Stethoscopes

Classic acoustic nurse stethoscope

The acoustic stethoscope is the most common. It has a chest piece fitted with a flat diaphragm for detecting the high-pitched sound of normal breathing. On the reverse, there's a bell designed for low frequency heart sounds. Some nurse stethoscopes use a tune-able diaphragm to distinguish different sounds. Chest pieces are made from brass, stainless steel, or plastic. The chest piece is connected to ear tubes by flexible pipes. Various features reduce unwanted noise, including double walled tubing and acoustic ear tips. Medical professionals use disposable single-use stethoscopes and nitrile gloves when there's a risk of contamination or infection.

Electronic doctor stethoscope for noisy environments

The electronic stethoscope is similar to the acoustic stethoscope, except that it electronically amplifies sound. This is useful in noisy surroundings. The stethoscope uses a piezoelectric crystal to detect sounds, and an amplifier converts the electronic signal to audible sound. Apart from benefiting those who are hard of hearing, sounds are electronically filtered to reduce unwanted interference, such as noise from equipment and medical facemasks. Electronic stethoscopes are battery powered and fitted with small headphones.

Specialized stethoscopes for monitoring specific patients

The standard doctor stethoscope intended for adult patients has a chest piece diameter between 1.3 and 2 inches that helps identify where sounds emanate from. For pediatric auscultation, a smaller diaphragm helps isolate sounds more effectively in small chests. These pediatric stethoscopes have brightly colored chest pieces to help young children relax. Neonatal stethoscopes use a 1-inch diameter chest piece suited to tiny chests.

The unique fetal stethoscopes uses large conical bells, similar in shape to otoscopes, to detect the faint fetal heartbeat. In cardiology, the stethoscope has short, thick tubing and tight fitting earpieces which block extraneous noise and improve acoustic quality aiding diagnosis. Two-headed stethoscopes are used in training to allow students to listen.

Types of stethoscope

As with other wholesale medical supplies, it's important to select the correct type of stethoscope with each application. Common stethoscopes brands include:

• 3M Littmann®
• Mabis®
• MDF®