Its no secret that medical peripherals for smartphones is a market that is likely to soon hit a period of exponential growth.

It’s a topic we’ve been covering for over a year, back to October 2009 when Zargis Medical began to quietly make moves suggesting a stethoscope peripheral for smartphones.

More recently, we covered a small mHealth startup called Mobisante that is testing out prototype for an ultrasound probe peripheral for smartphones.

Yesterday, TUAW ran a great story reporting on the latest newcomer to this burgeoning industry, a company called AliveCor that posted a sensational YouTube video demonstrating their simple single-lead EKG device built into an iPhone carrying case.

The technology itself is relatively straightforward and not significantly changed since first developed by Willem Einthoven about a century ago. What AliveCor has done is take two leads, an anode and a cathode, and build them into the iPhone case. These two leads are placed somewhere on the patient, for example either by placing the case on the patient’s chest or by having them hold the case with two hands. The electrical activity between the two leads is measured and transmitted wirelessly to the iPhone where it is processed and displayed as a familiar EKG tracing.

This is, to be sure, pretty cool stuff. But judging by some of the buzz this device is getting, including in the TUAW post, it seems like this device may be getting hyped up a bit more than it deserves to be based on its medical utility.

We’ve often come across developers and engineers making bogus claims, but this is certainly not the case here. It was developed by Dr. David Albert who, according to his LinkedIn page, has founded three medical device companies and was the Chief Clinical Scientist in Cardiology at GE Healthcare. So I feel comfortable trusting that the technology is legitimate. And it doesn’t seem like there were a ton of technical hurdles to overcome in the development of this technology. However, when it comes to assessing the utility of this device, the picture becomes far more nuanced.

One of the claims made is that this device will be a life-saving, home monitoring device. But its hard to imagine how. Take patients with atrial fibrillation – it is generally well accepted that these patients go in and out of their abnormal rhythm though at variable frequencies. It makes no difference, however, in their management. Or more generally, take the patient with palpitations who typically gets some form of portable cardiac monitoring (typically a Holter monitor, event recorder, etc). This is an area where the AliveCor device can certainly find a niche, as some of these devices are literally far more expensive versions of the iPhonECG where patient apply the device to their chest when they have symptoms.

However, other, and probably more useful, devices are worn continuously and record continuously, storing data that can be continuously recorded for weeks or even just storing the last several minutes of data in the event that symptoms occur. In the latter case, this way the analyzing physician can see a far more complete clinical picture.

When it comes to field use, either domestically or abroad, the applications are more limited than others seem to think. This device can not be used to look for myocardial infarctions or fixed conduction anomalies (i.e. disease of the cardiac conduction system like a left bundle branch block). What it can do is identify more obvious rhythms – Vtach, Vfib, SVT’s, and so on. Even in this case, anyone who has looked at an EKG before knows that it often takes the full 12-lead reading to really figure out whats going on.

Where it really wins is as a quick screening tool for providers in the field and a cheaper alternative to short-term, outpatient rhythm monitoring. In the former case, I can easily imagine EMS providers, for example, using this device to screen patients with vague complaints, in difficult situations (e.g. car accidents), and so on. Its small, its easy, and its quick – all critical for the first responder. The latter case, it would be a great cheaper alternative to patients who are being evaluated for paroxysmal rhythm abnormalities. I can only imagine how much money would be saved by evaluating low-risk patients (thinking of young women with a single syncope episode) using a device like this rather than a far more expensive traditional monitor.

This technology will fill a critical niche in healthcare, that is nearly certain. Combined with technology from industry giants like Medtronic, who we talked to at HIMSS about systems to remotely monitor patients with cardiac devices and alert medical personel when, say, their AICD fires, these devices will improve how we care for our patients. So while iPhonECG may not be have as broad a niche as some seem to suggest, it illustrates a way in which mobile medical technology can make diagnostics more portable while at the same time reducing cost.

As one of the founders of Mobisante commented in an interview with the MIT Technology Review, “Billions of dollars are being spent to make this platform more powerful, so it makes sense to ride that investment rather than try to duplicate it.” I think this is a fact that Dr. Albert clearly recognizes, embraces, and is using to enhance to tools available to physicians to improve how we practice medicine.

See the video of the device from Dr. Albert here.