So far there are no possibilities for restitution of vision abilities in people blind from hereditary retinal degeneration except electronic visual implants. Epiretinal and subretinal implants are ...already commercially available. Here the subretinal implant Alpha IMS (Retina Implant AG, Reutlingen, Germany) is presented, its technical construction, area of application, possible benefit for blind patients as well as surgical procedures including replacement, results from a clinical study in 29 patients, and safety issues. Subretinal implants are considered to have a number of advantages: the subretinal space is immunoprivileged, therefore less prone to proliferative vitreoretinal reactions; the fixation of the implant in between retina and choroid does not require scleral tacks; a retinotopically correct relation between perceived spot and retinal electrode is maintained in the visual field, thus shortening training times; natural eye movement and gaze help to localize objects; microsaccades are beneficial to avoid image fading; there are no devices attached to the face as all stimulation electronics are within the body; and resolution with 1500 pixels is the highest so far achieved.
The Alpha-IMS implant has received a CE mark for commercial use in Europe in 2013. Psychophysical testing and self-reported outcomes show restoration of useful vision in approximately half of the patients. Subretinal implantation surgery is safe. A new version (RETINA IMPLANT ALPHA AMS) with 1600 pixel and considerably improved longevity has received CE mark in March 2016 and providing centers have been recruited in several European countries.
Biomechanical modeling of laryngeal dynamics Dollinger, M.; Anxiong Yang; Stingl, M. ...
2008 First International Symposium on Applied Sciences on Biomedical and Communication Technologies,
2008-Oct.
Conference Proceeding
Interferences in the laryngeal area based on anatomical alterations or disturbances being only visible during vocal fold oscillations yield hoarseness. Most often, asymmetries caused by the vibrating ...vocal folds are the origin for this hoarseness. This work presents an enhancement of biomechanical models to simulate three dimensional vocal fold vibrations. The model consists of coupled mass-spring elements similar to Ishizaka and Flanagan (1972). The new model simulates the vibrations at 25 different positions for each vocal fold. The masses are arranged at 5 positions in longitudinal direction by 5 positions in vertical direction. The masses are capable to move in all three physical directions to better simulate human laryngeal vocal fold vibrations. The physical parameters applied in the model were chosen to visually fit real three-dimensional excised human vocal fold dynamics. Exemplarily, a symmetric dynamics simulation will be given.
