The overall high rate of successful cardiac catheterizations for diagnosis or angioplasty has been offset by the significant number of failures in these often crucial procedures. A common difficulty stems from the inability to precisely direct movements of the percutaneously introduced catheter tip by manual manipulation. Venous catheters must be manipulated through the pulmonary valve while arterial catheters and wires must be threaded around a sharp bend into the chosen branch of the coronary vessel and past an atheromatous obstruction. It is proposed to use the forces resulting from placement of magnetic or magnetizable materials in a spatially varying, externally controlled magnetic field to aid in positioning the catheter tip. The susceptible volume of the catheter, magnetized by the external control field, experiences a force due to the magnetic flux density gradient. With a suitable field configuration, an effective controller, and the use of the fluoroscopically obtained visual feedback normally utilized in the standard catheterization technique, the physician can apply precisely directed increments of force. In Phase I, various magnetic configurations and control approaches will be evaluated both in simulations and in a scaled, laboratory pre-prototype. The result will be a design for a practical magnetic guiding system which is compatible with existing catheterization laboratory equipment and techniques. In Phase II, a laboratory prototype will be fabricated and tested.
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