Device Lab 63

Stethoscope

A rotating head carries a membrane on one face and an open cup on the other. The user selects between two known responses by turning the head until it seats.

Also called: Stethoscope. Arabic: السماعة الطبية. Device Lab 63 of 69 in BMEssentia Medical City, 2 configurations.

Overview: the configurations

Dual-head acoustic stethoscope

A rotating head carries a membrane on one face and an open cup on the other. The user selects between two known responses by turning the head until it seats.

Single-sided tunable stethoscope

One membrane on a flexible surround. The response is changed continuously by contact pressure rather than by selecting a face, so there is nothing to turn and nothing to leave between positions.

How it works: the main parts

What each part does, from the Stethoscope lessons in the 3D Device Lab.

Diaphragm and its rim: The flat side. A thin stiff membrane held at its edge by a rim, resting against the body.
Bell side: The cupped side. An open cup with a rim, no membrane, held lightly against the body.
Chestpiece body and indexing: The head holds both sides and rotates between them. Its job is to make exactly one of them live at a time, and to make it obvious which.
Stem and the internal valve: The short tube from the head to the tubing, and the valve inside it that decides which face of the head is connected. It is the only moving part inside the instrument.
Acoustic tubing: The tubing is the path between the head and the ears, and it is the part most often blamed and least often examined. It carries pressure variation, not electricity and not light, and it does that only for as long as it stays sealed and stays supple.
Binaural tubes: The two metal tubes that carry sound from the flexible tubing into the ears. They are the most rigid part of the path and the part that decides what angle the tips meet the ear canal at.
Tension spring: The spring across the top of the headset decides how hard the tips are pressed into the ears. It is a comfort part and a performance part at the same time, and the two pull in opposite directions.
Eartips and seal: The tips are the only part that forms a seal, and a seal is the only thing standing between the listener and the room. They are also the cheapest part and the part users are least likely to think about.

Common faults and what to check

Most reported device problems (FDA MAUDE)

Device problem	Reports
Detachment Of Device Component	4
Break	3
Temperature Problem	2
Appropriate Device Problem Term/Code Not Available	2
Material Separation	2
Device Operates Differently Than Expected	2

Raw counts of adverse event reports for this device type (FDA product code DQD, LDE), all years. Not adjusted for the number of units in use, so they show what gets reported, not failure rates. Report text is never copied.

Planned maintenance checks

From the BMEssentia procedure library: every 24 months, about 5 minutes, electrical class II, applied part type B.

Check	Pass when
Chest piece, tubing and ear tips Inspect the diaphragm, bell, tubing and ear tips.	No cracks; seals intact.
Listening check Tap the diaphragm and the bell in turn; for electronic models check amplification and filter modes.	Sound in both; modes switch.

Recent FDA recalls

No FDA recalls were found for this device type's product codes in the last import.

Learn it, see it in 3D, ask about it

Ask Essentia about the Stethoscope: answers from named sources, with the device open in its 3D Device Lab beside the answer.
The Stethoscope on the BMEssentia Platform: the Device Library course, 13 sections from physics to maintenance.
BMEssentia Medical City: Device Lab 63, the Stethoscope fully assembled in 3D, with lab tasks and the simulations.

Previous: Dermatoscope. Next: Thermometer. All 69 devices.

Ask about the Stethoscope

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