A system for treating a selected dermatological problem and a head for use with such system are provided. The seismic data includes particle motion data. The hydrocarbon trap may be positioned in the exhaust gas passage of a vehicle such that hydrocarbons are adsorbed on the trap and stored until the engine and exhaust reach a sufficient temperature for desorption and oxidation of the hydrocarbons. The outermost rim members placed at the periphery of the dish form the aperture of the dish.