Diameter expansion cannula
First Claim
1. An apparatus for expanding the diameter of a blood vessel of a patient comprising:
- a cannula for passing fluid into and out of a blood vessel of a patient, said cannula having a proximal end and a distal end defining a predetermined length and diameter, formed of a braided construction which allows the length of said cannula to become longer and the diameter of said cannula to become narrower when tension is applied along the longitudinal axis of said cannula;
means disposed adjacent said distal end of said cannula for puncturing the blood vessel of a patient to permit insertion of said cannula into said blood vessel;
a removable sheath disposed over said cannula when tension is applied thereto such that the length of said cannula is longer and the diameter is narrower, whereby said sheath maintains the tensioned length and diameter of said cannula during insertion into the patient, whereby said cannula body is allowed to return to its predetermined length and diameter upon removal of said sheath from said cannula.
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Accused Products
Abstract
The present invention is a diameter expansion cannula apparatus which is used to establish fluid flow to a healthy blood vessel or to a diseased blood vessel. The cannula apparatus has a cannula which is coated with silicone and is formed of a braided construction which provides the cannula with an inherent resilience, yet allows the length of the cannula to become longer and the diameter of the cannula to become narrower when tension is applied along the longitudinal axis of the cannula. A peelable sheath is used to maintain the cannula in its elongated narrow state during insertion into a blood vessel. Removal of the sheath allows the cannula to return to its pre-tensioned diameter, thereby providing a radial force upon any obstruction within the blood vessel. The cannula apparatus is a self-contained unit which includes a sharpened point on the end of a balloon catheter to puncture the blood vessel of a patient and to assist the cannula in returning to its pre-tensioned diameter if any obstruction within the blood vessel prevents the cannula from returning to its pre-tensioned diameter.
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Citations
16 Claims
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1. An apparatus for expanding the diameter of a blood vessel of a patient comprising:
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a cannula for passing fluid into and out of a blood vessel of a patient, said cannula having a proximal end and a distal end defining a predetermined length and diameter, formed of a braided construction which allows the length of said cannula to become longer and the diameter of said cannula to become narrower when tension is applied along the longitudinal axis of said cannula; means disposed adjacent said distal end of said cannula for puncturing the blood vessel of a patient to permit insertion of said cannula into said blood vessel; a removable sheath disposed over said cannula when tension is applied thereto such that the length of said cannula is longer and the diameter is narrower, whereby said sheath maintains the tensioned length and diameter of said cannula during insertion into the patient, whereby said cannula body is allowed to return to its predetermined length and diameter upon removal of said sheath from said cannula. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of cannulating a blood vessel of a patient comprising:
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causing a cannula to be tensioned along its longitudinal axis into a narrow state; disposing a sheath around said tensioned cannula to maintain said narrow state; puncturing the blood vessel and simultaneously inserting said cannula into said patient through said skin puncture; removing said sheath from said cannula thereby allowing said cannula to expand back to a pre-tensioned state; and passing fluid through said cannula. - View Dependent Claims (14, 15, 16)
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Specification