Designing a Robot for Designing a Robot for Portable Raman Probe Portable Raman Probe

Positioning:Positioning:The Robo-ScannerThe Robo-Scanner

Presentation OutlinePresentation Outline

ObjectivesObjectives IntroductionIntroduction Hardware DesignHardware Design Software DesignSoftware Design Design AlternativesDesign Alternatives Problems EncounteredProblems Encountered Future GoalsFuture Goals

Main ObjectivesMain Objectives

To design & build a functional prototype To design & build a functional prototype that will correctly position raman probe to that will correctly position raman probe to scan pills & tissue scan pills & tissue

Incorporate Matlab for positioning & data Incorporate Matlab for positioning & data analysisanalysis

Send Matlab outputs to microcontroller Send Matlab outputs to microcontroller Write & implement Assembly code to Write & implement Assembly code to

translate Matlab code into motor translate Matlab code into motor movementmovement

Create model of different pill types Create model of different pill types

IntroductionIntroduction

Raman Spectroscopy [1,2]Raman Spectroscopy [1,2]

• Has numerous medical applicationsHas numerous medical applications• Physics-based technique that detects chemical Physics-based technique that detects chemical

composition of a samplecomposition of a sample• Each chemical has characteristic wavelength shiftEach chemical has characteristic wavelength shift• Can relate the peaks in a Raman spectrum to specific Can relate the peaks in a Raman spectrum to specific

chemicals & compare composition of a test samplechemicals & compare composition of a test sample

Two Applications for Portable RamanTwo Applications for Portable Raman

Raman SpectroscopyRaman Spectroscopy

Portable Verax Raman spectrometer made by InPhotonics

Raman SpectroscopyRaman Spectroscopy

Main ComponentsMain Components Erector setsErector sets Raman probeRaman probe 68HC11 microcontroller68HC11 microcontroller Breadboard/circuitryBreadboard/circuitry CamerasCameras DC step motorsDC step motors Printer railwaysPrinter railways

Hardware DesignHardware Design

First Step: First Step: • Build gantry frame using erector setsBuild gantry frame using erector sets• Purchase & fasten c-channels Purchase & fasten c-channels

Benefits of Gantry Design [3]Benefits of Gantry Design [3]

Perform pick & place applicationsPerform pick & place applications Provide better positioning accuracyProvide better positioning accuracy Easier to program with respect to motion Easier to program with respect to motion

due to X,Y,Z coordinate systemdue to X,Y,Z coordinate system Less limited by floor space constraintsLess limited by floor space constraints

Hardware Design …Hardware Design …

Second Step:Second Step:• Disassemble printer Disassemble printer

componentscomponents• Mount X & Y railways Mount X & Y railways

onto frameonto frame

Hardware Design cont.Hardware Design cont. Third StepThird Step::

• Create wheel mechanismCreate wheel mechanism• Mount cameraMount camera• Mount probe on Z-axisMount probe on Z-axis

Gigaware® 1.3MP PC Camera

Mechanical Design Mechanical Design

DC step motors used from DC step motors used from disassembled printersdisassembled printers

Change initial design concept of Change initial design concept of wheel mechanismwheel mechanism• To decrease drag & friction, remove To decrease drag & friction, remove

rubber treadrubber tread• Reposition wheel on top of c-channel Reposition wheel on top of c-channel

instead of insideinstead of inside

Final Product !Final Product !

Network OverviewNetwork Overview

68HC11

Breadboard

RS 232

Microcontroller DiagramMicrocontroller Diagram

Electrical ComponentsElectrical Components

LM741CN Op Amp (All 3 inverting)LM741CN Op Amp (All 3 inverting)

Software and Circuit DesignSoftware and Circuit Design

Wiring DiagramsWiring Diagrams

Software DesignSoftware Design

Second Step: Write code using Matlab ToolkitsSecond Step: Write code using Matlab Toolkits• Wavelets (pre-processing)Wavelets (pre-processing)• StatisticsStatistics• Image processingImage processing

Future ToolkitsFuture Toolkits• Camera calibration ~ 3D triangulation of 2 imagesCamera calibration ~ 3D triangulation of 2 images• Image acquisition ~ live video feedImage acquisition ~ live video feed

Matlab Matlab GUIGUI

Software DesignSoftware Design Imaging Processing Toolkit to position robotImaging Processing Toolkit to position robot

• Load video image from file (.jpg) from cameraLoad video image from file (.jpg) from camera• Convert image to grayscaleConvert image to grayscale• Threshold imageThreshold image• Count distinct objects in imageCount distinct objects in image• Find center of each distinct objectFind center of each distinct object• Convert pixel location to robot location Convert pixel location to robot location • Send location to HC11 by serial portSend location to HC11 by serial port

Image Processing ResultsImage Processing ResultsOriginal Image (with pills marked) Grayscale Image

Threshold Image Count Objects In Image

*Results depend on lighting, photo conditions*

Moving the RobotMoving the Robot Check to see if Check to see if

starting from home starting from home position position

Move robot from Move robot from home position to home position to desired pill locationdesired pill location

Collect spectra (use Collect spectra (use separate software)separate software)

Process software and Process software and output resultsoutput results

Move robot from pill Move robot from pill position to homeposition to home

Repeat for next pillRepeat for next pill

Processing DetailsProcessing Details

Preprocess Spectra Preprocess Spectra • Background SubtractionBackground Subtraction• Remove noiseRemove noise• Remove cosmic raysRemove cosmic rays

Principal Component Principal Component AnalysisAnalysis• Reduce dimensionality of dataReduce dimensionality of data

AlgorithmAlgorithm• Discriminant Function AnalysisDiscriminant Function Analysis• Neural Network AnalysisNeural Network Analysis

Spectral ResultsSpectral Results

Testing Assembly CodeTesting Assembly Code

Problems EncounteredProblems Encountered

Consider weight of raman probe in choosing Consider weight of raman probe in choosing initial robotic arm mechanicsinitial robotic arm mechanics

Devising efficient pulley systemDevising efficient pulley system Weight of printer railways & motorsWeight of printer railways & motors High coefficient of friction between wheel & High coefficient of friction between wheel &

aluminum c-channelaluminum c-channel Software development & implementationSoftware development & implementation Camera calibrationCamera calibration Coordinate triangulationCoordinate triangulation

Time constraints Time constraints

Design AlternativesDesign Alternatives

Possible Design Improvements:Possible Design Improvements:

Construct robotic armConstruct robotic arm Addition of proximity sensorsAddition of proximity sensors Swap microcontroller for new Swap microcontroller for new

motion controllermotion controller Incorporate AC servo motors Incorporate AC servo motors

in place of step motorsin place of step motors Autonomous positioningAutonomous positioning

Future GoalsFuture Goals Expand current design by Expand current design by incorporating more incorporating more sophisticated technologiessophisticated technologies

• Implement 3D triangulation using stereo Implement 3D triangulation using stereo camera calibrationcamera calibration

• Combine functions with Nurse-Bot or similar Combine functions with Nurse-Bot or similar applicationapplication

• Use robot for scanning cancerous tissue Use robot for scanning cancerous tissue samplessamples

• Optimize portable robot design requirements Optimize portable robot design requirements for OR usagefor OR usage

• Telepresence i.e. administer medicationTelepresence i.e. administer medication

Grand Finale Grand Finale

Final DemoFinal Demo

ReferencesReferences

[1] Huang, Z., McWilliams, A., Lui, H., McLean, D.I., Lam, S. [1] Huang, Z., McWilliams, A., Lui, H., McLean, D.I., Lam, S. and Zeng, H., and Zeng, H., Near-infrared Raman spectroscopy for Near-infrared Raman spectroscopy for optical diagnosis of lung cancer.optical diagnosis of lung cancer. Int J Cancer, 2003. Int J Cancer, 2003. 107107(6): p. 1047-52. (6): p. 1047-52.

[2] Cao, A., Pandya, A., Serhatkulu, G.K., Weber, R., Dai, H., [2] Cao, A., Pandya, A., Serhatkulu, G.K., Weber, R., Dai, H., Thakur, J.S., Naik, R., Naik, V., Auner, G.W., Rabah, R., Thakur, J.S., Naik, R., Naik, V., Auner, G.W., Rabah, R., and Freeman, D.C., and Freeman, D.C., A Robust Method for Automated A Robust Method for Automated Background Subtraction of Tissue Flourescence.Background Subtraction of Tissue Flourescence. Journal Journal of Raman Spectroscopy, 2006 (in press).of Raman Spectroscopy, 2006 (in press).

[3] [3] http://www.robots.com/faq.php?question=gantry+robothttp://www.robots.com/faq.php?question=gantry+robot