In 1976, the left ventricular diastolic time constant, Tau was found at John Hopkins. According to the definition, it can be accurately measured in a catheter lab, and soon, Tau was well accepted as the best index to describe left ventricular diastolic function. For the possibility of measuring it in the Echo lab and make it more accessible to clinicians, intensive investigation was done in 1990s at Harvard, Mayo Clinic, Cleveland, Osaka University, etc.
However, Mindray, the largest Chinese medical equipment company has just launched its Tau-measurable high-end ultrasound machine DC80. How? Why?