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Career Curriculum for Technology Project

Making a Stethoscope

This is a sample activity from the Engineering and Technology text that was a product of the NSF-funded CCfT Project.

Problem Situation:

A doctor uses a stethoscope to listen to the human heart.  As the heart beats, it causes the stethoscope to vibrate.  These vibrations are transmitted to the doctor's ears as sound.  A simple acoustic stethoscope consists of several parts.  A chest piece, which the doctor places against the patient's chest over the heart, vibrates with each heartbeat.  The resulting acoustic waves travel through an air-filled tube that leads to a three-way junction that leads to two earpieces.  The earpieces relay th acoustic waves into the doctor's ears.  The doctor is then able to hear the characteristic "lup-dup" sound of the heart beating and so evaluate the patient's health.

Your Challenge:

You work in the risk management department of a large corporation.  As part of the company's new safety regulations, each work area must have instructions for making basic medical equipment from everyday materials in case of dire emergency.  You have been asked to come up with guidelines for creating a working stethoscope from common equipment.

Safety Considerations:

1.  The information provided is not medical advice and is not intended to diagnose or treat any health
     conditions.  Likewise, do not use the stethoscope you create to diagnose or treat any health conditions.
2.  If you share a stethoscope with another person, clean the earpieces with rubbing alcohol before each use.

Material Needed:

1. Plastic funnel or cut-off top portion of pastic water bottle
2. Balloon
3. Plastic, rubber, or silicone tubing, at least 24 inches long
4. 3-way connector
5. Tape
6. Other commonly found materials

Clarify Design Specifications and Constraints:

You will make a functioning stethoscope using commonly found materials.  It will consiste of a chest piece with a diaphragm and at least one earpiece.  The stethoscope must allow the user to clearly hear a human heartbeat when placed on a subject's upper left chest.  It must work whether the subject is sitting, standing, or lying down, and the user must be able to count the subject's heartbeats.  Your stethoscope should work as well as a commercially available acoustic stethoscope.

Research and Investigate:

To complete the design challange, you need to first gather information to help you build a knowledge base.

1.  In your guide, complete the Knowledge and Skill Builder I: Acoustics.
2.  In your guide, complete the Knowldge and Skill Builder II: Cardiac auscultation.
3.  In your guide, complete the Knowledge and Skill Builder III: Heart rate.

Choose and Justify the Optimal Solution:

What decisions did you reach about the construction of a stethoscope?  How did you reach these decisions?

Display Your Prototypes:

Produce your stethoscope.  Include descriptions, photographs and/or drawing of it in your guide.

Test and Evaluate:

Explain whether your designs met the specifications and constraints.  What tests did you conduct to verify this?

Redesign the Solution:

What problems did you encounter that would cause you to redesign the stethoscope?  What changes would you recommend in your new design?

Communicate Your Achievements:

Describe the plan you will use to present your results to your class, and show what handouts you will use.