This activity page will offer:
An introduction to Functional Electrical Stimulation (FES).
model-making activity that address the mechanics of breathing.
into the use of FES as a breathing support strategy.
1 - Modeling
the Mechanics of Breathing
plastic cup (with hole drilled in bottom)
You should drill holes (about the same diameter as a drinking
straw) into the center of each cup. Drilling reduces the fumes
associated with burning a hole through the plastic material.
scissors to cut a segment of straw that is about 5 cm long.
the mouth of a balloon around one end of this straw segment.
Use a rubber band to secure the balloon to this straw. Make
sure that the seal is airtight.
the other end of the straw through the hole that your instructor
has drilled in the plastic cup.
the straw so that it sticks about halfway through the cup.
Use a small rope of clay to secure the straw's position
around the opening of the cup. Make sure that the clay seals
off the opening but doesn't pinch the straw closed.
a balloon in half widthwise. Discard the nozzle half.
stretch the rubber balloon skin over the mouth of the cup.
When you release the skin, the tension should secure the
stretched balloon in place.
up on the stretched balloon fabric. Now, pull it down. Notice
how these actions affect the appearance of the balloon inside
the cup. Record your observations.
the parts of the human respiratory system represented by
is this model fundamentally different from the human system?
happens to the balloon inside the cup when the rubber skin
wrapped around the base of the cup is pulled down? Why?
happens when the rubber skin is pushed upwards? Why?
upon this model, where would you insert the FES electrodes
on a person who was unable to breathe on his own? Why?
Critical Thinking Extension
you were in charge of programming the electronics that would
trigger an FES signal to the diaphragm. How often would you
send this signal to a person who normally experiences 7 inhalations
and 7 exhalations in a one-minute period? Explain.
Have you ever seen advertisements for electrical pad muscle
toners, used most often to tone the appearance of abdominal
muscles? These pads cause muscles to contract as a response
to surface electric stimulation. Think about it. How are the
mechanics of this device similar to FES? How are they different?
Although most people identify the diaphragm as the "breathing
muscle", its effect is not as great as the action of rib muscles.
The contraction and relaxation of the rib muscles causes the
chest to raise and lower. This action produces most of the
pressure change responsible for breathing. Only when we breathe
deeply do we really exploit the full potential of the diaphragm.
you may have discovered, misconceptions in science can sometimes
be passed along from source to source. Suppose you were to
ask your parents or friends about the mechanics of breathing.
What would they say? Are they aware of the role of the ribs?
Do they know that the lungs are not muscles, but passive structures
that inflate and deflate due to the changes in the surrounding
air pressure? Develop a survey using these and other questions.
Compare your results with those of other students to try to
uncover the misconceptions we often associate with breathing
A reflex action is an automatic and involuntary response during
which a motor signal is sent, not from the brain, but from
a lower level of the spinal column. Think about it. What type
of disorders or injuries would interfere with the knee-jerk
reflex? Would a person who has a spinal injury maintain this
reflex response? Why or why not?
The Cleveland FES Center is looking into the electrical activation
of the diaphragm, among other projects.
A story on FES with a downloadable movie file.
Electrical Stimulation (FES) Research,
Development and Clinical Service
A UK site that addresses the functional application of FES
activities in this guide were contributed by Michael DiSpezio,
Massachusetts-based science writer and author of "Critical
Thinking Puzzles" and "Awesome Experiments in Light & Sound"
(Sterling Publishing Co., NY).
Academic Advisors for this Guide:
Corrine Lowen, Science Department, Wayland Public Schools,
Panico, Science Teacher Mentor, Cambridge Public Schools,
Anne E. Jones, Science Department, Wayland Middle School,