B.F. Skinner performed an experiment with pigeons, in which he used
classical conditioning to train them to turn around twice before he fed
them. The pigeons afterwards
always turned around twice before eating, even though the food was already
available. It was his
contention that much of what we humans do is a conditioned rather than a
rational response. This
certainly applies to sonographers, who have bucket-loads of useless and
baseless habits. It takes a true genius can transcend the paradigms and
limitations of his time, and being as close to that as anyone you’ll
ever meet, I am going to try and defuse some of these useless habits.
There are several that currently peeve me, and a catharsis
(psychologically speaking, explaining the basis of a problem can lead to
its resolution, in time, at $90/hour) would be worthwhile for humanity in
general and sonographers in specific.
first of these is the dark-room scenario.
For the last two years I have been scanning in a 6th
floor room, well-illuminated by two large windows, with only the venetian
blinds closed to restrict the direct sunlight.
I can see the patient. The
patient can see me. I can see
the ultrasound monitor. I can
still see the ultrasound image. It
is not the brightest room in the hospital, but it is certainly not
particularly dim. If its
cloudy outside (in Sydney? Never!) I even turn on the lights!
What’s the big deal? Why
was I scanning in the dark all those years?
I have absolutely no idea. At
home, I don’t watch television in the dark.
I don’t turn off the lights to work on the computer.
Why did I do it at work? Force
of habit I suppose, like turning around twice before I sat down to lunch.
(Finally kicked that tough one, though. Coo. Coo.)
no-one bothered to explain to me (and most of the medical imaging
fraternity) about the dynamic range of the eye.
In everything above really, REALLY dim rooms (i.e. dark,
and with 20 minutes of adjustment, like the old pre-image-intensifier
fluoroscopy rooms), the rods of the eye are fully saturated and
we see with the cones anyway.
We are looking at our black and white images with our
colour vision. Any
potential for a gain in grey-scale detection in the normal range
of daily activities is mythical - literally sub-liminal. The rods’ main use in daylight is related to motion detection
- the corner-of-the-eye phenomenon.
Turning the brightness of the monitor up a bit is EXACTLY
the same as dimming the room lights as far as the brain is concerned,
so long as the average ambience remains the same.
The eye’s dynamic range responds to the whole field of vision,
not just what you are looking directly at in the field of a few
degrees of arc. Even if the room is dark, the brightness of the
monitor will saturate your black and white rods. I do not
get headaches in my well-lit room, as the relatively uniform light
from the background to that emitted from the monitor, creates no
stress on the old 'ocularities'.
real problem with viewing monitors is related to unwanted reflections.
Headaches can result from your brain continually trying to refocus
your eyes onto the reflected image. Obviously
room design and machine placement will affect the feasibility of this.
In fact I find dark rooms with bright monitors particularly tiring
on the eyes.
patients will appreciate it and you’ll see them in a new light
(predictable and unilluminating pun, sorry.)
It also reduces stress in the minds of the patients, who have take off
most of their their clothes and go into a dark room with someone like you.