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by LiesNStartupPR 3464 days ago
A 2 cent PZT buzzer is ridiculously far from an ultrasound probe, engineering wise, and your units are off by about three orders of magnitude. And soldering depoles PZT.

A transducer does not cost as much as a car (well, not a well made car), but a system does. That's the cart plus a number of transducers.

Yes, I only covered the transducer in that post, but as I noted, the systems and software deserve their own Pt II. It takes time to write this kind of stuff you know?

Your other points I try to answer in my updated blog post along with many others here in this thread.
1 comments
hwillis 3463 days ago
What units? Thickness mode resonant frequency? The cost? injection molding precision? The 100 micron thing? I have a PZT buzzer on my desk that I measured the thickness resonance, which is 5 cents in units of 10k. Injection molding accuracy is around a thou, but the precision and surface finish is impeccable. I also have on my desk parts with 0402 resistors- 500 microns wide, 350 microns tall. I soldered them by hand without magnification. 38 AWG wire is 100 microns wide. 100 microns is wide enough to drive a truck through.

Soldering with silver-lead depoles PZT. Bismuth solder does not and regardless repoling PZT is trivial- a couple hundred volts at most, and temperatures below the melting point of plastics.

The transducer is the only part of the system that should concievably be expensive, though. Doctors don't use special, medical-company made laptops- they use thinkpads or dell or whatever. The cart is unnecessary! It shouldn't be where the cost is coming from. The cart should add a few thousand dollars. The electronics have no business costing tens of thousands of dollars. The R&D, the software, and the transducers are the only plausible money sinks. If making a monitor is expensive, the companies should buy a cheap laptop and write an application to run on it.

I do really enjoy your posts but I am firmly in the camp that the price of ultrasound machines is an order of magnitude too high. I also think it needs to come down ASAP and that the future of cancer treatment really depends on regular ultrasound screenings and machine learning.

Edit: also, to back up my statements about the electronics: https://news.ycombinator.com/item?id=13245998

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