Digital technology for objective auscultation in traditional Chinese medical diagnosis

Auscultation is one of the Four Diagnosis Methods in traditional Chinese medicine (TCM). It has been researched through various methods, including digital techniques. This paper is aimed to review studies using digital signal processing techniques in recent years. Two kinds of methods (traditional methods and nonlinear methods) were illuminated briefly, including principles, main parameters and algorithms. According to the two methods, the studies were narrated and evaluated respectively, including tools, parameters, algorithms, aimed diseases and diagnostic effects. Researches on automatic stethoscope also been discussed, which research object was not speech but the sound of viscus. A new microcosmic technology - sonocytology and its application foreground in TCM was introduced simply, too. Finally, the conclusion was made. This survey provides a summary on the progress of digital processing techniques for auscultation in TCM, and will be useful for future researches in this area.