[aaron695]

It has nothing to do with the phone or the software it's the device, which if you could get down to a hundred $ or so it could be used by farmers of livestock.

This could be a revolution, but the Ultrasound Scanners need to be in the hands of low income farmers then imagine how quickly the dam ecosystem would develop across to humans.

I've been looking to get a cheap one from China, but you can't, I'm not sure why, but perhaps it needs a certain chip that is not made cheaply yet. There are DIY's around but seem immature.

If you want to change the world, get the price down for use on animals.

This is a good first step, but while the medical community is in change it'll move at a snail pace which means a lot of people will die.

[tim333]

I guess it's hard to make a decent one. You can get scanners from about $600 up from china. Apparently you need an array of transducers which cost a bit.

I'm not sure why the Africans need a $2000+ butterfly scanner rather than this kind of thing https://www.aliexpress.com/item/Veterinary-ultrasound-machin... ?

I presume the Chinese one isn't as good. The images do look a bit blurry.

[mtw]

I'm not sure you can mass market it. You need medical knowledge to make sense of ultrasound images. Unless you plan to use it for something else than medical

[bluGill]

A lot of farmers have a surprising amount of medical knowledge. It is common for farmers to do a lot of simple medical procedures on their animals. Large farmers in the US already have ultrasound machines for their cows - they don't need to know everything about how to read them to know signs that mean call in help (thus saving a lot of money)

[close04]

Knowledge of animal anatomy or certain medical procedures are no help in trying to decipher an ultrasound image. I don't think you can just plop an ultrasound scanner into a farmer's hands and have them to do anything truly useful with it, to justify the investment. Not without training.

One option would probably be to have a doctor remotely in a "command center" just looking at these as they are uploaded from the field, and relaying the diagnosis back to the farmer.

[bluGill]

How much training do you need though: A one day class can cover "this is is normal, this is where you need help". Of course these are animals: farmers are willing to make economic decisions here. The risk/cost of a rare disease going undetected vs time to learn how to accurately diagnose it (or pay someone who has the training) is something that can be talked about.

[close04]

> A one day class can cover

...probably not much more than a 1 day C++ course would offer a random person. :)

That's nowhere near what a farmer needs to read much into an ultrasound. It takes a medical student years of learning (medicine) topped by a lot of practice and experience in imaging until they are useful in actually reading an image. And even a 1-2 day course costs thousands of dollars.

It would be a massive expense for very little real life benefit. I'm guessing AI and a remote doctor would do better. I kept reading a lot of good news recently about AI helping with diagnostics in medical imaging so I guess we can't be too far.

[tonyarkles]

Over the weekend I had a veterinarian tell me that he wasn’t capable of properly interpreting an ultrasound! He did an x-ray and saw something concerning, but being Easter weekend there were no ultrasound techs in the office. I had to take my cat to a different clinic, where a pro successfully figured out what was going on.

I agree fully that a 1-day course isn’t going to be enough here. Radiologists go to school for a while to get good at both the imaging part and the interpretation part.

[moneil971]

In the article, the dr uploads the scan for confirmation. I agree the average person shouldn’t be trying to self diagnose from a scan, but anyone could upload a scan to a dr they couldn’t travel to.

[et2o]

Ultrasound is actually something that requires training and The imaging quality is very operator dependent. This physician is definitely reading the scans himself and acting upon them; uploading might just be for some kind of confirmation and formal quantification.

You can't just hand someone a probe and expect them to produce meaningful images. Especially in this kind of context where presumably they are getting used in dozens of different contexts; it really does require some medical reasoning and anatomical knowledge.

[et2o]

The price of a portable ultrasound has little to do with the electronics as far as I understand it. Production of the probe's ceramic transducer is expensive.

[itajaja]

Yes you are right, except for the fact that this probe uses a silicon chip instead of a piezoeletric ceramic transducer, and that's exactly the reason why it costs 2000 dollars.

[DoctorOetker]

Right, but that is what the parent is hinting/asking: can we make whatever expensive parts more cheaply? Can we find alternative measurement setups?

Regarding the price of piezoelectric transducers, the typical buzzers (i.e. the flat round piezo discs) are very cheap.

===

Idea 1: Using piezo buzzer elements (the piezo disks):

The piezo discs are ridiculously cheap, but large monolithic transducers. There is a trick to partition them into multiple transducers:

The piezo disc transducers are essentially: a steel membrane, onto which a thin layer of piezoelectric material is deposited, onto which a very thin and weak layer of metal is vaporized, onto which leads can be soldered (at low temperature).

The steel membrane defines the resonance frequency in its monolithic configuration, and can be thickened to make it less flexible, say by electrodeposition of copper in a copper sulfate bath, in order to make the steel membrane a more rigid base (since we are interested in the local pressures and not the global pressure which deforms the disc).

The thinnest metallic layer on top can be easily patterned even mechanically, see for example:

https://web.archive.org/web/20071214032759/http://www.geocit...

Here the single disc transducer is patterned into 4 independently transducing quadrants. For context on the motivation of that page, it is for actuating a scanning tip for a Scanning Tunneling electron Microscope (STM).

Essentially they just use a ruler and a fine blade to cut the metal layer, and then clean up any remains with a pencil eraser to clean the surface for soldering and eliminate any conductive burrs after the cut to prevent shorts between the quadrants. It's pretty genius.

For context on why they want the 4 quadrants for the STM see: https://web.archive.org/web/20121114015437/http://www.geocit...

So in theory you could lay out a grid of piezo sensors this way, and then solder afterwards, or alternatively pattern the thin metal layer in such a way with traces such that between the top pads of each new subtransducer there are thin traces going to the edge of the piezo disc...

The patterning could happen mechanically or perhaps more sanely lithographically: spin coat (on a CPU fan) some photoresist, pattern with minification (don't need 5nm resolution) then etch the metal layer away... This seems to be within financial reach of top universities of even the poorest nations...

The cheapest buzzer element on DigiKey (helpfully without leads presoldered): https://www.digikey.com/product-detail/en/murata-electronics...

$ 0.19827 @ 8k pieces

(Cheapest in the naive sense of sorting by price, ideally you'd go through the list of 107 active products and inspect the price as a function of quantity)

The largest buzzer element on DigiKey (larger to allow more sub transducers to be defined):

https://www.digikey.com/product-detail/en/pui-audio-inc/AB65...

$ 2.67 @ single piece $ 1.4 @ 1000 pieces

(Largest in the naive sense of sorting by diameter, ideally you'd again go through the list of 107 active parts, and check the datasheets or images to estimate the actual piezo area diameter as opposed to the metal base diameter)

For the full list of active (currently buyable) DigiKey piezo elements: https://www.digikey.com/products/en/audio-products/buzzer-el...

For patterning one could use an analog camera, and focus it on a high resolution monitor, try and develop a couple of times to find the best setting for final resolution. then place the piezo with photoresist in place of the film...(probably irreversibly modify the analog camera a bit). Photoresist should be relatively cheap if its consumption is properly planned.

===

Idea 2: Using pressure sensitive paints, and optical readout.

Wikipedia https://en.wikipedia.org/wiki/Pressure-sensitive_paint

Pressure sensitive paints work by sensing the local oxygen concentration, which may be problematic in aquous conditions, perhaps it could still work on dissolved oxygen? Perhaps variations on oxygen-based PSP could be designed for liquids (better impedance matching with human body).

Perhaps a layer of PSP can be cured/dried in a flexible foamed state (with trapped air bubbles). Such that it can be brought in contact with water but still retain trapped air?

===

Idea 3: Using "schlieren photography": I am unable to find it back, but years ago I saw a video (I believe from some israeli university/college) where they somehow used Schlieren photography in water (which is rather incompressible) to visualize the beam quality and spot size of the transducer & accoustic lens / ...

If Schlieren imaging was used to characterize the quality of the ultrasonic beam, it suggests that perhaps Schlieren imaging could be used directly, if properly miniaturized etc...

One can easily find papers on the subject of using Schlieren imaging for characterizing hydrophones etc...