Sent from my Verizon Wireless 4G LTE Smartphone
<div>-------- Original message --------</div><div>From: John Farber
<kg6i@comcast.net> </div><div>Date:08/04/2014 12:29 AM (GMT-08:00)
</div><div>To: amps@contesting.com </div><div>Subject: Deep Brain Stimulation
for Parkinson's treatment and RF in the ham shack </div><div>
</div>
-------- Original message --------
From: John Farber
Date:08/04/2014 12:29 AM (GMT-08:00)
To: amps@contesting.com
Subject: Deep Brain Stimulation for Parkinson's treatment and RF in the ham
shack
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 words.it 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 up.it 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 in.my 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.
e
I
.
nces
Sent from my Verizon Wireless 4G LTE Smartphone
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