The Johns Hopkins University

Ronald D Watkins

Henry R Halperin

Ronald David Berger

Harikrishna Tandri

Leslie Tung

David George Hunter

Ehud J Schmidt

An embodiment in accordance with the present invention provides a catheter solution that would maintain MRI-compatible metallic braiding or metallic covering on a surface of the catheter, and that also prevents cables disposed in an interior lumen of the catheter from effectively propagating currents induced from external signal transmissions, which could cause a rise in temperature of the cables themselves and of tissues surrounding the catheter. The present invention uses metals which are non-ferromagnetic and not highly paramagnetic, so they do not cause large susceptibility artifacts in the MRI field. The construction of the braid prevents most of the RF fields from penetrating into the anterior of the catheter. Therefore, there is no need or a reduced need to add heat amelioration components to each electrical cable inside the catheter.

MRI radio-frequency heating amelioration for metallic braided catheters

A magnetic-resonance-imaging-compatible (MRI-compatible) cardiac defibrillator includes: a defibrillator generator; first and second electric wires, each being electrically connected to said defibrillator generator; first and second defibrillation pads, each being electrically connected to a respective one of said first and second electric wires; and a low pass filter electrically connected between said defibrillator generator and said first and second electric wires to prevent a noise in an MRI image caused by a radiofrequency interference from the defibrillator as well as protect a patient and the defibrillator from MRI radiofrequency imaging signals, wherein said low pass filter has a cutoff frequency set such that differential mode noise at an MRI Larmor frequency is in an attenuated band while a system-test signal by said defibrillator generator is in a pass band of said low pass filter.

MRI-compatible cardiac defribrillator

MRI-compatible cardiac defibrillator

Growing community of inventors

Stanford, CA, United States of America

Ronald D Watkins