US Patent 9888763 Position detection of an oral care implement

An oral care implement (1) comprising: an electrode pair with an impedance formed therebetween when electrified; a frequency generator, electrically connected to the electrode pair, for applying a voltage with at least two different frequencies between the electrode pair; an impedance measurement unit, electrically coupled to the electrode pair, for measuring impedance values between the electrode pair at least at the different frequencies; and a contact determination unit, in communication with the impedance measurement unit, wherein the contact determination unit comprises a memory for storing a function, wherein the function correlates impedance values of a defined oral area at the different frequencies, and wherein the contact determination unit comprises a processor for processing the measured impedance values to the stored function so as to determine contact information of the electrode pair with the defined oral area.