System for continuous withdrawal of blood
First Claim
1. A system for continuously withdrawing blood from a subject comprising, means having openings only at opposite ends thereof insertable at one end thereof into a vein of the subject for providing a nonthrombogenic passageway for blood being withdrawn from the subject, said passageway having its inner surfaces permanently coated with an anti-coagulent substance to preclude clotting of the blood being withdrawn through said means and thereby render the system nonthrombogenic in operation, means externally of the subject and connected to the other end of said nonthrombogenic passageway-providing means for collecting the withdrawn blood, and means engaging only an extra-corporal intermediate section of said nonthrombogenic passageway-providing means for controlling the continuous withdrawing of the blood slowly from the vein at a predetermined constant rate and for a predetermined extended period during which the insertable means is in the vein of the subject.
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Accused Products
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 disposable 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 The subject may then move about for a selected period when blood is being slowly withdrawn at a prescribed rate and collected in a container within a housing supporting the device.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 growth hormone or any substance whose concentration in blood fluctuates widely. In addition, a portable microdiffusion chamber is incorporated between the indwelling catheter and the extra corporal tubing and is electrically connected through a sensing probe to an associated portable sensory responsive device. This permits analyzation of the extracted blood to determine the in vivo concentration of circulating concentrations of the diffusable fraction of biological materials in the blood.
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Citations
10 Claims
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1. A system for continuously withdrawing blood from a subject comprising, means having openings only at opposite ends thereof insertable at one end thereof into a vein of the subject for providing a nonthrombogenic passageway for blood being withdrawn from the subject, said passageway having its inner surfaces permanently coated with an anti-coagulent substance to preclude clotting of the blood being withdrawn through said means and thereby render the system nonthrombogenic in operation, means externally of the subject and connected to the other end of said nonthrombogenic passageway-providing means for collecting the withdrawn blood, and means engaging only an extra-corporal intermediate section of said nonthrombogenic passageway-providing means for controlling the continuous withdrawing of the blood slowly from the vein at a predetermined constant rate and for a predetermined extended period during which the insertable means is in the vein of the subject.
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2. A system for continuously withdrawing blood as recited in claim 1 wherein the vein-insertable end of said passageway-providing means is a catheter of a predetermined gauge size.
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3. A system for continuously withdrawing blood as recited in claim 1, wherein said anti-coagulent substance is heparin bound to the inner surfaces of said passageway that come in contact with blood.
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4. A system for continuously withdrawing blood as recited in claim 1, wherein said withdrawing means includes a milking device having a rotating eccentric member which engages an external section of the passageway-providing means and continuously controls the rate of passage of blood through said passageway-providing means.
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5. A system for continuously withdrawing blood as recited in claim 1, wherein said controlling means controls the rate at which blood is withdrawn such that the rate is constant.
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6. A system for continuously withdrawing blood as recited in claim 1, wherein said controlling means controls the withdrawal of blood through the nonthrombogenic passageway-providing means for the predetermined extended period of up to at least twenty-four hours.
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7. A system for continuously withdrawing blood as recited in claim 1, wherein said system is sufficiently light in weight and compact in size and further comprises means for attaching the system entirely to the subject to permit portability of said system and freedom of mobility of the subject while the blood is being withdrawn.
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8. A system for continuously withdrawing blood as recited in claim 1, and additionally means having a rigid passageway with openings at opposite ends thereof and insertable into the vein of the subject with one open end located within the vein and the other open end located externally of the subject for providing a rigid guide to facilitate the insertion of the one end of the nonthrombogenic passageway-providing means into the vein.
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9. A system for continuously withdrawing blood as recited in claim 8, and additionally means for permitting withdrawal of the guide-providing means from the vein of the subject while the one end of the nonthrombogenic passageway-providing means remains within the vein to facilitate withdrawing of the blood.
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10. A system for continuously withdrawing blood as recited in claim 8, wherein the guide-providing means includes a needle having a passageway with openings at opposite ends thereof and being of sufficient diameter to permit free relative movement of the nonthrombogenic passageway-providing means therethrough.
Specification