I have just a bit of personal experience in testing implantable pacemakers and
volumetric infusion pumps. I had been doing RF immunity studies for a
manufacturer, circa 1990, using an FDA standard (MDS-401-xxx?) for medical
electronic devices.
I exposed devices to fields as strong as I could create (10 kHz through 18
GHz, always at least 200 V/M, sometimes as high as 600 V/M), using both 1 kHz,
50% duty cycle and a 200 Hz, 10% duty cycle, gated at a 1 Hz rate. The devices
were tested first in open air, and then immersed in a rectangular tank of
saline solution (a crude attempt to simulate body tissue). I also exposed them
to 20 Oersted DC & 60 Hz magnetic fields (the infusion pumps had a magnetic
communications link for programming and monitoring).
The nice part is that, after some design changes, I was unable to elicit any
improper responses from the devices. Since these devices were so nicely
immune, I imagine that a person would feel the effects of tissue heating well
before the electronics are jeopardized.
I hope they still make them as good now. <g>
Ed
Ed Price
ed.pr...@cubic.com WB6WSN
NARTE Certified EMC Engineer & Technician
Electromagnetic Compatibility Lab
Cubic Defense Applications
San Diego, CA USA
858-505-2780 (Voice)
858-505-1583 (Fax)
Military & Avionics EMC Is Our Specialty
________________________________
From: Barker, Neil [ mailto:neil.bar...@e2v.com]
Sent: Friday, November 19, 2004 8:20 AM
To: 'drcuthb...@micron.com'; israe...@oms-it.co.il; emc-p...@ieee.org
Subject: RE: Heart pacemakers - Vulnerability to EM
I am no expert in this subject, and some of what I am about to say is
hearsay, but here it is for what it's worth.
Safety levels are generally based not on field strength, but on power
density. However, these levels are set for the power absorption of the body
(in W/kg) based on the heating effect. For comparison purposes consider the
acceptance levels applied to SAR testing. On this basis, I suspect that Dave's
amateur rig probably doesn't meet SAR acceptance levels, and should probably
have an exclusion zone around the antenna!
The original message was concerned with the effect on a pacemaker
rather than directly on the body itself. Clearly, if you disrupt a pacemaker
then it is the pacemaker that has an effect on the body.
I believe that the susceptibility depends greatly on whether they are
external pacemakers or implanted pacemakers. The implanted devices are much
less susceptible as they are completely surrounded by soft body tissue, which
is largely water in any case. External devices are much more susceptible, due
largely to the relatively long electrode wire. being long, this is generally
susceptible at fairly low frequencies, and I have heard that they can be
affected by the magnetic loops used in store doorways for security
(merchandise protection) purposes. I have no knowledge of their susceptibility
to E fields.
Best regards,
Neil R. Barker C.Eng. MIEE FSEE MIEEE
Manager
Compliance Engineering
e2v technologies (uk) ltd
106 Waterhouse Lane
Chelmsford
Essex
CM1 2QU
UK
Tel: +44 (0)1245 453616
Fax: +44 (0)1245 453410
e-mail: neil.bar...@e2v.com
Web: http://www.e2v.com < http://www.e2v.com/>
-----Original Message-----
From: drcuthb...@micron.com [ mailto:drcuthb...@micron.com]
Sent: 19 November 2004 14:47
To: israe...@oms-it.co.il; emc-p...@ieee.org
Subject: RE: Heart pacemakers - Vulnerability to EM
I don't know what the standards call for but it is quite
possible for a person to be subjected to an E-field exceeding 500 V/m very
near to an amateur radio station. This is the field at my operating position
when I am transmitting at 1.8 MHz. A cell phone held close to the body will
cause a field, at the body, of over 30 V/m.
Dave Cuthbert
-----Original Message-----
From: owner-emc-p...@listserv.ieee.org [
mailto:owner-emc-p...@listserv.ieee.org] On Behalf Of Israel
Sent: Thursday, November 18, 2004 4:55 PM
To: emc-p...@ieee.org
Subject: Heart pacemakers - Vulnerability to EM
Hi all
Heart pacemakers may be vulnerable to Electro Magnetic energy.
Has anyone idea about safe immunity levels ? about relevant standards
regarding this matter ?
Thanks !
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