Editing Stethoscope (section)

===Doppler===

A Doppler stethoscope is an electronic device that measures the [[Doppler effect]] of [[ultrasound]] waves reflected from organs within the body.  Motion is detected by the change in frequency, due to the Doppler effect, of the reflected waves.  Hence the Doppler stethoscope is particularly suited to deal with moving objects such as a beating heart.<ref>S. Ananthi, ''A Textbook of Medical Instruments'', pp. 290–96, New Age International, 2006 {{ISBN|8122415725}}.</ref>
It was recently demonstrated that continuous Doppler enables the auscultation of valvular movements and blood flow sounds that are undetected during cardiac examination with a stethoscope in adults. The Doppler auscultation presented a sensitivity of 84% for the detection of aortic regurgitations while classic stethoscope auscultation presented a sensitivity of 58%. Moreover, Doppler auscultation was superior in the detection of impaired ventricular relaxation. Since the physics of Doppler auscultation and classic auscultation are different, it has been suggested that both methods could complement each other.<ref>Mc Loughlin MJ and Mc Loughlin S. Cardiac auscultation: Preliminary findings of a pilot study using continuous Wave Doppler and comparison with classic auscultation Int J Cardiol. 2013 Jul 31; 167(2):5 90–91</ref><ref>{{cite book|url=https://www.amazon.com/Cardiac-Auscultation-Continuous-Stethoscope-ebook/dp/B00AXFB2IG/|title=Amazon.com: Cardiac Auscultation With Continuous Wave Doppler Stethoscope: A new method 200 years after Laennec's invention eBook: Mario Jorge Mc Loughlin, Santiago Mc Loughlin: Kindle Store|date=5 January 2013|publisher=Mario J Mc Loughlin |access-date=24 September 2015}}</ref>
A military noise-immune Doppler based stethoscope has recently been developed for auscultation of patients in loud sound environments (up to 110&nbsp;dB).