title: In vitro strain measurements in cerebral aneurysm models for cyber-physical diagnosis.
abstract: BACKGROUND
  The development of new diagnostic technologies for cerebrovascular diseases requires an understanding of the mechanism behind the growth and rupture of cerebral aneurysms. To provide a comprehensive diagnosis and prognosis of this disease, it is desirable to evaluate wall shear stress, pressure, deformation and strain in the aneurysm region, based on information provided by medical imaging technologies.
  
  
  METHODS
  In this research, we propose a new cyber-physical system composed of in vitro dynamic strain experimental measurements and computational fluid dynamics (CFD) simulation for the diagnosis of cerebral aneurysms. A CFD simulation and a scaled-up membranous silicone model of a cerebral aneurysm were completed, based on patient-specific data recorded in August 2008. In vitro blood flow simulation was realized with the use of a specialized pump. A vision system was also developed to measure the strain at different regions on the model by way of pulsating blood flow circulating inside the model.
  
  
  RESULTS
  Experimental results show that distance and area strain maxima were larger near the aneurysm neck (0.042 and 0.052), followed by the aneurysm dome (0.023 and 0.04) and finally the main blood vessel section (0.01 and 0.014). These results were complemented by a CFD simulation for the addition of wall shear stress, oscillatory shear index and aneurysm formation index. Diagnosis results using imaging obtained in August 2008 are consistent with the monitored aneurysm growth in 2011.
  
  
  CONCLUSIONS
  The presented study demonstrates a new experimental platform for measuring dynamic strain within cerebral aneurysms. This platform is also complemented by a CFD simulation for advanced diagnosis and prediction of the growth tendency of an aneurysm in endovascular surgery.
authors.affiliation: Department of Micro-Nano Systems Engineering, Nagoya University, Japan. shi@robo.mein.nagoya-u.ac.jp
authors.forename: Chaoyang
authors.initials: C
authors.lastname: Shi
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kojima
authors.forename: Hitomi
authors.initials: H
authors.lastname: Anzai
authors.forename: Carlos
authors.initials: C
authors.lastname: Tercero
authors.forename: Seiichi
authors.initials: S
authors.lastname: Ikeda
authors.forename: Makoto
authors.initials: M
authors.lastname: Ohta
authors.forename: Toshio
authors.initials: T
authors.lastname: Fukuda
authors.forename: Fumihito
authors.initials: F
authors.lastname: Arai
authors.forename: Zoran
authors.initials: Z
authors.lastname: Najdovski
authors.forename: Makoto
authors.initials: M
authors.lastname: Negoro
authors.forename: Keiko
authors.initials: K
authors.lastname: Irie
mesh_terms: D062186:Arterial Pressure; D001783:Blood Flow Velocity; D002536:Cerebral Arteries / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D003198:Computer Simulation; D003491:Cybernetics / Q000379:methods; D055119:Elastic Modulus; D006244:Hardness; D006801:Humans; D002532:Intracranial Aneurysm / Q000503:physiopathology*; D008955:Models, Cardiovascular; D033081:Shear Strength; D013718:Tensile Strength; D014655:Vascular Resistance