Blood transfer assembly

• US 4,765,344 A
• Filed: 10/06/1986
• Issued: 08/23/1988
• Est. Priority Date: 04/06/1984
• Status: Expired due to Term

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Boehringer Mannheim Corporation (Roche Holding AG)
• Inventors: Lape, Larry J.
• Primary Examiner(s): Richman, Barry S.
• Assistant Examiner(s): WARDEN, JILL ALICE
• Application Number:
  US06/915,977
• Time in Patent Office: 687 Days
• Field of Search: 215/100.5, 222/566, 222/571, 222/572, 222/575, 222/420, 128/770, 128/771, 422/68, 422/73, 422/56, 422/100, 422/99, 436/63, 436/69, 436/180, 356/39
• US Class Current: 600/583
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/150022 for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/150068 by tissue compression, e.g. with specially designed surface of device contacting the skin area to be pierced
• CPC Class Codes: A61B 5/150183 Depth adjustment mechanism using end caps mounted at the distal end of the sampling device, i.e. the end-caps are adjustably positioned relative to the piercing device housing for example by rotating or screwing
• CPC Class Codes: A61B 5/150305 Packages specially adapted for piercing devices or blood sampling devices kits for diabetes A61M5/003; packaging in general B65D
• CPC Class Codes: A61B 5/150343 Collection vessels for collecting blood samples from the skin surface, e.g. test tubes, cuvettes sampling from within body cavities A61B5/150015, A61B5/150045
• CPC Class Codes: A61B 5/150358 Strips for collecting blood, e.g. absorbent optical reagent test strips G01N21/8483; chemical reagent test strips G01N33/4875, G01N33/52
• 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 5/150755 Blood sample preparation for further analysis, e.g. by separating blood components or by mixing
• CPC Class Codes: A61B 5/150809 by audible feedback
• CPC Class Codes: A61B 5/15105 Purely manual piercing, i.e. the user pierces the skin without the assistance of any driving means or driving devices
• CPC Class Codes: A61B 5/15186 Devices loaded with a single lancet, i.e. a single lancet with or without a casing is loaded into a reusable drive device and then discarded after use; drive devices reloadable for multiple use
• CPC Class Codes: A61B 5/157 Devices characterised by integrated means for measuring characteristics of blood
• CPC Class Codes: A61B 5/7405 using sound
• CPC Class Codes: G01N 2021/478 Application in testing analytical test strips
• CPC Class Codes: G01N 21/4738 Diffuse reflection precedence is given to G01N21/55 - G01N21/57 if specular component is taken into consideration, e.g. also for testing fluids, fibrous materials

Abstract

An apparatus for forming a blood droplet of a controlled, generally uniform size from a finger which has been pricked to draw blood includes a "funnel" member providing an upper edge across which the finger is drawn to deposit blood on a surface down which the blood flows under the influence of gravity to a lower edge terminating at a point. The blood flows toward the point, forms into the droplet at the point, and, owing to gravity and the surface tension of the blood, forms into the substantially uniformly sized droplet which falls onto a test strip positioned beneath the point.

Claims

1. Apparatus for forming a blood droplet of a controlled, generally uniform size from a finger which has been pricked to draw blood and for positioning said droplet for analysis of a medically significant component thereof, the apparatus comprising means providing a first surface across which blood may flow under the influence of gravity, the first surface including a first vertically lower edge terminating at a point, the first surface including a second vertically upper edge across which a finger may be drawn to deposit blood on the first surface and means providing a second surface onto which a droplet of blood may be deposited, the second surface disposed beneath the point to receive the droplet after it is formed, said droplet being formed from the blood as it flows across the first surface toward the point, and, owing to gravity and the surface tension of the blood, develops at the point into the substantially uniformly sized droplet which falls into position on the second surface, the second surface comprising a reagent for reacting with a medically significant component of the blood to produce a visual indication of the concentration of the component in the blood.

2. The apparatus of claim 1 wherein the reagent is carried on a test strip and the means providing the second surface includes means providing a holder for holding the test strip.

3. The apparatus of claim 1 wherein the reagent is provided on a reagent carrier.

4. The apparatus of claim 3 wherein the reagent carrier is in the form of a reagent-bearing test strip and the means for providing the second surface comprises a means for holding the test strip in a fixed position beneath the point to form the second surface.

5. The apparatus of claim 4 further comprising a third upwardly concave surface with a curved contour corresponding generally to the cross section of a finger, the third surface intersecting with the first surface to define the second vertically upper edge of the first surface.

6. The apparatus of claim 5 wherein the means for providing the second surface comprises a base provided with a photoemitter and a photodetector positioned on said base so that a blood droplet falling from the point onto the second surface will interrupt a beam of light from the photoemitter to the photodetector and thereby provide a signal that droplet formation and positioning are complete.

7. A blood transfer apparatus comprising

a base for supporting indicator means for carrying a reagent for reacting with a medically significant component in blood to produce a visual indication on the indicator means of the concentration of the component in the blood, and

funnel means for forming a blood droplet from a pricked finger, the funnel means including a transfer surface having an upper edge across which an incision in the pricked finger may be drawn to draw blood from the pricked finger and a lower edge terminating at a point so that drawn blood flowing across the transfer surface forms into a uniformly sized droplet at the point owing to gravity and surface tension of the blood, the funnel means having a use position in which the point overlies the indicator means so the blood droplet falling under the influence of gravity from the point is deposited onto the indicator means.

8. The blood transfer apparatus of claim 7 wherein the indicator means comprises a test strip and the funnel means further includes a projection for engaging the test strip to hold the test strip on the base in a blood droplet-receiving position underneath the point on the transfer surface when the funnel means is in its use position.

9. The blood transfer apparatus of claim 7 wherein the funnel means further includes an upper concave surface with a curved contour corresponding generally to the exterior shape of a portion of a finger, and the upper concave surface and the transfer surface intersect to define said upper edge.

10. The blood transfer apparatus of claim 7 wherein the base includes a photoemitter and a photodetector situated in spaced-apart relation for detecting a blood droplet falling from the point onto the indicator means so that such falling blood droplet interrupts a beam of light from the photoemitter to the photodetector and thereby provides a signal that droplet formation and deposit is complete.