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[Amps] Deep Brain Stimulation for Parkinson's treatment and RF in the ha

Subject: [Amps] Deep Brain Stimulation for Parkinson's treatment and RF in the ham shack
From: John Farber <>
Date: Mon, 04 Aug 2014 00:29:00 -0700
List-post: <">>
I have been avidly following the discussion on rf exposure and the possible 
negative consequences on human heart pacemakers. Im scheduled for surgery in a 
few months for implantation of two electrodes entering the skull at the top of 
the brain and with very precise real -time positional monitoring, the ultimate 
placement of two small shielded leads which terminate in snd small gold 
electrodes. The area of the brain in which the electrodes are placed in my case 
is named the substancia nigra, the meaning of which I take to be important dark 
area. It lies way down at the base of the brain near the interface of the older 
"animal brain" which controls many autonomic activities and the "new brain" 
which incorporates higher thought, math, science, ham radio-sorry I couldn't 
resist the opportunity. The salient point to me at least, is the two leads will 
traverse nearly the entire distance from the top of my head down 
to.approximately the level between my ears, roughly 6 inches in length for each 
of the two leads. From the top of the skull the leads are buried 
sub-cutaniously (under the skin) down the side of the neck to the area just 
beneath the xxx bone where they connect to a sealed battery powered 
microprocessor-based controller. The controller sends precisely-timed electric 
pulses to the neurons of the section of the brain which is responsible for 
initiating and sustaining physical movement such as walking, reaching and 
tuning your rig or sending cw. The pulses of current have been found to help 
synchronize the more random firing of neurons occurring in the brains of 
Parkinson's sufferers. So it can be thought of in gross terms as a sort of 
"pacemaker for the brain". 
I think you can see why I reckon the current discussion may be serindipidy and 
quite relevant to my approaching situation as well. I queried my Neurosurgeon 
about all of this and despite his looking me squarely in the eye and displaying 
an excellent polished bedside manner as he fielded ham radio-centric very 
specific rf-related questions concerning specific frequencies and power levels, 
all I was given upon leaving his office, was his promise to seek answers and 
get back to me. So far no further word from him. The controller is made by 
Medtronics. My attempts to date to gain answers to my questions from Medtronics 
have resulted in frustration.  
Just as a seat-of-the-pants calculation of most likely frequencies to be wary 
of is dependent on the half-wave dipole length of the two wire runs from the 
brain implant terminating electrodes all the way down the side of the neck to 
the controller. Without the opportunity to measure the leads I have a general 
feeling that I probably should avoid high powered transmitters operating in the 
roughly 240-230 KHz range. On the subject of avoiding the very powerful ac 
magnetic fields produced by popular Linear yt? Amplifiers: I came up with a 
very simple but yet very dramatic method to demonstrate the silent, invisible 
magnetic flux fields reproduced by the hv transformer typically used in hf 
linears.obtain one or more supermagnets typically available for sale for a 
couple dollars at any common ham radio, computer or general electronics "geek" 
flea market,  garage (or as my buddy from New England calls them: tag sales) or 
electronics/computer "surplus" stores. To demonstrate the powerfull 
ac electromagnetic field produced by a linear amp's hv transformer, simply hold 
the supermagnet firmly (I'm serious folks), in one hand and turn in the linear. 
For most modern amps using one or more ceramic-metal tubes,  there will be a 
designed time delay of about 3 minutes before the hv transformer springs to 
life so you will most likely have to wait this out. Amps advertised as being 
"instant-on" use typically use glass envelope tubes such as the hugely popular 
3-500Z units. The amp I built around 1980 which was my attempt to build an hf 
amp from the ground up and cover 160- 10 m using a pair of 3-500Z tubes. I 
chose to incorporate step start circuitry for both the tube filaments as well 
as for the hv. The point being you may find amps using 3-500Z or similar glass 
envelope tubes may include a time delay albeit much shorter than 3 minutes. I 
used just a few seconds delay for each step start circuit amp.
In any case once the hv power transformer energizes, simply hold the 
supermagnet a few feet away from the linear being used for this test. Most 
folks to whom  I've shown this demonstration have been amazed both by the power 
of the radiated magnetic field as well as the consideral distance at which the 
field can be strongly felt. In my shack setup my Alpha 99 hf linear sits 
roughly 3 ft away from the left side of my body. Upon testing with the magnet 
it was clear I've been unknowingly bathing my body in powerful 120  Hz (the 
output of a 60 Hz power line frequency doubled by the full-wave bridge 
rectifier circuit in the amp's power supply) electromagnetic fields. I know 
there have been many studies on the effects of exposure to high levels of 
commercial power line frequencies over the years,  with no clear consensus over 
the highly debated topic. I do remember reading of one study done by NASA in 
the late 1950s or early 11-960s which clearly showed that long term exposure to 
em fields significantly different from those generated by the human body were 
positively shone to cause the physiological effects similar to those caused by 
stress.  When these effects became apparent, NASA decided to end the testing. 
So I'm quite concerned about not only strong near field rf-related exposure 
effects on a DBS system but also the effects of exposure to the day-1          
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Rd, Scotts Valley, CA 95066.  day to day.   





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