Apparatus and techniques are provided for precise measuring and monitoring of certain vital signs of patients that have been difficult to measure especially in emergency situations. Sensor may be used for detecting contraction and expansion in the vascular bed of the lining tissue of the external auditory canal during a cardiac cycle to obtain a better indication of certain physiological parameters. Such a signal generally may be superimposed with an additional signal that is primarily due to breathing activity of the patient. Based on various scenarios different sensors may be used to determine the signal due to breathing activity and thus the physiological parameter of interest may be derived. The signal corresponding to the physiological parameter of interest, for example, blood pressure may then be used to monitor the vital signs or control other medical equipment.