Method and apparatus for determining a blood flow during a vascular access dysfunction corrective procedure

Abstract

A method and apparatus for determining an angioplasty induced blood flow changes, wherein the apparatus includes the catheter having a port for introducing a blood property change in a downstream sensor. The downstream sensor and the catheter are configured to space the sensor from an adjacent vessel wall so as to minimize effects of the vessel wall during sensing of the blood property change.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application is a continuation of U.S. application Ser. No. 09 / 241,455 filed Feb. 2, 1999, herein incorporated by reference.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] Not Applicable. REFERENCE TO A “SEQUENCE LISTING”[0003] Not applicable. BACKGROUND OF THE INVENTION [0004] The use of intravascular catheters for treatment of the body is well known in the field of medicine. The use of dilation or balloon catheters has become widespread in the treatment, for example, of restrictions within the coronary blood vessels, such as stenotic lesions. In balloon angioplasty, a catheter carrying a balloon at its distal end is guided through the blood vessel to a point adjacent the lesion. The placement of the balloon is aided by use of a fluoroscope and radiopaque elements. The size and type of the balloon is generally selected by the physician based on his knowledge of the size and type of lesion. The balloon ...

AI Technical Summary

Benefits of technology

[0012] The present invention provides a method and apparatus for the real time determination of access flow during procedures to correct vascular access dysfunction. In particular, the invention provides for the determination of flow by dilution measurement. By determining intra-procedural access flow, the effectiveness of the surgical revision can be promptly assessed and appropriate remedial action promptly taken. As a physician can immediately and accurately determine intervention effectiveness, the procedure may be “tuned” to provide optimal access flow.

[0017] In addition, the blood property sensor may be configured to minimize wall effects on the signal from the sensor. That is, the sensor and catheter are configured to maximize sensitivity to the relevant blood property and minimize effects from the local region of the vascular wall. Further, the system is configured to balance the need for a sufficient indicator volume to produce a high quality dilution curve having an acceptable signal-to-noise ratio against an overwhelming of the initial access flow by the introduced indicator. The present system also allows for minimizing the effect indicator introduction on the measured blood volume.

Problems solved by technology

Though balloon angioplasty is well known as a safe and effective method for treatment of the vascular disease described above, there are still problems that arise during the procedure.

For example, stenotic lesions often have a highly irregular cross-sectional configuration, and may vary greatly in their hardness, both of which make for difficulty in determining what size and composition of balloon to use, and how often to inflate it.

These complications further compound the problem of determining the efficacy of the procedure.

However, each of these procedures is relatively complex in that it involves significant external equipment.

Thus, the patient is exposed to all the complications of the procedure as well as increased hospital time.

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