pediatric measurement device for early detection of plagiocephaly iphone app edition
DESCRIPTION
Pediatric measurement device for early detection of plagiocephaly iPhone App Edition. Cody Hall Chris Heelan Jorge Perez. Craniometer. Project goal To develop a low cost, safe, and accurate plagiocephaly measurement device for children aged infant to 24 months - PowerPoint PPT PresentationTRANSCRIPT
PEDIATRIC MEASUREMENT DEVICE FOR EARLY
DETECTION OF PLAGIOCEPHALY
IPHONE APP EDITIONCODY HALL
CHRIS HEELANJORGE PEREZ
CRANIOMETERProject goal
• To develop a low cost, safe, and accurate plagiocephaly measurement device for children aged infant to 24 months
• Digital solution that limits complexity as to lower price
Initial design• Physical Device
• Two digitial calipers used to detect linear distances and angles
CRANIOMETER PROS/CONS
PROSSimple Theory
• Directly sense angle using sensor• Calculate distances using
trigonometry
Simple UI• Three push buttons• Results clearly displayed on LCD
Easier to use with squirming childSimple design
• Increased reliability
Requires small investment by pediatrician
CONSHardware design
• PCB design/debugging• Component selection
Mechanical design• AutoCAD parts
Purchasing physical partsAssembling physical partsRequires physical contact with the infantThird-party required for manufacturing/marketing
IPHONE APPLICATIONNew design
• iPhone application• Use camera to take image of
infant’s head• Markers on paper provide
absolute distance calibration• PDF included with app
• Perform image analysis to calculate angles/linear distances
• Display results on phone
IPHONE APPLICATION PROS/CONS PROSUser already owns physical device
• No hardware to manufacture/purchase
Safer• No physical contact with child
App Store provides simple distribution methodFocus on purely software will allow for a more polished and professional productPotential Market
• Estimated 58,000 pediatricians in the United Stated (American Academy of Pediatrics)
• 94% of doctors own smartphones (compared to 59% in 2006)
• Doctors prefer iPhone (44%) to Blackberry (25%) and Andriod (25%)
• Estimated 24,000 potential customers• Verizon adding iPhone this year
CONSMore complex theory
• Calibrate pixels to distance using known markers in image
• Edge-detection processing to calculate linear distances
Requires pediatrician to own iPhoneMore complicated UI
• Also more complicated to design
Harder to use with squirming child• Camera must be parallel to child’s head
Requires designers to learn Cocoa (Objective-C) programming
HOW DO WE KNOW THIS WILL WORK?iPhone 4 Camera Specifications
• Back- Illuminated CMOS Sensor• 5-Megapixel Resolution (2592 x
1936)• Fixed aperture f/2.8• Permanent 3.85mm focal length
IPHONE CAMERA TESTINGThird party research
• <0.2% barrel distortion = Very GoodLow noise
• <2% under fluorescent lighting (ISO 144)Need to determine sharpness
• Rise distance
RESOLUTION30cm x 22cm area / 2592 x 1936 pixelsGives us a 0.13mm spatial resolution under perfect conditions
SEGMENTATION AND EDGE DETECTIONUse of histogram threshold
CONNECTED COMPONENT LABELING
NECESSARY LABELING METHOD TO MARK DIFFERENT CIRCLES
FIND THE CENTERS OF CIRCLES- STRIKE A CHORD
Find the maximum distance from one point on the edge to anotherTake midpoint as centerDistance between centers is determines pixel size
EDGE DETECTION ON A REAL PHOTO
CHALLENGESDeveloping efficient algorithms to work on iPhoneAutomated or assisted point selection process- GUI controlMaintaining millimeter resolution during heavy image processing
IPHONE APP DEVELOPMENTRequired
Computer running Mac OS-two designers own OSX machines
Register with Apple as a developer-two designers registered
Download/install SDK-two designers have successfully installed/used the SDK
Create application
Submit application to App Store for approval
HELLO WORLD! APP
APPLICATION PROGRAMMING
Learning Cocoa (Objective-C)• Stanford iPhone app development
lectures• Free from iTunes University• Full semester course (lecture videos
and PPT slides)• Other online coding/app tutorials• One team member proficient in C
programming• Layer underneath Objective-C
• One team member proficient in Java programming
• Object-oriented programming
IMAGE PROCESSING ALGORITHMSImageJ
• Free image processing program• Open source Java code• Port needed algorithms to Objective-C
• One designer proficient in JavaIndependent research
• Image processing tutorials online in many different coding languages
IMAGE PROCESSING LOCATIONTwo choices for image processing
• All processing written within application (Objective-C)• App is completely localized
• Processing performed on server running Python script• App captures/displays image and provides GUI• App sends image to server• Image processing offloaded to Python• Script sends results back to app