The signal from the electrodes would be processed by the electronic circuitry and converted into an infrared signal, similar to that used in a TV remote control.

BBC: Medicine over the mobile network

Infrared light is used mainly for optical communication--including for sending messages between a remote control and the TV.

FORBES: Magazine Article

The Control It All Remote transceiver then converts Bluetooth signals from the smartphone into infrared signals for the devices.

FORBES: Using the iPhone As a Universal Remote -- An Idea Whose Time Has Come

There's an infrared port that does nothing (Creative says it is going to bring out a wireless remote control).

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