570 
HEMODYNAMICS 
IIIH 
\ \ \ t\ \ \ \ I 
0.6 m 
'^HMtUAMMi^,,^, * 
Q |kor/s|troke 
HHH 
Q Cor/ 2 sec. 
y/////,/y////\ 
B.P.AO 
R.A.P. 
Pleurol P. 
40 bpm -1- 
// 
/\//,//i//Vi// 
PROPRANOLOL 
TREADMILL 
Figure 4. — Two recordings at 2.5 mm""\ 
evolving changes with the transition to exercise 
is reproduced at a paper speed of 2.5 mm sec"^ 
Another recording of the cardiovascular changes 
during transition from rest to exercise is shown 
at the right side for comparison. This recording 
was obtained in the same experimental session 
after the /S-blocker propranolol had been ad- 
ministered to the animal. 
EVALUATIONS 
We usually present individual recordings 
only as demonstration of experimental methods 
and/or illustration of results. The solution of 
research problems in our laboratory is, how- 
ever, always based on mean values from all re- 
peated experiments with each animal involved 
in a given project. For each animal we compute 
the mean rest values and the mean values for 
each of the fifteen successive two-second inter- 
vals of the studied activity. We do this for con- 
trol conditions and again for the investigative 
conditions (for instance after propranolol ad- 
ministration). All of the results are tested for 
their statistical significance. 
In order to be able to include the great 
amount of functional values into our evalua- 
tions, we feed the output of our implanted sen- 
sors not only to the Beckman R-dynograph, but 
also into a Sanborn Type 3907FM tape recorder. 
After completing the experiments, the monitored 
functions are played back from the tape re- 
