The Unwired Medic

Teaching EMS providers & other public safety pros about using mobile tech to improve their practice, patient care, continuing education, scene safety, general entertainment, & productivity.

July 28, 2016
by The Unwired Medic

O2 Amp Vein Glasses – Product Review

So I’ve seen these glasses advertised around the web and on Facebook talking about how EMT’s and Paramedics are using them to see veins for IV starts and to identify blood pooling, such as in hematomas.  I reached out to O2 Amp by 2ai Labs, and they sent me four different sets of these glasses to evaluate and report back on.

The Claims:O2 Amp by 2ai Labs

See veins more distinctly, identify blood pooling, see shifts in blood concentration in tissues (i.e., blanching, or capillary refill or lack thereof).

The Premise; How does it work:

Color shifts in vision can enhance the viewing of certain color spectra, allowing the user to perceive certain colors with more intensity, such as veins and capillaries.

By tinting the lenses, a color shift is introduces that obscures the undesirable range of color and enhances others. This is a tough one to tackle, because people don’t all perceive colors identically. For instance, I have a bit of color-blindness, which is not uncommon for men. I noticed that I perceived some things less intently than other users I shared this experience with, and other things more intensely than others.O2 Amp Glasses by 2ai Labs

In order for most of these glasses to do what we expect of them, you will require a pretty strong light.  In fact, the manufacturer recommends you start learning how to use these glasses in full sunlight.  I agree.  Alternatively, exam lights and tactical flashlights offer very strong light to help make these glasses work for you most efficiently.  My best results were obtained in direct sunlight.

My results:

I tried taking these to our only regional trauma center’s ER and worked with a couple nurses and a few medics that passed through while I was there.  Results were not exactly overwhelming.  Even with a tactical flashlight emitting over 300 lumens, I and the others that were using them were still not feeling like we had fared any better with or without the glasses.  There are a couple possible reasons that things didn’t go so swimmingly:

  1. Doubt/Bias: Any product that claims to allow one to perceive something differently by just applying a tint to your eyes seems dubious.
  2. Experience: We work under ostentatious circumstances and we in the ER and in the field are often called to be expert phlebotomists, finding veins where there seem to be none readily available and starting IV’s and performing blood draws.  We have additional training and experience in gaining IV access beyond the typical clinical provider.  The only medical staff I have encountered that are on par with emergency personnel are surgical suite medical staff and blood bank phlebotomists (incidentally, I worked in a whole blood donation bank for almost a year and that is where I gained a significant portion of my own phlebotomy skills).  One nurse who tried the glasses said maybe I should take these to the floor nurses and let them try, since they don’t do too many IV’s comparatively.
  3. It’s a scam: Yes, it’s possible, but I don’t think it is likely.  I have read the literature provided by the manufacturer and I don’t believe it is a scam.

O2 Amp Oxy-Iso SunglassesI also took these glasses to my EMS station and worked with a few fellow medics to see what they thought.  We were already outside doing simulations and it seemed like the perfect time.  Of the four varying tints of glasses we tried, they all yielded positive results, but the darkest of the purple tints, the sunglasses style O2 Amp glasses, showed the most benefit in finding veins.  Tactical flashlights just didn’t do these glasses as much justice as the sunlight.  Maybe the LED doesn’t emit a broad enough light spectrum to compare with sunlight.  The end result was that provided you had a bright enough light, like sunlight, they worked fairly well.  In the back of the ambulance with all the lighting up and the tac light, you could still do well with these glasses.

My verdict:O2 Amp Oxy-Iso Sunglasses by 2ai Labs

The O2 Amp glasses by 2ai Labs are a promising development in rapid vein identification.  Caveats are warranted for people with color blindness – your mileage may vary – but that is why I enlisted the help of many other practitioners to help me properly evaluate these glasses.  As the manufacturer claims, they are an alternative to the more expensive Vein Light devices.  They seem to deliver fairly well, when placed under more ideal circumstances.  They may not be the best in helping in low-light circumstances, of which EMS’ers find themselves in abundance of.  I’m happy to have been given the opportunity to try these glasses out.  On another note, I have been in contact with the manufacturer several times since receiving these glasses, and they have been helpful in ensuring I get the best results from my product evaluation.  I think their customer service has been excellent.

Bare Arm - No Glasses

My forearm in bright sunlight. Decent enough veins.

Bare Arm - Oxy-Iso Glasses

Bare arm in direct sunlight. Oxy-Iso Sunglasses placed over the lens of the camera. Results in the image are not as evident as with the naked eye. The blue tint in the veins is more prevalent. Smaller, less bulging veins are more noticeable when viewing through the glasses than through the camera. The difference is probably due to automatic color correction of the camera in processing the digital image.












I have been asked by O2 Amp to include the following notes, which may help their users get the most out of their glasses purchase and to clarify some of the science behind why their product works:

Thanks, Chris, for reviewing our product.

Some follow-up notes:

(1) We like to emphasize that, If one should be wearing protective glasses anyway, then one might as well wear glasses that enhance health signs and veins. If lighting conditions are good, then you get perceptual advantages. But if lighting conditions are not good, well, then it becomes basically clear protective eyewear. So, we view them less as a competitor among the vein finders, and more of a “wear these protective eyewear instead and you’ll sometimes — with good light — get perceptual advantages.”

(2) The Oxy-Iso is stronger in some sense, indeed, than the Oxy-Amp Paramedic Vein Glasses. But (a) the Oxy-Iso also cuts out a lot more light, making it even more difficult indoors, and (b) it blocks the other blood dimension we can see, variations in concentration of blood (what the green Hemo-Iso amplifies), making one better at seeing veins, but potentially worse at seeing clinical signs more generally. That’s why we recommend the Oxy-Amp Paramedic Vein Glasses to paramedics, because it blocks only a very narrow band of bad signal (and the light pink is a functionless side effect of the way we have to manufacture it), and so leaves one’s general clinical sense unhurt, but only better. …because paramedics need their general clinical signs sense intact.

(3) It’s more than just tints that make the tech work. I realize you’re speaking without jargon for a general audience, but, say, merely finding some filter (or colored glass, say) having the same tint won’t reproduce the effect. It has to have the spectral filter function of ours. (Said differently, for any tint, there are infinitely many spectra that differ in how they modify colors, but still all have the same tint.)

(4) In our experience, the Oxy-Amp is not successful for hospital workers — perhaps because they’re more a hostage to interior lighting constraints, or are less the type that carries tool kits around with them — than paramedics, where we have had good results.

(5) Even though paramedics tend to do their procedures inside the truck, their initial encounter is usually outside the truck, and in daylight the Oxy-Amp makes all clinical signs easier to see, not just veins. Out hope is that paramedics have our Oxy-Amp tech as their sunwear, so they get the UV protection needed, but also clinical enhancement.

Thanks again.

Dr. Mark Changizi

June 27, 2016
by The Unwired Medic

Leadership’s Voice

A friend of mine shared an article from EMS Leadership Academy with his link preface saying:

Classic leadership advice: “Its not what you say; its what they think it means.” (sic)

You’re trying to get your message across. Something needs to change, and maybe the impetus for the change wasn’t something negative that happened as you hear everyone suspects. Maybe it was benign or you felt it was a good direction to go, but still, you’re getting pushback. Let me give you a nickel’s worth of free advice…

If they aren’t getting your message, saying it louder won’t change anything.

It’s not a hearing problem. It’s an interpretation problem. Maybe you should consider changing your delivery rather than getting frustrated with their interpretation.

May 7, 2016
by The Unwired Medic

Do you even realize?

You probably pay no mind to it…

We do it every day. We start our shift on the computer, running our checksheets, checking our e-mail, logging in to our ePCR programs to check for QA kickbacks and open charts. We get in the rig. You get assigned a post or a call and you look at the CAD and GPS. You check your smartphone or tablet for CAD info on the call you’re about to go in to. You might start prefilling the ePCR now. Your eyes leave the screen long enough to clear intersections.

You’ve on scene and you’ve made patient contact. You’re back to the screen entering demographics, meds, allergies, vital signs. You move to the box with your patient. All your tech is coming together to form a mural of diagnostics on your patient and it too goes into the ePCR. You make it to the ER and now you have to finish your documentation with your final vitals, handoff report, diagnostics, and what have you. You’re back in the rig and at it all over again.

Maybe you’re lucky enough to have a few minutes to rest, so you pull out your phone and check your texts and Facebook. There’s that viral game everyone is playing and you’ve dropped a bit on the leaderboard, so you pop over to the game and play for just a couple minutes before you get back to charting or working on that online CE due by the end of today. Maybe you’ve got more time and a station. A cushy recliner to fall back into has your name on it, and you need to decompress so you watch a movie with the crew.

Do you even realize?

You’re now spending virtually every waking minute of your day in front of one display screen or another. Do you know what it is you have been unwittingly doing to yourself? Do you realize why you have that mild, nagging headache? Do you realize why you keep rubbing your eyes? You aren’t tired yet. You haven’t felt the need to grab an energy drink. So what could it be?

What you are unwittingly doing to yourself is constantly barraging yourself with artificial blue light (1). Every computer screen, smartphone, tablet, and television we encounter now emits this artificial blue light. It has been linked to sleep disorders by interfering with our Circadian rhythms, and it affects our blink rates, giving us dry eyes, and it even gives us headaches.

Sleep in public safety is precious enough. Need we discuss how many accidents and medical errors are attributed to sleep deprivation? It’s a well-known fact. Dry eyes due to less blinking can cause corneal scarring and abrasions, loss of visual acuity, and even ulcerations (2). There are many things that contribute to headaches, including medications, fatigue, stress, sleep apnea, and eye strain.  Some studies suggest night owls exposure to light contributes to cancer, diabetes, and even more health disorders and recommended wearing blue light blocking eyewear (3).  Emergency Services personnel work around direct blue lights regularly when we are responding to and on scene of emergency calls.

What can you do about it?

Many of us wear corrective lenses now, yours truly no longer being an exception to this. I worked for a blood bank for a year near the beginning of my EMS career and that was where I had my first blood exposure. From that moment on, I vowed to wear some kind of lenses in front of my eyes. I always wore clear lenses, even though I didn’t need them to be corrective. The problem is typical lenses don’t do anything about light outside the non-visible UV spectrum.

Recently, I came across a brand of glasses called “Gunnar”. I found them at the annual CES event in Las Vegas about three years ago, and I tried them out. I found them to be extremely comfortable and after a couple minutes, felt like my eyes weren’t working so hard to focus on the computer displays in their booth.

Gunnar Phenom - Amber Tint

Gunnar Phenom – Amber Tint

Fast forward to the present and I’ve decided to give Gunnars a good long look (pun intended). I work in front of computers constantly in my full-time healthcare IT job where I have a wall of big screen monitors watching the health of hundreds of computer systems and I have three monitors on my desk, and when I’m not there, I’m studying to complete my degree online, I’m frequently on my smartphone, or I’m watching my LCD TV’s, or I’m reading a book on my tablet. On the ambulance, I’m blessed with a somewhat inefficient ePCR system and it isn’t unusual to take an hour or more to fill in a chart and check off all the special little boxes that are required to keep me out of PCR jail.

I’ve gotten out of the habit of turning my screen brightness to max when I can avoid it, and I try to get away from the tech for at least a half hour before bed, but I’m finding I still have headaches quite frequently. I’ll be due for some new eyeware soon under my insurance plan, so I’ll get my own prescription Gunnars then. A coworker of mine has a prescription set and he really enjoys them. They look sharp, are minimal in design, and are even becoming a favorite amongst gamers.

Gunnar has a couple lens tints, including sunglasses, regular clear (they call them “crystalline”), and amber. For what we do in public safety and patient care, I wouldn’t recommend the amber tint lenses, as they will shift color perception, which we depend on to assess a patient’s skin color (think cyanosis, pale, and even jaundice), so I’d stick with the crystalline lenses and the sunglass tints.

Remember, you don’t need a corrective lens prescription to wear these. The most common use of Gunnars is non-prescription. Prescription frames and lenses are available though. A nice feature about Gunnars is that they coat both the outside AND the inside of the lenses with an anti-reflective coating. Personally, I can attest to how annoying it is to have an anti-reflective coating on the outside, only to have a little light cause eye reflection on the inside (where you see your own eye refracting light onto the lens and creating distractions from your view).

They’re reasonably priced, especially given that they completely block the blue light wavelengths from all the assorted displays we spend our days and nights in front of. They also offer a wide range of styles so you can pick what’s best for your face and style. Check them out at On their site, you’ll find a few different pages describing the benefits of each type of frame and lens, and a “How Do They Work” page as well.


I do not own a pair of Gunnars, yet. They are going to be my next prescription eyewear purchase due to the research I have done and due to trying a demo set on and wearing them for a bit to get a feel for them. I believe they are the genuine article and not a gimmick, so much so that I applied to be a brand ambassador for them and was accepted. This status with Gunnar thus far has resulted in me getting a free Gunnar t-shirt and nothing else, so really, I haven’t been incentivized to write this article, as I already have plenty of t-shirts… especially from EMS product and service vendors. 😉

Check out the references I used to compile this article below. If you have any experience with Gunnars, please drop me a comment and let me know what you think of them. Thanks for reading!


(1) – Source: VSP Blog at

(2) – Source: NIH’s National Eye Institute at

(3) – Source: Harvard Health at

February 5, 2016
by The Unwired Medic

When “FREE” isn’t…

I like free as much as the next guy. In fact, I count on it to provide reviews on new tech for public safety here for you to read about.  What I don’t like is false advertising, like when you are given a code to redeem for a “free” product (in this case, a Bluetooth tracker for your keys, purse, or whatever you want to attach it to) and you sign up on the site and are told you’ll get an e-mail with instructions on how to complete the offer redemption.  Now they have the code, probably specially generated for the event or marketing campaign which is fine and probably a smart business decision to track marketing effectiveness, and they also have your e-mail address. Then they send you the “offer” to complete, and it takes you back to their site. The product is free, and suddenly, you see “+ S&H“. REALLY? You didn’t think to mention that when I visited your vendor booth at CES and talked with the rep for 10 minutes about your product, or to put that slightly totally relevant information on the “free” offer card, or on the special website page you dedicated to it BEFORE I submitted my e-mail address? You had to wait until the page where you paroxysmally ask for credit card information?

FREE *plus S&H - image by Fotomedic

…image by Fotomedic

Too bad! I was really looking forward to writing a review article here to share with the public safety community. Wouldn’t a relatively inexpensive product like that be useful for preventing crews from leaving jump bags and $25,000 monitor/defibrillators, or portable ultrasounds, or laptops and tablets, or apparatus and narc cabinet keys on scene?

I’d love to publicly shame the company that opted to use this disappointing tactic on its guests and potential customers, but I apparently have more integrity than they do, and I don’t post negative reviews.

January 29, 2016
by The Unwired Medic

Leave your headphones on while auscultating

Is it possible that you can still keep your Bluetooth headset on while you auscultate a patient’s chest? Absolutely!AfterShokz_Trekz_Titanium_Ocean

At CES 2016, I was fortunate enough to make my way over to the Aftershokz booth in the Health and Fitness exhibit hall. Aftershokz makes a lineup of bone conduction headsets for athletes. The benefit they were touting is that you could still enjoy your music and keep your ears free for hearing traffic, someone approaching, and the general sounds of your environment. Well, that sounded right up the public safety alley to me.

I took a quick tour through their booth and listened to some focused sounds under a few sets of uni-directional speakers with their new premier product, the Trekz Titanium. Impressive is an understatement. The recordings playing for ambience were from CentralAfterShokz_Trekz_Titanium_Ocean_front Park in NYC. I was able to hear the cars driving by, the birds chirping, the conversations of passersby, and more, plus I still heard the music – all of it. At the end of the demo, I was given an opportunity to review this fine headset for myself in a much less controlled environment, so of course, I jumped on it!

Let me say that my experience with them has been mixed. If you were expecting a flawless, OMG, DROP EVERYTHING AND GET THESE kind of review, that’s not exactly what you’ll find, but it’s close. That said, I think this is by far the best Bluetooth headset I’ve come across. No, they aren’t perfect, but they are excellent.

I spent the next day with these things on my head, walking around the CES exhibit halls, which are plenty noisy, listening to music, talking with a couple friends I go with to the annual show, and carrying on conversations with vendors galore. At the end of the day, my ear lobes were sore and I had some pressure sAfterShokz_Trekz_Titanium_Ocean_controlspots developing in front of my ears on my jawbone (not to the point of damaged skin, but noticeable). What I quickly surmised was that you shouldn’t spend an entire day with these headphones on, but that they would still be excellent for even up to four hours of continuous use while engaging in sports and fitness, walking, and even shift work. The rest of the time, they’ll rest unobtrusively around your neck, ready to slip back on to hear that music or take that important phone call. I learned that I can keep them on and running all day long and slip them on and off my head as needed.

Right now, I’m dealing with a doozie of an upper respiratory infection that has managed to work its way into my lungs, flaring up my asthma and giving me bronchitis. Inspiratory and expiratory wheezing, ronchi, and

even diminished bases at times. I was able to distinguish all this without removing my Aftershokz Trekz Titanium bone conduction headset. One of the major drawbacks I have encountered using ANY other Bluetooth headset was that I couldn’t have access to the headset while auscultating a chest. That is no longer going to be a problem for EMS practitioners with the Trekz Titanium.

As far as sound quality goes, I hope you aren’t expecting an audiophilic experience, because you’ll want to get a set of noise-canceling and isolating earbuds, and you might want to upgrade those silicone ear pads to the ones you can get from
the brand Comply (trust me, you won’t be disappointed). You are dealing with bone conduction sound here, so there is some expected drop in audio quality, but it isn’t that much. Although you might miss out on the finer details of a concerto, you’ll have no problem rocking out to your choice of music for a workout at any reasonable volume, from background noise to drowning out the world. Compared to a couple other bone conduction headsets I’ve tried, the Trekz Titanium is by far the best. Volume range is no limitation here either. You can make them uncomfortably loud if needed.

What may surprise you is the superb call quality you’ll experience. Now, I own a Plantronics Voyager Pro headset, given to me at a previous CES a few years ago. I’d consider its call quality to be well above average, but the Trekz Titanium surpasses it. Although I do still work in the field in EMS, my full-time job is in I.T. working in a Data Center for the only trauma center in Northern Nevada. I haven’t been able to find a phone or headset that will allow me to be standing in front of a computer system in the Data Center while talking at a conversational voice to the system engineer on the other end of the line. In my own truck, I have to at the very least roll up my windows or turn off the heater/AC and turn off the stereo, and often just plain pull over to be a part of a phone conversation with even my best Bluetooth or wired headset. The road and ambient noise is just too much, and I have a pretty well-appointed truck. Not so with the Trekz Titanium. I can be standing next to an in
dustrial Data Center Air Conditioner or rolling down the road with my stereo on and AC at full blast and my caller can’t even tell. Noise cancellation is hands down the best I have encountered. I know there are plenty of commercials advertising that their headsets will allow you to talk clearly to someone while you are in a rock concert or by a running locomotive, but this is definitely the real deal.

Placing a call is as easy as pressing and holding the button on the left earpiece. You will be prompted to state your call command and you can say to text or call a person in your contacts, or with my Android, it would eve
n search Google Now. A short press will start music, pause it, and resume it. I used it regularly with Google Music a
nd had no problem starting or stopping music. If the app closed itself, it would open the app and start from the first song in the library. Ideally, you would set your playlist, start it, put your phone away where ever you store it while you work out and just go. Range away from the headset was greater than 30 feet through an exterior building wall for me. I would have liked another set of buttons to skip forward and back on tracks, but that will have to be done on the phone itself.

Battery life has been far in excess of what the advertised expectancy is. I have left them running for several days and only found battery life to be medium after listening to about 3 hours of music per day and taking about half a dozen calls on them. No disappointments here. They recharge with a typical micro-USB charger, like most smartphones and accessories take.

So the pros and cons:

  • Pros:

    • Excellent Outstanding call quality.
    • No removal to auscultate to you can be online with medical control or your supervisor while assessing a patient’s breath and chest sounds or responding to a summons on a 2-way radio.
    • Long battery life – several days with moderate use, and quick to charge.
    • Decent, but not audiophile, audio quality. More than adequate to entertain you while walking, running, working out, etc.
    • Great volume range.
    • Lightweight – your head and neck won’t complain about extra weight wearing you down.
    • The call/voice command button is easy to get to, even with a gloved hand.
    • Includes a carrying case for protection when you are not wearing them – I’ve not used the case because I’m almost always wearing them!
    • Sweat and dust resistant. They are meant for working out with, after all.
  • Cons:

    • One Size Fits All – Non-adjustable headband means that on no necks like me, it sticks out the back making it move off the ideal placement when I lean back, but not really that bothersome. You’ll get use to it in a couple hours and adjust as needed. If you have a muscular head and neck, maybe it wouldn’t be too big of a deal.
    • No padding at all on the ear loops – This hard plastic only headset meant my earlobes were quite tender after wearing for more than about 3-4 hours. For me, I would just leave it on my neck until I was listening to something and then drop them back down when finished.
  • Neither Pro Nor Con:

    • The amount of tension exerted against the law was sufficient to keep the headset in place, which is great for exertional activity, but if left for a couple hours or more, then it could cause skin breakdown. Give yourself a break after a couple hours of use.
Where I'd Rather Be

Where I’d Rather Be

My final verdict

The Trekz Titanium by Aftershokz is a fantastic headset for what we do in public safety, able to handle sweat, snow and drizzle, dust, and you can keep wearing them while you take care of patients, run your patrol beat in a squad or on bike, work out at the station, or even while you hike through the forest on a rescue mission. You don’t have to worry about them incidentally falling off. They offer superb call quality and a pretty good audio quality for music on par with a decent set of headphones, but they leave your ears free to hear your pager, station tones, and 2-way radio, or even somebody walking up to you.

They retail at $129.99 and seem to only be available at the Aftershokz website for now, but older models are available on Amazon, so I suspect since it’s a new model, it’s just a matter of time before they are available elsewhere. They come in Ocean blue (like mine), lime green, and a nice, subtle gray.

Check out the literature and manufacturer specs here:



AfterShokz_Trekz_Titanium_Technology AfterShokz_Trekz_Titanium_How_it_works