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[Amps] Fwd: Deep Brain Stimulation for Parkinson's treatment and RF in t

Subject: [Amps] Fwd: Deep Brain Stimulation for Parkinson's treatment and RF in the ham shack
From: John Farber <>
Date: Tue, 05 Aug 2014 20:42:45 -0700
List-post: <">>

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<div>-------- Original message --------</div><div>From: John Farber 
<> </div><div>Date:08/04/2014  12:29 AM  (GMT-08:00) 
</div><div>To: </div><div>Subject: Deep Brain Stimulation 
for Parkinson's treatment and RF in the ham shack </div><div>

-------- Original message --------
From: John Farber
Date:08/04/2014 12:29 AM (GMT-08:00)
Subject: Deep Brain Stimulation for Parkinson's treatment and RF in the ham 

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 (fmri ?) to 
facilitate the placement of two small shielded leads which terminate in tiny 
gold electrodes. The area of the brain in which the electrodes will be  placed 
is named, in my case, the substantia nigra, the meaning of which I take to be 
roughly "important dark area". When i fIrst learned of this impressive new 
surgical procedure which is designed to offer a bit of hope to the many people 
suffering from the insidious neurological disease named for the physician who 
first described it, Parkinson's dIsease,  I was very interested. That was 
because Parkinson's is not much fun. It's usually described by three 
three.following scary words: progressive, chronic and incurable. In sim
 pler is a disease which only gets worse, goes on and on and it has no 
cure. It affects a person's ability to walk, stand, reach and hold things, 
talk, swallow, control their facial muscles and stabilizing muscles requIred to 
smile or even sit also causes deep depression and/or dementia In about 60 
% of sufferers. The famous actor and TV star, Michael J. Fox established and 
funded through ongoing very generous donations, many millions of dollars, the 
Michael J. Fox Foundation which is dedicated to finding a cure for Parkinson's. 
Mr. Fox by his own admission has been very lucky

 It's located  lies way down at the base of the brain near the interface of the 
old  er "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 collar bone where they connect to a sealed battery powered 
microprocessor-based pulse 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 s
 ynchronize the more randomised 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 serindipidous 
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 there has been 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 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. If you would like to perform the demonstration you should 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 electr
 onics/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 on 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 just  have to wait this out. Amps advertised as being 
"instant-on" 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.The practical effect noticed is the ac em field 
interacting with the steady-state permanent magnetic field produced by the 
hand-held supermagnet results in a very strong vibration felt in the hand 
holding the supermagnet.
So I'm interested in both potential problems caused by the DBS system being 
affected by rf pickup from legal limit hf or 6 m 
r tedday to day.   





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