Abstract: A method (400) for calibrating a gyroscope (28) of an oral care device (10) includes the steps of: scheduling (420) a data acquisition scheme comprising a plurality of time points; obtaining (430) sensor data by the gyroscope at each of the plurality of time points; determining (440) whether the oral care device was experiencing motion at any of the plurality of time points and, if so, discarding those time points from further analysis; determining (450) a calibration model using the obtained sensor data; generating (460), based on the obtained sensor data and the determined calibration model, one or more parameters describing a behavior of the gyroscope; and calibrating (470), using the one or more parameters, gyroscope data obtained during a cleaning session.

Abstract: A panel-acoustic transducer comprises a plate-like actuator (4) and a panel (5). The panel (5) has two substantially perpendicular axes of symmetry (AS,Al). The plate-like actuator (4) is coupled to the panel in such a way that: —the actuator (4) is coupled to the panel substantially symmetrically with respect to both symmetry axes (AS,Al) of the panel (4); the plate-like actuator (4) is so arranged that, in operation, at least the first five odd excitation modes ((1,1), (3,1), (1,3), (3,3), (5,1)), in order of increasing frequency, are actuated with alternating signs. Cusps in the power spectrum of the transducer are thereby prevented.