PEMF & Pacemakers, can we use this together?
We regularly receive emails asking "Can we use PEMF with a pacemaker or implantable cardioverter-defibrillator (ICD)?" The answer to this question is not straightforward.
The following information about electromagnetic fields and static magnetic disturbance signals will explain some more on this subject.
There exists two different electromagnetic energy sources: passive magnetic fields like static magnets and active magnetic fileds like electromagnetism.
It is impossible to state that a certain amount of static magnetic energy affects an implanted active device like a pacemaker or defibrillator. The correct functions of a pacemaker is tested at the hospital by placing a strong magnet directly over the device to force it to works for testing (e.g. measuring how long the battery will last). This does not cause disturbances for the correct working of the device. To say that a certain magnetic level will cause life threatening disturbances is questionable.
Another matter is electromagnetic disturbance, which are plentiful in our modern wireless world. The functioning of the above mentioned active implanted electronic devices does depend on the measurement functions performed by them, e.g. a pacemaker only generates pulses to the heart when it detects that the heart does not contract in the correct rhythm. Similarly an implanted defibrillator only comes into action if it detects that a life threatening electrical disturbance of the heart is happening. These measurements are actually disturbed in these devices by strong external electromagnetic pulses.
Anti theft systems or electronic article surveillance (EAS) systems in shops are used to identify articles as they pass between the gates at the exit of stores.
There are three different types of EAS systems where a tag or label is attached to a product. If the tag is not deactivated or removed an alarm will sound when passed between the gates at the exit.
In Radio Frequency (RF) Systems a small disposable electronic circuit with antenna is attached to a product and responds to specific frequencies generated by a transmitter. The response signal from the label is then detected by a receiver to trigger the alarm. RF systems transmit frequencies between 2 - 10 MHz.
In Electromagnetic (EM) systems a magnetic strip is attached to the label. This magnetic strip will be deactivated upon payment by a high intensity magnetic field.
If the strip is not deactivated (the goods are not paid for) then the strip response is detected at the exit gate and the alarm will sound. This system makes use of high intensity fields between 1- 70 kHz
In Acousto-magnetic systems the transmitter generates a pulsed RF signal of ~ 58 kHz to activate the tag in the surveillance zone.
When the pulsed signal ends the tag responds by generating a single frequency signal. The tag signal is then detected by a receiver and the response signal analyzed, which in turn controls the alarm.
Implanted pacemakers and ICD's conform to specific standards for electromagnetic disturbances and interferences but it is still possible that very strong external electromagnetic pulsing signals may disturb the correct working of the implanted device. This is the reason why there are warnings to avoid exposure to electromagnetic signals (cell phones, shoplifting gates, airport security gates etc.).
Because many different frequencies and intensities are used in above devices these warnings are important since the resulting inducted intensities and frequencies are simply unpredictable.
PEMF devices which are battery powered, like PEMF bone growth stimulators, generate electromagnetic pulses with very limited energy levels. The magnetic fields generated during the pulsing time depends on the pulse width (= pulse duration) and pulse amplitude (similar to the volume knob on your radio) creating the amount of energy generated during the pulse duration time.
Both the pulsed amplitude and the distance from the active coil of the PEMF device to the implanted active electronic device or its catheter are important. Only a small amount of energy is required to disturb the correct measurement functions of an implanted pacemaker or defibrillator. It is probably unreasonable to expect that battery powered PEMF devices, only able to transfer small amounts of electromagnetic energy, have any chance of disturbing an active implanted device as long as the coil is not placed in on top of the pacemaker or ICD.
In the manuals for PEMF devices is written that active implanted devices are contraindicated. Nobody will tell otherwise only because of possible legal implications. However use of such a battery powered PEMF device on a leg even in case of a pacemaker or ICD seems not to be any problem. It is simply unthinkable to forbid a person with a pacemaker to enter a shop with anti-theft gates. The warning signs at the entrances of shops are only to avoid litigation! Did you hear of somebody with a pacemaker laying on the floor behind such a gate at the entrance of a shop because his pacemaker stopped working?