Expandable intravenous catheter and method of using

A method of catheterizing a patient to permit increased fluid flow into the patient which comprises:

• providing a first catheter tube member including means to expand its diameter from a contracted insertion diameter to an expanded operational diameter to increase the capacity of the fluid which can flow therethrough, such means to expand the diameter of the first catheter tube member including providing the first catheter tube member with a sidewall which substantially overlaps itself in its contracted state and locking means on the sidewall of the first catheter tube member to maintain it in an expanded state;
• inserting the first catheter tube member at a contracted diameter into a patient's vein;
• inserting a second member into the first catheter tube member to cause the first catheter tube member to expand to its operational diameter;
• and
• providing fluid to the patient through the first catheter tube member.

An apparatus for inserting a catheter into a vein and expanding the catheter's fluid carrying capacity once inserted which comprises:

• a first catheter tube member including means to increase its cross-sectional diameter from a contracted insertion diameter to an expanded operational diameter;
• a second member adapted to insert into and expand the first catheter tube member, the second member having a cross-sectional diameter substantially greater than the insertion diameter of the first catheter tube member;
• the means to increase the cross-sectional diameter of the first catheter tube member comprising an elastic sidewall of the first catheter tube member which is capable of increasing substantially in diameter from a contracted state to an expanded operational state;
• wherein the first catheter tube member is inserted into the vein in its contracted state and the second member is then inserted into the first catheter tube member causing it to expand to its operational diameter;
• and
• wherein the first member is constructed from material which expands over its entire length when expanded at its proximal end, and the second member comprises a shortened tube of greater diameter than the contracted diameter of the first member, the insertion of the second member into the proximal end of the first member causing the first member to expand to its operational diameter along its entire length.