Nasal valve elastography: quantitative determination of the mobility of the nasal valve

Abstract

Background: The nasal valve area is the narrowest region of the entire upper airway. Numerous procedures and spreader devices are published to widen the nasal valve or to stabilize it, but the indications are based only on the surgeon's experience. Methods: In 30 healthy volunteers the deflection of elastic steel elements touching the lower nasal side at its deepest point was precisely measured by means of strain gauges. The deflection was calibrated by standard calibration devices. A special 4-phaserhinomanometer (4RHINO/ Rhinolab/Germany) with a protective face mask allowed simultaneous measurements of the airflow and differential pressure. All signals were recorded simultaneously on both sides. The measurements have been carried out as unilateral measurements according to anterior rhinomanometry. Results: Surprisingly the lateral nasal wall is already moving during quiet breathing. The airflow and its acceleration as well as the pressure difference generating a complete closure of the nose can be determined and has expectedly a high variance between individuals. Conclusions: The elastography confirms the loops in 4-phase-rhinomanometry as symptomatic for the nasal valve elongation and will after developing as medical product allow the systematic quantitative measurement of the influence of the nasal valve on the nasal air stream.

Comprehensive measurement of obstruction in nasal allergen challenges—a critical update

“…The validity of 4PR for the visualization of the elasticity of the lateral wall has been recently confirmed in a clinical study [7]. Moreover, this phenomenon could be confirmed by the application of optical distance sensors and strain gauges.…”

“…This informs also about the part of mucosal and skeletal obstruction with different treatment options and can be used before and after treatment to see its effect. (7) The subjective sense of obstruction is a combination of the feeling of power, needed for inspiration, of the temperature gradient generated by the air stream, and probably also of wall-shear-stress. All these sensations follow the basic law of Weber-Fechner in psychophysiology from the 19th century.…”

Rhinomanometry Versus Computational Fluid Dynamics: Correlated, but Different Techniques

“…Movement of the lateral nasal wall has a major impact on the pressure-flow curve of the human nasal cavity. [57][58][59][60] Thus, incorporating wall elasticity into CFD models using fluid-structure interaction techniques 61 is another area that requires further development. Fourth, steady-state CFD simulations smooth out the hysteresis in the ascending and descending parts of inspiration observed in unsteady simulations.…”

Measurement of Nasal Obstruction: Rhinomanometry as Basic Method in Functional Rhinology

“…The higher volume speed on the longer side of an asymmetric wing releases an under pressure, which takes a plane off. Akmenkalne could first show objectively by measuring the inwards motion with high sensitive strain gauges, that this motion starts not only by intended "sniffing" but in very low inspiratory flow rates [7]. A detailed description for the quantitative evaluation of the "inspiratory loop area" of 4PR and respective statistic data were recently, for the first time, published by Gagnieur et al [8].…”

“…Akmenkalne et al could first show objectively by measuring the inward motion with highly sensitive strain gauges that this motion starts not only by intended "sniffing" but also in very low inspiratory flow rates. 8 A detailed description for the quantitative evaluation of the "inspiratory loop area" of 4PR and respective statistic data were recently, for the first time, published by Gagnieur et al 9 The effectiveness of the Bernoulli effect depends on the width of the nasal entrance as well as on the flux and the anatomic shape and the elastic properties of the nasal wall. The flow-dependent measurement of the movement of the lateral nasal wall was named "elastography" and the determination of its mechanic properties as compressibility; the elasticity modulus (E) is named "elastometry."…”