Dr. Zhen Xu describes the earliest days of her histotripsy research as a PhD student under Charles Cain, who told her not to read any papers on ultrasound therapy so her thinking would not be limited by convention. With no tissue to experiment on, she found a local slaughterhouse in the Yellow Pages and collected pig hearts from their dumpster every Thursday for a year of ultrasound trials that kept failing. When lab mates complained the repeated ultrasound bursts were too loud, she responded by both increasing the power and shifting the pulse repetition rate above 20 kilohertz, out of the range of human hearing.
- 01
The slaughterhouse initially charged five to ten dollars for the pig hearts before giving them away for free once they realized she kept coming back.
- 02
Xu frames her reasoning as an engineer's instinct: if a hammer does not work, try a bigger hammer, so she raised the ultrasound power rather than abandoning the approach.
- 03
She notes human hearing range runs from 20 hertz to 20 kilohertz, which is why repeating ultrasound bursts within that range were audible and disruptive to her lab mates.
458 words · auto-generated from the episode video
9:41about this paper, about like the fact that your lab mates thought that the ultrasound was too loud. And that was maybe an impetus for you to make it quieter. And maybe that. Yeah. So what happened is why, you know, basically volunteered myself to look for this impossible non-invasive surgery technique. And I came in with no background in ultrasound therapy at all. And I was like, how do I do it? And I talked to Charles Cain, my mentor, and trying to get guidance. And Charles literally said, um, you know, just go ahead and
10:22explore and don't read any papers. And I was like, Oh my God, why? And he said, you're doing something entirely new. And I don't want your innovative mind to be limited by the conventional thinking. So I, you know, like just don't read papers and I go and explore. So what I did is I started to open up the yellow page. I don't know if nowadays kids even know that, but you know, it's a phone book. So I found a number from, uh, for a local slaughterhouse. Cause I said, I need to get some tissue to do experiments. If I, you know, I, I was trained as an engineer. So if I, uh, don't know anything and I just should try.
11:07And because, uh, Dr. Ludomirsky mentioned a congenital heart disease. So I said, okay, what do I get? So I called a slaughterhouse and they were slaughtering pigs every week. And I said, can I come and get some hearts from the pig? And they were not selling those. So I went, uh, you know, I would go, uh, every Thursday morning at them. And then, uh, uh, the owners just like take me to a huge dumpster, uh, where they dump all the organs. And he just gave me like this plastic trash bag, just, you know, take whatever you want. You got it for free? Um, well, they figured out very quickly. I immediately got it for free. It was five bucks and 10 bucks.
11:49They made it out of business. So I would get a pig hearts by dumpster diving every week in a local slaughterhouse. And they get that, you know, trash bag back to the lab, but now do experiments, uh, uh, by dissecting a heart tissue, uh, right. And, and then try ultrasound, the parameters on those. And I tried, uh, you know, weeks and a month and a whole year, uh, I was, you know, I failed and failed and failed and didn't get anything. Uh, and for ultrasound therapy, a typical thing you do is, uh, well, ultrasound is called ultrasound because it's beyond our hearing range, right.