What is Cardiac Catheterization?

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Cardiac catheterization is most commonly used to collect blood samples from the heart, to measure pressure and blood flow in the heart’s chambers and in the large arteries around the heart, to measure the oxygen content in different parts of the heart, to examine the arteries of the heart and to perform a biopsy on the heart muscle. The procedure is used on patients to diagnose or evaluate cardiac amyloidosis, cardiomyopathy, coronary artery disease, congenital heart defects, pulmonary hypertension and problems with the heart valves.
Cardiac Catheters that are commercially available contain metal wire braiding technology that adjusts their mechanical properties to favor safer, easier and more efficient operations of the catheters. However, these catheters are not meant to be anywhere near a strong magnetic field which is encountered in MRI machines. Thus, making it difficult for doctors to image the position of the catheter while using it on a patient. Current fluoroscopically guided ablation catheters have a poor soft-tissue contrast and the process of using them exposes the patient and the surgical team to a high dose of X-ray radiation. When these ferromagnetic catheters are introduced in an MRI system, they disrupt the images as well as extensively increase in temperature. An MRI compatible catheter is needed to avoid these problems without compromising the required mechanical properties.
The MR catheter in focus employs a Copper-Nitinol braided polymer tube as the deflectable tip and a Nylon braided tube as the shaft. Carbon-fiber control rods are used to provide additional performance enhancements. The catheter is steered with a knob which is attached to a steering piston at the catheter handle. ...

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...wire, a Copper-Nitinol braided polymer tube is used instead of stainless steel which is the material used for many non-MRI compatible catheters. An only Nitinol braided tip does not qualify for being strong and rigid enough, although it does not affect the temperature of the Catheter in a magnetic field nor does it distort the images produced by an MRI machine, which is why copper was used with it. Parts of the tip was made of small bands of Nitinol, to provide it for a kink-free tip. Both, braided tubing and the integrated carbon fiber control rod contribute to the shaft’s flexural and axial rigidity.
The mechanical properties of the non-ferromagnetic materials of the cardiac catheter (strength and heat conductivity) and their electrical properties (non-ferromagnetic conductance) contribute towards being important technical aspects of it. However, it is

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