Gerhard Sommer

Gerhard Sommer

Graz University of Technology
Institute of Biomechanics
Stremayrgasse 16/2
8010 Graz, Austria

Phone: 0316-873-35505
Phone (overseas): ++43-316-873-35505
Fax: 0316-873-35502
Fax (overseas): ++43-316-873-35502
E-mail:

 

Biography

Education

10/08: Ph.D. Biomechanics, Graz University of Technology, Austria (with distinction)
2003: M.Sc. Technical Physics, Graz University of Technology, Austria
1995: Graduation certificate from Technical High School


Professional Appointments

Since 11/18: Assistant Professor, Institute of Biomechanics, Graz University of Technology, Austria
7/13 – 10/18: Senior Postdoctoral Researcher, Institute of Biomechanics, Graz University of Technology, Austria
11/08 – 6/13: Postdoctoral Researcher, Institute of Biomechanics, Graz University of Technology, Austria
5/07 – 10/08: Research Assistant and Doctoral Student, Institute of Biomechanics, Graz University of Technology, Austria
10/06 – 6/07: Assistant of the lecture and the laboratory tutorial of the course ‘Orthopedic Biomechanics’, Royal Institute of Technology (KTH), Department of Solid Mechanics, Stockholm, Sweden
10/05 – 6/06: Assistant of the lecture and laboratory tutorial of the course ‘Introduction to Biomechanics’, Royal Institute of Technology (KTH), Department of Solid Mechanics, Stockholm, Sweden
3/05 – 6/05: Assistant of the course ‘Material Mechanics’, Royal Institute of Technology (KTH), Department of Solid Mechanics, Stockholm, Sweden
12/04 – 4/07: Doctoral Student, Department of Solid Mechanics, Royal Institute of Technology (KTH), Stockholm, Sweden
4/03 – 11/04: Doctoral Student, Group of Computational Biomechanics, Institute for Structural Analysis, Graz University of Technology, Austria

Research Grants

8/19 – 7/23: PI of the Austrian Science Fund (FWF) Stand-Alone Project: "Biomechanical investigation of arterial damage", grant no. P 32713
3/17 – 9/20: PI of the Austrian Science Fund (FWF) Stand-Alone Project: "Multiscale biomechanical investigation of human aortas", grant no. P 30260–B31
7/11 – 6/14: PI of the Austrian Science Fund (FWF) Stand-Alone Project: "Biaxial tensile and triaxial shear measurements and modeling of human myocardium", grant no. P 23830-N13

Awards and Honors

2019: Award from Graz University of Technology, Medical University of Graz and University of Graz for inventing a "Cardiac Simulation Device", presented during the event "Von der Wissenschaft zur Innovation"
2014: Inventum Award 2013 'Silver Medal' by the Austrian Patent Office for the invention of a unique human bone screw
together with Dr. K. Pastl (orthopedic surgeon, Linz) and Dr. H. Plank (Graz University of Technology)
2010: Second place at the ‘Stefan-Schuy-Preis’ award 2010 of the Austrian Society of Biomedical Engineering for an excellent publication in the field of biomedical engineering with the publication: Biaxial mechanical properties of intact and layer-dissected human carotid arteries at physiological and supraphysiological loadings by G. Sommer, P. Regitnig, L. Koeltringer, and G.A. Holzapfel in American J. Physiology - Heart Circulation Physiology, 298: 898-912, 2010.

Publications

M.A. Geith, L. Nothdurfter, M. Heiml, E. Agrafiotis, M. Gruber, G. Sommer, T.G. Schratzenstaller and G.A. Holzapfel [pdf]
Quantifying vascular damage by investigating stent-triggered mechanical and morphological alterations in coronary arteries.
Acta Biomaterialia, in press.
A.K. Saxena, E. Biro, G. Sommer and G.A. Holzapfel
Esophagus stretch tests: Biomechanics for tissue engineering and possible implications on the outcome of esophageal atresia repair performed under excessive tension.
Esophagus, in press.
M.A. Geith, J.D. Eckmann, D.Ch. Haspinger, E. Agrafiotis, D. Maier, P. Szabo, G. Sommer, T.G. Schratzenstaller and G.A. Holzapfel [pdf]
Experimental and mathematical characterization of coronary polyamide-12 balloon catheter membranes.
PLoS ONE, 15:e0234340, 2020.
Y. Yang, K. Li, G. Sommer, K.-L. Yung and G.A. Holzapfel [pdf]
Mechanical characterization of porcine liver properties for computational simulation of indentation on cancerous tissue.
Mathematical Medicine and Biology, in press.
W. Zhang, A. Capilnasiu, G. Sommer, G.A. Holzapfel and D.A. Nordsletten [pdf]
An efficient and accurate method for modeling nonlinear fractional viscoelastic materials.
Computer Methods in Applied Mechanics and Engineering, 362:112834, 2020.
S. Budday, M. Sarem, L. Starck, G. Sommer, J. Pfefferle, N. Phunchago, E. Kuhl, F. Paulsen, P. Steinmann, V.P. Shastri and G.A. Holzapfel [pdf]
Towards microstructure-informed material models for human brain tissue.
Acta Biomaterialia, 104:53-65, 2020.
S. Sherifova, G. Sommer, C. Viertler, P. Regitnig, T. Caranasos, M.A. Smith, B.E. Griffith, R.W. Ogden and G.A. Holzapfel [pdf]
Failure properties and microstructure of healthy and aneurysmatic human thoracic aortas subjected to uniaxial extension with a focus on the media.
Acta Biomaterialia, 99:443-456, 2019.
T. Sigaeva, G. Sommer, G.A. Holzapfel and E.S. Di Martino [pdf]
Anisotropic residual stresses in arteries.
Journal of the Royal Society Interface, 16: 20190029, 2019.
G. Sommer, Ch. Benedikt, J.A. Niestrawska, G. Hohenberger, Ch. Viertler, P. Regitnig, T.U. Cohnert and G.A. Holzapfel [pdf]
Mechanical response of human subclavian and iliac arteries to extension, inflation and torsion.
Acta Biomaterialia, 75:235-252, 2018.
S. Budday, G. Sommer, J. Haybaeck, P. Steinmann, G.A. Holzapfel and E. Kuhl [pdf]
Rheological characterization of human brain tissue.
Acta Biomaterialia, 60:315-329, 2017.
S. Budday, G. Sommer, C. Birkl, C. Langkammer, J. Haybaeck, J. Kohnert, M. Bauer, F. Paulsen, P. Steinmann, E. Kuhl, G.A. Holzapfel [pdf]
Mechanical characterization of human brain tissue.
Acta Biomaterialia, 48:319-340, 2017.
J.A. Niestrawska, C. Viertler, P. Regitnig, T.U. Cohnert, G. Sommer and G.A. Holzapfel [pdf]
Microstructure and mechanics of healthy and aneurysmatic abdominal aortas: experimental analysis and modeling.
Journal of the Royal Society Interface, 13:20160620, 2016.
O. Gültekin, G. Sommer and G.A. Holzapfel [pdf]
An orthotropic viscoelastic model for the passive myocardium: continuum basis and numerical treatment.
Computer Methods in Biomechanics and Biomedical Engineering, 19:1647-1664, 2016.
G. Sommer, S. Sherifova, P.J. Oberwalder, O.E. Dapunt, P.A. Ursomanno, A. DeAnda, B.E. Griffith and G.A. Holzapfel [pdf]
Mechanical strength of aneurysmatic and dissected human thoracic aortas at different shear loading modes.
Journal of Biomechanics, 49:2374-2382, 2016.
C. Sherif, E. Herbich, R. Plasenzotti, H. Bergmeister,U. Windberger, G. Mach, G. Sommer, G.A. Holzapfel, T. Haider, M. Krssak and G. Kleinpeter [pdf]
Very large and giant microsurgical bifurcation aneurysms in rabbits: Proof of feasibility and comparability using computational fluid dynamics and biomechanical testing.
Journal of Neuroscience Methods, 268:7-13, 2016.
G. Sommer, A.J. Schriefl, M. Andrä, M. Sacherer, Ch. Viertler, H.Wolinski and G.A. Holzapfel [pdf]
Biomechanical properties and microstructure of human ventricular myocardium.
Acta Biomaterialia, 24:172–192, 2015.
G. Sommer, D.Ch. Haspinger, M. Andrä, M. Sacherer, Ch. Viertler, P. Regitnig and G.A. Holzapfel [pdf]
Quantification of shear deformations and corresponding stresses in the biaxially tested human myocardium.
Annals of Biomedical Engineering, 43:2334-2348, 2015.
A.J. Schriefl, T. Schmidt, D. Balzani, G. Sommer and G.A. Holzapfel [pdf]
Selective enzymatic removal of elastin and collagen from human abdominal aortas: uniaxial mechanical response and constitutive modeling.
Acta Biomaterialia, 17:125-136, 2015.
J. Tong, T. Cohnert, P. Regitnig, J. Kohlbacher, R. Birner-Gruenberger, A.J. Schriefl, G. Sommer and G.A. Holzapfel [pdf]
Variations of dissection properties and mass fractions with thrombus age in human abdominal aortic aneurysms.
Journal of Biomechanics, 47:14-23, 2014.
G. Sommer, A. Schriefl, G. Zeindlinger, A. Katzensteiner, H. Ainödhofer, A. Saxena and G.A. Holzapfel [pdf]
Multiaxial mechanical response and constitutive modeling of esophageal tissues: Impact on esophageal tissue engineering.
Acta Biomaterialia, 9:9379-9091, 2013.
G. Sommer, M. Eder, L. Kovacs, H. Pathak, L. Bonitz, C. Mueller, P. Regitnig and G.A. Holzapfel [pdf]
Multiaxial mechanical properties and constitutive modeling of human adipose tissue: a basis for preoperative simulations in plastic and reconstructive surgery.
Acta Biomaterialia, 9:9036-9048, 2013.
N. Famaey, G. Sommer, J. Vander Sloten and G.A. Holzapfel [pdf]
Arterial clamping: Finite Element Simulation and In Vivo Validation.
Journal of the Mechanical Behavior of Biomedical Materials, 12C:107–118, 2012.
G. Sommer and G.A. Holzapfel [pdf]
Constitutive modeling of the biaxial mechanical response of intact and layer-dissected human carotid arteries.
Journal of the Mechanical Behavior of Biomedical Materials, 5:116–128, 2012.
J. Tong, G. Sommer, P. Regitnig and G.A. Holzapfel [pdf]
Dissection properties and mechanical strength of tissue components in human carotid bifurcations.
Annals of Biomedical Engineering, 39:1703-1719, 2011.
G. Sommer [link]
Mechanical Properties of Healthy and Diseased Human Arteries – Insights into Human Arterial Biomechanics and Related Material Modeling.
Verlag der Technischen Universität Graz, 2010.
G. Sommer, P. Regitnig, L. Költringer, and G. A. Holzapfel [pdf]
Biaxial mechanical properties of intact and layer-dissected human carotid arteries at physiological and supra-physiological loadings.
American Journal of Physiology: Heart and Circulatory Physiology, 298:H898-912, 2010.
V. Prot, B. Skallerud, G. Sommer and G.A. Holzapfel [pdf]
On modelling and analysis of healthy and pathological human mitral valves: two case studies.
Journal of the Mechanical Behavior of Biomedical Materials, 3:167-177, 2010.
G. Sommer, T.C. Gasser, P. Regitnig, M. Auer and G.A. Holzapfel [pdf]
Dissection properties of the human aortic media: an experimental study.
ASME Journal of Biomechanical Engineering, 130:021007, 2008.
G.A. Holzapfel, G. Sommer, M. Auer, P. Regitnig and R.W. Ogden [pdf]
Layer-specific 3D residual deformations of human aortas with non-atherosclerotic intimal thickening.
Annals of Biomedical Engineering, 35:530-545, 2007.
F. Schmid, G. Sommer, M. Rappolt, P. Regitnig, G.A. Holzapfel, P. Laggner and H. Amenitsch [pdf]
Bidirectional tensile testing cell for in situ small angle X-ray scattering investigations of soft tissue.
Nuclear Instruments & Methods in Physics Research / B, 246:262-268, 2006.
G.A. Holzapfel, G. Sommer, T.C. Gasser and P. Regitnig [pdf]
Patient-specific biomechanical analysis of plaque rupture during balloon angioplasty using MRI and mechanical testing.
In: J. Burša and V. Fuis (eds.), "Proceedings of the Conference on Human Biomechanics 2006", Brno University of Technology, Brno (2006), 22-31.
G.A. Holzapfel, G. Sommer, T.C. Gasser and P. Regitnig [pdf]
Determination of the layer-specific mechanical properties of human coronary arteries with non-atherosclerotic intimal thickening, and related constitutive modeling.
American Journal of Physiology / Heart and Circulatory Physiology, 289:2048-2058, 2005.
F. Schmid, G. Sommer, M. Rappolt, C.A. Schulze-Bauer, P. Regitnig, G.A. Holzapfel, P. Laggner and H. Amenitsch [pdf]
In situ tensile testing of human aortas by time-resolved small angle X-ray scattering.
Journal of Synchrotron Radiation. Applied Radiation and Isotopes, 12:727-733, 2005.
G.A. Holzapfel, G. Sommer and P. Regitnig [pdf]
Anisotropic mechanical properties of tissue components in human atherosclerotic plaques.
Journal of Biomechanical Engineering, 126:657-665, 2004.

Patent

Cardiac Simulation Device – EP 19 17 9022

PR Work

"The stuff that hearts are made of" [pdf]
Appeared in the Austrian Newspaper "Die Presse", p. 36, September 17, 2016 (in German).

University Administrations

Since 1/20: Deputy Dean of Studies for “Biomedical Engineering”, Graz University of Technology, Austria
Since 12/14: Deputy Head, Institute of Biomechanics, Graz University of Technology, Austria
Since 10/07: Administrator of the Biomechanics Laboratory, Institute of Biomechanics, Graz University of Technology, Austria


Biographical Sketch

Gerhard Sommer was born as the second child of Christine Sommer (nurse) and Fritz Sommer (locksmith) on April 23, 1976, in Feldbach, Austria. After graduating from the Technical High School for Mechanical Engineering in Weiz in 1995, he started his undergraduate study in "Technical Physics" at Graz University of Technology. In the year 2002, he met Dr. Christian A.J. Schulze-Bauer and Professor Gerhard A. Holzapfel who introduced him to the fascinating area of soft tissue biomechanics.As a consequence, he started his Master Thesis in this area in the same year, which he finished with distinction in 2003. The title of his thesis was "Layer-specific mechanical response of human coronary arteries", and it was supervised by Professor Holzapfel, Dr. Schulze-Bauer and Professor Windholz. After his Thesis, Professor Holzapfel gave him the opportunity to continue with a Doctoral Thesis in the field of biomechanics supervised by Holzapfel. He continued to explore the mechanical properties of human soft tissues, especially of the human cardiovascular system. His first project dealt with the mechanical behavior of highly stenotic human iliac arteries and their related plaque components. At the same time a further project with F. Schmid, H. Amenitsch, C.A.J. Schulze-Bauer and G.A. Holzapfel about the reorientation and redistribution of the collagen structure of human arteries during tensile testing was utilized by the aid of small x-ray scattering at the Synchrotron laboratory "Elettra" in Trieste, Italy. In the beginning of 2004, Sommer began to investigate the dissection properties of the human aortic media. In the end of 2004, he and his advisor moved to Stockholm to initiate biomechanical research on an experimental and theoretical basis at the Royal Institute of Technology (KTH), Department of Solid Mechanics. In Stockholm he was employed as a Ph.D.-Student. His tasks were concerned with setting up an experimental environment for biomechanical analysis, and he was also a Teaching Assistant for several courses.In 2005, Sommer started to investigate the biaxial mechanical properties of human common and internal carotid arteries and their underlying layers by means of extension-inflation tests at the laboratory in Stockholm. In the beginning of the year 2007, together with Professor Holzapfel, he rejoined Graz University of Technology within a newly established Institute of Biomechanics. Since April 2007, he is working as a Research Assistant in this new Institute of Biomechanics. His responsibilities are to set up and lead the biomechanics laboratory, to help out in the supervision of Master-Students, being a Teaching Assistant, and to perform research. In October 2008 he finished his PhD Thesis entitled "Mechanical Properties of Healthy and Diseased Human Arteries and Related Material Modeling" with distinction.