Impedance Measurements at the Eardrum as an Aid to Diagnosis

1963 ◽  
Vol 6 (4) ◽  
pp. 315-327 ◽  
Author(s):  
Alan S. Feldman
Keyword(s):  
Middle Ear ◽  
Acoustic Impedance ◽  
Rapid Determination ◽  
Clinical Investigation ◽  
Acoustic Method ◽  
Clinical Measurement ◽  
Impedance Measurements ◽  
The Status ◽  
Conductive Hearing

The clinical measurement of acoustic impedance at the eardrum is described. Significant modifications of the traditional Schuster bridge by Zwislocki led to the development of an acoustic impedance bridge that permits a sufficiently reliable and rapid determination of absolute acoustic impedance. The results of clinical investigation with this instrument demonstrate the value of the acoustic method in the evaluation of the status of the middle ear mechanism. The presence of conductive hearing losses due to various middle ear conditions may be detected and differentiated by objective and quantitative impedance measurements.

An Acoustic Method for Clinical Examination of the Ear

1963 ◽  
Vol 6 (4) ◽  
pp. 303-314 ◽  
Author(s):  
J. Zwislocki
Keyword(s):  
Clinical Examination ◽  
Middle Ear ◽  
Acoustic Impedance ◽  
Acoustic Method ◽  
Suggested Method ◽  
Supplementary Information ◽  
Impedance Measurements ◽  
Acoustic Resistance

An objective acoustic method is suggested for diagnostic examination of the ear. It provides supplementary information to the otoscopic and audiometric examinations. The acoustic method is based on impedance measurements at the eardrum by means of an acoustic bridge that is calibrated in absolute acoustic resistance and compliance units. The obtained values can be read directly on the instrument dials and no time consuming computations are required. The article includes an explanation of the concept of acoustic impedance, an analysis of the middle ear mechanism and of the acoustic effects of middle ear pathologies, in addition to a description of the suggested method.

Acoustic Impedance Measurements in Cleft-Palate Children

1975 ◽  
Vol 40 (1) ◽  
pp. 13-24 ◽  
Author(s):  
Fred H. Bess ◽  
H. Donell Lewis ◽  
David J. Cieliczka
Keyword(s):  
Hearing Loss ◽  
Cleft Palate ◽  
Middle Ear ◽  
Acoustic Impedance ◽  
Pure Tone ◽  
Cleft Lip ◽  
Impedance Measurements ◽  
High Incidence ◽  
Middle Ear Disease

Clinical acoustic impedance findings in a group of 40 children with cleft lip or palate and a group of 20 noncleft children are presented. The cleft subjects exhibited a high incidence of hearing loss and aural pathology. The data suggest that impedance measurements lend pertinent supportive information to routine pure-tone audiometric testing in the detection and management of middle-ear disease in the cleft-palate population.

Weak Beam Imaging and Diffraction Studies of Stacking Faults in Silicon

1976 ◽  
Vol 34 ◽  
pp. 590-591
Author(s):  
T. Y. Tan ◽  
W. K. Tice
Keyword(s):  
Fast Neutron ◽  
Rapid Determination ◽  
Stacking Faults ◽  
Imaging Method ◽  
Large Reduction ◽  
Dislocation Loops ◽  
Fringe Spacing ◽  
Weak Beam ◽  
Kinematical Theory

In studying ion implanted semiconductors and fast neutron irradiated metals, the need for characterizing small dislocation loops having diameters of a few hundred angstrom units usually arises. The weak beam imaging method is a powerful technique for analyzing these loops. Because of the large reduction in stacking fault (SF) fringe spacing at large sg, this method allows for a rapid determination of whether the loop is faulted, and, hence, whether it is a perfect or a Frank partial loop. This method was first used by Bicknell to image small faulted loops in boron implanted silicon. He explained the fringe spacing by kinematical theory, i.e., ≃l/(Sg) in the fault fringe in depth oscillation. The fault image contrast formation mechanism is, however, really more complicated.

Methods for rapid determination of pecan (Carya illinoensis) seed viability

2017 ◽  
Vol 45 (2) ◽  
pp. 455-464
Author(s):  
T.T. Xue ◽  
J. Liu ◽  
Y.B. Shen ◽  
G.Q. Liu
Keyword(s):  
Rapid Determination ◽  
Seed Viability ◽  
Carya Illinoensis
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