Creating a medical-grade app to monitor blood pressure on your mobile phone

March 21, 2022
Riva Health’s system promises to take medical-grade blood-pressure readings using a mobile phone and use frequent measurements to vastly improve blood pressure management. Image courtesy of Riva Health.
Riva Health’s system promises to take medical-grade blood-pressure readings using a mobile phone and use frequent measurements to vastly improve blood pressure management. Image courtesy of Riva Health.

Search on “heart rate monitor” in the Google Play store or Apple’s App Store and you’ll find dozens of apps capable of taking your pulse.

Do the same on “blood pressure monitor” and you’ll find a bunch of apps, too. But it doesn’t take much fine-print reading to see that none actually record your blood pressure – they’re all just data trackers for systolic and diastolic numbers coming from a traditional blood pressure cuff. That’s despite blood pressure measurements generally being far more consequential to one’s health – and despite the fact that the standard approach of having one’s arm noosed hasn’t changed in 125 years.

Tracking blood pressure using the standard tools on a smartphone – specifically, the flash’s bright light and a camera – turns out to be much, much harder than sensing the blunt-force emanations of a pulsing human heart.

There is at least one app out there that looks to be able to do it, though you won’t find it online just yet. Its creators at startup Riva Health are hard at work with the UCHealth Care Innovation Center to develop much more than just another download. The aim is to harness the near-ubiquitous enabling technology of the smartphone to take and record frequent, highly accurate blood-pressure (and, yes, heart rate) measurements without the cuff. Those measurements will in turn enable a consistent, day-in-day-out program – one involving both artificial intelligence and real, live human medical experts – capable of managing patients’ blood pressure far more quickly and precisely than is typical right now.

It could be a huge deal. Dr. Richard Zane, the CU School of Medicine Emergency Medicine chair as well as UCHealth’s chief innovation officer, describes hypertension – high blood pressure – as having an “exponential impact” on human health because of its complicity in so many other states of disease: heart attacks, strokes, aneurysms, heart failure, eye damage, kidney damage, metabolic syndrome, dementia, the list goes on. And high blood pressure is alarmingly common. In the United States, 116 million people – nearly half the adult population – have high blood pressure; only about 20% of them have it under control.

“A billion people on this planet have hypertension,” Zane said. “Half to two-thirds are not properly managed.”

A photo of Dr. Richard Zane
Dr. Richard Zane, UCHealth chief innovation officer and professor and chair of Emergency Medicine at the CU School of Medicine.

Mobile-phone-based blood-pressure sensing software

Riva counts among 16 partners the UCHealth Care Innovation Center has on a roster of companies specializing in areas ranging from data science and artificial intelligence, digital patient experience, personalized medicine, virtual and augmented reality tools, wearables, and virtual health. Those partners are the precious metals mined from more than 700 proposals Zane and colleagues have vetted in the past three-and-a-half years. UCHealth and Care Innovation Center partner CU Innovations together invested $5 million in Riva in an opening, $15.5 million funding round announced in March 2021. Most of the local money came from UCHealth, and it put Zane on the startup’s board.

This would appear a sizable bet for a new company with nascent technology, but there’s more to the story. Cofounder and PhD bioengineer Tuhin Sinha had been leading the development of the mobile-phone-based blood-pressure sensing software for the better part of five years under the aegis of Vital Labs. The software analyzes the blood pressure waveform detectable via a finger placed on the cell phone camera for 20 to 30 seconds, about the same amount of time it takes using a cuff (they’re shooting for 10 to 20 seconds, Sinha says). By the time Zane downloaded the app to his phone a few months ago, the system was well-proven. His initial reaction: “Wow – this actually works.”

Sinha’s cofounder was another risk mitigator. Dag Kittlaus is a serial entrepreneur best known for cofounding the company that created Siri, later to be bought by Apple to soothe and inform untold billions with her AI-powered voice. Kittlaus, a rare survivor of pancreatic cancer, wanted to channel his energies into a promising health care play. He grilled Sinha on everything from the technology to the business plan. His satisfaction blossomed into enthusiasm and he signed on as Riva’s CEO.

Monitoring programs for a blood pressure app

While the idea of achieving medical-grade blood pressure readings using a nonmedical device already in billions of pockets seems like the big story, Riva’s leaders and Zane now seem much more interested in the potential of the monitoring programs this technological leap looks to enable.

The alarming shortcomings of current blood-pressure management regimens boil down to intermittency. While at-home cuffs and apps to track blood pressure over time do exist, a minority of those with high blood pressure are dedicated users. It’s a hassle, and even if you have the measurements, it often takes a doctor visit to make adjustments. The vast majority of hypertension patients only get their blood pressure taken when actually at the doctor’s office anyway. The physician then adjusts the meds and sends the patient off again until the next appointment.

Riva Health cofounder Tuhin Sinha. Photo courtesy of Riva Health.
Riva Health cofounder Tuhin Sinha. Photo courtesy of Riva Health.

“The patient disappears, and that period is relatively opaque,” Sinha said.

Riva’s goal is to turn this staggered process – one that can take weeks or months to get blood pressure under control – into a continuous flow of care. If checking one’s blood pressure becomes as easy as scrolling Instagram (and much less time-consuming), one can do so several times a day. Rather than a single giant pixel delivered occasionally through a cuff, an accumulation of data points starts to paint a picture that renderers more sharply and more quickly. Sinha believes Riva patients will have their initial blood pressure back under control in days rather than weeks or months, and that ongoing monitoring will keep it under much better control.

“We want to take these clinical measurements in real-time, and we’ll have clinical staff monitoring it real-time. It becomes intensive cardiovascular-disease management between visits as opposed to just reacting when a patient has chest pain,” Sinha said.

‘Technology-enabled care’

To Zane, Riva Health “democratizes blood-pressure management” while fitting perfectly into a UCHealth’s innovation portfolio aiming to employ AI and other technologies to combine virtual health (Zane prefers the term “technology-enabled care” because of misperceptions that virtual health is something less than “real” health care) with in-person care to enable UCHealth and others to more effectively and efficiently take care of people.

“I want doctors only making doctor-level decisions, and the same with nurses and techs,” he said. “I want technology to make it easier, not harder; faster, not slower; and to move us down the path of least resistance.”

Riva’s blood-pressure monitoring program would handle the basic blocking and tackling of blood-pressure management, he says, leaving the trickier clinical calls to UCHealth physicians. UCHealth is pursuing similar efforts in lipid management, diabetes, and wound care, Zane adds, and initiatives in virtual health and remote patient monitoring follow a similar playbook.

The UCHealth-Riva Health partnership – which Sinha described as “a great opportunity with a world-class institution” – goes beyond financial investment. Two clinical trials aim to prove Riva’s and Zane’s belief that high-frequency remote blood-pressure monitoring will pay dividends in terms of patient well-being and care efficiency. Zane is confident that it will – and that Riva and others are helping move health care in the right direction. UCHealth will begin piloting the app in two clinical practices within the next month or two, Zane said.

“I think this is emblematic about what is going to happen – and should happen – across many disease states,” Zane said.

About the author

Todd Neff has written hundreds of stories for University of Colorado Hospital and UCHealth. He covered science and the environment for the Daily Camera in Boulder, Colorado, and has taught narrative nonfiction at the University of Colorado, where he was a Ted Scripps Fellowship recipient in Environmental Journalism. He is author of “A Beard Cut Short,” a biography of a remarkable professor; “The Laser That’s Changing the World,” a history of lidar; and “From Jars to the Stars,” a history of Ball Aerospace.