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Alumni - Promotionsprojekte

Appli­ca­ti­ons of Non-Invasive Ocular Signal Measurements

Marga­ret Deibel – Hector Fellow Eberhart Zrenner

Ziel dieser Arbeit war es unter anderem eine neue in-vivo-Methode zur nicht-invasi­ven Messung des Ziliar­mus­kels eines Menschen während der Anpas­sung der Augen­linse zu entwi­ckeln. Aus den Ergeb­nis­sen des Projekts wurde ein Hilfs­mit­tel entwi­ckelt, das die aufge­zeich­ne­ten neuro­na­len Signale, die vom Ziliar­mus­kel produ­ziert werden, nachahmt und so die Anpas­sung der Augen­linse mit Hilfe einer Flüssig­kris­tall-Linse simuliert.

Several goals were pursued in the develo­p­ment of this work, inclu­ding the develo­p­ment of a novel in vivo method to measure the ciliary muscle of a human subject non-invasi­vely during accom­mo­da­tion, the charac­te­riza­tion of the recor­ded muscle signals based on the accom­mo­da­tive abili­ties of the subject, and the develo­p­ment of a device that would utilize the recor­ded muscle signals to mimic the appro­priate level of accom­mo­da­tion for the user, actua­ted through the use of a varia­ble refrac­tive lens.

Prior to the develo­p­ment of an assis­tive device, trials to record the accom­mo­da­tive signals of the ciliary muscle during accom­mo­da­tion were perfor­med, using a custom contact lens electrode. 

Three groups, each compo­sed of ten subjects, were exami­ned: control subjects, presby­opic subjects, and pseudo­pha­kic subjects. From these trials, it was disco­vered that the novel recor­ding method used produ­ced results that were both useable and repeatable.

Using the results from the ciliary muscle studies, an assis­tive device was develo­ped.  In preli­mi­nary proof-of-concept trials, the visual acuity of presby­opic subjects at near targets was found to signi­fi­cantly increase when using the device, while the far visual acuity remained unaffec­ted. This proves that the device is able to use the neural signals produ­ced by the ciliary muscle in order to simulate accom­mo­da­tion through the use of a liquid crystal lens, the refrac­tive power of which is control­led by electri­cal ciliary muscle response.

RR Lyrae stars as tracers of substructure and Galactic archaeology

Diagram of the final accom­mo­da­tion experi­ment set-up develo­ped at the Insti­tute for Ophthal­mic Research

Marga­ret Deibel

Eberhard Karls Univer­si­tät Tübingen

Betreut durch

Prof. Dr. Dr. h.c. mult.

Eberhart Zrenner

Medizin, Biolo­gie & Ingenieurwesen

Disziplinen Eberhart ZrennerHector Fellow seit 2012