TECHNOLOGY AND MEDICINE—LION 403 
in spite of, the treatment. In other words, the mere observation of 
the clinical end result is unsatisfactory because it is incomplete. Only 
that type of medical research which investigates the action of the 
treatment step by step will lead to the finding of natural laws which 
will always be valid and which, in the hands of the physician, will be 
a valuable guide to him. 
This type of research also indicates how medical instruments should 
be fashioned so that better results may be obtained. For example, re- 
search on high-voltage X-rays has shown that it is possible to obtain 
an increase in X-ray energy in the depth of the body in such a way 
that the surface layers through which the beam passes are relatively 
little affected. This knowledge is of greatest importance in the treat- 
ment of deep-seated tumors, and the development and production of 
appropriate equipment for clinical use follows as a logical consequence 
of such research. This single example is sufficient to show that phys- 
ical and technological research may brilliantly complement clinical 
observation in furnishing the guiding principles for supplying medi- 
cal men with new equipment. 
DIAGNOSTIC APPLICATIONS 
A great need for research and development may be anticipated in 
the field of physical diagnostic methods and instruments, and here 
again technological developments are able to make substantial con- 
tributions to medicine. One of the most commonly used instruments 
in the doctor’s office, the stethoscope, belongs in the category of such 
physical diagnostic tools, and its development illustrates the benefits 
which modern technology can bring to the medical sciences. 
When the stethoscope was first introduced into practical use in 1819 
by René Laénnec, it consisted of a rigid hollow tube with enlarged end 
pieces. In this form it was used for a long time until the stethoscope 
with flexible tubing and a membrane at one end was developed. Me- 
chanical resonance is employed to some extent in the flexible-tubing 
stethoscope and provides some amplification over a narrow but useful 
frequency band. Today, through the use of a microphone and a suit- 
able electronic amplifier, the electronic stethoscope makes possible the 
reproduction of the sounds of heartbeats for large audiences. At the 
same time, the instrument is able to record all aspects of systolic and 
diastolic contractions or, using filters, to select for special study any 
range of the frequency components of heartbeats. At present, the 
electronic stethoscope is used primarily for research, but there are other 
electronic instruments which have been adopted in standard routine 
examinations in medical practice. 
Research on physical diagnostic methods and the development of 
instruments required for diagnosis are particularly promising at pres- 
