Biomedical Engineering Reference
In-Depth Information
eye doctors developed a new laser technique by which they could cure
some of these patients within an hour. So, after having been almost blind
for 40 years, these patients were suddenly able to see. After 40 years, the
cataract vanished from one moment to another. The main question here
is: What does such a patient see as soon as the bandage is removed from
the eyes after the laser surgery? Will he say,
“
'
Doctor, I
m delighted to
finally see you
”
?
The reality is that these people see almost nothing in the beginning.
What once was vague is now suddenly sharp. Unfortunately, the eyes do
not even know what it is to focus on an object. Once they learn to focus,
they see sharp colors and lines but they still have no idea what they see.
After a few days, they find out that some colors in a specific pattern
belong together. Two black dots, each with a colored circle around them
and some dark lines on the top and the bottom, always seem to move
together. Later, they discover that these are the eyes of a person. Step by
step, they learn that the pattern is more complicated and that other things
like a mouth, nose, and ear also belong to the face. They learn to differen-
tiate between foreground and background. Once a face is recognized and
stored in our database, it is a difficult job to find the differences between
two faces, especially when these faces change all the time, not only in
expression but also in position. For the eyes, this is much more compli-
cated than the children puzzle of
It takes
about a half year to recognize friends at a party. Even after years, when
these people do a face recognition test, they score badly compared to peo-
ple with normal sight. Now let
“
finding the 10 differences.
”
'
s translate the cataract example to the
cases in this topic.
When growing up, children learn how to perceive.
Case 1
A pump regulates the pressure of the oil in the cooler. Experienced
operators can
the sound that is produced by the pump. Based on
what they hear, they can estimate whether there is fluid or gas in the
pipe, how high the pressure is, and the quality of the parts of the pump
(for example, when the bearings need to be replaced). A new employee
on the job probably only hears that the pump is working and cannot
interpret that sound any further to gain extra information from it.
A new operator will slowly learn to distinguish different sounds that the
“
read
”
