Abstract

A vibrometer which detects the variation of the speckle interference pattern of reflected waves as a means of determining the amplitude and frequency of vibrations of structures, including small anatomical structures. A wave source such as a laser delivers wave radiation to the object whose vibration is to be measured. The diffuse reflectance from the textural surface of the object reflects the incident wave radiation as a speckle interference pattern which is detected by a detector, such as a photodetector. The wave radiation source may be a continuous-wave laser, and the photodetector detector may be a phototransistor connected to a wide-bandwidth amplifier. As the object vibrates, the speckle interference pattern moves. The variation in the speckle interference pattern across the detector carries amplitude and frequency information regarding the vibrating object.

Other References

• Keilson, et al., "Spontaneous Cellular Vibrations in the Guinea-Pig Cochlea" (Acta Otolarynol, 1993, pp. 591-597
• Eiber, "Mechanical Modelling of the Human Middle Ear", Abstracts of the Second European Conference on Engineering and Medicine, 1993
• "Laser Vibrometer", Polytec, undated
• "Polytec Scanning Vibrometer," Polytec, undated
• Gyo, et al, "Measurement of the Ossicular Vibration Ration in Human Temporal Bones by Use of a Video Measuring System," Acta Otolaryngol
• (Stockholm) 103, 87-95, 1987
• VonUnge, et al, "Displacement of the Gerbil Tympanic Membrane Under Static Pressure Variations Measured with a Real-time Differential Moire Interometer," Hearing Res. 70, 229-242, 1993
• Kossl, et al., "Basilar Membrane Resonance in the Cochlea of the Mustached Bat," Proc. Natl. Acad. Sci. USA, 92, 276-279 (1995)
• Decreamer, et al., "A Method for Determining Three-Dimensional Fibration in the Ear," Hearing Res. 77, 19-37 (1994)
• Goode, et al., "Measurement of Umbo Vibration in Human Subjects--Method and Possible Clinical Applications," Am. J. Otol. 14, 247-251 (1993)
• "Combined fibre optic laser velocimeter and electronic speckle pattern interferometer with a common reference beam," Meas. Sci. Tech. 4,578-582, 1993
• "Laser interferometer microscopic for the measurement of nanometer vibrational displacements of a light scattering microscopic object," J. Acoustic Soc. Am. 83, 1667-1674, 1988
• "Opto-electronic system for displacement and vibration measurement," Rev. Sci. Instrum. 58, 1678-1681, 1987
• "Simple method of measuring vibration amplitudes at better than nanometer sensitivity," Rev. Sci. Instrum. 59, 2626-2628, 1988
• "Minimum detectable phase shift in spectrum-analysis techniques of optical interferometric vibration detection,"Applied Optics 5997-6002, Oct. 1992
• "Double-pulse electronic speckle interferometry for vibraton analysis," Applied Optics, 7857-7863, Dec. 1994
• "Four-beam two-focus differential laser velocimetry system", Aug. 1992
• "Two-frequency displacement measurement interferometer based on a double-heterodyne technique," Rev. Sci. Instrum., 254-255, Jan. 1991
• "Measuring small vibrations with interferomtery," Am. J. Phys. 58, 919-922, Oct. 1990
• "Non-contact surface vibration analysis using a monomode fibre optic interferometer incorporating an opean air path," The Institute of Physics, 1985
• "The effect of tympanic membrane performation size on umbo velocity in the rat," Laryngoscope, 71-76, Jan. 1996
• Radio Electronics, vol. 58(10), 40-44, 1987
• "Advances in the development of the interferometic otoscope," Laryngoscope, 263-267, Mar. 1996
• "Sound pressure gain produced by the human middle ear," Otolarngology-Head and Neck Surgery, 113(4), 349-355, Oct. 1995
• "On the acoustic coupling of the eardrum," 207-208, undate