Apple apparently wanted its smartwatches to focus heavily on health-related features, but the company was forced to changed direction mid-development. According toThe Wall Street Journal, the company originally envisioned a device that can monitor heart rate, blood pressure and stress levels (based on the conductivity of the skin). Unfortunately, the sensors they tested just didn't pass muster, which isn't entirely surprising, since we've reviewed plenty of wearables with patchy heart rate monitors in the past. The company's engineers found that hairy arms, dry skin and even how tightly the watch is worn can affect the results, and they didn't find a solution in time.

http://www.engadget.com/2015/02/17/a...-features-cut/