Integral catheter and blood tester

• US 5,368,029 A
• Filed: 04/16/1992
• Issued: 11/29/1994
• Est. Priority Date: 04/16/1992
• Status: Expired due to Fees

• Current Assignee: Brent W. Poole, David A. Holcombe
• Original Assignee: Brent W. Poole, David A. Holcombe
• Inventors: Poole, Brent W., Holcombe, David A.
• Primary Examiner(s): Cohen, Lee S.
• Assistant Examiner(s): Parker, Marianne
• Application Number:
  US07/869,452
• Time in Patent Office: 957 Days
• Field of Search: 128/632, 128/636, 128/637, 128/917, 604/169, 604/192
• US Class Current: 600/368
• CPC Class Codes: A61B 2562/0295 Strip shaped analyte sensors for apparatus classified in A61B5/145 or A61B5/157
• CPC Class Codes: A61B 5/14503 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors A61B5/1459, A61B5/1464, A61B5/1473, A61B5/1482, A61B5/14865 take precedence
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/15003 for venous or arterial blood
• CPC Class Codes: A61B 5/150221 Valves
• CPC Class Codes: A61B 5/150259 Improved gripping, e.g. with high friction pattern or projections on the housing surface or an ergonometric shape
• CPC Class Codes: A61B 5/150389 Hollow piercing elements, e.g. canulas, needles, for piercing the skin
• CPC Class Codes: A61B 5/150519 Details of construction of hub, i.e. element used to attach the single-ended needle to a piercing device or sampling device
• CPC Class Codes: A61B 5/150992 Blood sampling from a fluid line external to a patient, such as a catheter line, combined with an infusion line; blood sampling from indwelling needle sets, e.g. sealable ports, luer couplings, valves tubing connectors and couplings A61M39/00
• CPC Class Codes: A61B 5/1535 comprising means for indicating vein or arterial entry A61B5/1545 takes precedence
• CPC Class Codes: A61B 5/157 Devices characterised by integrated means for measuring characteristics of blood
• CPC Class Codes: A61B 5/6848 Needles
• CPC Class Codes: Y10S 128/917 Body fluid, devices for protection therefrom, e.g. aids, hepatitus

Abstract

An integral catheter and blood tester includes a needle unit which is receivable within a conventional catheter intravenous tube and housing. The catheter supports a piercing needle and interior chamber. A transparent tester housing is coupled to the needle unit and supports a test strip and test patch which extends into the flash chamber of the catheter needle. A constricting valve surrounds the test strip to maintain closure of the flash chamber. Once the catheter and needle have been inserted into the desired blood vessel, a quantity of blood is introduced into the flash chamber so as to wet the test patch. The test patch may, for example, include conventional litmus material used to test the pH of the test sample. Once the flash process is complete, the needle and tester housing are withdrawn from the catheter to permit conventional intravenous coupling to the catheter. Thereafter, the tester housing is separable from the needle unit to permit discarding of the needle unit. The separation process causes the test strip to be wiped substantially clean of excess blood by the constricting valve. The tester housing provides a protective clear shield about the contaminated test patch which facilitates visual examination thereof while precluding inadvertent contact with the blood contaminated test patch.

Claims

1. For use in testing a blood sample, an integral catheter and blood tester comprising:

a catheter having a hollow tube;

a needle unit having a needle unit housing partially removably received within said catheter, said needle unit housing defining an interior chamber and having a needle extending from said chamber terminating in a piercing end and removably received within said hollow tube;

a blood tester having a blood tester housing removably couple to said needle unit, and said blood tester further comprising a test strip supported by said blood tester housing and supporting a test patch having a test surface, said test patch extending into said interior chamber when said blood tester housing is coupled to said needle unit;

valve means supported by said needle unit for receiving said test strip and for wiping blood from said test surface when said blood tester housing and said needle unit are separated; and

shield means, supported by said blood tester housing, for shielding and partially surrounding said test strip and test patch.

2. An integral catheter and blood tester as set forth in claim 1 wherein said needle unit includes an extending portion having a flash chamber therein communicating with said needle and supporting said valve means.

3. An integral catheter and blood tester as set forth in claim 2 wherein said blood tester housing includes an interior cavity for receiving said extending portion of said needle unit.

4. An integral catheter and blood tester as set forth in claim 3 wherein said test strip and test patch are supported within said interior cavity.

5. An integral catheter and blood tester as set forth in claim 4 wherein said valve means defining a resilient member having a closing orifice therein and wherein said test patch and test strip pass through said orifice when said needle unit and said blood tester housing are coupled.

6. An integral catheter and blood tester as set forth in claim 1 wherein said shield means include a transparent wall formed in said blood tester housing forming a transparent wall about said test patch and test strip.

7. An integral catheter and blood tester as set forth in claim 1 wherein said shield means include a transparent sleeve slidably supported upon said blood tester housing slidable between a retracted position and an extended position in which said sleeve extends beyond said test patch.

8. An integral catheter and blood tester as set forth in claim 7 wherein said shield means further includes spring means for urging said sleeve toward said extended position.

9. An integral catheter and blood tester as set forth in claim 1 wherein said blood tester housing defines a bore passage and wherein said blood tester includes a rod slidable within said bore passage, said rod having a first end extending into blood tester housing and supporting said test strip and said test patch and a second end extending outwardly from said housing terminating in a grip portion.

10. An integral catheter and blood tester as set forth in claim 9 wherein said rod is movable between a first position extending said test patch into said interior chamber and a second position in which said test patch is withdrawn into said blood tester housing.

11. For use by a user in testing a blood sample, a method of blood testing comprising the steps of:

inserting a removable needle and an intravenous tube of a combination catheter and blood tester having an interior flash chamber and a test patch supported within said interior flash chamber into a blood vessel;

flashing a quantity of blood into said flash chamber to wet said test patch;

withdrawing said catheter needle and said blood tester from said intravenous tube;

separating said catheter needle from said blood tester and said test patch;

wiping excess blood from said wetted test patch during said separating step;

shielding said test patch from inadvertent contact with the user following separation; and

visually observing said wiped test patch to evaluate said blood.

12. A blood tester for use in combination with a catheter, said blood tester comprising:

a blood tester housing defining an interior chamber and means formed in said blood tester housing for coupling said blood tester housing to the catheter;

a test strip having a test patch supported upon said test strip;

support means for supporting said test strip within said interior chamber and for exposing said test patch to said interior chamber and withdrawing it from said interior chamber; and

wiping means for wiping said test patch when it is withdrawn from said interior chamber.

13. A blood tester as set forth in claim 12 wherein said blood tester housing defines a generally cylindrical passage and wherein said support means includes a piston movable within said generally cylindrical passage.

14. A blood tester as set forth in claim 13 wherein said piston includes an elongated rod extending toward said interior chamber and wherein said elongated rod supports said test strip so as to extend said test patch into said interior chamber when said piston is moved toward said interior chamber.

15. A blood tester as set forth in claim 14 wherein said piston defines a generally circular disk and wherein said test strip extends generally perpendicularly therefrom.

16. A blood tester as set forth in claim 15 wherein said support means includes a piston seal coupled to said piston.

17. A blood tester as set forth in claim 16 wherein said wiping means includes an absorbent member supported within said generally cylindrical passage interposed between said piston and said interior chamber and defining an aperture, said piston movable to extend said test strip through said aperture and to withdraw said test strip therefrom.