US 12,329,981 B2
MRI-compatible cardiac defribrillator
Henry Halperin, Baltimore, MD (US); Ehud J. Schmidt, Boston, MA (US); Ronald D. Watkins, Stanford, CA (US); Harikrishna Tandri, Ellicott City, MD (US); David Hunter, Baltimore, MD (US); Leslie Tung, Columbia, MD (US); and Ronald D. Berger, Baltimore, MD (US)
Assigned to The Johns Hopkins University, Baltimore, MD (US)
Filed by The Johns Hopkins University, Baltimore, MD (US)
Filed on Nov. 15, 2021, as Appl. No. 17/526,254.
Application 17/526,254 is a continuation of application No. 16/467,373, granted, now 11,185,707, previously published as PCT/US2017/065441, filed on Dec. 8, 2017.
Claims priority of provisional application 62/432,079, filed on Dec. 9, 2016.
Prior Publication US 2022/0314010 A1, Oct. 6, 2022
Int. Cl. A61N 1/39 (2006.01); A61B 5/055 (2006.01); A61B 5/361 (2021.01)
CPC A61N 1/3904 (2017.08) [A61B 5/055 (2013.01); A61N 1/3925 (2013.01); A61B 5/361 (2021.01)] 20 Claims
OG exemplary drawing
 
1. A magnetic-resonance-imaging-compatible (MRI-compatible) cardiac defibrillator, comprising:
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;
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 generator as well as protect a patient and the defibrillator generator from MRI radiofrequency imaging signals; and
a plurality of radiofrequency (RF) traps tuned to an MRI Larmor frequency of an MRI scanner and placed on the first and second electric wires at regular increments to attenuate waves induced by a body-coil of the MRI scanner to prevent or reduce temperature rises in the first and second electric wires, the first and second defibrillation pads, or both,
wherein said low-pass filter has a cutoff frequency set such that differential mode noise at the 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,
wherein the low-pass filter passes frequencies below 22 MHz and has approximately 120 dB attenuation at 63.8 MHz.