Senior Design P09052 Molecular Imaging System Upgrade Ben McGee Brandon Luquette Aaron Phipps Patricia Heneka Dien Nguyen

Project Description To develop a research prototype of a clinical system capable of performing depth-resolved optical molecular imaging of a stationary human hand – Integration of Qioptiq Linos’s Optigrid with existing Carestream molecular imaging platform. – Prototype must be functional and flexible enough for Carestream to investigate for commercialization

Existing Platform

Proposed Modifications

Optigrid Functionality Motors provide 120 o phase shifts and focus – Grid moves on the x-axis um to complete a phase change – Improves Clarity – Grid moves 2 mm on the z-axis to focus image – 30 line pair/mm on a 10x10 mm square – Lines spatially modulate the illumination  A portion of the OptiGrid at 200x y xz

Design Objective Projection of the Optigrid at an angle while maintaining focus

Mechanical Design Solution

30 º 17 in Implemented Mechanical Design Optigrid Light Source Lens Fixture

System Analysis and Calibration Characterization – Capable of projecting grid at spatial frequencies ranging from 0.8 – 1.4 line pair/mm Grid starts with spatial frequency of 30 line pairs/mm Grid must be uniform and undistorted over image plane Calibration – Developed a system specific procedure to provide repeatable phase movements Processing – Depth discrimination proof of concept using depth of modulation analysis

System Characterization.8 line pair/mm 1.4 line pair/mm Projected at a 30 o angle  Steepest angle capable of the system  The system was set to a zoom of 40 pixels/mm Magnified using Computar C mount lens  Different Lenses provide different spatial frequency ranges Captured with a blue excitation filter and a green emission filter Calibration images taken with non glossy white target on platen

Calibration Coarse Calibration – Capture images in a general range of 30, 55 and 90 V – Calculate phase at each point – Determine approximate voltages for 120 o phase shifts.

Demodulation Images are combined to eliminate the projected frequency using Incorrectly phase shifted images have residual lines Misaligned image Properly aligned image

Processing Phase shifted images were captured of the phantom block – Fluorescent sheets were inserted between polycarbonate sheets The block was imaged at two spatial frequencies

Depth Discrimination Intensity Horizontal Spatial Coordinate Phase By assessing the depth of modulation at each pixel of the image, and monitoring its value at each phase shift, information about the depth of the pixel can be assessed.

Depth Discrimination Squared error away from the mean at each point is used to evaluate the depth at each point. Image of Phantom Block Surface plot of MSE for each pixel MSE

Recommendations Projection Angle – A shorter rail will result in a steeper projection angle which would reduce distortion Edmund Technical Drawings P/N: NT P/N: NT54-929

Recommendations Automation – The calibration process is very time consuming and prone to human error. – Timing is very critical to achieving repeatable phase shifts in the Optigrid. Calibration Procedure Modifications – Warm up routine – Increase the number of phase shifts

Thanks! Dr. Gilbert Feke – Carestream Health Linda Antos – Qioptiq Linos Imaging Solutions Dr. Daniel Phillips – RIT EE Faculty Dr. Maria Helguera – RIT Imaging Science Faculty Carestream Health – Primary Sponsor Qioptiq Linos Imaging Solutions - Sponsor Dr. Robert Doolittle – RIT Biomedical Science Faculty Heather Drake – Medical Science Faculty