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.