讲座名称：Progress and challenges in axial transmission measurements of guided modes in cortical bone: From lab experiments to clinics

讲座时间：5月18日 下午15:00-16:00

讲座地点：曲江科技园 西五楼 A228（北楼二楼东侧）

讲座学者：Minonzio Jean-Gabriel 博士

Cortical bone porosity has been evidenced as being a major if not the major `footprint' of bone loss and fragility. Several studies report that cortical bone behaves like a waveguide. Measurements of guided mode wavenumbers together with appropriate waveguide modeling have therefore the potential for providing estimations of effective stiffness coefficients (which are largely determined by cortical porosity) and also cortical thickness. However, data interpretation is challenging due to the heterogeneous, dissipative and irregular nature of the wave guide. Moreover surrounding and internal tissues modify the guided modes. This paper presents current progress, made by the Laboratory of Biomedical Imaging (LIB, UPMC, Paris) and the spin-off company Azalée, in the measurement of the wavenumbers of guided wave modes, using a multi-transmitter multi-receiver axial transmission probe. The guided mode wavenumbers are obtained after projection of test vectors onto the basis of the singular vectors of the transfer response matrix, at each frequency. The SVD-based method has been validated, first on isotropic elastic and visco-elastic plates, then on bone-mimicking plate and tube phantoms made of transverse isotropic absorbing material. The effect of soft-tissue mimicking layers on top of a bone mimicking phantom has also been studied. Finally, ex vivo validation on human radius and first clinics finding obtained using the approach will be presented.

Minonzio Jean-Gabriel

Position : CNRS - Researcher (Chargé de Recherche), Laboratoire Imagerie Bioméciale (LIB), Université Pierre et Marie Curie (UPMC), Paris, France, Research topics: guided waves, ultrasonic cortical bone characterization, clinical measurement, array signal processing

2009 – Researcher at LIB, cortical bone characterization with guided waves

2008 – 2009 POST DOC : Laboratoire d’Imagerie Paramétrique, UPMC, Paris

2007 – 2008 POST DOC : University of Rochester, NY

2006 – 2007 ATER : (One-year temporary lecturer and researcher) Université Denis Diderot Paris

Project: time-reversal invariants in electromagnetism (LOA)

2003 – 2006 PhD Université Denis Diderot Paris 7

Title: Decomposition of the time-reversal operator applied to ultrasonic characterization and imaging

Supervisors: C. Prada et M. Fink, Laboratoire Ondes et Acoustique (LOA)

PhD award by DGA

2002 – 2003 Master’s Degree studies in physical acoustics, Université Denis Diderot Paris 7

1999 – 2003 ESPCI, Industrial Physics and Chemistry Engineering School, Paris, France