Kris and Jim Bensing are watching “House of Cards” in their Blaine living room while upstairs their son Joe, an eighth-grader at Northdale Middle School in Coon Rapids, races street rods on his PlayStation 4.

Jim looks at his watch. It says 128. He relaxes, and returns to his program. The sound of screeching tires from the video game echoes down the stairwell. A revolution in patient-driven health care has just taken place.

Joe Bensing is among thousands with Type 1 diabetes who use Dexcom continuous glucose monitors (CGMs) modified to allow them to transmit real-time blood sugar levels for display on phones and smartwatches.

The software to put this essential information into patients’ hands was developed by crowdfunded hackers, not medical device makers, and it was not approved by regulators.

But families demanded ways to remotely view glucose data in real time. Doing so lets parents quickly adjust a child’s insulin levels or treat blood sugar problems with a juice box and rest. Active management helps avoid emergency care and catastrophic outcomes like amputated limbs and death.

“You constantly have to be on top of it,” Kris Bensing said. “You can’t just take a day off or say I’m not going to worry about it.”

Before the advent of unauthorized mobile display of continuous glucose data, Kris and Jim Ben­sing would have interrupted Joe’s video-gaming or his cello practice to take a reading. They would have been anxious letting him go to a sleepover or to the science museum without one of them tagging along.

“When they can look at it, I don’t have to worry about it as much,” Joe Bensing said. “I can just do my own thing.”

Companies like Minnesota-run Medtronic are now launching authorized systems attempting to do the same thing, but it remains to be seen whether families will drop their cheaply built systems in favor of the approved versions.

Type 1 diabetics often interact with their disease more than 100 times a day. Those who use wearable medical devices typically take a “bolus” of insulin before meals plus a much smaller “basal” dose all day using hip-mounted insulin pumps made by companies including Medtronic and Johnson and Johnson’s Animas subsidiary.

The breakthrough came when device companies like California’s Dexcom started selling continuous glucose monitors, which are worn on the body and send reasonably reliable data to a handheld console showing a patient’s estimated glucose level plus some indication of whether the number is changing rapidly.

But many were not satisfied.

“The device itself is awesome. [But] why can’t I see the data from that receiver wherever I am?” John Costik remembered thinking. The New York parent wrote the original software after having to give his FDA-approved data-receiver to his son’s day care. “I said, ‘You know what? This is crazy. There’s a USB port on the CGM. There is software that talks to the CGM through that port. Let me figure out how it is talking.’ … That is exactly what I did.”

That reaction helped start the citizen collective called Nightscout, which rallies behind the hashtag #WeAreNotWaiting. Joe Ben­sing and thousands of people with diabetes now use the Nightscout app to retrieve glucose data that their monitors have been engineered to send to secure Internet sites.

Companies like Medtronic and Dexcom now find themselves in an unexpected race against their own patients, who are demanding access to medical data that was once considered proprietary in some circles. It’s a reversal of the traditional medical-device design process, in which patients passively receive devices after corporate engineers and regulators have had their say.

“What we’re doing with Nightscout is turning that on its head and saying, ‘We want to be at the table with you. In fact, we are not waiting,’ ” said Lane Desborough, a Nightscout co-founder and a former chief engineer in Medtronic’s diabetes division. “Collectively we will be able to innovate faster.”

Medtronic and Dexcom are now releasing their own mobile-data display systems, but they have less functionality than the systems that were designed by unpaid freelancers and published with little more than a Facebook page and volunteer tech support. But the system of open-source software tools and, in some cases, special cords to transmit data to the cloud have never been approved by the FDA. It would likely be illegal “off-label” marketing for Medtronic or Dexcom to endorse them.

The devicemakers point out that the FDA had not yet released the rules for how such programs would be regulated when Nightscout started publishing its instructions for how to hack the devices to make them remotely display data.

“The argument that Dexcom isn’t moving fast enough isn’t fair,” said company CEO Kevin Sayer. “The fact is, it was Dexcom working with the FDA who developed the standards for this type of activity.”

The numbers show that Dexcom is a fast-moving company. The San Diego-based firm is on pace to more than quadruple its revenue in four years, to $360 million this year, analysts predict. Sayer said Dexcom has had five devices approved by the FDA in a year’s time, including the Dexcom Share CGM that Joe Ben­sing uses in a modified form to transmit data to the cloud.

As sold, the Share is only compatible with Apple operating systems, though Sayer noted that Dexcom has agreements with several companies to develop other “secondary-display” systems. The Ben­sings like the Share because it’s capable of using a Bluetooth connection to talk to an Android smartphone with the Nightscout app.

When the FDA approved the Share in January, the agency was well aware the public already had access to applications that did the same thing:

“Devices like the Dexcom Share were previously available through open-source efforts, but were not in compliance with regulatory requirements,” the FDA news release said.

Meanwhile, Medtronic has made its diabetes business a stand-alone division located in California that analysts expect to put up $1.9 billion in device revenue in the current year. That would represent 25 percent growth in four years’ time.

Much of Medtronic’s energy is focused on long-term development of a system to allow glucose-monitor readings to determine insulin doses via an automated insulin pump. But earlier this month Medtronic announced FDA approval for a device called the MiniMed Connect, which transmits glucose-monitor data for display on Apple devices. The device goes on sale this fall.

“Science lumbers. But this is a time for technology in diabetes. … There will be new things probably every year coming out, at a more rapid cadence than we’ve ever seen in the past,” said Dr. Francine Kaufman, chief medical officer at Medtronic Diabetes. “People argue, ‘Why did that take so long?’ At the same time, everyone is saying, ‘Never have a security breach possible.’ … There is always a yin and a yang to all of this.”

Kris Bensing said that for her, the convenience offered by Nightscout overshadowed the risk that a malicious hacker might try to peek at her son’s blood numbers.

Medtronic and Dexcom both say they’re attuned to patients’ preferences. In the era of crowdsourced software, they may have no choice.

“What the families urgently and acutely feel is that they need to move now,” said Dr. Joyce Lee, a health care design expert and a Michigan pediatrician treating diabetes patients. “They’ve said, ‘We’re fed up, we’re not waiting for the next technology to be approved by some regulatory agency. We need to monitor our children.’ ”


Twitter: @_JoeCarlson