Watch crown having a conductive surface

A wearable electronic device comprising:

• an enclosure;
• a crown configured to rotate and translate relative to the enclosure and comprising:
• a conductive shaft configured to extend through an opening in the enclosure;
• an inner crown body structurally coupled to the conductive shaft and defining an exposed conductive surface that is conductively coupled to the conductive shaft, the exposed conductive surface defining an electrode configured to detect a voltage of a user in contact with the electrode to determine an electrocardiogram of the user;
• an outer crown body positioned around the inner crown body;
• an isolator positioned between the outer crown body and the inner crown body;
• and
• a retainer configured to compress the isolator between the outer crown body and the inner crown body;
• and
• a processing system electrically coupled to the electrode through the conductive shaft and configured to determine the electrocardiogram based at least partially on the voltage detected at the electrode.

An electronic watch comprising:

• an enclosure defining an opening;
• a crown positioned along a side of the enclosure, wherein the crown is rotatable relative to the enclosure and translatable relative to the enclosure and comprises:
• a conductive inner crown body electrically coupled to the processing unit, the conductive inner crown body defining an exposed conductive surface, the exposed conductive surface defining an electrode configured to detect a voltage of a user in contact with the electrode to determine an electrocardiogram of the user;
• a shaft extending from the conductive inner crown body and through the opening;
• an outer crown body surrounding the conductive inner crown body;
• and
• an isolator positioned between the conductive inner crown body and the outer crown body and electrically isolating the conductive inner crown body from the outer crown body;
• and
• a processing unit positioned within the enclosure and conductively coupled to the electrode through the shaft, the processing unit configured to determine the electrocardiogram of the user based at least in part on the voltage detected at the electrode.