Resmed masks with magnets and coronary stents

[stillaliveca]

I have been using the Resmed Airtouch F20 facemask for some time and I am comfortable with it. it does use magnets.

I have 4 coronary artery stents made largely of chromium.

I received a notice that Resmed is advising users of masks with magnets to discontinue their use if they have any of a long list of medical implants/devices and they do include stents in that list.

I would like to hear from others who have received the same notice and who have coronary artery stents.

[dmemanski]

I just got a pacemaker, and I found out that there is now a non magnetic version of the Airfit F20, called the Airfit F20 NM. Yay!

[G. Szabo]

I received a notice that Resmed is advising users of masks with magnets to discontinue their use if they have any of a long list of medical implants/devices and they do include stents in that list.

Quantitative determination of magnetic force on a coronary stent in MRI

Nina Lopič 1, Andreja Jelen, Stanislav Vrtnik, Zvonko Jagličić, Magdalena Wencka, Radovan Starc, Aleš Blinc, Janez Dolinšek
Affiliations expand

• PMID: 23125054
   
  
• DOI: 10.1002/jmri.23831
  

Abstract
Purpose: To introduce an analytical method for a quantitative determination of magnetic force on a coronary stent in the magnetic resonance imaging (MRI) magnet that is generally applicable to metallic implants. Magnetic forces on metallic implants in the MRI magnets are traditionally determined empirically by measuring deflection from the vertical plane at the central axis of the magnet and at the point of the largest force along the longitudinal axis of the magnet.
Materials and methods: Magnetic and chemical characterization of the stents was performed by a commercial magnetometer and energy-dispersive X-ray spectroscopy. Magnetic force on the stents fabricated of paramagnetic alloys (surgical stainless steel and cobalt-chromium) was determined by measuring the stent's magnetic dipole moment and employing the on-axis magnetic field profile of an MRI magnet.
Results: The maximum force on the stainless steel stent was found to be F(S,max) = 0.18 mN, whereas on the cobalt-chromium stent it was F(C,max) = 0.06 mN.
Conclusion: The magnetic force on the investigated paramagnetic stents is even smaller than the gravitational force acting on the stents in the Earth's gravity field, so that it has no physiological impact on the stented vessels.

Comment of G.Szabo:
The magnetic field strength of MRI is orders of magnitudes higher than the magnets on your mask. 

[slowe]

MRIs induce a huge magnetic field compared with the dinky magnets used in these masks (google mri metal videos) and the MRI is considered medically safe for stents implanted in recent years. The heart moves to perform its function and so do any implanted stents. Any deflection due to the mask magnets is insignificant compared to the forces experienced every heartbeat. The warnings for stents are just lawyer mumbo jumbo. Implanted cardiac devices (pacemakers, implanted cardiac defribillators, etc) are a different beast and can be impacted by small magnetic fields. These latter devices warrant the cautions published by the makers of the magnetic masks. All IMHO with 30 yrs of medical knowledge.

[Rodgui]

Hi, I am inclined to think this is backside covering by Resmed, in case of future legal cases against the company. I have one stent and a pacemaker fitted and took up the matter with the doctor who fitted the pacemaker. He assured me there was no worries regarding magnetism to the pacemaker caused by the magnetic buttons on my mask. If you have any doubts, by all means change to the updated mask, which I think is not available here in Australia yet.