In the past, there was really no difference in the auscultation effect of stethoscopes. Nowadays, there are many kinds of stethoscopes. Different grades of stethoscopes are not very different when listening to normal sounds, but there is a world of difference when listening to noise. In general, the higher the quality of the stethoscope, the stronger the ability to discriminate the noise, and the longer it takes to use. A clinician should always have at least one pair of better quality stethoscopes.

Difference in auscultation effect

In general terms, the bigger and heavier the stethoscope, the better the sound pickup effect; on the contrary, the smaller and lighter the lighter, the more convenient the carrying, the dazzling new stethoscope is designed to solve this contradiction.

Auscultation head size

The larger the contact surface between the auscultation head and the body, the better the sound picked up. However, the surface of the human body has a curvature. If the chest piece is too large, the head cannot be completely in contact with the human body. The sound can not only be picked up well, but also leaks out of the gap. Therefore, the size of the auscultation head should be based on clinical needs. At present, the diameter of the stethoscope chest is almost uniform between 45-50 mm, and the special diameter such as the pediatric chest is 30 mm, and the newborn is 18 mm.

Stethoscope material

The material plays an important role in the sound effect, and the sound is transmitted through air or matter, and finally the heat is lost. The transmission of sound waves has almost no attenuation in heavy metals and is prone to attenuation in lighter metals or plastics. Therefore, high-grade stethoscopes must use heavy metals such as stainless steel or titanium.

Conductive part of the stethoscope

The sound pipeline is also very important. The larger the inner diameter of the tube, the shorter the length, and the thicker the tube wall, the better the effect of the stethoscope. The international standard length is 27 inches. The material of the modern stethoscope's sound pipeline is generally PVC, which has good sound effect and beautiful appearance, but has poor tensile resistance, and is often bent and easily broken after stretching. The stethoscope should be hung flat on both sides of the neck after use. This can be seen in foreign TV series and is the standard method of wearing a quality stethoscope.

The difference between the cup type (bell type) auscultation head and the membrane type head

The stethoscope was conceived by Mr. Finlay of France. His stethoscope is a cup-type (bell type), the pickup range is all audible audio frequencies; and the membrane-type head has a film that filters out low-frequency sounds with a frequency less than 200 Hz, making it more HF-high. sensitive. When using it, it must be applied to the human body with force. The membrane-type head can be made larger than the cup-type head, so the volume of the membrane-type head is stronger than the cup-type head.

Clinical application of the head

At the heart auscultation, the membrane-type head can listen to high-frequency sounds well, and the cup-type head is suitable for listening to low-frequency sounds or noises. Modern stethoscopes are double-sided stethoscopes. Both the membrane and the cup are available on the auscultation head. The conversion of the two stethoscopes only needs to be rotated 180o. Experts suggest that the clinical doctor should use a double-sided stethoscope. Another patented technology, called floating membrane technology, allows the membrane-type auscultation head to be a cup-type head in a special way to listen to low-frequency noise. Both normal and abnormal lung sounds are high-frequency sounds, and the auscultation of the lungs can only be done with a membrane-type head.

The cold circle on the head

At the time of the diagnosis, the teacher taught that the stethoscope should be in the hand for a while before giving the patient auscultation, so as not to stimulate the patient with the cold metal on the stethoscope. The use of the anti-cold ring on modern stethoscopes is more user-friendly, reducing the stimulation of cold metal to patients.

Stethoscope earplugs

It is very important that the earplugs can be well adapted to the ear. If the earplugs are not suitable, the sound will leak out, and the external noise can also enter the confused auscultation effect. Professional stethoscopes are generally equipped with closed earplugs that are excellent in both sealing and comfort.

Ear cone of stethoscope

The new type of stethoscope ear springs are made of tough steel, adjustable to the appropriate tightness, comfortable to wear, and easy to adjust the orientation of the earplugs. Since the ear canal is not completely 90° perpendicular to the side, but is slightly inclined rearward, the earplug should be tilted slightly forward when worn. The ear tip of a high quality stethoscope can be pre-fixed in an anatomical direction, called an anatomically correct ear piece.

The above technology combined with a closed earplug with high fidelity effect allows the user to enjoy the unprecedented auscultation effect and comfort brought by the use of high quality stethoscope.