Performance Evaluation of Coupling Variants for an Active Middle Ear Implant Actuator: Output, Conductive Losses, and Stability of Coupling With Ambient Pressure Changes.

Introduction: This study aims to investigate the performance of an active middle ear implant actuator for various coupling configurations. Actuator output and conductive losses were measured, and the stability of coupling was evaluated by challenging the link between actuator and ossicles through pressure events in magnitudes that occur in daily life.

Methods: Actuator coupling efficiency and the occurrence of conductive losses were measured in 10 temporal bones through laser Doppler vibrometry on the stapes footplate for various coupling types (incus short process with and without laser hole, incus long process, stapes head).

Middle Ear Actuator Performance Determined From Intracochlear Pressure Measurements in a Single Cochlear Scala.

Hypothesis: Intracochlear pressure measurements in one cochlear scala are sufficient as reference to determine the output of an active middle ear implant (AMEI) in terms of "equivalent sound pressure level" (eqSPL).

Background: The performance of AMEIs is commonly calculated from stapes velocities or intracochlear pressure differences (PDiff). However, there are scenarios where measuring stapes velocities or PDiff may not be feasible, for example when access to the stapes or one of the scalae is impractical.

Optimum Coupling of an Active Middle Ear Actuator: Effect of Loading Forces on Actuator Output and Conductive Losses.

Introduction: The desired outcome of the implantation of active middle ear implants is maximum coupling efficiency and a minimum of conductive loss. It has not been investigated yet, which loading forces are applied during the process of coupling, which forces lead to an optimum actuator performance and which forces occur when manufacturer guidelines for coupling are followed.

Methods: Actuator output was measured by laser Doppler vibrometry of stapes motion while the actuator was advanced in 20 μm steps against the incus body while monitoring static contact force.

Redox imaging and optical coherence tomography of the respiratory ciliated epithelium.

Optical coherence tomography (OCT) is an emerging technology for in vivo airway and lung imaging. However, OCT lacks sensitivity to the metabolic changes caused by inflammation, which drives chronic respiratory diseases such as asthma and chronic obstructive pulmonary disorder. Redox imaging (RI) is a label-free technique that uses the autofluorescence of the metabolic coenzymes NAD(P)H and flavin adenine dinucleotide (FAD) to probe cellular metabolism and could provide complimentary information to OCT for airway and lung imaging.

Visualization and quantification of injury to the ciliated epithelium using quantitative flow imaging and speckle variance optical coherence tomography.

Mucociliary flow is an important defense mechanism in the lung to remove inhaled pathogens and pollutants. Disruption of ciliary flow can lead to respiratory infections. Multiple factors, from drugs to disease can cause an alteration in ciliary flow.