Networking and interdisciplinary knowledge transfer
Alumni - Doctoral projects
© Margaret Deibel

Appli­ca­tions of Non-Invasive Ocular Signal Measurements

Margaret Deibel – Hector Fellow Eberhart Zrenner

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 Univer­sity of Tübingen

Super­vised by

Prof. Dr. Dr. h.c. mult.

Eberhart Zrenner

Medicine, Biology & Engineering

Disziplinen Eberhart ZrennerHector Fellow since 2012