Citing anonymous sources within Apple, reports in Bloomberg and the New York Times over the past weeks continue to add to the pile of leaks and rumors about two of Apple's currently under-development health devices: a wrist-worn glucose sensor and an EKG built into the Apple Watch. Combined with Apple's public efforts like the Stanford Heart study, previously documented conversations with the FDA, and participation in the FDA's pre-certification program, these efforts are starting to look like serious future products and features.

Bloomberg reports that Apple is working on an ECG sensor that would be built into the Apple Watch itself (not into the strap, like the recently-cleared Kardia Band). The user would hold sensors on both sides of the watch with their opposite hand, then the device passes a feint electrical pulse thorugh their chest.

The feature is still in development and may not even find its way into a product. If it does however, Apple would be able to do something very similar to what Kardia is doing with its band. Using the already-existing built-in heart rate sensor and algorithms that the company will refine via its recently announced heart study at Stanford, it could detect potential arrhythmias and then prompt the user to escalate to an ECG, then to a doctor if necessary.

Apple was in talks last year with the FDA about "two possible (and related) products in the cardiac space." If one of those was the algorithms being used in the Stanford study, the other could be this built-in EKG sensor. 

Meanwhile, on the diabetes side, two anonymous sources confirmed to the Times that Apple is working on a noninvasive continuous glucose reader, a project that began at the end of Steve Jobs's life as he battled both cancer and diabetes. The existence of that team was reported in April by CNBC.

Both these systems seem like they could be a ways off from release, but that makes Apple's participation in the FDA's pre-certification pilot even more interesting. By the time these devices are ready for FDA clearance, precertification could mean that process is less of a roadblock then it might have been in the past.