The FDA yesterday made an announcement that could put the kibosh on the plans drummed up by Apple and Samsung to put a non-invasive blood glucose sensor on their smartwatches. Such a feature would allow insulin-dependent diabetics to test their blood sugar painlessly and inexpensively using these devices. Currently, to determine how much insulin they need to take before each meal, a diabetic uses a small needle called a lancet to draw blood from his/her finger. A drop of the blood is placed on an expensive non-reusable test strip which has already been inserted inside a machine called a glucometer.