2t2 • Alternatives to Animal Use in Research, Testing, and Education 
Figure 9-1.— Computer Simulation of 
Cariovascular Dynamics for 
Use in Teaching Physiology 
Overview of a computer simulation of the complete 
cardiovascular system, showing student-controlled variables 
such as heart rate (HR%), total active blood volume (BV%), 
and total peripheral resistance (TPR%). 
SOURCE: N.S. Peterson and K.B. Campbell, “Teaching Cardiovascular Integrations 
With Computer Laboratories,” Physiologist 28(3): 159-1 69, 1985. 
• pH regulation and carbon dioxide (24), 
• pulsatile hemodynamics in the aorta (5), 
• determinants of cardiac output (16), 
• effects of medically important drugs on the 
circulatory system (25), 
• simulation of the digestion of a meal (25), 
• responses of organisms to exposure to high 
and low temperatures (25), 
• influence of hormones on muscle cells (25), 
and 
• renal excretory response to volume and os- 
molarity changes (12). 
Computer simulation of a particularly sophisticated 
laboratory exercise— for example, one that is too 
difficult for beginning veterinary students to per- 
form— can enable students to carry out laboratory 
exercises they otherwise would not have had (13). 
Table 9-7 summarizes the advantages, disadvan- 
tages, and barriers to substituting computer mod- 
els of biological systems for animals in education. 
Some characteristics apply to one type of computer 
application more than another. Viewed as a whole, 
the descriptors of computer simulations listed in 
table 9-7 illustrate the potential as well as the limi- 
Table 9-7.— Advantages, Disadvantages, and 
Barriers to Using Computer Simulations in Education 
Advantages: 
Quality of teaching material: 
• Simplification. Some biological events that are too 
complicated or not accessible to human study by vivisec- 
tion or dissection are better approached through com- 
puter simulation. 
• Quantitative skills. Physical mechanisms and mathemat- 
ical variables that underlie biological events are em- 
phasized. 
• Emphasis. Student attention is shifted from techniques 
to concepts, supporting lecture and textbook material. 
• Reliability. Strong consistency from experiment to ex- 
periment. 
• Response time. Simulations yield immediate results. 
Cost and efficiency: 
• Long-range cost reduction. Following initial purchase 
of computer hardware, computer laboratory costs are 
often lower than relatively high animal laboratory costs. 
• Speed and coordination. Increased teaching efficiency 
through expeditious testing, drills, and tutorials. 
• Laboratory availability. Increased access for students to 
laboratories. 
Disadvantages: 
• Biological complexity. Computers cannot be programmed 
to simulate many integrative interactions between inter- 
nal organs. 
• Missed experiences. In the view of some teachers, stu- 
dents should have experience with living tissue. 
• Biological variability. Computers do not accurately por- 
tray the large degree of uncertainty that arises from bi- 
ological variability, whereas comparisons of animals do 
present this concept. 
• Publication of results. Developers of computer simula- 
tions sometimes find publication of their work in the 
usual scientific journals difficult since some simulations 
require ponderous documentation; in cases where pub- 
lications are intrinsic to tenure and other faculty deci- 
sions, computer modelers may be discriminated against. 
• Student attitudes. In some cases, dubious student out- 
look on computer replacement of animals undermines 
teaching of concepts. In other cases, simulations may ' 
unintentionally train students (e.g., medical students) to 
ignore the behavior and appearance of patients and to 
place unwarranted importance on data from instruments. 
Barriers: 
• Incompatibility. Hardware components and software sys- 
tems often are not interchangeable; this is especially 
true of graphic simulations. 
• Computer limitations. Some complex digital computer 
programs are not fully realistic because they must ap- 
proximate biological processes that are continuous and 
simultaneous by using a series of discrete steps. The 
only way to make such a computer approximation more 
realistic is to reduce the time the computer takes be- 
tween steps. This may require more sophisticated 
hardware. 
• Tradition. Widespread lack of training in mathematic 
modeling leads many talented people to write textbooks 
rather than computer models. 
• Proprietary considerations. Many of those who are de- 
veloping programs or catalogs of programs for commer- 
cial purposes will only disseminate useful information 
about computer simulations if they are paid, restricting 
applications. 
SOURCE: Office of Technology Assessment. 
