Abstract: The invention relates to a portable electronic device, like a shaver, a toothbrush, a walkman, a telephony unit, etc., said device being arranged to measure a signal representative of a physiological condition of a user during a conventional usage of said device. In an embodiment of the electric shaver (25), it is provided with a first contact surface (26) comprising a plurality of shaving heads (26a, 26b, 26c). The shaving heads are manufactured from an electrically conducting material, usually a metal and are suited to provide a good electrical contact to the individual's skin during shaving, thus constituting a first electrode. The second contact surface (28?) is provided on the housing of the shaver, in particular on a grip portion (28) thereof, where a contact to a hand of the individual is enabled. The second contact surface (28?) comprises a second electrode (29).