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Hello everyone, I'm going to be doing something different today,
and instead of presenting a traditional medical topic,
I'll be reviewing a newly available digital stethoscope - The Thinklabs One
I've been using it for the past 6 months,
alternating with traditional stethoscopes and the more widely known competing digital model, the Littmann 3200.
I think I've finally gotten significant enough experience to offer an informed opinion.
The Littmann 3200, which I have right here, this was the first exposure I had to digital stethoscopes
I had purchased the 3200 a couple years ago after losing my Littmann Cardiology III
I really wasn't sure what to expect as I literally had never used a digital stethoscope before purchasing my own.
While I certainly enjoying learning about and using new technology, I'm also skeptical of using any new technology in clinical
medicine before it has demonstrated is a record of accuracy and specific diagnostic utility.
On the whole, I initially was a bit disappointed with the 3200.
The sound reproduction was just so-so,
The bundled software was terrible.
The Bluetooth connection felt 5 years out of date, as soon as I got it out of the box.
The ambient noise reduction technology was unnoticeable.
And then finally, it was incomprehensible why Littmann insisted on making it look as much as possible
as a traditional scope, when there was absolutely no reason to do so.
Unfortunately, over time, my opinion of the 3200 has only dropped further.
It now gets significant amount of feedback noise, even when not immediately adjacent
to monitoring devices.
And the display stopped working after 18 months, which makes recording and playing back sounds
practically impossible, which was essentially the main reason I purchased it.
Overall, for me, the Littmann 3200 has been a huge disappointment
So I've been anxiously awaiting a small startup to come up with a disruptive innovation to
the concept of the stethoscope.
because it did not feel like such a disruption would come from a traditional medical equipment company.
And now, a small company called Thinklabs has come out
with the so-called One Digital Stethoscope.
It's not the company's first product, but it's clearly the most innovative.
As soon as I heard about it, I ordered from their website, which appears to be the only
way to get a hold of one.
So here is the box that it arrived in. It may seem like I'm being superficial,
but I must say that I was already impressed.
The fact that the packaging makes me feel like I'm opening an Apple product is an indication
that Thinklabs is committed to not just improving the function of the stethoscope, but its design also.
Inside the box we find this smaller case to carry the stethoscope
around on the wards or in clinic.
Inside is the actual stethoscope and the first thing to comment on is obviously the fact
that it doesn't really look like a stethoscope at all.
It's just a stethoscope head.
Since it's digital, there's no actually reason for the bulky rubber tubing and ridiculous earpieces
of conventional stethoscopes, which Littmann inexplicably copied for the 3200.
Instead, there is a standard 3.5mm jack, into which you could theoretically connect anything
from your cell phone ear buds to high end Bose noise cancellation headphones.
Thinklabs includes a surprisingly high quality set of small earphones, which is initially
located with some other accessories under this panel.
So let's take a look at the device itself.
First, it has a nice feel to it, although the padding included in the case suggests
it's probably relatively fragile, and I would not want to drop it.
There's a diaphragm on one side, through which sound will be passing, and a display on the
other.
There are 2 LED scales.
The top display shows frequencies that are currently being transmitted.
And the bottom one displays the current volume on a scale of 1 to 10.
There are 4 buttons located around the outside.
I don't know if this was intentional, but the fact that they are not evenly spaced allows
you to know which you are pressing even if you can't directly see the device.
For example, if you are reaching around and underneath a relatively immobile patient
you can still tell with some practice which button is going to be the volume button
and which one is going to be the frequency button.
To turn it on, push any button.
and you see some lights light up.
Once on, these 2 bottom buttons control the volume.
I never need it that high. Down around here is usually much better.
The top 2 buttons control the frequency filters.
So you can change which frequency is being transmitted. So this is high frequency and here is kind of all frequencies.
To turn it off, the device will either automatically turn off after a relatively short period of time, which you can
adjust, which I found to be a little bit tricky adjusting that.
Or alternatively, you can manually turn it off by simultaneously holding down these 2 buttons diagonal like this.
and it will turn itself off.
The stethoscope has an internal lithium ion battery which is charged via the same earphone
jack using this USB charger here, and cable.
The cable just plugs right into the earphone jack like that, and this just plugs into any kind of outlet.
Let me talk about its performance.
That is, how well does it actually work.
The frequency range sounds to be substantially greater than what is delivered with either
conventional scopes or the 3200.
Many of you probably learned in school the traditional bell vs. diaphragm dichotomy,
in which the bell mode of the stethoscope is best for low pitched sounds like an S3
or S4, while the diaphragm is best for high pitched sounds such as S2 splits, lung sounds,
and most murmurs.
However, in practice, these 2 options usually don't seem all that different at the bedside.
Well, the difference between the high and low frequency filters with the Thinklabs One
is definitely noticeable, and one of its major attributes.
Another pro is the volume range.
This thing can get really loud, much more so than the 3200, and much more so than a
person with normal hearing will ever need.
On the 10 point volume scale, setting the scope to anything above 5 becomes painful.
I can't state this with certainty from personal experience, but I imagine that individuals
with hearing impairment who have struggled with auscultation will find this to be a huge benefit.
The actual reproduction of pathologic sounds is pretty good.
I'd say that the sensitivity for hearing extra heart sounds matches that of the 3200,
and both surpasses non-digital stethocopes.
The clarity of murmurs and lung sounds as heard through the Thinklabs One is about equal
to the conventional Littmann Cardiology III, both of which surpass the 3200.
So to rate the overall subjective sound quality and diagnostic sensitivity, first is the Thinklabs One, then
the cardiology III, and last is probably the 3200.
There is one major issue with performance: there is a significant amount
of transmitted white noise, even in a quiet environment.
From hours and hours of editing auscultation recordings for my teaching,
I've gotten used to listing to heart and lung sounds through white noise.
But it's still annoying, it probably reduces sensitivity for picking up pathology, and will require
an adjustment period for anyone who is picking up the Thinklabs One without previously
using another digital stethoscope.
Given how advanced the device appears to be in other aspects, I'm not sure why there isn't
a better working, realtime noise reduction solution.
The website makes a number of practical suggestions on how to reduce this problem, including lowering
the volume and applying a different degree of pressure with the stethoscope on the chest
wall.
But I found those to be only modestly helpful.
Next up is the software and ease of recording.
Unlike the 3200 which records sounds directly and then transmits them to a computer via
bluetooth, the Thinklabs One is unable to record sound without being attached
to an additional device, such as a smartphone, tablet, or a portable digital recorder like
this Zoom H4N.
The benefit is presumably that it allows more space within the stethoscope for better audio components.
The downside is that you need to carry around something else if you want to record anything,
and the actual recording process becomes more cumbersome.
To connect everything together, you'll need this tiny accessory which is named the ThinkLink.
One port for the incoming signal from the stethoscope.
One port for outgoing signal to the earphones.
And one port for outgoing signal to the recording device.
The recommended software for recording and analyzing sounds,
which is not included in the cost, is an app uncreatively called Stethoscope,
which I've used on an iPad.
This is by far my least favorite aspect of the Thinklabs One.
It's both featureless and clunky at the same time, and it is surprisingly non-intuitive
despite its simplicity.
It's real only redeeming quality is that it allows you to email the audio file,
or upload from your tablet directy to your computer when synched.
Aside from the interface which makes it hard to do even simple things, another major complaint
with the software is that there is, once again, no available noise reduction effect.
If the stethoscope itself lacked the computing power for this, there is no reason it could not
be included in the app, which would make bedside analysis of subtle sounds easier.
I recommend forgetting about Stethoscope App altogether, and instead,
either using your phone's native sound recorder app,
which for both Androids and iPhones works just as well, if not better.
Or alternatively, recording it with a dedicated digital recorder, which is what I now do.
For an example of how well the sound is recorded by the Thinklabs One,
here's a recording from a patient I saw recently with aortic stenosis.
This is the unadulterated, raw audio file that was recorded using the Zoom H4N.
[heart sounds with systolic murmur...]
And here's that same recording after running it through a noise removal filter in the unrelated, free desktop program Audacity.
[heart sounds with systolic murmur...]
After running it through a noise cancellation filter, the recording is pretty good.
If I was going to include it in one of my videos or in a class,
I would probably spend a little more time trying to clean it up even more,
but for minimal processing, this is pretty good, and certainly much better than the 3200.
Since I have been using this stethoscope for about 6 months now,
let me talk about its durability.
So although the sound quality produced from the included earphones was really quite surprisingly good,
they unfortunately fell apart after 2 weeks of moderate use,
which was kind of a bummer.
So I've been using cheap replacements from an old iPhone since then
Other than that significant disappointment, the stethoscope has held up perfectly over the first 6 months
and seems easy to clean with conventional alcohol swabs.
So here's the breakdown of how I would score various aspects of the Thinklabs One, and
I'll compare it to the Littmann 3200.
For design, which is the One's greatest strength, it gets a A, while the 3200, looking like a conventional stethoscope, gets a C.
For performance, including the quality of recordings, the One gets a B, compared to a C for the 3200.
They both get Ds for their absolutely miserable software.
For durability, the One gets downgraded to a B due to the earphones falling apart after a few weeks.
The 3200 gets a D due to a failure of the display after 18 months.
Although 18 months is a much longer period than a couple of weeks,
the non-functional display has rendered it practically incapable of recording and playing back sounds,
which is it's only real advantage over a conventional scope.
Finally, the cost of each...
As of January 2014, as far as I know, the Thinklabs One is available only from the company website,
and sells for 499 dollars, not including the optional 99 dollar Bluetooth upgrade.
The Littmann 3200 can be purchased at numerous websites and many medical bookstores,
and has an average retail price of around 400 dollars.
So in summary, I honestly think the Thinklabs One is the biggest single advancement in the stethoscope
since its invention.
The radically different approach to design is awesome.
The sound quality is great but not yet perfect.
Unfortunately, the software is very weak.
Is it worth the 500 dollar price tag?
I think so. but probably only if you are a cardiologist,
a gadget fan, are hearing impaired,
or teach the physical exam.
For everyone else, as much as I personally like the device,
you probably will want to hold off until either the price tag comes down just a little bit,
or the sound quality improves with a more robust solution to noise reduction.
I hope you enjoyed this review
Feel free to post questions or comments about either digital stethoscope below,
including your own personal experience with either model.
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