A Brief History of Tau with Links You Might Need!

Wednesday, October 25, 2017

Why can Mindray make the first Tau-measurable ultrasound machine?

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?

Let’s begin with a short Chinese story written about 2,300 years ago. There was a nerd who lived in Zheng, a small country within China. One day, he was planning to buy a pair of shoes. He measured his feet first, wrote it down on a piece of paper and went to the market. Once at the market, he realized that he’d forgotten the piece of paper, so he went back to fetch it. Upon his return at the marketplace, the market had closed. So he didn’t get the shoes. Others asked him why not just try the shoes on? The guy’s answer: Oh, I’d rather believe in the measurement instead of my feet. The author of the above story was a politician and philosopher intending to reform the old world. He was trying to persuade people to be more pragmatic and not to adhere to bureaucratic rules. 2,300 years passed, and we have more rules apparently. Like most things, rules can be a double-edged sword. The key is still and always will be the people. Making sense is more important than the rules, should be the message.

I published my first paper (in Chinese) to calculate Tau in an Echo lab in 1995. In 2008, I made the theory more persuasive and published several papers in English. For the last ten years, some researchers have verified my theories and their papers were still under review for publication. In the meantime, I contacted people from GE, Phillips…and Mindray for the possibility to integrate my formulas into the chosen software. My proposal is crystal clear; the theory deduction process is presumption free, which means no verification is necessary. For my simplified Tau equation, only one minor presumption is used. Interestingly, the published data (Nishimura, Circulation 1993) made a perfect verification for this simplified Tau equation. Some people are still not so sure if this is acceptable.  I think it is not only acceptable; it is more than appropriate, because it is very, very, objective! Lucky me, Mindray shared my point of view and made the first Tau-measurable ultrasound machine in the world.

Thank you, Mindray! You made my dream come true.

Currently, The rules for a mathematical equation to be integrated into an echo machine are pretty strict. First the theory is to be verified and published in a decent journal; next, the method needs recommending in the ASE guideline; next the method needs approval from FDA; next the echo machine manufacturers need decide if the equation should be integrated into their machines or not.

Generally speaking, rules are great, but they could be troublesome for people like our nerd in Zheng.  

Unfortunately, my theories are still stuck in the verification process. Usually the journal’s peer review system needs 3 reviewers, we found it hard to find appropriate reviewers, as the mathematical deduction process is a little bit involved for echocardiographers. I don’t think even Einstein would have any chance of getting his relativity theory published under our peer review system. Yes, there are some Tau experts in this world. We have tried to ask them for help with the review, only to find they are not as helpful as expected.

If you still think rules have to be kept at any cost, this next example is kind of telling: An expert from Harvard developed a formula to calculate Tau. This method was verified in Cleveland and published in Circulation. It was even recommended by the ASE diastolic guideline (2008).  Had I not written a letter to JASE to prove it wrong, there may have been a possibility that the FDA would soon have approved it. Looks like the rules can be taken advantage of, and in the wrong hands, could be misleading.

Making sense is the goal of rules, not vice versa. 

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