Whatever activity we are involved
in, be it sitting and reading The Micro
User or competing in a quadrathon, our
brains make sure that the body
processes are maintained between fine
limits.
This system of feedback, or homeos
tasis, involving the body organs and the
brain is essential to life. At last there is a
software package designed to demons
trate this vital physiology in a form
intelligible to all biology students.
Physiological Simulation is an MEP
subsidised biology package published
by Heinemann Computers in Education.
It is designed for use with pupils
aged 13 and above.
The program's greatest asset is that it
allows physiological investigations to
occur which would not normally be
within the scope of school laboratory
facilities. It also allows the effect of a
simple variable to be assessed in a
complex physiological system.
Put simply, the user (playing the part
of the brain) has to keep the body,
(played by the computer) alive while
performing one of a dynamic range of
activities, such as running, sleeping,
walking, hockey, rock-climbing and
rowing.
The user begins by opting to use
preset values or to input pupil details
(sex, age, mass, blood volume and vital
capacity), activities (already mentioned)
and parameter values (breath, volume,
rate of breathing and sweating rate).
Do not let the idea of measuring pupil
blood volumes put you off. The detailed
booklet provided has a simple-to-use
nomogram which enables this variable
to be quickly calculated from the
subject's height and mass. Vital
capacity is easily measured in class
using the normal spirometer apparatus.
Once these data have been provided
dynamic graphs show the person's
progress over a simulated 50 minute
period. A colour monitor is an
advantage as the background colour
changes from red to blue, while the
display remains white.
Apart from a clock showing the time
elapsed, graphs of oxygen debt, sugar
used, oxygen supply, body temperature
and water loss are all provided. A word
of warning: the interpretation of the
oxygen debt graph needs clear explan
ation before the simulation otherwise it
is very misleading.
The user must maintain all five of
these variables within displayed upper
and lower limits or the activity ceases
and a message indicates the reason for
failure, for example "Person is DEAD"!
The secret of success is to freeze the
action when the body is in danger and
change either the parameters or activity.
Unfortunately the axes of the graphs do
not show any scale or units. This facility
would make the graphical display more
intelligible and bring the software up to
A-Level requirements.
Once the simulation has finished it is
possible to begin the program again,
terminate it or display further options
such as beginning a comparative
simulation for a second person. After
such a comparison the user can replace
any one of the two sets of data and try
another comparison.
The program is well "studentproofed".
It is very difficult to make an
error which throws the program
haywire.
Clearly such a package is of most use
in a teacher demonstration situation -
maybe using more than one monitor if
the group is large - or possibly by the
more able pupil in small well-supervised
groups.
Hard copy is not provided for users.
This is a pity as a printout would
provide a permanent study/revision
piece.
A program is only as good as the
mathematical model it is based on. The
medical data used was mainly derived
from a Swiss sample taken in 1956-57.
One cannot help but wonder how
different the pupils are today when
compared with those used for the
present values, but the program's saving
grace is that it does allow fresh data to
be inserted. The source of the
calculations used to plot the graphs is
not disclosed - a glaring omission.
The notes for teachers are well
documented on the whole and
particularly useful for teachers using
computer-aided learning material for
the first time. It is unfortunate that no
bibliography is provided to aid teachers
in background/further reading.
Visual presentation in this software
package is top class. The program is fun
to use, but be prepared to spend an hour
or two in preparation time to master its
principles first. It is not an instant
lesson, nor is it designed to be one, but it
is a flexible and powerful educational
tool which should be in every biology
teacher's "toolbox".
At £12.50 - for disc or tape - this
package is good value for money and
recommended for use by all secondary
school biologists.
1st December 1983
