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Subatmospheric method and apparatus for expanding blood vessels to facilitate puncture with a cannula

  • US 4,664,651 A
  • Filed: 03/01/1985
  • Issued: 05/12/1987
  • Est. Priority Date: 03/01/1985
  • Status: Expired due to Term
First Claim
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1. A method for distending the blood vessels comprising the veins and the arteries in an isolated portion of a patient'"'"'s body remote from the patient'"'"'s heart and thereafter puncturing one or more of said vessels with a cannula, said method comprising the steps of:

  • (a) placing said isolated portion of the patient'"'"'s body within a chamber capable of supporting at least a partial vacuum;

    (b) forming a substantially airtight seal between said chamber and said isolated portion of the patient'"'"'s body;

    (c) restricting the venous blood flow from said isolated portion of the patient'"'"'s body by circumferentially constricting the patient'"'"'s body at a point approximately coinciding with the point at which said substantially airtight seal is formed between said vacuum chamber and said isolated portion of the patient'"'"'s body until said venous blood flow from said isolated portion of the patient'"'"'s body substantially ceases;

    (d) subjecting said isolated portion of the patient'"'"'s body to a partial vacuum within said chamber for a period of time sufficient for the patient'"'"'s systolic arterial blood pressure to engorge the blood vessels contained within said isolated portion of the patient'"'"'s body with blood, to substantially equalize the pressure of the blood in the veins and the arteries and to substantially distend said blood vessels;

    (e) gradually increasing said constriction of the patient'"'"'s body until the arterial blood flow to said isolated portion of the patient'"'"'s body substantially ceases;

    (f) venting said chamber to atmosphere and thereafter removing said chamber from said isolated portion of the patient'"'"'s body while circumferentially constricting said isolated portion of the patient'"'"'s body to a degree sufficient to substantially prevent the flow of blood to and from said isolated portion of the patient'"'"'s body, whereby the blood vessels in said isolated portion of the patient'"'"'s body are in an engorged, highly visible and highly distended condition; and

    (g) inserting a cannula into one of said engorged, highly visible and highly distended blood vessels in said isolated portion of the patient'"'"'s body and thereafter releasing said circumferential constriction of the patient'"'"'s body to restore normal blood circulation to and from said isolated portion of the patient'"'"'s body.

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