Apparatus for continuously sampling plasma

• US 4,976,270 A
• Filed: 03/28/1989
• Issued: 12/11/1990
• Est. Priority Date: 03/28/1989
• Status: Expired due to Fees

• Current Assignee: Vanderbilt University
• Original Assignee: Vanderbilt University
• Inventors: Black, David L., Parl, Fritz F., Bradley, Charles A., Benge, Herman
• Primary Examiner(s): HINDENBURG, MAX F
• Application Number:
  US07/329,801
• Time in Patent Office: 623 Days
• Field of Search: 128/760, 604/4-6
• US Class Current: 600/573
• CPC Class Codes: A61B 5/15003 for venous or arterial blood
• CPC Class Codes: A61B 5/150229 Pumps for assisting the blood sampling
• 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 5/150992 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 5/155 Devices specially adapted for continuous or multiple sampling, e.g. at predetermined intervals devices loaded with multiple lancets simultaneously A61B5/15146

Abstract

A method and apparatus for continuously sampling plasma are disclosed. The method of the present invention comprises removing blood from the patient, separating a substantially small portion of plasma, and returning the blood to the patient. The removing, separating, and returning steps are performed continuously and simultaneously with each other. The apparatus of the present invention relates to a double-lumen cannula or venipuncture needle for the removal and returning of blood to the patient at the same site.

Claims

1. An apparatus for continuously sampling plasma in a closed system for a patient comprising:

means for removing a continuous flow of blood from a patient at a site on the patient and for returning removed blood to the patient at said site;

means for creating a blood flow path including pumping means and tubing means, said tubing means communicating between said means for removing and returning blood, and said pumping means; and

means for separating the plasma component from the removed blood in said blood flow path;

said removal and return means comprising a cannula body formed of flexible material having proximal and distal ends;

said body having on outflow lumen and inflow lumen extending from said proximal end to said distal end;

said body also having a rigid, one-piece removable core extending the length of and within both lumina from the proximal to distal ends and being looped at the proximal end, said core being utilized to insert said apparatus into a blood vessel.

2. An apparatus for continuously sampling plasma in a closed system from a patient comprising:

cannula means for removing a continuous flow of blood from a patient at a site on the patient and for returning removed blood to the patient at said site;

means for creating a blood flow path including pumping means and tubing means, said tubing means defining a closed loop leading from and returning to said cannula means, with said pumping means being located along said closed loop;

separating means for separating the plasma component from the removed blood in said blood flow path, said separating means comprising a filtering membrane wall portion of said tubing means having pores of a size sufficiently small to retain cellular blood components within said tubing means while allowing plasma to pass therethrough; and

collecting means comprising a chamber communicating with said tubing means through said filtering membrane wall portion and having a removable collecting member slidably received in said chamber for collecting and retaining a sample of plasma.

3. The apparatus of claim 2 in which said collecting member comprises a card for receiving said plasma, said card including a reagent strip containing a solid phase reagent for reaction with said plasma.

4. The apparatus of claim 2 in which said collecting member includes a concavity facing said filtering membrane wall portion for receiving and retaining a sample of said plasma.