System for continuous withdrawal and analysis of blood

• US 4,008,717 A
• Filed: 03/05/1976
• Issued: 02/22/1977
• Est. Priority Date: 01/15/1973
• Status: Expired due to Term

• Current Assignee: Johns Hopkins University
• Original Assignee: Johns Hopkins University
• Inventors: Kowarski, Allen A.
• Primary Examiner(s): Medbery, Aldrich F.
• Application Number:
  US05/664,178
• Time in Patent Office: 354 Days
• Field of Search: 128/214 R, 128/214 B, 128/278, 128/334 R, 128/2 F, 128/348
• US Class Current: 600/364
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• 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 5/150267 Modular design or construction, i.e. subunits are assembled separately before being joined together or the device comprises interchangeable or detachable modules
• CPC Class Codes: A61B 5/150366 Blood collection bags, e.g. connected to the patient by a catheter comprising means for removing a small sample of collected blood from the bag collection bags as such A61J1/05, A61M1/0209
• 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 5/150755 Blood sample preparation for further analysis, e.g. by separating blood components or by mixing
• CPC Class Codes: A61B 5/150946 Means for varying, regulating, indicating or limiting the speed or time of blood collection
• 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
• CPC Class Codes: A61B 5/157 Devices characterised by integrated means for measuring characteristics of blood
• CPC Class Codes: A61L 29/085 Macromolecular materials
• CPC Class Codes: A61L 33/0011 Anticoagulant, e.g. heparin, platelet aggregation inhibitor, fibrinolytic agent, other than enzymes, attached to the substrate
• CPC Class Codes: A61M 25/0111 Aseptic insertion devices
• CPC Class Codes: C08L 5/10 Heparin; Derivatives thereof
• CPC Class Codes: Y10S 128/01 Motorized syringe

Abstract

A small, portable, constant withdrawal device is connected to tubing, including a catheter, whose internal walls are coated with heparin. The catheter is inserted intravenously through a disposal needle into a subject such as a human being. The subject may then move about for a selected period when blood is being slowly withdrawn at a prescribed rate and collected in a container within a housing supporting the device. The collected blood may then be analyzed to permit the measurement of the integrated concentration of glucose, growth hormone or other material in blood. In addition, a portable microdiffusion chamber is incorporated between the indwelling catheter and the extra corporal tubing and is electrically connected through a sensor probe to an associated sensory responsive device. This permits continuous analysis of the withdrawn blood to determine the in vivo concentration of circulating concentrations of materials in the blood.

Claims

1. A system for continuously withdrawing blood from a subject and determining in vivo concentration of biological materials in the blood, comprising,

means insertable into a vein of a subject for providing a passageway for blood being withdrawn from the subject,

means engaging only an extra-corporal section of said passageway-providing means for controlling the withdrawing of the blood slowly from the vein at a predetermined constant rate and for a predetermined extended period,

means connected to an extra-corporal section of said passageway-providing means for causing diffusion of a diffusible substance of the blood into an amount of diluent, and

means for detecting and measuring the concentration of said diffused substance whereby said means responds by the generation of electrical energy in relation to the concentration of the diffused substance, and

wherein all blood engaging portions of the system are non-thrombogenic.

2. A system as recited in claim 1, wherein all blood engaging portions of the system are rendered non-thrombogenic by treatment thereof with heparin.

3. A system as recited in claim 1 wherein said diffusion means includes a first chamber means connected in line with said passageway-providing means for permitting the withdrawn blood to pass therethrough, a second chamber means positioned adjacent to said first chamber means, and containing an amount of diluent, each of said first and second chamber means having an open wall, a membrane separating said open walls of said chamber which permits the diffusion of a diffusible substance of the blood into the diluent.

4. A system as recited in claim 3 wherein said detecting and measuring means includes a probe mounted within said second chamber means which responds by the generation of electrical energy in relation to the concentration of a diffused substance, and a recording device electrically connected to said probe for recording the detected and measured energy.

5. A system as recited in claim 1 wherein said system additionally includes a mixing chamber disposed intermediately on said passageway -- providing means and adapted to receive blood therefrom, means for feeding diluent into said mixing chamber at a predetermined rate, mixing means located in said mixing chamber for mixing said diluent and said blood together, and wherein all blood engaging portions of the system are non-thrombogenic.

6. A system as recited in claim 5 wherein said means for detecting and measuring the concentration of diffused substance is disposed in a sensing chamber located at a position remote from, but operatively connected to, said mixing chamber.

7. A system as recited in claim 6 wherein said detecting and measuring means includes a probe mounted within said sensing chamber.

8. A system as recited in claim 7 wherein said probe has a tip and wherein a membrane is disposed over said tip to form a cavity defined by said probe tip and said membrane.

9. A system as recited in claim 8 wherein said cavity contains a diluent.

10. A system as recited in claim 9 wherein said means for feeding diluent into said mixing chamber at a predetermined rate comprises a milking device in operative association with a diluent reservoir.

11. A system as recited in claim 10 wherein said mixing means located in said mixing chamber includes a magnetic stirring bar driven by a magnetic stirrer located outside said mixing chamber and magnetically coupled to said magnetic stirring bar.

12. A system as recited in claim 11 wherein all blood engaging portions of said system are non-thrombogenic, being rendered non-thrombogenic by treatment thereof with heparin.

13. A system as recited in claim 1 wherein said system additionally includes a mixing chamber disposed intermediately on said passageway -- providing means and adapted to receive blood therefrom, means for feeding diluent into said mixing chamber at a predetermined rate, mixing means located in said mixing chamber for mixing said diluent and said blood together, and wherein said diluent contains a non-thrombogenic material.

14. A system as recited in claim 13 wherein said non-thrombogenic material is heparin.