Evaluation of the Parameter "Mean Impedance" for Representing Eustachian tube Functions During Pressure Increase and Decrease in Pressure Chamber Measurements.

HYPOTHESIS: The hypothesis of the study is that the mean impedance (MI) during compression and decompression provides additional information of the Eustachian tube (ET) function.

BACKGROUND

The continuous impedance measurement in a pressure chamber can provide valuable information about the opening function of the ET.

METHODS

Around 55 ear-healthy volunteers were examined in a pressure chamber. These were subjected to a decompression phase and a compression phase. The pressure change was constantly 20 kPa/min. Using evaluation software, the MI could be determined for both ears in each case for the phases of compression and decompression.

RESULTS

In 49 participants, we could interpret the data successfully. On average, an output value (without pressure changes) of the impedance of 0.58 ±0.11 Pa on the right side and 0.43 ± 0.1 Pa on the left side were measured. During decompression, 0.098 ± 0.05 Pa (right) and 0.087 ± 0.043 Pa (left) could be determined. For compression, values of 0.086 ± 0.044 Pa on the right and 0.079 ± 0.045 Pa on the left were detected. The retest reliability was higher with an intraclass correlation coefficient for the decompression MI of 0.833 than the 0.772 compression MI.

CONCLUSIONS

It is possible to measure MI in healthy subjects during compression and decompression. This value represents a good average in terms of the pressure tolerance of the middle ear. In future, studies will be required to determine whether MI will be a useful parameter in differentiating normal and abnormal ET function.