Christina Farr, CNBC:

[Apple] is expected to take these health ambitions a step further by introducing an electrocardiogram or “ECG” sensor that measures the heart’s rhythm — and not just the heart rate.

That’s according to Apple analyst Ming-Chi Kuo, who issued a research note seen by CNBC on Monday.

Lots of rumors sprang from Kuo’s research note. This bit about adding an ECG is fascinating. Here’s why:

Apple releasing an ECG is a big deal for people with certain diseases. But it’s also complicated because the company would need to figure out how to communicate sensitive medical information to consumers without freaking them out. The last thing Apple would want to do with its device is send tens of thousands of anxious users into the emergency room thinking they’re having a life-threatening medical problem when they’re not.

And:

If Apple shows the ECG reading to a consumer, then yes. That would make the Apple Watch a regulated medical device.

Two very interesting issues. Solving this problem would be a big step towards being able to add a wider variety of sensors to the Apple Watch and other Apple devices and accessories. Good read.

UPDATE: From this Reddit thread (hat tip to Simon), making the case that there will not be an ECG Apple Watch:

First and foremost, ECG stands for electrocardiogram and is a measure of depolarization and repolarization of the heart during the cardiac cycle. ECG is electrical activity and can’t not be measured with LED. Pulse oximetry can be used for heart rate and even pulse wave velocity, but not the electrical activity of the heart. However, let’s entertain the though of an electrode based ECG sensor in the Apple Watch. In a clinical 12-lead ECG, 10 electrodes are placed on the left arm, right arm, left leg, right leg as well as 6 “precordial” electrodes. These 10 electrodes are paired up into 12 different “leads” which are grouped into limb leads (I,II,III), augmented limb leads (aVR, aVL, aVF) and precordial leads (V1-V6).

The reason for using so many electrodes is to look at the electrical activity from a number of directions. One could imagine one electrode placed on the back of the Apple Watch (left arm) and one electrode on the bezel, allowing one lead from the left arm to the right arm, which is normally referred to as lead I. This gives us a lateral view of the electrical activity, which could show us an ECG-trace, but would be nowhere near enough for diagnosis (Edit: It has been pointed out that the Kardia device can use a single-lead ECG to detect atrial fibrilation).

Second, and this is the kicker. Osram is actually a manufacturer of LED-ECG. But the ECG stands for Electronic Control Gear and has nothing to do with cardiology.

Interesting, informative, but not enough to throw cold water on this rumor, at least for me. We shall see.