Mary,
You asked about measuring the frequency of internal tremor (i.e., the
number of cycles per second). This could be done accurately with an
electrocardiogram (as Rene said). But since you probably do not have any
electronic instruments, you can only estimate the frequency by comparing it
with the frequency of other things.
To get a feeling for a frequency in the right general neighborhood, count
as fast as you can. With practice, when I am on, I can count "one, two,
three, four, five, six" in one second, i.e. I can count 6 counts per second
(or 6 Herz, abbreviated 'Hz'). Try it yourself. You can measure the
frequency of counts by counting to 6 five times while the second hand of a
clock moves 5 seconds. Six Hz is about as fast as one can count.
It is not fast enough. The internal tremor that I had before I started
medication was roughly twice that fast. But I can deliberately shake my
arm and hand back and forth with a frequency about the same as that of the
internal tremor.
You can measure the frequency of the shaking by using the flashing of your
computer screen. I do not mean the flicker of a monitor when the computer
refresh rate is not properly adjusted. I mean the normal refreshing of the
image on a computer or TV screen. The screens flash on and off more
completely than fluorescent lights because the former cycle more slowly
than the latter, and because the persistence of the phosphors that produce
visible light from the latter is longer than the brief time the alternating
current to the lights is nearly off. Most people are not bothered too much
by the flashing of TV or computer screens because of the persistence of
vision of their eyes. The frame rate of TV is 30 Hz, but its flash rate is
60 Hz because of interlacing. My computer can be set to refresh the
monitor at 60, 72, or 75 Hz. In order to minimize flicker I set the
frequency to the value that best matches my monitor. This frequency is 72
Hz.
To measure the frequency of shaking, point one finger near your computer
screen and shake your arm, hand, and finger repeatedly up and down about
one inch. (I have to do it deliberately because I usually do not have
tremor.) Because of the persistence of vision of your eye, you will see
several images of your finger displaced over the one inch.
If I do this about as rapidly as I can, I see about 6 images of my finger.
That means that the computer flashes about 6 flashes per cycle of my arm
up and down. Divide the first number by the second to get
( 72 flashes per second ) / ( 6 flashes per cycle) = 12 cycles per
second
or 12 Hz. This is roughly the frequency of my fastest deliberate shaking,
which as I recall is the same as the frequency of the internal tremor.
Baldwin, 63/4
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From: [log in to unmask]
Sent: Friday, September 26, 1997 9:46 AM
To: [log in to unmask]
Subject: internal tremor
When I was diagnosed with PD four years ago, I felt an internal tremor
or shakiness, or nervousness or tenseness. It was a strong pulsing at a
frequency of 5 to 20 cycles per second that I felt throughout my
body---
>>>>>>>>You & others have mentioned ".......cycles per second......" I'm
very interested in knowing how one measures this. Perhaps then I can do so
when I am experiencing this phenomenon. Thanks! Mary Legan<<<<<<<<<<
