I would certainly take everything that the doctor says seriously. One of the sources referenced above gives a distance of two feet from things that could generate strong electromagnetic interference (EMI). Your doctor is not an engineer and not in a position to make a technical call. Hardly any motor vendors publish any quantitative data on interference levels to ICD's unless it would be a motor that directly pertains to use in medical equipment. I doubt that any of them would be willing to assume any additional liability by saying that it is OK to use them in close proximity to an ICD.
The question about shielding was brought up by Richard. The only practical method of shielding needs to be done at the source and without having access to lab equipment to measure actual field strengths, a jury rigged hookup is just as likely to increase the level of interference as it is to reduce it.
The "bad boy" motors are ones that produce high transient volage spikes which can produce interference to other electronic equipment such as radios. This would include universal motors (the kind that have brushes and are loud) used in routers, shop vacs, drills, hand sanders, dremel tools, biscuit jointers, and in variable speed mini lathes. Probably the worst-of-the-worst offenders that you are likely to encounter are the variable frequency drives used with three-phase motors -- the type that has become popular in the more expensive lathes. A well designed lathe with a variable frequency drive ought to have both line reactors and load reactors installed to reduce EMI, but I have not seen one yet that does (maybe because it might add $100 to the price tag without any obvious benefit to the average turner).
The Johns Hopkins reference mentioned high power things such as arc welders and large motor-generators. The implication is that the typical fractional horsepower induction motor is not the real problem, but that is just an off-the-wall guess and not a guarantee.
My dad had a combination pacemaker/ICD installed about one year ago, so I am sensitive to this issue. During that time he has determined what things he is able to do and so far has not found any problem with motors, cell phones, microwave ovens, and other potential household EMI radiators. My discussion with his cardiologist indicates that modern pacemakers are exceptionally well tolerant of considerably higher levels of EMI than these devices were several years ago.
If I remember things correctly, there will be a period of greatly reduced activity anyway until things are healed and they are certain that the wires are firmly implanted in the heart muscle. My dad cetainly does feel a lot better now that he has the pacemaker installed and I am sure that you will also. Remember and obey the following two rules:
- do what the doc says!
- when you are not sure what to do, refer to rule 1.
Bill
