Dr. Shoji Kudoh

“Grand Master Calligraphers Are Picky About Ink Brushes”
Recommendation for “Doctorphonette NEO”
Dr. Shoji Kudoh Chairman, Japan Lung Sounds Association Chairman, Board of Directors, Japan Anti-Tuberculosis Association Professor emeritus, Nippon Medical School
In Japan, there is an old proverb saying, “A grand master calligrapher is not picky about ink brushes.” Actually, however, good calligraphers do use good ink brushes. Similarly, medical doctors, clinical nurses and physical therapists who listen to sounds in their patients’ body to make diagnoses do choose good stethoscopes. The most important points in performance of stethoscopes are sensitivity to capture every small sound, and the S/N (signal-to-noise) ratio to block out ambient noises. A stethoscope captures fine inner vibrations transmitting to the skin surface from inside the body, and converts it to air vibration to deliver to the listener’s ear. This conversion is performed by the chest piece pressed against the skin. If the chest piece is of poor quality, the sensitivity of the stethoscope will be significantly deteriorated. To ensure sensitivity, quality of the diaphragm is critically important, but also condition of contact with the skin is important as well. Even when using a chest piece called bell type that has no diaphragm, only a slight floating of the edge from the skin will let sounds escape and impair the sensitivity. The sound captured by the chest piece is transmitted to the listener’s ear by way of the tube, which plays the role of delivering the sound without weakening. If the tube is too thin or light, it will not only let the inner sound escape but also invite ambient noises into the tube. External noises will also come in when the ear pieces do not fit the earholes. In the case of audio equipment to listen to music, their performance is measured by how well noises are kept at a low level compared to the music or sound you intend to listen to ? this is what the S/N ratio means. In the case of stethoscopes, the elements that affect the S/N ratio most are the tube’s quality and the ear pieces. When we consider all these factors, we find that a stethoscope is something quite complex. When choosing a stethoscope, “cheap and nasty” is out of the question, but high prices do not always mean good quality or performance. What “good calligraphers” should choose is performance. “Doctorphonette NEO” is a stethoscope with the highest-class performance, produced through years of efforts by the development project members who have thorough knowledge about characteristics of stethoscopes. The manufacturer KENZMEDICO is a long-standing partner of our Lung Sounds Conference. I expect that a stethoscope like this will spread widely from Japan to the world as a “KENZ brand” product.
July 2016