A high power ultrasonic transducer includes a first ultrasonic transducer cell and at least one second ultrasonic transducer cell disposed on the first ultrasonic transducer cell. The probe may be disposed on either of the posterior blade and the anterior blade, depending upon physiological factors varying with each patient and procedure. The variable optical attenuator is instructed to maintain the desired attenuation level of the optical signal. Such an arrangement allows for better monitoring of the user’s vicinity in an emergency situation without the need for prolonged user participation in narrating or describing the emergency situation. The system may combine the light from the multiple sources when illuminating a mask.