Apple has an idea of a new biometric recognition approach on your iPhone, to make the process seamlessly “magical”.
The sensor, as Apple describes it, could be completely hidden from view, and the “electrical signals generated by the user can be transmitted from the user’s skin through the electronic device housing to the leads.”
Then, using these signals, the electronic device as medical solution can “identify or authenticate the user and perform an operation based on the identity of the user. In some embodiments, the electronic device can determine the user’s mood from the cardiac signals and provide data related to the user’s mood.”

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