TITLE: Physics Applications: Interventional Medicine Using Magnetic Navigation Systems

SPEAKER: Dr. Randall Ledford ,

Complex navigational maneuvers have been constrained in interventional medical applications by the lack of a method of precise control of the invasive devices. A novel magnetic navigation system (MNS) that generates external magnetic fields to control the precise movement and location of a magnetized catheter has been developed. The MNS is composed of a system of biplanar fluoroscopy, computer control and two super conducting magnets. The first applications are applications in cardiology and neurology. Ablation of atrial fibrillation and other complex arrhythmias would greatly facilitated by more precise control of ablation catheters. It has been demonstrated that the MNS can establish stable endocardial contact, record intracardiac electrograms, and ablate endocaridal tissue. Biventricular pacing is an emerging technology for the treatment of refractory heart failure. Deployment of a pacing lead is frequently difficult and limited by the ability to navigate into specific branches of the cardiac sinus (CS). In neurology, navigation to the location of aneurysms is possible with great improvements in both control and speed. A magnetic, quick hardening embolic may be used to stabilize the aneurysm and prevent subsequent rupture. A key to the development of the MNS was the design of an accurate magnetic field simulator. Early superconducting magnet implementations are being replaced with two permanent magnetic nodes, each with 360 individual magnets. The composite field vector is generated by the MNS based on specific navigation coordinates via a graphical user interface overlaid on the biplanar fluoroscopic images. The simulator is capable of accurately predicting the magnetic field vector with less than 1 percent error. Human clinical procedures have been successfully completed and the MNS has received FDA approvals. The first MNS systems are planned for installation later this year in Mayo, Johns Hopkins, Barnes Jewish and other hospitals.

Note: Dr. Ledford received his B.S. in Physics from WFU and PhD from Duke University. The seminar will be an equation-less session with animation and video. As such, it will be understandable (hopefully) and enjoyable (with a little luck) by faculty, graduate students and undergraduates alike. It would also be of interest to those in the medical school in neurology and cardiology.