Electromagnetic radiation transparent device and method of making thereof

Abstract

A medical device includes a pattern of electrically conductive material. The pattern of electrically conductive material has an anti-antenna geometrical shape such that the anti-antenna geometrical shape substantially prevents the medical device from creating an imaging artifact and / or substantially allows imaging of a volume within the medical device. The pattern may be formed by multiple “figure-8” shaped electrical conductors, multiple “figure-8” emulating electrical conductors, multiple sine-wave-like shaped electrical conductors, multiple zig-zag patterned electrical conductors, by multiple electrical conductors, each having sequential conductive loops, and / or a single conductor weaved into a loop mesh. The electrically conductive material may be titanium, tantalum, nitinol, stainless steel, and / or NbZr.

Description

PRIORITY INFORMATION [0001] This application claims priority from U.S. Provisional Patent Application, Ser. No. 60 / 497,591, filed on Aug. 25, 2003. The entire content of U.S. Provisional Patent Application, Ser. No. 60 / 497,591 is hereby incorporated by reference.FIELD OF THE PRESENT INVENTION [0002] The present invention is directed to stent designs, deployment devices for stents, and the fabrications thereof. More particularly, the present invention is directed to stents which produce little or no magnetic resonance image artifacts and the fabrications thereof. BACKGROUND OF THE PRESENT INVENTION [0003] The use of stents as a medical corrective and preventive device is well known. [0004] For example, U.S. Pat. No. 5,133,732 discloses that a stent can be implanted into a body vessel. The stent is a cylindrical body formed by a coiled generally continuous wire with a deformable zig-zag structure. The stent is further provided with means for preventing the stent body from stretching a...

AI Technical Summary

Benefits of technology

[0019] One aspect of the present invention is a medical stent. The medical stent includes a pattern of electrically conductive material. The pattern of electrically conductive material has an anti-antenna geometrical shape such that the anti-antenna geometrical shape substantially prevents the medical stent from creating an imaging artifact.

[0020] Another aspect of the present invention is a medical stent. The medical stent includes a pattern of electrically conductive material. The pattern of electrically conductive material has an anti-antenna geometrical shape such that the anti-antenna geometrical shape substantially allows imaging of a volume within the stent.

[0021] Another aspect of the present invention is a medical stent. The medical stent includes a pattern of electrically conductive material. The pattern of electrically conductive material has an anti-antenna geometrical shape such that the anti-antenna geometrical shape substantially prevents the medical stent from creating an imaging artifact and substantially allows imaging of a volume within the stent.

Problems solved by technology

When the field is not uniform, image distortions called “image artifacts” result.

Additionally, if the gradient fields deviate significantly from their ideal linear character over the imaging volume, image artifacts develop.

Medical devices which are placed into a patient's body can cause the magnetic fields of the MRI system to deviate from their preferred characteristics for clear imaging.

If a medical device comprises metallic components (such as iron), image artifacts result due to the metal's magnetic susceptibility properties distorting the MRI system applied magnetic fields.

Additionally, if the medical device comprises conductive components, eddy currents develop in these conductive components when the MRI system's oscillating magnetic fields are applied.

Due to the image artifact problems, described above, inherent in metallic, conductive stents, it is not possible to obtain clear MR images of the interior volume of the stents.

However, the handmade prototypes lacked a radial force comparable to standard stainless steel stents.

The power deposited into the patient body, measured as the Specific Absorption Rate (SAR) can be harmful to the patient undergoing an MRI if set too high.

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