ResMed F20 mask magnets & pacemakers

[WLKSRQ]

I have an implanted pacemaker/ defibrillator and, as such, need to be careful of coming into close proximity of certain magnetic fields. I'm otherwise interested in trying the new ResMed F20 mask but I'm hesitant because of its magnetic clips. I've checked the F20 manual and they suggest keeping at least a 2 inch separation between device and magnet. Being an active sleeper I can envision myself violating this standard. So my question is this: Is Resmed's suggestion overly conservative or is there reason for me to stay clear of the F20? Thanks in advance.

[PaulaO2]

Where are the clips? On the mask frame? I cannot see how you could get your face within 2" of your chest without hurting yourself.

Go to your local supplier and ask to see the mask and tell them your concerns. Try it out there.

[WLKSRQ]

The magnets are on the mask frame. If I c**k my head towards my left (heart side), which I can picture myself doing occasionally while sleeping, I estimate the distance from pacemaker to magnet could be as little as 3-4 inches. Compounding this concern are some electromagnetic entities suggesting a minimum distance of 6 inches (the pacemaker is positioned just below the collarbone). Again, I'm wondering if these are ultra-conservative recommendations. Beyond any insights from this and other apnea forums, I plan to raise this with a electrophysiologist and my cardiologist. Also will see my DME as you suggest. Thanks.

[Sleeprider]

We live on a giant magnet as the Earth's iron core spins beneath us. If the magnet in the F20 is a concern, you better be prepared to avoid most electric motors, overhead wires, your electric meter, speakers, electric coils, roadway traffic sensors, jet travel, telephone equipment, electric clock radios and wireless communications towers.

In a different class, don't get a MRI or take tours at an electric generating plant, or other large turbines. The field of this mask must be something close to a refrigerator magnet. There are bigger problems out there, but you will have to recognize and pick your risks.

[WLKSRQ]

Sleeprider -- I'd like to think I'm mis-reading your post but its tone strikes me as being somewhat sarcastic. Much of what you offer up in inconsistent with commonplace EMI standards and guidance published by Medtronics and other manufacturers of pacemaker/defibrillator devices. Re your refrigerator magnet analogy, why would Resmed make such a big cautionary point (in its F20 user manual) against letting the F20's magnetic field come into close proximity to such medical devices?

[Sleeprider]

In truth I don't know the magnetic field strength of the mask, but I suspect is is close to what would be used to attach a common permanent magnet to a refrigerator. I'll stick by it. I think medical warnings tend to be very conservative in order to err on te side of avoiding liability, even when risk is really unforeseeable. I have been seeing power cord adapters for smartphones that probably have similar magnetic force. I just don't see this affecting a deep inplant, but you're the one that has to judge the risk. There are a lot of non-magnetic alternatives.

I wasn't kidding. You are exposed to much stronger magnetic fields daily.

[eseedhouse]

We live on a giant magnet as the Earth's iron core spins beneath us.

Which has a field strength of less than 1 Gauss at the earth's surface. Any magnet you meet in a motor or on a mask to hold stuff on will have a field thousands of times that. So your comparison is misleading at best.

A magnetic field drops off as the square of the distance from the field source. The difference between 1" and 4" is a factor of 16. The field at 2 inches will be 4 times as week as at 1".

I think the people to ask are the suppliers of your pacemaker. I doubt that a steady field even a few inches away will be a problem, but that's just a guess.

Just as an irrelevant aside, every electron in your body is a tiny magnet. If they all shared the same direction of spin you yourself would be a giant magnet, but they don't, their spin direction is pretty well random so it all cancels out.

[WLKSRQ]

The magnetic field strength of the F20 mask is 400 milliTesla per Resmed's user manual, which is above "safe" thresholds I've seen cited by a few EMI entities. BTW, my device isn't deep, it is just beneath the skin surface. But I agree with you about medical warnings erring on the conservative side in the interest of liability exposure. My cellphone and bluetooth audio earbuds often come in close proximity with my device, with no ill-effects after 8 years. I'm due for a device replacement during the next few months, so I'll raise the issue with the electrophysiologist. Regarding non-magnetic alternatives, I've tried pillows and nasals (without success due to mouth breathing) and two full face masks with conventional headgear attachments. The F20 as marketed caught my eye regarding its comfort and leak performance, and I so much want it to be a viable choice for me.. Thanks for sharing your thoughts.

[srlevine1]

I have an implanted pacemaker/ defibrillator and, as such, need to be careful of coming into close proximity of certain magnetic fields. I'm otherwise interested in trying the new ResMed F20 mask but I'm hesitant because of its magnetic clips. I've checked the F20 manual and they suggest keeping at least a 2 inch separation between device and magnet. Being an active sleeper I can envision myself violating this standard. So my question is this: Is Resmed's suggestion overly conservative or is there reason for me to stay clear of the F20? Thanks in advance.

I have an implanted Medtronic Reveal Linq loop recorder and asked Medtronic the same question. They wouldn't comment on any device they have not tested in their laboratory.

It is my understanding that the key issues are: battery discharge, service mode changes, introduction of noise in the sensing circuit, and in the case of pacemaker/defibrillators, accidental or untimely discharge.

So I was wondering if I could replace the magnetic closure using "Velcro dots" which are easily available?

Since this is a life-critical issue, I will try the Velcro route or wait until there is some significant information from a trusted and credible source like the manufacturer.

Here are some resources .

Interference of neodymium magnets with cardiac pacemakers and implantable cardioverter-defibrillators: an in vitro study.

Effects of External Electrical and Magnetic Fields on Pacemakers and Defibrillators: From Engineering Principles to Clinical Practice

Best of luck. Keep us posted if you find a credible answer.

[Sleeprider]

The magnetic field strength of the F20 mask is 400 milliTesla per Resmed's user manual, which is above "safe" thresholds I've seen cited by a few EMI entities. BTW, my device isn't deep, it is just beneath the skin surface. But I agree with you about medical warnings erring on the conservative side in the interest of liability exposure. My cellphone and bluetooth audio earbuds often come in close proximity with my device, with no ill-effects after 8 years. I'm due for a device replacement during the next few months, so I'll raise the issue with the electrophysiologist. Regarding non-magnetic alternatives, I've tried pillows and nasals (without success due to mouth breathing) and two full face masks with conventional headgear attachments. The F20 as marketed caught my eye regarding its comfort and leak performance, and I so much want it to be a viable choice for me.. Thanks for sharing your thoughts.

It seems you knew the answer. Thanks for posting some data on the actual field strength. Comparing my off-the-cuff estimates with real data, I see the maximum recommended magnetic field for pacemakers is only 0.5 mT. I was correct in assuming that the strength of a refrigerator door magnet exceeds that (5 mT) by 10 times, but am surprised that the F20 mask seal is so much stronger at 400 mT. Most fields I listed, (the earth's core being an outstanding error) are considerably higher than that. I have spent much of my working life around generators and dynamos that have very strong fields and posted warnings.

There are avoidable risks, and you're wise to pay attention to them. Magnetic fields are so pervasive, I would think it difficult to avoid them all. I learned something here...thanks!