1. March 2004 Chuck DiMarzio, Northeastern University 10471-14-1 ECEU692 Subsurface Imaging Course Notes Part 14: A Pause to Reflect Profs. Brooks and DiMarzio Northeastern University Spring 2004

2. March 2004 Chuck DiMarzio, Northeastern University 10471-14-2 From Our First Lecture... Some Examples Some Technologies NSF Center; CenSSIS at NU Taxonomies and Architectures of the Field

3. March 2004 Chuck DiMarzio, Northeastern University 10471-14-3 Some SSI Examples Landmine Detection [Acoustic, GPR, EM, NQR] Tunnel and Bunker Detection [Acoustic, GPR, EM] Excavation Planning [Acoustic, GPR, EM] Luggage Screening [X-Ray, NQR] Ocean Imaging [HSI] Breast Tumor Detection and Classif.[X-Ray, US, DOT] Stroke Differentiation [DOT, MRI] Functional Brain Imaging [DOT, MRI] Cardiac Imaging [Ultrasound, EKG] Retinal Imaging [HSI, Vis] Vulnerable Plaque in Coronary Artery [Vis, US, OCT] Fetal Imaging [DOT, Ultrasound]

4. March 2004 Chuck DiMarzio, Northeastern University 10471-14-4 Model Subsurface Problems Problem Geometry –A* Looking through one material to see another which is below it. –B* Looking through one material to find inhomogeneities in it. Application Areas –1* Air/Space, 2* Terrestrial, 3* Ocean, 4* Medical, 5* Biological * Letters and Numbers Refer to Next Slide

5. March 2004 Chuck DiMarzio, Northeastern University 10471-14-5 Model Subsurface Problems 1 Air/Space3 Ocean2 Terestrial4 Medical5 Biological Landuse Atmospheric Gasses Landmine Detection Pollution Mapping Dermatology Functional Brain Mapping Excavation Planning Mapping Mitochondria ICM Cell Counting A B CORAL REEFS Seabed Mapping River Plume

6. March 2004 Chuck DiMarzio, Northeastern University 10471-14-6 Example Problems for the Course Geometries –Semi-Infinite Slab Lab in HW2 –Two-Layers HW3 –Embedded Object Lab in HW4 SSI Technology –Hyperspectral Imaging Lab in HW2 Coursework –Experiments –Analysis

7. March 2004 Chuck DiMarzio, Northeastern University 10471-14-7 Some SSI Technologies X-Ray Light (UV, Visible, Infrared) Ground-Penetrating Radar Electrical Impedance Tomography Magnetic Resonance Imaging Acoustics and Ultrasound Electromagnetic Sensors Passive Electromagnetic Imaging Seismics Others ~Wavelength

8. March 2004 Chuck DiMarzio, Northeastern University 10471-14-8 Different Types of Waves 10 0 5 15 10 20 10 -4 10 -2 10 0 2 4 6 8 f, Frequency, Hz. k/(2  ), Wavenumber, m Sound (Real) DPDW Light (Real) (Imag) 10059_1 1m 1mm 1km 1m1m mm mm cm m km

9. March 2004 Chuck DiMarzio, Northeastern University 10471-14-9 10471-15-1.jpg Wave Behavior Absorption Reflection Refraction Diffraction Interference Scattering Thanks to Emmanuel Bossy, BU Remember HW 1?

10. March 2004 Chuck DiMarzio, Northeastern University 10471-14-10 Light in Skin and More keratinocytes melanocytes collagen and elastin Stratum Corneum, 5-10  m Epidermis, 50-100  m Dermis, few mm Basal cell cancer (RCM) Optical Imaging Vis NIR Diffusive Imaging NIR Vis

11. March 2004 Chuck DiMarzio, Northeastern University 10471-14-11 Probe system 1. Definition & Scope of SSI Probe(s) 1 2.. I Medium & object are characterized by physical properties, to which the probe waves are sensitive. One or more probes transmit one or more waves, which are launched into the medium after processing by some probe system. The waves are characterized by their location, power, frequency, waveform, polarization, etc One or more detectors characterized by their location, sensitivity, or noise, detect the waves after processing by some detector system 1 2.. J Detector(s) Detector system object Medium Thanks to Prof. Bahaa Saleh, Chair of ECE at Boston University for the concept for this and following slides.

12. March 2004 Chuck DiMarzio, Northeastern University 10471-14-12 Examples of wave-dependent properties Density Compressibility Acoustic Dielectric constant Conductivity Nuclear spin Electromagnetic Refractive index Absorption coeff. Fluorescence Optical Absorption X-Ray Electrical/Magnetic Conductivity Permeability Particle Beams Electron,Positron,.. Scattering Emission of x-ray or secondary emission Thanks to Prof. Bahaa Saleh

13. March 2004 Chuck DiMarzio, Northeastern University 10471-14-13  Density, Porosity, Stiffness  Chemical composition, pH  Metabolic information  Ion concentration  Physiological changes (e.g., oxygenation)  Extrinsic markers (dyes, chemical tags) Examples of Underlying Parameters Goals of SSI Estimate –Distribution of Measured Parameters or –Underlying Parameters Related to Them, or –Object Shape or Features or Detect the Presence of a Target or Classify Objects Based on Measured Parameters Thanks to Prof. Bahaa Saleh

14. March 2004 Chuck DiMarzio, Northeastern University 10471-14-14 Rough Surface Inhomogeneous / Layered Medium Absorption Dispersion Scattering Diffusion Clutter Electro- magnetic Optical/ IR X-ray Acoustic CW Pulsed Modulated Coherent Multi- Spectral Classical Quantum Outside InsideAuxiliary Partially Coherent Object Nonlinear Absorption Scattering Nonlinear Scattering Diffusive Phase Object Depolarizing Stationary Moving Absorption Fluorescence Probe Taxonomy of SSI. object Medium Surface ProbesDetectors Thanks to Prof. Bahaa Saleh

15. March 2004 Chuck DiMarzio, Northeastern University 10471-14-15 i i j Transmitter (Probe) & Receiver (detector) Patterns j Probe Pattern: Region in the medium occupied by the probe wave, in the absence of the target & clutter Detector Pattern: Region in the medium to which the detector is sensitive, I.e.,, if a source were to exist within this medium, it would be detected. Architectures of SSI Thanks to Prof. Bahaa Saleh

16. March 2004 Chuck DiMarzio, Northeastern University 10471-14-16 1 2.. I 1 2.. J Probe System Detector System Interaction regions { ij} are small & do not overlap significantly Localized SSITomograhic SSI i j ij 1 2.. I 1 2.. J Probe System Detector System i j ij LP MVT Interaction region V ij = region in the medium to which the signal of detector j is sensitive, when probe wave i is active Interaction regions { ij} are large & do overlap significantly Localized vs Tomographic SSI Thanks to Prof. Bahaa Saleh

17. March 2004 Chuck DiMarzio, Northeastern University 10471-14-17 Transverse Scanning Axial Scanning Transverse Gazing Axial Scanning Example i) Distributed Probe/ Localized Detection LP Thanks to Prof. Bahaa Saleh Example: Photography

18. March 2004 Chuck DiMarzio, Northeastern University 10471-14-18 Good transverse resolution Poor axial resolution LP Example ii) Localized probe/ distributed (bucket) detection Thanks to Prof. Bahaa Saleh Two-Photon Scanning Laser Microscopy

19. March 2004 Chuck DiMarzio, Northeastern University 10471-14-19 Both axial & transverse resolution LP Example iii) Confocal probe and detection Thanks to Prof. Bahaa Saleh

20. March 2004 Chuck DiMarzio, Northeastern University 10471-14-20 Transverse resolution by scanning Axial resolution by time of flight sectioning Example iv) Pulsed Coaxial probe and detection LP Thanks to Prof. Bahaa Saleh

21. March 2004 Chuck DiMarzio, Northeastern University 10471-14-21 Computed transverse & axial resolution MVT Example v) Axial Tomography Thanks to Prof. Bahaa Saleh

22. March 2004 Chuck DiMarzio, Northeastern University 10471-14-22 Generally poor axial and transverse resolution Example vi) Diffusive Photon Density Waves Thanks to Prof. Bahaa Saleh TransmissionReflection

23. March 2004 Chuck DiMarzio, Northeastern University 10471-14-23 Generally poor axial and transverse resolution Example vii) Time-Domain Photon Migration TransmissionReflection

24. March 2004 Chuck DiMarzio, Northeastern University 10471-14-24 Why Did We Choose What We Did? It’s at least somewhat representative of the scope of SSI We know it well It allows you to explore problems in depth It allows you to do some experiments in our labs