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RE: [RFI] rf and insulin pumps

To: "S. Markowski Jr." <km9m-zig@comcast.net>, rfi@contesting.com
Subject: RE: [RFI] rf and insulin pumps
From: "Cortland Richmond" <ka5s@earthlink.net>
Reply-to: ka5s@earthlink.net
Date: Sun, 13 Feb 2005 23:13:48 -0800
List-post: <mailto:rfi@contesting.com>
Immunity testing is almost certainly to European standards. 

Here're radiated field immunity requirements from the draft ETSI EN
301-489-27,
titled,

Electromagnetic compatibility and Radio spectrum Matters (ERM);
ElectroMagnetic Compatibility (EMC) standard for radio equipment and
services;
Part 27: Specific conditions for Ultra Low Power Active Medical Implants
(ULP-AMI)
and related peripheral devices (ULP-AMI-P)
-------------------------------------------------------------------

[excerpt from ]Table 4: Special conditions for EMC immunity tests

The following conditions apply:
- for non-life supporting equipment, the test level shall be 3 V/m
(measured unmodulated);
- for life supporting equipment, the test level shall be 10 V/m (measured
unmodulated);
- for equipment and/or systems intended to monitor or measure a
physiological parameter, the physiological simulation frequency
restrictions specified below shall apply. When the modulation frequency of
2 Hz is used, then it is not necessary to additionally test with a
modulation frequency of 1 kHz...
[SNIP]
The test shall be performed over the frequency range 80 MHz to 2 500 MHz.
The appropriate exclusion band as defined in clause 4.3 and sequence may
be excluded from this requirement.
-------------------------------------------------------------------
Source: http://webapp.etsi.org/action%5CV/V20040528/en_30148927v010101v.pdf


Note that the modulation mentioned is 80 percent AM. This increases the
peak field to as much as 18 V/m.

A handheld radio may produce fields close to or higher than the
(unmodulated) limits above:
[quote]
 Even a 1-W radio will generate electric-field levels of 1 V/m to 5 V/m at
a distance of 3 ft, and of 3 V/m to 15 V/m at 1 ft. A useful formula to
predict the electric field levels is:

E = (5.5*(PA)^2) / d   (Note: retyped in ASCII)

where
E = electric field level in volts/meter
P = power to the antenna in watts
A = antenna gain (assume 1 or less for the typical ?rubber duck? antenna)
d = distance from the antenna in meters 
[end quote]
Source: Troubleshoot RF Immunity Problems
http://www.reed-electronics.com/tmworld/article/CA187463.html


For 5 watts, the formula above gives a bit over 12 V/m at 1 meter distance. 


I hope the preceding post, and this information will be of some help.

Cortland RIchmond
KA5S

> [Original Message]
> From: S. Markowski Jr. <km9m-zig@comcast.net>
> To: <rfi@contesting.com>
> Date: 2/13/2005 7:49:37 PM
> Subject: [RFI] rf and insulin pumps
>
>[snip]
> The question:  Does anyone on the list have any knowledge of amateur 
> gear interfering with such devices?  And if not firsthand knowledge, any 
> idea where else to check?
>
> Thanks and 73,
> Zig - KM9M



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