Hydration has long been considered a simple, self-regulated process: drink when you’re thirsty. But according to Professor Mark Kendall, CEO and Founder of healthtech startup WearOptimo, this conventional wisdom misses a serious, often undetected health issue—chronic mild dehydration. His solution? A pain-free, AI-powered wearable sensor that monitors hydration with clinical accuracy and real-time feedback.

“We’re comfortable in the knowledge that we have clinically proven the only wearable on the planet that genuinely monitors hydration,” Kendall said in an interview with Drug and Device World.

A Flawed Landscape: Why Current Solutions Don’t Work

Kendall explains that previous attempts at wearable hydration sensors have relied heavily on sweat or light-based technologies—both of which fall short. Sweat sensors don’t correlate with hydration because people can be dehydrated without sweating. Similarly, light-based approaches suffer from motion artifacts and interference from skin scattering.

In contrast, WearOptimo’s sensor uses microelectrodes to reach just a few microns into the viable epidermis—the skin layer most sensitive to changes in hydration. “They’re only a hair’s width into the skin,” Kendall explains, “and it feels just like a sticker.” This enables ultra-high fidelity monitoring without discomfort.

What most people don’t realize, Kendall says, is just how widespread and dangerous mild dehydration is. “About half of Americans—and that reflects much of the world—are chronically and mildly dehydrated,” he notes. “If it were a disease in its own right, the impact would be equivalent to diabetes.”

Citing findings from Nature Reviews Nephrology, Kendall warns that long-term mild dehydration can reduce life expectancy by four years and increase the risk of dementia by 48%. The issue is compounded by the fact that the thirst reflex often doesn’t activate until dehydration becomes more severe—meaning people often don’t know they’re already affected.

Real-Time Monitoring and Behavior Change

Unlike a one-off blood test or subjective thirst, the WearOptimo sensor provides continuous hydration monitoring. Clinical trials show that at just 1.5% dehydration—below the threshold where people feel thirsty—the sensor outperforms gold standard blood draws.

“Imagine you’ve got a real-time readout of your hydration level. You take a drink, and you can see the level come back up,” says Kendall. This feedback loop can help modify behavior in real-time, especially for people in physically demanding environments.

WearOptimo has conducted a randomized crossover study involving 45 healthy adult participants. The study was designed so that the participants restricted fluid intake for 24 hours, followed by light exercise in a hot and dry environment (40°C, 20% humidity). Participants then performed the same exercise routine but with continuous fluid replacement.

Each participant’s hydration status was assessed via body weight, blood osmolality, urine samples, and vital sign monitoring. The microwearable was worn continuously during both sessions and placed on either the shoulder, sternum, or hand.

The primary endpoint was to evaluate the sensor’s ability to correctly classify participants as dehydrated or euhydrated. The data show that WearOptimo’s Hydration Microwearable sensors outperformed the ‘gold standard’ of serum osmolality (achieved via blood draws), demonstrating significantly greater accuracy (i.e. sensitivity and selectivity) at the typically hard to measure levels of mild dehydration.

Kendall emphasizes that WearOptimo’s solution is the result of decades of research in medical engineering and skin science. The sensor’s intelligence is driven by bespoke AI/ML models, developed by a seven-person team over three to four years. “This wasn’t possible even two years ago. It’s the convergence of biosensing, microelectronics, and AI,” he says.

Strategic Rollout: From Athletes to Hospitals

Kendall states that the initial commercial rollout for the device will focus is on elite athletes, industrial workers, and military personnel—groups that experience large hydration shifts and stand to benefit most from precise monitoring. “Elite athletes regularly dehydrate themselves beyond what is ethical in clinical trials,” Kendall notes. “That gives us better data to refine our AI models.”

Industrial sectors like mining and military units offer ideal testing grounds due to the intensity of physical demands and relatively healthy populations. These sectors also don’t require immediate regulatory approval, speeding up the rollout.

Beyond these early adopters, the potential clinical applications are vast. “Emergency departments, ICUs, aged care settings—these are areas where better hydration monitoring could significantly improve outcomes and reduce hospital stays,” he says.

Though WearOptimo is launching in Australia first, it is fundamentally a global venture, according to Kendall. “Most of our advisory board is mostly based in the US,” Kendall says, referencing members like Moderna co-founder Professor Bob Langer at MIT.

With its blend of clinical accuracy, user comfort, and real-time feedback, WearOptimo’s hydration sensor could become a standard in both healthcare and everyday wellness—empowering people to act before dehydration becomes a problem they can feel.