1. Stability of the standard incus coupling of the Carina middle ear actuator after 1.5T MRI
- Author
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Dennis Ducreux, Jean-François Papon, Nicolas Verhaert, Marie-France Bellin, F. Benoudiba, Guy Fierens, and Jérôme Nevoux
- Subjects
Medical Implants ,Incus ,Diagnostic Radiology ,Electric Impedance ,Medicine and Health Sciences ,Tomography ,Materials ,Multidisciplinary ,medicine.diagnostic_test ,Radiology and Imaging ,Physics ,Magnetism ,Condensed Matter Physics ,Magnetic Resonance Imaging ,medicine.anatomical_structure ,Physical Sciences ,Middle ear ,Magnets ,Medicine ,Engineering and Technology ,Anatomy ,Research Article ,Biotechnology ,Materials science ,Imaging Techniques ,Science ,Materials Science ,Bioengineering ,Neuroimaging ,Research and Analysis Methods ,Diagnostic Medicine ,medicine ,Humans ,Displacement (orthopedic surgery) ,Electrical impedance ,Ossicles ,Mechanical Engineering ,Middle Ear ,Resonance ,Temporal Bone ,Biology and Life Sciences ,Magnetic resonance imaging ,Computed Axial Tomography ,Ossicular Prosthesis ,Magnetic Fields ,Ears ,Medical Devices and Equipment ,Actuator ,Tomography, X-Ray Computed ,Head ,Actuators ,Biomedical engineering ,Neuroscience - Abstract
Limited data is available concerning the safety of active middle ear implants (AMEI) during Magnetic Resonance Imaging (MRI). Measurements in temporal bones are the gold standard for preclinical assessment of device safety. In this study the coupling stability of an actuator as used in a fully implantable AMEI was determined in temporal bones. Eleven temporal bones were implanted with the actuator according to the manufacturer’s surgical guidelines. The actuator was coupled on the incus short process as recommended for sensorineural hearing loss. Temporal bones were exposed 10 times to the MRI magnetic field by entering the MRI suite in a clinically relevant way. Computed Tomography (CT) images were acquired before and after the experiment to investigate the risk of actuator dislocation. Based on the electrical impedance of the actuator, the loading of the actuator to the incus was confirmed. Relative actuator displacement was determined on the CT images by comparing the initial with the final actuator position in 3D space. Impedance curves were analyzed after each exposure to check the loading of the actuator to the ossicles. Analysis of CT images with a 0.30.6 mm in-plane resolution indicate no actuator displacement. The maximum detected change in impedance for all actuators was 8.43 Ω at the actuator’s resonance frequency. Impedance curves measured when the actuator was retracted from the short process after the experiment still indicate the presence of a clear resonance peak. No actuator displacement or dislocation could be detected in the analysis of CT images and the measured impedance curves. Impedance curves obtained when the actuator was retracted from the incus short process still show a clear resonance peak, indicating the device is still functional after the MRI exposures. ispartof: Plos One vol:15 issue:4 ispartof: location:United States status: Published online
- Published
- 2020