The 20th century saw impressive
applications of engineering technology in diagnosis, as
well as the application of such technology in other fields
of medicine.
Electrocardiogram (testing
heart function); electroencephalogram (brain); electroretinography
and related techniques (vision) may be briefly mentioned.
And in the category of imaging: the "classical"
X-ray and its 3-dimensional development, computer tomography
(CT); ultrasonic echography
Such advances continue,
particularly in making such high-tech diagnostic methods
more "accessible"; but more recently the most
striking progress has been in biochemical detection methods.
These have a long history, but have recently advanced rapidly,
with the development of highly selective and specific biochemical
tests which are easy to use -- sometimes so easy that they
have moved out of the laboratory altogether. These have
great potential in mass-screening tests; but here the problems
tend to be not so much technical, but more organisational
and economic.