We’ve been using the Butterfly iq (model ) device in a project here in Sierra Leone. We are 6 weeks into a 6 month period, here is what we have found so far.
Summary
Overall the device will get you diagnostic images of most organs that you will need for point of care ultrasound. It is a lot cheaper than other devices but costs can rack up quite a lot for an individual user. It would be a limited to general bedside use as issues with overheating and battery would limit it’s use in a clinic/list setting when you need it use it all day and some there are some limitations on cardiac views for formal echocardiography. It’s main limitations for global health is it needs to be connected to the internet on a fairly regular basis.
The hardware
Our device set us back about 2000 pounds, although the monthly fee was waived with butterfly’s global health programme. The butterfly iq comes in a small box with the probe itself, a charging dock, various plug adapters. One good improvement is that the cable on the IQ+ is inter-changable as I see this being a part of the device that could break after prolonged use (has the feel of a phone charging cable, we all know how many of these we can get through).
It is a three in one probe. Reporting to give all of the applications of a curvilinear, linear and phased array in one. It has a rectangular footprint about double the size of a normal phased area (or cardiac probe).
It comes with either a android USB-C or a apple lightening charging cable. Initially we thought USB-C would be cheaper option. But the app/device is only compatible with fairly high spec android devices (we used a Samsung Galaxy S8 , full list of compatible devices on butterfly website). This adds another significant cost.
You can easily hold it in one hand, it does tend to get quiet warm after minimal use and will overheat after a period of continuous use. This wasn’t a massive problem for use at 25-28 degrees here, but in hotter climates this may be an issue (it almost certainly would have been frequent problem when if I had it when I worked in Sudan). This and it’s limited battery life and slow charging (they state get 2 hours of use on the website, takes 5 hours to charge) would limit continuous use.
I understand why it has a wireless charging pad, I imagine this makes it more robust, however does make it a bit annoying as you need a flat surface to charge it up.
A single probe is all you need
The software
The app is easy to use and pretty intuitive. If you have used a smartphone before it should be fairly easy to pick up. There is no decision to decide which probe to use of course, instead you are presented with a list of organs or scanning indications. A swipe up/down changes your depth and a left/right changes your gain. There are just 3 buttons for freezing, taking photos, cineloop, videos and higher function options screen (doppler , m-mode ect.)
When you save scans they remain in the outbox on the device until connected to internet and then are connected to the cloud. This is great if you have good internet and what to review your or students images/videos as you could access this from any laptop or computer. However, in a limited internet setting it becomes a bit annoying to try and keep track of scans.
Several other features make it clear it wasn’t designed for a low resource/global health setting in mind. The app software needs updated quiet regularly (seems like once a month). This would be fine except it stops the app working after a period of time without updates. If you are far from decent internet for a period of time this would make device unusable. In addition, the patient details screen does not allow you to enter age (lots of our patients are unsure of their DOB) and there is no function that allows multiple doctors to label scans as there own. It would be great if you could filter by person scanner, but you have to pay more to add more official “users” to the butterfly account.
There is a subscription model that charges you for ongoing use, luckily we were approved for the global health programme that gave this to us for free.
The basic screen with modes, freeze, video and higher function options.
The scans
Overall it is pretty good. Certainly for abdomen views it is great. The only drawback is sometimes it is difficult to get a very broad view, this is only really a problem if you want to measure a large liver or spleen. The lung mode is very focused on the pleura (like a linear probe on other devices) and if you want to look for anything else you have to use abdomen mode (but myself and my colleagues found this on our Sonosites machines too). You can get surprisingly good cardiac views despite the probe feeling like has quiet a big footprint. However, you do have to rock the probe a bit more to sometimes get the right cardiac views and slightly harder than a full cardiac device.
It has needle guiding mode for access and nerve block. I have used these less but will update when my anaesthetic colleagues have had a chance to trial these indications.
The butterfly comes with some automatic AI functions which have some promise. If you get a “cardiology standard” 4 chamber view it can use an AI version of Simpson method to identify an estimated LVEF. I would be very suspicious of any number this gave but would have to put it in the hands of a cardiologist before judging fully. Similarly it can give a estimated bladder volume. However, this is fairly technical to use and I think anyone would could do use this function would be able to give a rough estimated that would be just as useful clinically. It’s inter-rater reliability seemed low or a few goes we tried.
Summary
Pros
Pretty effective single probe device
Very usable images for all day to day POCUS indications.
Affordable in comparison to other ultrasound devices.
cons
Subscription model
more reliant on internet access than they initially claim
can overheat.
Overall though, on looking at other devices available, I cannot see a more affordable, ultra portable device that will get you diagnostic images for a variety of indications.