Posts tagged Tubing

Doctors diagnose and treat problems before they become a cause for concern, by using stethoscopes that help them listen to any irregular sounds in a patient’s body.

The two-sided stethoscope was the result of a realization by David Littmann, the inventor of the Littman stethoscope, that listening to low and high pitch sounds were two completely different processes, and needed to be treated accordingly, for stethoscope design.

That led to the introduction of Littman’s two-sided stethoscope – the open side facilitates listening to low pitch sounds while the closed side is useful for listening to high pitched sounds.

Accordingly, the Littman stethoscope has a two-sided piece, one side of which is made up of a diaphragm to magnify body sounds, and the other side is a bell which is a hollow cup that helps transmit the skin-vibrating sound of the patient.

A doctor uses the bell to listen to low frequency heart sounds, while using the diaphragm side to pick up sounds at a higher frequency. Both the sides are useful for listening to a person’s heartbeat, and problems like weak heartbeat, irregular beat, or other irregularities, if any, are revealed, in this process.

Shorter tubing length of a stethoscope can lead to improved acoustic response, according to health care professionals. Medical students are advised to buy a stethoscope with the shortest tube.

As market leaders, the manufacturers of Littman stethoscope took it on themselves to test the truth about the length of the tubing.

They explained it with an analogy about a garden hose, an increase in whose length results in a decrease in pressure at the end of the hose. This happens because of frictional and other internal forces. A similar effect takes place when the tubing length of a stethoscope is increased. But as the length of the tubing in a stethoscope is small, the decrease in acoustic pressure is unlikely to affect its performance.

On the other hand, if the tube length is increased, resonant frequency decreases. This helps pick up low frequency sounds. Heart sounds are low frequency sounds . which fall below 150 Hz.

Taking the above factors into account, there is no tangible difference in acoustical performance between Littman stethoscopes with shorter tubing versus those with longer tubing. Instead, there may be some enhancements to low frequency sounds. Consequently, doctors can listen to both low and high frequency sounds, with a single stethoscope.

Instruments with longer tubing are more appropriate for people who wear stethoscopes around their neck as they drape better. To decide optimal tube length, one should also consider the height and arm length of the practitioner.

Also, many practitioners prefer treating sicker patients with infectious disease from a distance, while auscultating. A practitioner’s lower back can get stressed owing to prolonged bending – longer tubing also does away with the need to bend.

The manufacturers’ reputation for research and innovation has meant that most cardiologists and specialists who expect the maximum amount of accuracy and amplification of sound from their stethoscopes demand Littman stethoscopes.