caa a22 4500 605480168 CHVBK 20210128100413.0 cr unu---uuuuu 210128e20151001xx s 000 0 eng 10.1007/s10544-015-9988-z doi (NATIONALLICENCE)springer-10.1007/s10544-015-9988-z Measuring localized viscoelasticity of the vitreous body using intraocular microprobes [Elektronische Daten] [Juho Pokki, Olgaç Ergeneman, Semih Sevim, Volker Enzmann, Hamdi Torun, Bradley Nelson] Vitrectomy is a standard ophthalmic procedure to remove the vitreous body from the eye. The biomechanics of the vitreous affects its duration (by changing the removal rate) and the mechanical forces transmitted via the vitreous on the surrounding tissues during the procedure. Biomechanical characterization of the vitreous is essential for optimizing the design and control of instruments that operate within the vitreous for improved precision, safety, and efficacy. The measurements are carried out using a magnetic microprobe inserted into the vitreous, a method known as magnetic microrheology. The location of the probe is tracked by a microscope/camera while magnetic forces are exerted wirelessly by applied magnetic fields. In this work, in vitro artificial vitreous, ex vivo human vitreous and ex vivo porcine vitreous were characterized. In addition, in vivo rabbit measurements were performed using a suturelessly injected probe. Measurements indicate that viscoelasticity parameters of the ex vivo human vitreous are an order of magnitude different from those of the ex vivo porcine vitreous. The in vivo intra-operative measurements show typical viscoelastic behavior of the vitreous with a lower compliance than the ex vivo measurements. The results of the magnetic microrheology measurements were validated with those obtained by a standard atomic force microscopy (AFM) method and in vitro artificial vitreous. This method allows minimally-invasive characterization of localized mechanical properties of the vitreous in vitro, ex vivo, and in vivo. A better understanding of the characteristics of the vitreous can lead to improvements in treatments concerning vitreal manipulation such as vitrectomy. Springer Science+Business Media New York, 2015 Vitreous body nationallicence Microprobe nationallicence Viscoelasticity nationallicence Magnetic microrheology nationallicence Atomic force microscopy nationallicence Vitrectomy nationallicence Pokki Juho Institute of Robotics and Intelligent Systems, ETH Zurich, Tannenstrasse 3, 8092, Zurich, Switzerland aut Ergeneman Olgaç Institute of Robotics and Intelligent Systems, ETH Zurich, Tannenstrasse 3, 8092, Zurich, Switzerland aut Sevim Semih Department of Electrical and Electronics Engineering, Boğaziçi University, 34342, Istanbul, Turkey aut Enzmann Volker Department of Ophthalmology, Inselspital, University of Bern, 3010, Bern, Switzerland aut Torun Hamdi Department of Electrical and Electronics Engineering, Boğaziçi University, 34342, Istanbul, Turkey aut Nelson Bradley Institute of Robotics and Intelligent Systems, ETH Zurich, Tannenstrasse 3, 8092, Zurich, Switzerland aut Biomedical Microdevices Springer US; http://www.springer-ny.com 17/5(2015-10-01), 1-9 1387-2176 17:5<1 2015 17 10544 https://doi.org/10.1007/s10544-015-9988-z text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10544-015-9988-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Pokki Juho Institute of Robotics and Intelligent Systems, ETH Zurich, Tannenstrasse 3, 8092, Zurich, Switzerland aut NATIONALLICENCE 700 1- Ergeneman Olgaç Institute of Robotics and Intelligent Systems, ETH Zurich, Tannenstrasse 3, 8092, Zurich, Switzerland aut NATIONALLICENCE 700 1- Sevim Semih Department of Electrical and Electronics Engineering, Boğaziçi University, 34342, Istanbul, Turkey aut NATIONALLICENCE 700 1- Enzmann Volker Department of Ophthalmology, Inselspital, University of Bern, 3010, Bern, Switzerland aut NATIONALLICENCE 700 1- Torun Hamdi Department of Electrical and Electronics Engineering, Boğaziçi University, 34342, Istanbul, Turkey aut NATIONALLICENCE 700 1- Nelson Bradley Institute of Robotics and Intelligent Systems, ETH Zurich, Tannenstrasse 3, 8092, Zurich, Switzerland aut NATIONALLICENCE 773 0- Biomedical Microdevices Springer US; http://www.springer-ny.com 17/5(2015-10-01), 1-9 1387-2176 17:5<1 2015 17 10544