Evaluation of Eustachian tube function with perfect sequences: technical realization and first clinical results
- 183 Downloads
The aim of this study was the introduction of a specific class of signals, the so-called perfect sequences (PSEQ), in a novel approach for sonotubometry of the Eustachian tube (ET). Sonotubometry using PSEQ stimuli was performed on 20 healthy subjects in order to gauge its potential for clinical applications. In a series of 320 measurements ET opening was probed, which was induced by dry and water swallowing, Toynbee maneuver, and yawning. All sonotubograms were analyzed with respect to their shape, increase of sound intensity, and opening duration. In 298/320 measurements (>93%) the subjects reported subjective ET openings. The evaluation of the recorded sonotubograms showed good detection of ET opening for the inducing maneuvers of swallowing (dry and water swallowing) and the Toynbee maneuver, with 90, 86, and 80% valid sonotubograms, respectively. Yawning led to only 40% valid sonotubograms. In total, 237/320 (~74%) sonotubograms were classified as valid. The evaluation of the sound level increase during ET openings showed that it was significantly higher in measurements with dry and water swallowing, as well as Toynbee maneuvers (mean 17.1, 19.0 and 17.2 dB, respectively), than with yawning (mean 10.17 dB; P < 0.0001). Nasal decongestion was found to have little influence on the results (P > 0.05). Sonotubometry using PSEQ stimuli is a novel sonotubometry methodology that provides valuable information regarding the auditory tube patency. By further technical refinements of the method, a diagnostic tool with high sensitivity and specificity could be developed.
KeywordsSonotubometry Eustachian tube Perfect sequences
Part of this work was supported by the Deutsche Forschungsgemeinschaft (DFG), grant MA 3917/1–1. The authors thank Dr. A. Haselhuhn Aachen University, Institute of Biometrics for the statistics and Mr. C. Miller, Schaumburg, IL, USA for the translation.
- 4.Di Martino E, Antweiler C, Kellner A et al (2004) Einsatz neuer akustischer Signale zur Tubenfunktionsuntersuchung. HNO Inf 29:104Google Scholar
- 7.Andreasson L, Ivarson A, Luttrup S et al (1984) Eustachian tube function measured as pressure equilibration and sound transmission capacity. A comparison in healthy ears. J Otorhinolaryngol Relat Spec 46:74–83Google Scholar
- 9.Murti KG, Stern R, Cantekin E et al (1980) Sonometric evaluation of Eustachian tube function using broadband stimuli. Ann Otol 89:178–184Google Scholar
- 11.Lüke HD (1992) Korrelationssignale. Springer, BerlinGoogle Scholar
- 13.Ipatov VP (1979) Ternary sequences with ideal periodic autocorrelation properties. Radio Eng Electron Phys 24:75–79Google Scholar
- 14.Antweiler C, Dörbecker M (1994) Perfect sequence excitation of the NLMS algorithm and its application to acoustic echo control. Ann Télécommun 49:386–397Google Scholar
- 15.Antweiler C, Antweiler M (1995) System identification with perfect sequences based on the NLMS algorithm. Int J Electron Commun (AEU) 49:129–134Google Scholar
- 16.Antweiler C, Telle A, Vary P et al (2006) New otological diagnostic system providing a virtual tube model. In: Proceedings of biomedical circuits and systems conference (BIOCAS). London, Great Britain, pp 21–24Google Scholar
- 17.Antweiler C, Vary P, Di Martino E (2006) Virtual time-variant model of the Eustachian tube. In: Proceedings of IEEE International symposium on circuits and systems (ISCAS). Island of Kos, Greece, pp 5559–5562Google Scholar
- 20.Muenker G. (1972). Function analysis of the Eustachian tube. methods and clinic. PhD thesis, University of Freiburg, GermanyGoogle Scholar