Ever since Apple (NASDAQ:AAPL) launched the first iPhone nearly seven years ago, developers have released mobile apps and connected devices to improve the lives of diabetes patients. These products helped diabetics track meals, insulin dosages, glucose levels, and medications. One major breakthrough was Sanofi's (NASDAQ:SNY) iBGStar Meter for iOS, which converts any iPhone into a strip-reading glucose monitor for type 1 diabetics.

Sanofi's iBGStar. Source: Sanofi.

Yet one product has remained elusive -- a wireless, continuous glucose monitor, or CGM, for smartphones that would eliminate daily pinpricks, remain concealed as a mobile app, and alert the user via push notifications when glucose levels hit certain thresholds. Such a device would also enable better tracking of daily glucose levels and allow easy data sharing with family members and medical professionals.

Medtronic (NYSE:MDT) could soon make that dream a reality with its new Bluetooth-enabled CGM for iOS, known as Guardian Mobile. The FDA has not approved the system yet, but the company recently told MobiHealthNews that it will start a "pivotal clinical trial" for the device later this fall. The Guardian Mobile would be a major upgrade for the company's top CGM, the Medtronic Guardian, which communicates wirelessly to a pager-sized device with a custom display.

What the Guardian Mobile would mean for the CGM market
If approved, Medtronic's Guardian Mobile could be the first smartphone CGM to hit the market. The only potential competitors in this field are Dexcom (NASDAQ:DXCM), which filed a patent in January for a similar device, and Senseonics, which raised over $84 million to develop an embedded continuous glucose monitor that can last for six months under the skin before being replaced.

The Guardian Mobile would help Medtronic expand its reach in the growing global CGM market, which Allied Market Research estimates will grow from $194.8 million in 2012 to $568.5 million by 2020. That growth, unfortunately, will be fueled by rising diabetes rates across the world.

The Guardian Mobile would also help Medtronic expand its presence in the mobile health, or mHealth, market, which Grand View Research estimates will grow from $1.95 billion in 2012 to $49 billion by 2020. This growth is expected to be fueled by growing smartphone shipments, which research firm IDC expects will rise from 1 billion units last year to 1.7 billion units in 2018. The Guardian Mobile CGM and app wouldn't be Medtronic's first move into the mHealth market -- the company has already launched 70 consumer-facing iOS apps for patients and doctors.

Therefore, a device that straddles both the CGM and mHealth markets could achieve a much higher growth rate than standalone CGMs.

What the Guardian Mobile would mean for Medtronic
Medtronic and Dexcom are the largest players in continuous glucose monitors, and split the $250 million U.S. market roughly in half last year, according to Raymond James.

Medtronic's Guardian system. Source: Medtronic.

However, Medtronic made a breakthrough last September with FDA approval of the MiniMed 530G with Enlite, a first-generation "wearable artificial pancreas" that connects a CGM to an insulin pump. The CGM signals the pump to halt insulin delivery once glucose levels drop below a preset threshold. Since the introduction of the MiniMed 530G, Medtronic's diabetes group has reported double-digit revenue gains for three consecutive quarters. The diabetes group is Medtronic's smallest business, accounting for 9.7% of its top line, but it is also the fastest-growing unit.

During Medtronic's most recent conference call, CEO Omar Ishrak noted that the MiniMed 530G helped the company gain market share in pumps and CGMs simultaneously. The MiniMed 530G could face competition soon from Dexcom and Johnson & Johnson's (NYSE:JNJ) Animas Vibe, a similar "artificial pancreas" that has already been approved in Europe, Australia, and Canada. That's why Medtronic is preparing to launch a second-generation device, the 620G, which predictively shuts off insulin delivery before low thresholds are met.

Along with the MiniMed 530G, the Guardian Mobile could help the company's diabetes business continue growing and widen its lead over Dexcom and other CGM competitors.

A Foolish final word
Medtronic's Guardian Mobile could be the first step toward linking diabetes patients to cloud-based solutions, although the system won't initially be compatible with Apple's HealthKit. That would certainly fit into Medtronic's long-term strategies -- in the past, it connected pacemakers to the Internet via its CareLink network. If systems such as Guardian Mobile are eventually synchronized with HealthKit, cloud-based electronic health reordss, and wearable technology, they could considerably improve the lives of type 1 diabetics within the next decade.