information element ie as described in u s patent application ser no 11 367 036 filed mar 1 2006 and entitled configurable physiological measurement system or a sensor life indicator sli as described in u s pat no 7 186 966 entitled amount of use tracking device and method for medical product both incorporated by reference herein fig3 illustrates an unbalanced electric motor 300 having a motor body 320 a rotary shaft 340 and an unbalanced flywheel 360 the motor body 320 is generally cylindrical and accommodates the shaft 340 which extends along a center axis of the body 320 electrical leads 380 extend from the body 320 opposite the shaft 340 so as to electrically connect the motor 300 to the cable 120 fig1 when the motor 300 is activated by a monitor 500 fig5 via the cable 120 fig1 the shaft 340 rotates the flywheel 360 in an embodiment the flywheel 360 is a generally semi circular disc centrally mounted to the shaft 340 when the shaft 340 rotates the flywheel 39 s eccentric imbalance causes the motor as a whole to vibrate at a predetermined frequency according to the motor rotational speed this vibration u201c pulses u201d a tissue site which creates a pulsatile blood flow in other embodiments the unbalanced motor 300 is configured with rotational.