1. Hadamard Transform Imaging
Paul Holcomb
Tasha Nalywajko
Melissa Walden

2. Problem Definition
Current 3D imaging systems for brain surgery are too slow and possess too low of a resolution to be effective in an operating room setting

3. Why is this important? 71% mortality rate for diagnosed brain tumors
Correlation between complete resectioning of tumors and improved prognosis
Complete resectioning requires knowing the location of the tumor, especially tumor margins
Imaging in a clinical setting should be fast

4. Design Criteria
Must produce image in less than 20 minutes (current analysis time)
Must accurately reproduce area of interest in the brain
Must distinguish healthy versus tumor tissue
Must be small enough to be usable in an operating room setting
Must interface with operating microscope

5. Cost/Benefit Analysis
Decreased Cost
Less downtime in OR
No analysis fees
Less recurrence of tumors  fewer surgeries
Increased Benefit
Shorter surgeries
Tumor removal: ~100%
Improved patient prognosis

6. Design Objective
Construct imaging system using digital micro-mirror device and Hadamard transform for use with operating microscope in a clinical setting

7. System Design Hadamard Transform Decreased imaging time Increased SNR
Hadamard Matrix Definition
Inverse Hadamard Transform
Digital Micro-mirror Device
Allows use of Hadamard Transform

8. Fourier vs. Hadamard Imaging
Wuttig and Riesenburg, “Sensitive Hadamard Transform Imaging Spectrometer”

9. Design Goals
Acquire an accurate image (SNR better than current imaging techniques) of the reflectance spectrum of the brain tissue
Image area in a short period of time (less than 20 minutes, optimally less than 3 minutes)
Distinguish between normal and tumor tissue using gathered image data

10. System Diagram Illuminate sample with white light
Collect and collimate reflected light
Decrease image size to 10mm x 10mm square
Disperse image spectrally using diffraction grating
Compress image vertically to 160um x 10mm
Apply Hadamard matrix with DMD
Recollimate image and collect with CCD camera
Apply inverse Hadamard transform using software
Overlay spectral image with imaged area

11. Lens system for image demagnification (M = 0.4)
Stage 1
Lens system for image demagnification (M = 0.4)

12. Lens and mirror system for vertical image compression
Stage 2
Lens and mirror system for vertical image compression

13. Drawn to scale…

14. Design Timeline January: Test white light source and camera lens using
reflectance standard, align and test Stage 1
February: Align DMD, align and test Stage 2, align Stage 3
March: Continue Stage 3 alignment, test Stage 3, test system
using reflectance standard to determine SNR
April: Test system using normal and tumor tissue samples,
present data at Senior Design Day