Quantitative sonographic imaging of human hard tissue by mathematical modelling of scanning acoustic...

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Transcript of Quantitative sonographic imaging of human hard tissue by mathematical modelling of scanning acoustic...

  • Quantitative sonographic imaging of human hard tissue by mathematical modelling of scanning acoustic microscopy data QUASIMProf. Dr. R.SaderProf.Dr.M.GrotePh.Dr. L.Beilina

  • Main objectivesDevelopment of quantitative sonographic imaging by mathematical modellingTesting Clinical application of ultrasound diagnostics

  • KSI Krmer Scientific Instruments GmbHIs a private company located in Herborn, GermanyEstablished in 1990Provide support and development for the high technology Scanning Acoustic Microscopy (SAM)Main directions are research, nondestructive testing and the process control industry ___________________________________ www.ksi-germany.com

  • KSI WINSAM 2000Scanning Acoustic Microscopetransmitterreceiveracoustic lenstransducerCoupling fluid(water)sample

  • KSI WINSAM 2000 Production and failure analysisRepeated informationDetailed informationShows processing and in-service defectsScan field300 X 300mmScanning Acoustic Microscope

  • Mathematical Model ofScanning Acoustic Microscopetransmitterreceiveracoustic lenstransducerCoupling fluid(water)sampleG 1C 0C(x)G 2G 2G 2

  • Computational mesh

  • Computational AlgorithmInitial guessc=c0Solve forward problemSolve adjoint problemCompute gradientand new chIf gradient > epsstopnoyes

  • Adaptive AlgorithmInitial guessc=c0Solve forward problem on Kh, Tk Solve adjoint problem on Kh, Tk

    Compute gradientand new chIf gradient decreasesstopnoyesInitial mesh K0Initial time partition T0

    Residuals > tolrefine elements Construct new mesh Kh Construct new time partition Tkyesno

  • Solution of the forward problemc=0.5 inside a spherical inclusion and c=1.0 everywhere else in the domain. Isosurfaces of the computed solution are shown at different times.

  • Solution of the forward problemSolution of the forward problem with exact value of the parameter c=0.5 inside a spherical inclusion and c=1.0 everywhere else in the computational domain. We show isosurfaces of the computed solution at different times.

  • Adaptively refined meshes

  • Reconstructed parameterReconstructed parameter c(x) on different adaptively refined meshes. Isosurfaces of the parameter field c(x) indicating domains with a given parameter value are shown.22528 nodes, c =0.6626133 nodes, c = 0.53133138 nodes, c=0.51