An ear-worn heart monitor, from Quanttus co-founder David He's MIT thesis.

Cambridge, Massachusetts-based Quanttus, a stealthy MIT startup working on wearable vital sign monitoring, has raised $19 million in first round funding from Khosla Ventures and Matrix Partners. The company has previously raised $3 million in seed funds from Vinod Khosla.

“Quanttus is pushing monitoring into many high value use cases from cardiac disease and hypertension monitoring to stress,” Khosla said in a statement. “The team’s approach to using real-time physiological data will create powerful new tools for consumers and healthcare providers that will change how we understand our health.”

Although the company is still thin on details, Quanttus is developing wearable monitors that the company says "can capture and analyze more than half a million vital sign data points per day." The wearables will combine with an analytics engine that will translate the data from the devices into insights for daily health and living. The company plans to use the investment to continue developing the technology.

“From busy professionals to those focused on living a healthy lifestyle, athletes to people living with chronic health conditions, we want to help the world get better and be better with wearable devices and digital experiences that blend with life instead of interrupting it,” Shahid Azim, CEO and co-founder of Quanttus, said in a statement.

Khosla Ventures has previously made significant investments in the digital health space including Jawbone, AliveCor, CellScope, Ginger.IO, and Misfit Wearables. Matrix, on the other hand, is fairly new to health investing, with a portfolio that includes EHR analytics company QPid.

“There is a lot of excitement around wearables, but what makes Quanttus different is the sophistication of its technology," Stan Reiss, general partner at Matrix Partners, said in a statement. “Quanttus was developed for a specific purpose by a very serious technical and design team out of MIT. It is not a reaction to a trend but rather combines groundbreaking research with meaningful data in an elegant form factor.”

Back in August, Xconomy's Gregory Huang wrote about Quanttus as a potential player in the digital health space after catching wind of the company's trademark filing and cofounder David Da He's MIT thesis. The trademark filing indicates that part of the company's offering will involve online chat rooms or bulletin boards for health discussion. The thesis, more interestingly, proposes a heart-rate monitor worn on the ear rather than the chest. Since then, however, Azim told MIT technology review that the technology was a "smartwatch-like" device that sits on the wrist. According to MIT Technology Review, the device is being validated in trials at Massachusetts General Hospital and Brigham and Women's hospital.