Biomedical subjects

P M Vanpeperstraete

Publications and source records attributed to P M Vanpeperstraete.

8 recordsLinked to original sources

PubMed1983

A search for the most suitable imminent components and probe tone frequency in tympanometry.

The relative occurrence of bell-shaped and various types of W-shaped susceptance-conductance and admittance-phase tympanograms at a probe-tone frequency of 660 Hz was determined from registrations on normal ears. The diagnostic value of the susceptance-conductance versus the admittance-phase representation of tympanograms was studied on pathological middle-ear systems. Using probe-tone frequencies from 510 Hz up to 910 Hz, tympanograms for all four imminent components were recorded on 10 pathological ears and the diagnostic value compared. From the combination of these studies we conclude that the admittance-phase approach at a probe tone frequency between 500 and 700 Hz is a good choice.

Acoustic Impedance Tests↗

PubMed1983

Optimizing tympanometric variables for detecting middle ear traumas.

The combination of the results of different studies lead to the conclusion that the susceptance-conductance immittance audiometer at 660 Hz is not the only useful instrument for the detection of middle-ear traumas. Measurements at probe-tone frequencies from 510 up to 910 Hz prove that the admittance tympanogram combined with the electrical phase angle tympanogram recorded in the 500-700 Hz frequency range have definite advantages.

Acoustic Impedance Tests↗

PubMed1982

Incudo-stapedial joint pathology: a tympanometric approach.

Two-component tympanometry with a high probe-tone frequency enables a better distinction to be made between mobile but normal middle-ear systems and middle-ear systems suffering from necrosis, luxation, or disruption. Susceptance and conductance tympanograms obtained from 14 patients with confirmed pathological middle-ear lesions and 8 postmortem temporal bones, experimentally manipulated either surgically or with a 1 N HCl solution, were compared to tympanograms obtained from 80 normal subjects of an earlier study. With a 660-Hz probe tone, normal middle ears generate bell-shaped or normal sharp W-shaped patterns, whereas the pathologies of the middle ear give rise to irregular multi-extrema tympanograms. The differences between the two types of multi-extrema curves are discussed in detail. The use of phase-angle tympanometry is recommended to enable a quick and accurate distinction between normal and abnormal types of multi-extrema tympanograms. This study also points out clearly that 220-Hz tympanograms do not allow clear differentiation between pathological and normal middle ears.

Acoustic Impedance Tests↗

PubMed1981

The diagnostic value of phase-angle tympanograms.

The diagnostic value of susceptance, conductance, resistance, reactance, admittance and phase-angle tympanograms is compared. Phase-angle tympanograms seem to be best suited for the discrimination between normal W patterns and broad irregular curves obtained from ossicular disruptions, luxations and necroses. Several possibilities are proposed: phase-angle tympanograms at the drum, phase-angle tympanograms at the tip of the measuring probe and corresponding phasor curves. The best choice will depend on the kind of data processing and/or measuring equipment available.

Acoustic Impedance Tests↗

PubMed1980

Tympanometry-detection of middle ear pathologies.

Two component susceptance-conductance tympanometry at a probe tone frequency of 660 Hz is superior to admittance tympanometry at 220 Hz for the detection of an ossicular discontinuity, a luxation or a necrosis. It is, however, essential to understand well the difference between non-pathological W-patterns and pathological broad multi-extrema tympanograms. The systematics of normal W-patterns is reviewed and the influence of the sign and magnitude of the pumpspeed on the shape of both types of tympanograms is discussed.

Acoustic Impedance Tests↗

PubMed1979

On the asymmetry of susceptance tympanograms.

The origin of the tail asymmetry of susceptance tympanograms was investigated. A flow-measuring device enabled an accurate determination of ear-canal volume changes produced during tympanometry. From these measurements one finds that not only is the asymmetry due to the earcanal volume change but that finite drum susceptances exist at high transtympanic pressures. This residual susceptance was found to differ in the two tails of the tympanogram. Although no absolute values of those drum susceptances can be computed, it is possible to indicate which pressure side has the greater residual susceptance.

Acoustic Impedance Tests↗

PubMedDate not supplied

Impedance and admittance tympanometry. I. Experimental approach.

In this experimental study a procedure is developed which enables the conversion of susceptance and conductane tympanograms to reactance and resistance tympanograms. Special attention was given to the subtraction of the ear canal admittance. The procedure was applied to bell-shaped and W-notched susceptance and conductance tympanograms. Computed reactance curves showed always an inverted-V shape, computed resistance curves were always flat.

Acoustic Impedance Tests↗

PubMedDate not supplied

Impedance and admittance tympanometry. II. Mathematical approach.

The W-notching of susceptance, conductance and admittance tympanograms, as well as inverted-V shapes, found at high probe tone frequencies are explained, starting from realistic assumptions on the shape of resistance and reactance tympanograms. Necessary conditions for obtaining the different types of tympanograms are given. The theory shows that no pathology is necessary to explain W-notching or inverted-V shapes at higher-frequency probe tones.

Acoustic Impedance Tests↗