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Biomedical subjects

D Mrowinski

Publications and source records attributed to D Mrowinski.

58 records · Page 4Linked to original sources
PubMedDate not supplied

Experimental investigations on the suitability of the carbon dioxide laser for stapedotomy.

Surgery of the footplate may cause a number of possible complications such as cochlear hearing defects or even complete loss of hearing. This has made it necessary to look for improved techniques. When a laser is used for stapedotomy, the energy transmitted to the cochlea must be reduced to the lowest possible level. We thus investigated the carbon dioxide laser to determine whether it would prove to be more advantageous than the argon laser. Animal experiments showed that CO2 laser irradiation is well tolerated. Tests performed on isolated petrous bone resulted in the development of a new surgical instrument suitable for stapedotomy using the CO2 laser. Temperature and pressure measurements were carried out on a simplified model of the human cochlea. Our findings indicated that, with both types of laser, the irradiation required to perforate the otosclerotically thickened footplate adversely affects temperature and pressure development in the cochlea.

Animals↗
PubMedDate not supplied

Phase-dependent suppression of transient evoked and distortion product otoacoustic emissions by a low-frequency tone.

The subjective recording of the masked threshold of short acoustical stimuli with a loud tone of 30 Hz (phase audiogram) has been used for the clinical diagnosis of endolymphatic hydrops (EH). In normally-hearing subjects, a marked modulation of the threshold was found, depending on the phase of the low-frequency tone. A very small dependence was found in patients with Menière's disease, due to the micromechanical changes in the basilar membrane (BM). The same phase relationship becomes apparent in low-frequency suppression of otoacoustic emissions. The amplitudes of TEOAEs are controlled by the phase-dependent displacement of the BM. The suppressed TEOAEs have to be measured separately in each phase relationship. During recording of suppressed DPOAEs, the low-frequency suppressor is permanently superimposed on the pair of primary tones. After time averaging and a moving short-time FFT, the spectral values of the DPOAEs are obtained depending on the phase of the low-frequency tone. Modulation depends also on the masker level, the levels of the primary tones, and on their frequency range. The method of low-frequency suppressed DPOAEs is an objective method to diagnose EH and could be a useful tool in human inner ear research.

Acoustic Stimulation↗