Abstract: A biometric device configured to be attached to a portion of a body of a user measures biometric data of the user. The device includes an optical emitter, a wavelength filter, an optical sensor and a processor, for sending a light to the body of a user, receiving light received from the user, filtering and processing it to measure biometric data of the user, including for example, heart rate and blood flow rate. In addition, the biometric device may include other sensors, such as a galvanic skin response sensor, an ambient temperature sensor, skin temperature, motion sensor, etc., to enable the biometric device to measure arousal or conductivity changing events, ambient temperature, user temperature and motion associated with the user. Additionally, information from each sensor may be used to further filter noise in one or more signals received by the sensors to provide biometric data to the user.