Methoden zur biomechanischen Analyse weichen Gewebes im Kehlkopf
Medizinische Physik, Biomedizinische Technik
Zusammenfassung der Projektergebnisse
Despite the ever growing relevance of the service sector and communication-based professions, our knowledge and understanding of the complex phonation process is only limited. An in-depth analysis of the underlying fluid-structureacoustic-interaction is mandatory. However, the investigation of the vocal folds as oscillation structures largely rely on the evaluation of high-speed recordings of the mucosal surface. There is still a lack of measurement techniques that give scientists and clinicians the ability to measure structural composition and biomechanical characteristics of the vocal folds which influence the phonation process. An in vivo and non-invasive mechanical analysis of the vocal folds would be highly desirable for fundamental research as well as pre-surgical evaluation in the clinical routine. In order to analyze the biomechanical properties of soft tissue inside the larynx, two novel methods have been developed. Both investigate the elasticity of the tissue, but differ in the measurement location and application. The elastography ultrasound is able to determine the static Young’s modulus, the Doppler-laser-vibrometer based dynamic pipette aspiration specifies the dynamic Young’s modulus over a range of 100 Hz to 1000 Hz of the near surface tissue. Both methods were used to examine different laryngeal configurations generated from typical manipulation procedures on the vocal folds (VFs), in order to evaluate the produced changes in the tissue characteristics during full-larynx phonation experiments. Different degrees of adduction of the arythenoid cartilages and variable elongation of the vocal folds by increased load on the thyroid cartilage lead to variable levels of pre-stress in the vocal fold. The influence of these manipulations on different elasticity parameters like the static and dynamic Young’s modulus could be detected and visualized by the developed methods. Furthermore, during hemi-larynx experiments the contact pressure and movement of the VFs have been investigated with a piezo-resistant pressure sensor and specifically developed read-out unit. This unit is able to measure contact pressures with a local resolution of 27.6 Sensel/cm² over a size of 28.5 mm×15.2 mm reaching a frame-rate up to 1200 Hz. In the pending analysis, dynamic parameters of of the dynamic experiments, simultaneous high-speed recordings of the superior vocal fold surface will be correlated with the contact pressures. In summary, the results of this project will allow extensive and unprecedented interpretation of the dynamic phonation process. This will contribute to a comprehensive understanding of the complex interrelations in phonation. It will provide relevant insights for surgical procedures like injection augmentation and tissue engineering for vocal fold implants. Furthermore, the correlation of biomechanical parameters and 2D high-speed parameters will enable the validation of indirect parameters that estimate tissue properties like elasticity and stiffness from velocities and acceleration of the vocal folds in the high-speed recordings. In turn, this will enable a meaningful transfer from ex-vivo results to in-vivo cases in the clinical routine.
Projektbezogene Publikationen (Auswahl)
- “Acoustic Pressure Pipette Aspiration Method Combined with Finite Element Analysis for Isotropic Materials”. In: Applied Sciences 9.18 (2019), p. 3875
M. Maghzinajafabadi, R. Lamprecht, M. Semmler, and A. Sutor
(Siehe online unter https://doi.org/10.3390/app9183875) - “An acoustic pressure pipette aspiration method for isotropic materials”. In: Journal of Physics: Conference Series. Vol. 1379. 1. 2019, p. 012017
M. Maghzinajafabadi, R. Lamprecht, M. Döllinger, M. Semmler, et al.
- “Elastography of vocal folds”. In: Journal of Physics: Conference Series. Vol. 1379. 1. IOP Publishing. 2019, p. 012016
R. Lamprecht, M. Maghzinajafabadi, M. Döllinger, M. Semmler, and A. Sutor
(Siehe online unter https://doi.org/10.1088/1742-6596/1379/1/012016) - “Imaging the vocal folds: A feasibility study on strain imaging and elastography of porcine vocal folds”. In: Applied Sciences 9.13 (2019), p. 2729
R. Lamprecht, M. Maghzinajafabadi, M. Semmler, and A. Sutor
(Siehe online unter https://doi.org/10.3390/app9132729) - “A Quasi-Static Quantitative Ultrasound Elastography Algorithm Using Optical Flow”. In: Sensors 21.9 (2021), p. 3010
R. Lamprecht, F. Scheible, M. Semmler, and A. Sutor
(Siehe online unter https://doi.org/10.3390/s21093010) - “Comparison of Multiple Moisture-Measurement Techniques Applied on Biological Tissue”. In: tm - Technisches Messen 88.s1 (2021), s101–s106
R. Lamprecht, F. Scheible, and A. Sutor
(Siehe online unter https://doi.org/10.1515/teme-2021-0065) - “Dynamic Biomechanical Analysis of Vocal Folds Using Pipette Aspiration Technique”. In: Sensors 21.9 (2021), p. 2923
F. Scheible, R. Lamprecht, M. Semmler, and A. Sutor
(Siehe online unter https://doi.org/10.3390/s21092923) - “Elastography of a gelatin M5 model mimicking the true vocal folds”. In: The Journal of the Acoustical Society of America 150.4 (2021), A192
R. Lamprecht, F. Scheible, M. Semmler, and A. Sutor
(Siehe online unter https://doi.org/10.1121/10.0008093) - “Seeking the source of vocal fold lesions towards measuring contact pressures during phonation with a pressure-sensing-matrix at hemi-larynx experiments”. In: The Journal of the Acoustical Society of America 150.4 (2021), A192
F. Scheible, R. Veltrup, C. Schaan, R. Lamprecht, M. Staggl, M. Semmler, and A. Sutor
(Siehe online unter https://doi.org/10.1121/10.0008092)
