A self-mixing laser-diode interferometer for measuring basilar membrane vibrations without opening the cochlea

A laser-diode forms the basis of a displacement sensitive homodyne interferometer suitable for measurements from poorly reflective surfaces. The compact and cost-effective interferometer utilizes the self-mixing effect when laser light reflected from a moving target re-enters the laser cavity and ca...

Full description

Saved in:
Bibliographic Details
Published in:Journal of neuroscience methods 2005-10, Vol.148 (2), p.122-129
Main Authors: Lukashkin, Andrei N., Bashtanov, Mikhail E., Russell, Ian J.
Format: Article
Language:English
Subjects:
Algorithms
Animals
Basilar membrane
Basilar Membrane - anatomy & histology
Basilar Membrane - physiology
Cochlear mechanics
Ear, Middle - anatomy & histology
Ear, Middle - physiology
Ear, Middle - surgery
Guinea Pigs
Hearing - physiology
Interferometry
Interferometry - instrumentation
Interferometry - methods
Lasers - standards
Organ of Corti - physiology
Round Window, Ear - anatomy & histology
Round Window, Ear - physiology
Round Window, Ear - surgery
Self-mixing
Signal Processing, Computer-Assisted - instrumentation
Vibration
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A laser-diode forms the basis of a displacement sensitive homodyne interferometer suitable for measurements from poorly reflective surfaces. The compact and cost-effective interferometer utilizes the self-mixing effect when laser light reflected from a moving target re-enters the laser cavity and causes phase dependent changes of the lasing intensity. A piezo positioner was used to displace the interferometer with known frequency and amplitude as a basis for real-time calibration of the interferometer's sensitivity. The signal-processing algorithm is described that allows measurements in presence of high amplitude noise leading to variation of the interferometer's operating point. Measurements of sound-induced basilar membrane displacements were made in the intact cochleae of rodents by focusing the laser beam of the interferometer through the transparent round window membrane. The interferometer provides a viable means for making subnanometre mechanical measurements from structures in the inner ears of small mammals, where opening of the cochlea is not practicable.
ISSN:0165-0270
1872-678X
DOI:10.1016/j.jneumeth.2005.04.014