Method and apparatus for measuring acoustic power flow within an ear canal

摘要

PCT No. PCT/US97/13953 Sec. 371 Date Jan. 29, 1999 Sec. 102(e) Date Jan. 29, 1999 PCT Filed Aug. 12, 1997 PCT Pub. No. WO98/06324 PCT Pub. Date Feb. 19, 1998A system and method for accurately determining the power flow within a test subject's ear canal. A calibration device (300) is used in conjunction with a probe device (400) that measures the frequency response of a cavity. The probe (400), with eartip (440), is inserted into a patient's ear and a transducer (460,470) emits a periodic signal into the ear canal. The transducer (460,470) also measures the frequency response of the ear canal and relays the data back to a digital signal processor. The same probe setup (400) is then calibrated by measuring the frequency response of a plurality of cavities (340a, 340b, 350c, 350d) having known geometries. Mean cavity length is solved for based upon the known geometries of the plurality of cavities. Consideration is also given to spreading mass wave phenomena due to point source transducer emission. Cavity temperature for calibration purposes is maintained as close as possible to body temperature thereby negating a farther source of error. Several measurements, including cavity impedance and pressure reflectance, are calculated from the frequency response data obtained. This data, in turn, yields valuable diagnostic information for determining ear pathologies in humans. The method and apparatus of the present invention is quick, easy, and efficient thereby lending itself to clinical use.