheral surface of the housing;

a rod attached to and extending backward from the lancet unit toward the open rearward end of the housing;

a plunger provided in a rear region of the housing and having a seal attached to a forward end of the plunger, the seal being in sliding and airtight contact with an inner peripheral surface of the housing;

an inner cylindrical member which extends forward of the plunger;

a flange formed integral with a rear end of the rod;

a spring separator formed around the rod and integral with the inner cylindrical member;

a hookable member fitting in a rear recess of the lancet unit, the hookable member being engageable with a rearward rim extending radially and inwardly from the inner peripheral surface of the housing;

a first partition attached to and closing a rear open end of the inner cylindrical member;

a first spring, a second spring and a third spring all accommodated in the housing between the lancet unit and the plunger, wherein the second spring intervenes between the lancet unit and the spring separator and urges the lancet unit forward to move the needle outwardly of the frontal end of the housing, and the third spring is interposed between the spring separator and the flange and urges the lancet unit to be retracted behind the frontal end, when the plunger is pressed, and wherein the first spring is interposed between the lancet unit and the first partition and urges said plunger to move toward said open rearward end and to reduce the air pressure in the housing, when the plunger is released;

a fourth spring disposed partially in an internal cavity of the plunger and between the first partition and the rear region of said cavity; and

an air sealing means disposed in a rear region of an internal cavity of the plunger for exhausting air out of the housing, but inhibiting air from entering the housing through the internal cavity of said plunger.

2. The suction-type blood sampler as defined in claim 1, further comprising a cap attached to the frontal end of the housing, and at least one lug formed in and integral with an inner periphery of the cap, with the lug being behind a frontal end thereof so as to delimit the forward movement of the lancet unit.

3. The suction-type blood sampler as defined in claim 1 or 2, wherein the air sealing means is a check valve.

4. The suction-type blood sampler as defined in claim 1 or 2, further comprising a second partition for dividing the interior of the plunger into the internal cavity and a rear compartment disposed adjacent to and behind the internal cavity, wherein the second partition has a bore in which a check valve as the air sealing means is secured, and an air exhausting aperture is formed through a cylindrical wall defining the rear compartment.

5. The suction-type blood sampler as defined in claim 1, wherein the seal is an O-ring.