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What's up with WATT, Pt I (or "What's Wrong with Tech Journalism?")

It's been a while since I covered Energous (whose ticker symbol is WATT . Other posts are here , here , here , here , here , here , and...

Friday, December 30, 2016

Quick guide to spotting non-existent tech

I covered this earlier in a different post, but I wanted to highlight this list from an article in The Register, as a "Quick guide to spotting non-existent tech". Read the company press then go through this checklist when questioning their claims and whether there's more sizzle than steak.
  • Refusing to give a launch date.
  • Refusing to talk about the tech, claiming confidentiality or trade secrets.
  • Using news of investments or hires as evidence of technological progress.
  • Promoting itself on a big stage rather than in a small room.
  • Offering a well-crafted message and vision but becoming immediately vague when pushed on actual details.
  • Offering "exclusive access" – with restrictions.
  • Confusing working hard with making progress.
What's interesting in this is how many of these points require a compliant press, many of whom prefer publishing hagiographies rather than investigative pieces - after all it's quicker, easier, and doesn't end up making enemies among some rich and well connected people. Look at the months and years of work it took for John Carreyrou to uncover what was happening at Theranos, all the lawsuit threats and denials by the company. Isn't it much easier to do a puff piece on Elizabeth Holmes and how she just wanted to save the world? Garrett Reim of the LA Business Journal tweeted a comment on this yesterday following an article on the Unethical Side of Silicon Valley by Erin Griffith (which I'll comment on in a separate post).
This hits the nail on the head, though I think he may be being a little kind - and don't know which of the terms "enabling", "willfully ignorant", or "complicit" is more apt. That may sound harsh, but remember that the press is part of an ecosystem, and it's clear the incentives now reward them more for page views than accuracy or in depth reporting. They're supposed to be watchmen, but some are making money while choosing to look the other way.

How to improve this situation? All I can suggest is to follow the work of the good journalists, and ignore the 'work' of stenographers posing as reporters. Subscribe to the publications that do the hard work, and deny the others the benefit of claiming page views. In the end, money talks.

Monday, December 26, 2016

Medical Ultrasound Systems Pt III, Where I Talk About Some of the Interesting Portable Devices That Are Now Available

I hope everyone had a great Christmas. Having taken a couple of days off, there were some questions that came in on the two previous posts I wanted to answer and give some decent answers to, mostly regarding the newer portable devices that are available. I have not personally used these devices so can only go by what I have read online and can estimate based upon images, specs etc, and am neither endorsing nor criticising. This is also not an exhaustive list.

First of all, new products testing out the new parts of the market are great, and I'm really glad to see them. For those of you who think that the "Cabal of Wicked Ultrasound Engineers" is trying to protect their vast and profitable market from cannibalisation, I can just say that there are so many imaging modalities and opportunities still to be exploited within ultrasound that as premium features migrate to lower cost systems, I have no doubt that the premium systems will add new features and still provide value at the high end. This will result in a larger market for ultrasound that is split into multiple segments and price points, which I think benefits patients as well as the entire industry and all the people in it.

So onto the products. First, Lumify. This is a handheld device from Philips for use with tablets, here's a basic review of one. They currently have three transducers, which look to be one each for cardiac, abdominal, and vascular. Both power and data use a micro-USB cable to the tablet, which seems to be Android only, I'm going to guess that Apple taking 30% of the price via the app-store is a product killer. Given they charge $199/mnth and up, I'm assuming (given a 36 month period which is usual) that purchase price is between $7000 and $10,000 but have no hard data one way or another on that. At that price, it would be cheaper to buy a tablet, pre-install the software, and sell it than pay the 30% Apple tax. As an aside, I'm surprised Apple don't have a program for hardware and larger companies to pay a smaller percentage or fixed fee in order to open up this type of market for their products.


It looks to use the standard micro-USB B connector, which means up to 480 Mbps data and depending on what they use for power can supply between 2.5 and 10W at 5 Volts from my reading of the spec. All power is supplied from the tablet/phone, which will limit the total usage time since a phone has around a 5Wh battery, and tablets maybe 30 Wh. Both tablet and phone will be using power as well for some computation, graphics, and display, all of which are big power draws. I posted a link to the Verasonics system specs in a previous thread, which noted between 8 and 100W supply, so you can imagine that use time will be severely limited between charges. Also note that the Verasonics system supplies up to 190V signals, so at 5V supply there's going to need to be some electronics to step up the drive signal.

Looking at the probe images, the handles are large, there may be not just electronics in there but perhaps also a small battery to extend use time. It would be interesting to know what a sonographer thinks using it, as I expect it to be heavy, as well as potentially awkward to hold especially if a fair amount of force has to be applied for a good acoustic window, but it does have the advantage of a very thin and light cable.

Given it's USB, there have to be ADC's in the transducer taking it to digital, and you can see with a limit of 480 Mbps, that if you assume 100 channels that's basically 5 Mbps per channel, for a multi-MHz probe. It's clear that some form of compression, early beamforming etc is going on. Where those compromises are made I can't say, as I have no images etc to evaluate it on beyond marketing.

There's more than just basic b-mode imaging (an explanation of imaging modes is here) in these probes according to the website, which is good to see and more than I expected. I can't evaluate anything on image quality, and have to expect that a lot of compromises have been made in order to create them within a very limited power and computation budget. Other reviews of similar products seem to indicate that as a basic imaging device it performs well, though certain more precise or complex imaging needs (such as needle location) are not well supported. To expect such a system to do everything that a full cart does is, of course, ridiculous, and it's a question of whether the team created a product that's useful enough to serve a function.

These products have been out on the market for over a year, nearly 2 now, and I've yet to hear a huge buzz regarding them, though I think the general consensus is an appreciation for the work that went into them and that a good job was done. Is it enough? Over time the market will tell - perhaps a further generation or two of development is needed to really have them take off.

Note that all these type of products still require FDA clearance to be sold as medical devices, so it seems that regulatory compliance is definitively not what is stopping ultrasound at a lower price point. The existence of these devices is a pretty good proof point that the regulation-as-the-bad-guy argument is not appropriate. Further, despite the claims that sub $3,000 systems surely can be made on this blog and others, note that even with all the compromises made, and the screen/computation cost externalised, the price point is still estimated to be $7,000 to $10,000.


Another similar product just out is from Vancouver based Clarius, having also just been FDA approved (go regulation). This is an entirely wireless device, though if you look at the pictures the handle is enormous and has to be held in a very non-traditional manner, as what I assume is the large battery pack and vents for air cooling (or maybe not, I just saw a picture of one underwater) take up the majority of the device. Specs say it weighs 1.2 lbs, which is pretty heavy, and claims ~45 minutes usage. I'd really like to hear a sonographer's take on using this for extended periods - though extended use may not be the target use case. Online prices seem to also be in the $7,000 to $10,000 range. It uses wireless-N so has similar bandwidth limits to the Lumify, and so most if not all the processing will have to be done in the handle. It seems to support fewer imaging modes than the Lumify, but does use iPads, so would be interesting to know how that economic model works (transducers and software sold separately, with most cost in the hardware side?). Hard to say more, but it looks like a first generation device that's made compromises to achieve some very specific goals (like all good engineering does!), I'll be interested to see how it does in the market.


Just as another point, I wonder how the support for these devices works when it's connected to a standard, general use, tablet/phone? Having supported commercial software on multiple OS's, it's a support nightmare when you have to deal with OS versions, drivers, firmware, and all the other variations that a non-dedicated hardware platform brings. I might be tempted to simply sell the tablet with the transducer as a dedicated device that's locked down and save myself the support headache.

There are also some very low cost devices I see on Alibaba, such as here, claiming to be $200 to $1,500 for a wireless transducer. To include the transducer, the electronics, the battery, the wifi, the software at that price (esp $200!), I simply don't believe it, you just can't even buy the parts for that, let alone pay for labor or make a profit, even under the most generous assumptions. The devices covered above will meet a need and deliver performance, this no-name thing, just no. You'll get what you pay for here, but feel free to go buy one if you want to prove me wrong!

So in summary - and remembering I've not used these devices myself and am only going by what's online - they look to be interesting devices that serve a limited function, and have made compromises to meet the lower cost and portability goals. It's low cost, no frills, and great that this part of the market is being tested - and the market will respond. If they meet a need, at the right price, they'll be bought, and companies will move more resources toward it, and over time as electronics and battery tech improves, they'll get smaller, lighter, and higher performing. I don't, however, know if there is pressure for the premium systems coming down in price range, just more and better capabilities added, and the overall market growing.

Friday, December 23, 2016

Medical Ultrasound Systems Pt II, Where I Stand by My Statements That They're Actually Inexpensive

So my recent post on ultrasound systems costs got a lot of attention, more than any article in some time, mostly due I think to a thread in HackerNews dedicated to it. My original post had some good questions pop up in the comments, and same in the HN thread, along with some replies that clearly had particular assumptions about the medical ultrasound industry. I'll try to address them all in this post.

Now, for those of you who are genuinely interested to get answers, I want to provide them as best I can, and any snark in my post here is not aimed at you. For those who want to sit on the sidelines and snipe, the snark most definitely is. Each of those groups, please read what I write with that in mind.

First the more technical side of things. (When I reference a conference, I'm meaning this one the IEEE UFFC Society International Ultrasound Symposium. There are others, but this is a great example.)

1) "What about more electronics in the transducer, and GPUs for beamforming?"
Good question, and transducers are already headed in that direction. After Philips introduced the first real 2D array in around 2003 that was enabled by sub array beamforming electronics in the transducer, there have been advances in that area. However it's important to understand that development of electronics (usually an ASIC) dedicated to a single transducer application is a large investment in money, manpower, and time, then there's the integration of that in the acoustic stack, and making the whole thing work together. It typically takes a substantial team several years to develop that product, and while advances in processes available make this far easier in 2016 than it was in 2003, it's still a lot of work to do. Each of the large companies has a small number of 2D arrays available, but they have to offer substantial benefits over their 1D counterparts as, no surprise, they are a lot more expensive.

Further, make an array 2D instead of 1D and now you've got new data processing challenges - volumes instead of planes, thousands of individual signals instead of ~200. It's all the more computation, so even though the compute available today is increased over the past, the demands are growing too. At some point the computation available economically will exceed the need, but we're not there yet.

But what about the regular 1D arrays? Well, yes there can be more electronics put into there, but remember there are 10 to 20 transducer types per system (cardiac, abdominal, vascular, obstetrics etc each with their own needs), and what makes more sense - a single system with all the common hardware for sampling and beamforming that serves multiple transducers, or all the electronics replicated in each transducer and a simpler system? Economically, right now it makes sense to have all common components in the system, but if electronics get much cheaper/better, then that equation will change and it's something under observation all the time.

If you look here, you'll see the specs for Verasonics open platform which is a nice hardware package for someone to learn, test, and develop ultrasound on, though commercial premium ultrasound systems are often specced somewhat higher. Sampling is up to 62.5MHz, 14 bit, 256 channels - that's up to 224 Gb/s, or around an entire Blu-ray DVD per second. Thunderbolt will get you to 40 Gbps, so place that all in context and realise that as good as modern electronics are, the demands from high end ultrasound are still beyond it. That will change in time, but again, we're not there yet.

Also note that the voltage that system supplies is up to 190V p-p, which means you can't use the smallest process nodes and get a lot of electronics on each wafer, you have to stick with a process node capable of handling that, so larger electronics and higher cost - and that's not likely to change anytime soon, the fundamental physics limits performance per volt (again, at least for now until better materials come along). The last several years have seen an improvement with the advent of single crystal piezoelectrics, but right now there's nothing on the horizon giving such a leap again in sight.

Then there's heat. Electronics generate heat, it's just in their nature. A few watts in something as small as a handheld transducer can rise in temperature very quickly, and either burn the patient or the sonographer. There are stringent FDA rules as to how hot a transducer can get, and performance is always limited to make sure that never happens - the transducer basically performs worse than it could in order to be safe. If the electronics for each channel produces 50mW then on a 200 channel probe that's 10W, and will be too much - but if the electronics are 5mW it's 1 Watt total and now gets more interesting. If power consumption could be so low, then it's more of a size/economics argument, not practicality.

Now beamforming. To begin with, for the technically minded among you, here's a great presentation covering that topic in way more detail than most need. It's from 2005 so a little outdated on some specs, but the basics are still the same. For everyone else, beamforming is taking the raw data and creating an image from it. This involves taking that large flow of data (that 224Gbps), performing a ton of maths operations on it depending on what the imaging mode is, and displaying it, basically a lot of signal processing. The presentation ends with a summary of trends "Analog electronics into probe, digital electronics into software" and that is exactly what is happening, with GPUs now powerful enough to begin to take over from specialised hardware beamformers in some cases, and is likely to increase in speed over the next few years. It will take some time before you see it in the clinic as systems tend to last a decade or more, but it's coming.

So as far as electronics are concerned, there is progress, it is happening, but some of the intense demands of ultrasound mean that the electronics isn't quite there yet, or is only just getting there, and at the same time demands are growing as 2D devices become more prevalent. I expect in 20 years that we'll be looking at a different ecosystem for ultrasound, as cost and performance of electronics shifts workloads between system and transducer.

2) "What about micromachined devices or 3D printing of them?"
Another great question, and something that's been investigated in ultrasound over the last couple of decades. MEMS have been the subject of a lot of funding by both companies and industry for over 20 years for ultrasound. For example, in the early 1990's cMUTs (Capacitive Micromachined Ultrasound Transducers) were hailed as the next great thing in ultrasound, and today in 2016, outside certain specific applications, we're only just starting to see the first commercial devices. That's not due to a lack of effort on the industry's part, all the major players have put major investments into it, but it hasn't quite panned out. There have been issues, many of which have been dealt with, but overall at this time they simply can't outperform piezoelectrics and standard manufacturing in quality and price. There's still work to be done in them, and if they can be made a little better, a bit more consistent, and a bit lower cost, then they will grow in a number of areas, but they need to reach that level of performance that makes them viable. At that point then cost can come down as demand grows, and that virtuous cycle will push more lower cost applications out there. Check out the conference I noted above, there were multiple sessions dedicated to this topic there, and it's got a lot of people working in it. Foundries and semiconductor companies would love to have another high volume application for their fabs, but the right mix of performance, cost, and demand aren't there yet.

pMUTs (piezoelectric Micromachined Ultrasonic Transducers) are being looked at but have some additional difficulties on top of cMUTs. Piezo materials tend to be lead based for good performance, and people don't tend to like lead in their semiconductor fabs, essentially it is often 'not process friendly'. The materials that are, such as ZnO and AlN, are much lower performing so it's limited to applications like FBARs (filters in your phones). There's some promise with scandium doped AlN for better performance, and fabrication methods that allow for better performing piezos, and it's a field to watch but there are still issues. Again, the conference I mention above had a special session on exactly this topic with invited speakers, and was a big draw. Smart experienced people in this field are interested and it will grow.

And 3D printing? It's tough to print some of the active materials and other specialised components of a transducer, but again it's being looked at.  GE, among others, is putting huge company efforts into this, and they and others have given presentations on this effort (again, that conference mentioned - it's almost as if smart people in the industry are thinking about this kind of stuff! :) ) So again, early days, but advanced manufacturing is coming, and it will help with performance, reliability, and prices.

3) "I can buy off the shelf parts for $x, why does the system cost more than $x?"
Quite simply because it takes a lot of effort and manpower to put together a reliable, robust, validated platform upon which people's medical decisions can be based. This would be the case with or without regulation, any product takes this amount of work. If you build something poor quality, you get one sale and no repeat business, and word travels fast - in a competitive world like ultrasound, you lose your name quickly and you're done. Each transducer has to support multiple imaging modes - b-mode, harmonic, doppler etc - and each takes time to program and validate. Then you have to support it, and keep your customer happy, all while keeping your staff paid well enough to not jump ship to the latest social app, and be building the next generation of improved systems. Basically, standard business issues and costs that face any long term enterprise. Oh, and profit, that helps to keep companies going, products being made, and new advances worth funding.

In summary - this stuff is coming, but it's not as easy as you might think, and it's not a microphone on a smartphone that can fail or be disposed of in a couple of years.

Want to be a part of it and learn more? Please do, our industry is always looking for talented people to help make ultrasound better. Attend conferences, take it as a postgraduate course of study, join an ultrasound company or start one. Want to really get involved? Message me, I'm well connected in the industry and will put you in touch with anyone I can to help.

Now the more business side of things - and again, remember the snark is not aimed at those with genuine questions and interest:

4) "You didn't give detailed costs of all the components to prove it's priced low"
First of all, doing so would lead to an exceptionally bland article reading more like a parts list, where I wanted to give more of an idea of what is involved in building a system and that it's not as simple as you would think. The original piece in Medium was based on a number of statements about the simplicity of ultrasound and I wanted to make the point it's a difficult, multi-disciplinary task with a lot of trade-offs. To someone versed in the field, it basically read as "I can build a soapbox derby car for $100, if I stick a motor in it I have a car! Why do these car companies charge $50,000 for one of their cars!?!" (I exaggerate, but not by much.)

Secondly, I actually have to be careful about stating specific numbers, both in pricing and capabilities. I've done work for a number of ultrasound manufacturers, and I have to be sure I do not release any proprietary information, so I tend to err on the side of caution here and make sure to be certain that everything I talk about is already public domain. I'm happy when people not encumbered by such restrictions pitch in.

Lastly, the market is highly competitive, and the fact that it's not priced lower is indicative that something is both worth paying for and priced correctly. If you think the market isn't competitive, I'm not sure what I can say to convince you otherwise, but this next part will try.

5) "There's a conspiracy among manufacturers to keep prices high"
I have to say, hearing this surprised me. I've been in the industry for over 20 years and never once even seen the hint that this is happening in ultrasound, with massive evidence pointing instead to intense competition. It's a multi-billion dollar market (est ~$6 billion), with several large international players (this link here has some of the larger, this link here shows dozens of smaller ones, this market research report mentions 25 companies), and regulated in a way that it's hammered into everyone to be sure there's no price fixing, collusion/cartels, or other anti-competitive behaviour. Companies have moved up and down the rankings significantly over the last decades, each is always looking (ethically and legally) for a technical or price advantage over its competitors. Medical ultrasound is also a heavily regulated market, and multiple countries (esp the EU and US) will come down hard on a company in this space participating in anti-competitive behaviour.

In every company I've worked I've seen strong pressure to simultaneously raise quality and reliability while lowering costs, and if you look at systems on the market today compared to the past then there have been major improvements at the top end where prices have remained fairly constant, and this has had the knock on effect of allowing the introduction of lower cost and capability systems further down the chain that exceed the capability of yesterday's premium systems.

If someone could start a company that produced ultrasound systems at quality and consistency, with volume, but lower cost, I guarantee you they would be bought by one of the bigger players to incorporate and take advantage of that technology. So if you feel there is a conspiracy, and that ultrasound systems are in fact easy to make, then feel free to start that company yourself and take advantage of the free money everyone else is passing up. Or, even better, I'll help you - quite seriously, email me, tell me what we're doing wrong, and I'll either find a way to hire you, get you a job in the industry, or let's start that company and make our millions. Seriously, mail me and let's do that, or if you're certain there's a conspiracy then I can provide you with the contact details for various regulatory agencies in various countries who would love to see your evidence they can prosecute with.

To make it clear - few industries actually operate in a market that has such intense competition, among many large players, each trying to provide the customer with the best price and quality mix to make the sales, and leapfrog their competition. This is not an "Intel own 99% of the server market and have little competition to drive prices down", it's more like competition in the car industry where there are many players competing.

6) "Engineers don't know what they are doing and are passing up really obvious and simple things that will make the products much faster, better, and cheaper."
This industry is made up of thousands of dedicated engineers, researchers, and support staff who are smart, highly educated, very experienced, and highly capable. If they wanted to, many could move to doing things like apps, social media, or whatever the fad of the moment is and make more money with less stress. But they don't, because they love what they do, they live to make technology better, or faster, or cheaper, and because they know that the work they do in ultrasound imaging helps people and makes a difference. That they'd willingly pass up technology advances and better methods just goes against character, and given the attitude of these people and the competition in the industry, if management decided for them not to pursue such benefits, they'd leave for another company or start their own. 

There are multiple professional organisations that are dedicated solely to ultrasound, and heavily to the medical side of that. IEEE UFFC is one such organisation, I'm heavily involved in it, and there are several others. The IEEE is non-profit, solely concentrating on technology, and does not support any single company or commercial interest. They produce peer reviewed journals on state of the art in transducers, materials, electronics, systems, and imaging, and every year have a conference where a couple of thousand people attend and present, discuss, and learn about the best practices and technologies. This year I watched presentations on 3D printing of transducers, new materials, rapid imaging techniques made possible by GPUs, micromachined devices, and advanced electronics for transducers (This page has a list of talks and the abstracts if you want to see what was covered). These are things that companies are spending plenty of resources researching, universities have students doing Ph.D's on them, and over time will make their way into products as the technology matures and becomes reliable and cost effective.

If you feel that, without experience in this industry, you are already superior to those who have worked in it for years, then send me your resume. I know companies that will hire someone so skilled to give them an advantage over the competition, or will hire you as a consultant. Or I'll help you get an abstract accepted to the IEEE UFFC conference so you can get your knowledge out there. I'll work with you to get a grant from the NIH or NSF to develop your technology and patent it, or just put it out there online for the world to see - do it for the benefit of the world. Or admit it's armchair quarterbacking. Plenty of options.

Summary - The field is made up of smart, dedicated, and committed people who strive to make quality, well priced products at a variety of price points that make technical and economic sense. Please don't make statements that are predicated on them being stupid, ignorant, or greedy without some evidence to back it up.

7) "All the costs are regulatory, without the FDA we'd have safe machines at a fraction of the cost!"
This is going to be tough to disprove without giving internal costs from various companies, and I can't, and won't do that. I know that regulatory is certainly an aspect of it, but doing a headcount it's not in the top few for costs. There are engineering tests and documentation burdens, but they're really not far beyond what any engineering team concerned with good record keeping and producing a safe device would do. And importantly, having clear regulations allows all participants to compete on a level playing field, knowing that everyone is playing by the same rules.

Yes, you can buy a veterinary, unregulated ultrasound machine from AliBaba. Good luck with it giving you a quality or even useful image, not injuring you, being reliable, or getting any support on it. Or getting it to do a fraction of the things a premium ultrasound system will.

Once again, there's a reason that ultrasound is the most widely used medical imaging modality, and is incredibly safe, and part of that is the FDA and similar regulation.

8) "Are you stupid you can't make a transducer without sharp edges!"
This is to reply to one specific comment. Ultrasound is unlike MR and CT in that it is both operator and patient dependent - each image can be different and some skill is required. The acoustic window in which clinically useful images can be gained sometimes involves placing the transducer in a location, and applying sufficient force, that it can be uncomfortable for the patient. If the patient starts to move because it's uncomfortable, it makes getting a good image harder. Some transducers have a tradeoff of minimised size for access to certain locations, but maximised acoustic area for good image, which can lead to corners that are not very smoothly rounded, and while not 'sharp' as in 'cuts the patient', might lead to more discomfort than necessary if not designed correctly. Oh, and yes building a 200 wire cable with minimal crosstalk is easy, doing it and making it flexible so a sonographer can use it (like I said in the original post), and at a reasonable cost isn't. Congratulations to the person that asked that question and showed their genius in how dumb we ultrasound people are - you actually managed to annoy me with those comments! You, in particular, are an author I aimed the "Since you're so smart, why don't you clean up in our industry of charlatans and idiots?" snark at.

9) "Phones are cheap and have a ton of technology in them, why aren't you that cheap?"
>Several hundred million phones are sold every year, probably 4 orders of magnitude more than ultrasound systems. On average they last about 18 months to 2 years, compared to a decade or more for an ultrasound system. No-one's life depends on them. One of the simplest things here is there just isn't the economy of scale for ultrasound to hit those price points. Perhaps it's a chicken-and-egg thing, that the "killer app" for ultrasound isn't here because it's too expensive, but if the demand is there then the tech will come. Got that application? As some have noted, there are rumours that's what Butterfly Labs are working on, but despite being well connected in the industry, I've heard nothing on what they are really doing after several years of effort. I hope they produce something astounding, but until then, no smartphone market economies of scale for ultrasound. 

OK, I'm done for now and leave you with this, once again - If you can make a difference in this industry in price, performance, reliability, or application then get in touch, there are companies and universities that want good people to work on this. Don't armchair quarterback or cite imaginary conspiracies, get involved. 

Merry Christmas everyone.

Wednesday, December 21, 2016

Why Are Medical Ultrasound Systems so Inexpensive? or "It's Always Easy When It's Someone Else Doing the Work", Part 1

Hackernews linked to a Medium post on ultrasound devices today, entitled "Why are Ultrasound Machines So Expensive?" which, being my core area of expertise with over 20 years in the industry, I was interested to read. Sadly it fell into the category of posts by someone with training in one area, which leads to an overconfidence of knowledge over what happens in another area, a lack of appreciation for the complexity and difficulty of the jobs of others, and as a result misses many of the subtleties (or not so subtleties) of an intensely difficult technical field. 

The premise of the article is "Why is even a cheap ultrasound system over $30,000 when I can buy the bits and pieces for next to nothing and it's really easy to make? It's not that hard, I looked into it for a couple of hours!".  While a premium ultrasound system with transducers can be $150,000 or more (a fraction of the price of CT and MRI systems) it's the most common medical imaging modality in the world for a reason - so allow me to refute this position that it's simple and overpriced.

What's my knowledge in this area to be able to comment? My Ph.D. was in the modelling, design, construction, and testing of this type of device. For 13 years I led a consulting group that produced the industry standard modeling software for ultrasound, and participated in and led many projects that designed and built ultrasound devices for a wide variety of industries, including medical. I am the Associate Editor in Chief of the IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, the leading peer-reviewed journal for this subject, and chaired the IEEE Ultrasound Technical Program Committee for Transducers. I have worked in some of the largest medical ultrasound suppliers in the world, and worked with some of the smaller ones too. I've built and delivered commercial software critical for a business, around the world, and supported it for years. There's not many people with my background to evaluate the technical from both the hardware and the software side of things.

FYI, what I'm writing here is generic information, and not tied to any one company in particular, so there's nothing proprietary in what I'm about to say. Those of you wanting to learn more yourselves, I highly recommend Tom Szabo's book "Diagnostic Ultrasound Imaging: Inside Out" for a readable, and broad, coverage of the topic.

Let me start with demolishing this argument in one really quick paragraph citing not anything technical but Economics 101. If you can really build an effective ultrasound system that people want to buy for significantly less than the currently available price when you've no expertise in the field, then why hasn't someone else with vast experience in the field gone and done exactly that? Or why hasn't one of the major companies massively dropped their prices to corner the market? If there's collusion between the companies to fix prices, why hasn't a government somewhere sued them (and believe me, from being inside these companies, they are paranoid about playing by the rules and not accepting kickbacks or doing anything seen as fraudulent).  I'll cover the FDA and regulatory later, but for now take my word that while it's a part of the cost, it's not the majority, and seriously, you don't want to use these things without strong safety regulations.

Next, let me cover that I've built hardware and software, and as difficult as software is, hardware is harder. If you make a mistake in developing hardware, you don't recompile the fix to get a new product in an hour, you rework and then rebuild taking weeks or months sometimes. With hardware you have to ship a product that works, you don't get to fix it in the field with an update, you don't get to ship with an EULA or a warranty that says "as-is", and you have to support the same product in the field sometimes for decades. With software you can develop your product in a small room with a laptop, but the tools to build hardware can be expensive and large with high running costs. Software also doesn't have suppliers who change materials, formulations, prices, or even go out of business and leaving you at a loss for components. If you want to mitigate all those risks for hardware compared to software, you need people to do so, and they cost money.

Now having said that, on to the technical. An Ultrasound System is made up of three major components - the transducer, the system, and the software. The transducer is what you hold in your hand, contacts the patient, and transmits and receives the ultrasound. There are multiple available transducers for every system, each with its own application, so a system has to support a potentially wide range of transducers.



The transducer is connected via a cable to the system, which has all the electronics to receive the signals and convert to an image to be displayed, and allow the sonographer to change settings etc. The software runs on the system, and allows for the display of the image, though these days the lines between where the hardware and software boundaries for imaging are, are getting blurred somewhat. In hospitals it's usually a cart, but there are some more compact (and more limited) systems available.



Let's take the transducer (some of these images are taken from this presentation, or here, which are good intros)



Starting from the top, you've got the lens (the bit that contacts the patient). This has to perform a certain amount of focussing of the ultrasound, and attenuate the signal enough you don't get reverberations at the skinline and obscure the image, but not so much you lose too much signal. It's got to ensure good contact with the patient, thick enough to be part of the insulation, and robust enough to be cleaned/disinfected as well as dropped and mistreated over the years of lifetime. Thickness has to be consistent across the surface, if you shift too much of a % of a wavelength over the surface then you'll distort the image. And remember ultrasound wavelengths are usually on the 100 micron order. But that's simple, right?

Then we have the matching layer, designed to ensure coupling ultrasound from the high acoustic impedance piezoelectric to the low impedance body. These days it's usually more than one, and each has to be a specific thickness, density, stiffness, and attenuation. Sometimes you need them conductive, and sometimes insulating. They also need to be machinable (diced, see below), and constant thickness, just like the lens above.

Then we come to the piezoelectrically active material - this is what converts electricity to vibration, and vice versa. Again it has to be a specific thickness, and consistent across the surface to a level you measure in microns. Which material you use is important, the cheap stuff is variable and lower performing, the stuff that's specced tightly and performs well is expensive. It has to not depole (lose its piezoelectric effect) at temperatures you run the probe, and withstand high electric fields across it. Piezoceramic like PZT has been the staple for years, but these days, to support the advanced imaging modes demanded, it can be single crystal piezoelectrics, which are more expensive, higher performing, but harder to work with. PVDF, sputtered materials, and the cheap  PZT you make buzzers with are essentially useless for this type of work, despite being 'piezoelectric'.

Then there's the backer, a material that absorbs just the right amount of acoustic energy, so that you get a short pulse coming out the front that can image, but not so much that it reduces the signal to an amplitude too small to work. It's also in the thermal path, usually can't be electrically conductive, and not so large that the sonographer notices the weight.

Next you have to bond them all together, make sure they stick. The bondline has to be thin enough that it does not disturb the acoustic path, but not so thin that there is delamination and it's not a robust device. That means micron bonds, consistently across the surface. Easy, right?

Now you've got your acoustic stack. OK, now you can dice it - cut it into the elements that generate the image. Yes, you have to make many elements to make an image - in most transducers there are around 100 to 200 elements, left to right, across. A device with 20 elements, as the Medium article posited, are useless for any serious imaging application. You have to cut through all those matching layers and piezoelectric, electrically and mechanically isolating each from the neighbour, but not breaking the thin sections you leave, while making them thin enough that grating lobes and other artifacts don't spoil your image.

Then you have the flex circuit, to take the signal to and from each element, and it's got to be precisely aligned with the elements, that's on the 100 micron order to position (yes, each element is around the width of a human hair or two), and then it's got to connect to the cables off to the system - all 100 to 200 wires down a cable that's a couple meters long, and thin/light enough for someone to use 8 hours a day without getting repetitive strain injuries. Do you know how thin that makes each wire? Try calling a few cable vendors and ask for a small diameter cable with 200+ connectors that will actually conduct a signal without significant crosstalk and let's see where you end up on price.

Finally, you have to put it into a housing that's ergonomic for the sonographer to use, large enough to hold the acoustics, small enough not to be heavy, and not sharp to hurt the patient. On top of that it also has to be designed so that it doesn't get so hot it burns the patient or the medic.

Simple!

Right. And that's the most basic version. I haven't gone into multi-row probes, those on a curved backer, exotic materials, those with electronics in the handle, what the dimensions of each section have to be to give the right acoustics, steering, spectral response, thermal characteristics, electrical impedance to match to the system, or all the other difficult things that in reality you have to deal with if you build and sell these devices.

Oh, and I forgot about consistency, reliability and cost. These devices have to last for years, be close enough in consistency from device to device the system can image with them and the user doesn't know the difference, and be low enough cost that the user will buy them and the company makes a profit. Ever made a protoype? Ever made 2 of them? 4? 100? 10,000? And made them all the same? Yep, it's a different world when you have to start selling and supporting products.

Ooops, I forgot, and testing to meet your own internal specs as well as those of the FDA and other regulatory agencies, to make sure that these devices don't electrocute or burn you, and give the right medical data so that you aren't misdiagnosed and receive the right treatment. 

And I haven't even got to the system or software yet (I'll try to get to a part II on that). Just the transducer requires people with knowledge of acoustics, imaging, clinical need, materials, mechanical design, electronics, thermal, processing, regulatory, safety, chemical compatibility, user experience, reliability, QA, business, and a whole host of things I just don't have room to list. Then you need the support staff, the building, HR, admin.

This takes a huge amount of expertise and effort - almost as if some people's lives depend on it.

I've got a lot of experience designing and building these things. Could I setup a company to do it, and do it well? Yes. Could I do it significantly cheaper than others do it right now? Nope.

Put that all together, and you have an incredibly complex electromechanical product with components on the micron scale, that has to work reliably in the field for years, reproducible across all that are made without the benefit of mass volumes (no millions of devices here), upon which medical decisions that lives can depend are made - and that's just the transducer - so you need to ask "Why are medical ultrasound systems so inexpensive?"