Oura just made its ring 40% smaller. Here’s how they did it

For years, the smart ring has been pitched as a piece of jewelry that happens to read your sleep stages, your heart rate variability, and your blood oxygen. In reality, though, most smart rings are chunkier than anything you would pick at a jewelry store—something that many consumers find annoying. Oura, the Finnish-founded, San Francisco-based company that helped invent the category over the past 12 years, has heard the complaint from its own customers repeatedly. “The feedback we alwa...