Dr. Zhen Xu describes what happened right after she first produced the histotripsy effect: she went back to confirm it was repeatable, but in doing so destroyed the most expensive equipment in her advisor's lab. When she published and presented the parameter set that created the effect, other scientists in the field said it was impossible, both because no commercial ultrasound equipment could produce those settings and because no one, including Xu herself, understood the underlying mechanism of how the cavitation was being controlled. She describes this as a eureka moment followed by a long stretch of work to build custom equipment and figure out how the effect actually worked.
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Xu calls the specific settings that produced the effect her 'magic parameter set,' discovered before she understood why it worked.
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The confirmation experiment that proved the effect was repeatable also broke the lab's most expensive piece of equipment.
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Scientific peers rejected the finding on two grounds: existing commercial ultrasound equipment could not generate the needed parameters, and the cavitation mechanism behind the effect was unexplained.
481 words · auto-generated from the episode video
14:56And I remember I had that piece of pig heart tissue in the water tank. And in front of me, I saw there's like, almost like a smoke coming out of the pig heart tissue, but it can't be because it's in a water tank. And within a minute, I saw a hole through that pig heart tissue. And I thought I was dreaming. Cause it's like, I dreamt it so many times. And I was like, this can be too, this just can be too. So I repeated second time and I repeat it again. And my rule of thumb is if we repeat three times, it must be true. And that's why I started running into Charles' office and I like, Charles, Charles,
15:38you need to come over. Something really special just happened. And that was in 2002 when I first discovered hysterectomy. That is such a cool story. So from dumpster diving, you went from dumpster diving for pig hearts to like this eureka moment. My site, you know, special silent whole sequence. And then the funny thing is, even though it was occurring, supposedly repeating beyond our hearing range, but when cavitation occurred, it make this crackling sound. So it's still not really quiet. But that was a serendipity that led to the discovery and honesty speaking at
16:18the time, I had no clue what was the underlying mechanism. I had no clue how it worked. So I first discovered this specialized parameter set, this magic parameter set. Then I had to go back. It was really funny because, you know, this big discovery, I was so proud of it. And literally within a month later, I went to Charles' office again. And I said, Charles, there's good news and bad news. And Charles is like, what? I was like, good news is I was able to repeat it. So it's true. So it's true. Yeah.
16:59The bad news is I just broke the most expensive piece of equipment in the lab and I'm too poor. I can pay for it. But I realized at the time that histotripsy required a very different set of equipment. And it just couldn't be produced even with best commercial ultrasound equipment at the time. So then, you know, that's why after I published that paper and presented it to the scientific peers, they all came back and said it's impossible.
17:39Why is the parameters you talk about cannot be produced by any commercial ultrasound equipment, even the best one. Secondly is that nobody had a clue how it worked. We think it's cavitation, but how do you possibly control cavitation to do this? So it's impossible. No equipment, no mechanism. So it was a eureka moment followed by a long period of time where I had to really figure out, you know, give up our own equipment and really understand