Transcript
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Intracranial Hematoma Detection
G.K.I. Abayarathna : 050001A
Gartheeban Ganeshapillai : 050131V
E.D.R. Kumara : 050234N
W.M.D. Soysa : 050440R
Supervised By: Dr. A. A. Pasqual
Project Presentation
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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What – Whom - How
Intracranial Hematoma (IH) is a highly fatal, albeit treatable, secondary injury.
Traumatic Brain Injury (TBI), the most prevailing cause of fatality in an accident, is one of the prime causes of IH.
Post-surgery complications is another prominent cause for IH, which requires continuous monitoring.
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Incidence
In USA, on average 2 out of 1000 peoplesuffer by IH.
In Sri Lanka, on average 10 patients undergo surgery for IH, daily at National Hospital, Colombo alone, most of them transferred from peripheries only after showing external symptoms.
There are only 4 teaching hospitals with the facilities to treat IH, in Sri Lanka.
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Solution!
Affordable,
Portable,
Safety abiding, device to assist in
on-site detection,
continuous monitoring, and
prioritizing the CT scan
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Objective
Indicating the existence of extra-cerebral hematomas
Deliverables
Indication
Visual imaging
Comparison and analysis
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Problem
Multiple claims address the problem with disparate technologies, and we set
out to find the most viable!
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Tasks
1. Research to understand the problem and background
2. Experiment to find viable methods for detection, ascertainment and visualization
3. Development of a prototype – proof of concept
4. Design of semi-automatic algorithms
5. Enhance the accuracy, performance and implement machine-learning on the availability of adequate data
6. Field test
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Intracranial Hematoma (IH)Intracranial bleeding occurs when a blood
vessel within the skull is ruptured or leaks.
Leads to increases in intracranial pressure.
Severe increases in intracranial pressure can cause potentially deadly brain.
Early identification, prior to neurological deterioration, is the key to successful surgical treatment.
Continuous monitoring and serial scans are used
to detect delayed hematomas.
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Types of IH
Extra-cerebral.
Epidural hematoma
Subdural hematoma
Subarachnoid hematoma
Intra-cerebral.
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Between 750 – 850 nm wavelength
Water has a low absorption
Oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb) have detectable absorption.
Greater concentration of hemoglobin in an acute hematoma
Extra vascular blood absorbs NIR light more than normal brain tissue due to greater hemoglobin concentration.
Near Infra-red (NIR)
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Bidirectional Associative Memory (BAM)
A recurrent neural network.
Used to establish hetero-association.
Popular for recognizing predetermined patterns such as characters.
Adopted for post detection integration –to identify and filter out improbable detections.
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Others
Optical Density
o▲OD = log (I1/I2)
o▲ OD= log Io/Il - log Io/Ih
= log Il/Ih
Threshold detection
Pre-detection integration
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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iHD Terminal Sensor & Data
Acquisition Subsystem
Processing & Controlling Subsystem
Input Output Subsystem
Power Management Subsystem
Communication Subsystem
Firmware
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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iHD Mobile Application
Data collection and Management
Normalization
OD Calculation
Threshold detection
Post detection integration
Visualization
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Continuous scan
Continuous scan over injured side and healthy side.
Approximately,200 x 400 samples in 7 secondsover 16cm.
Automatically stopped after 10 seconds
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Localized scan
On four predefined locations on the head.
A : Frontal area
B : Temporal area
C : Parietal area
D : Occipital area
First on the left side, followed by the right side.
400 samples per scan.
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Sampling
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Transfer
Over any media supporting serial profile.
Eg: RS232, Bluetooth.
Layered Communication architecture.
Communication protocol specification.
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Data management
Additional data such as Record ID, MO ID, etc are stored.
Data is stored in XML.
Maximum compatibility and extensibility.
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Analysis
Normalization -used to account for unequal number of samples.
Threshold based semi-automatic detection
BAM based filtering
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Design - algorithms
Direct visual comparison with reference scans
Optical Density (OD) calculations
Adopting radar system principles
Instead of few localize scans, continuous scan over whole length
For each subject scan calculate corresponding reference value from reference scans by averaging
Variable threshold to detect a hematoma for a given probability of error.
Post detection integration to eliminate improbable cases
Threshold detection to identify hematomas semi-automatically
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Visualization
Intensity based color maps.
Semi-automatic detection and visualization.
Approximate estimation of the location of hematoma.
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Safety Following FDA regulations
Heating Cell damage is probable above 41˚C.
Cerebrum temperature is 35˚C, which gives 6˚C buffer.
NIR of 50 mW/sq cm contributes to 0.5˚C (sunlight 50mW/sq cm).
LED Output Light output of an LED is 30% of the input
850 nm LED uses 50 mA continuously. Around 40mW per LED.
Use of PWM 50 mW/sq cm applied for 0.5 s will be able to penetrate more than
25 mW/sq cm applied for the full 1 second.
However it generates the same amount of heat.
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Best practices followed …
Modular design in hardwareIsolated sensor, LED, communication and I/O subsystems
Rapid prototyping for enclosureElegant, user-friendly design
Design of communication protocol and abstractionTo structure the communication
Use of .Net 3.5 platformFor broader availability, usability, and code reuse
Use of OOPCode reuse, organization, and maintainability
Hosted at http://fyp.theebgar.net
Project repository, Knowledge base, Public Gateway
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Results
700 mV through healthy side on reception, with the noise floor at 50 mV, maximum of 1.2 OD can be identified.
Hair absorption is high, needs higher power transmission
5 minutes for complete scan:Each scan takes 10 seconds, and data-transfer is instantaneous
Analysis in iHDMA is almost instantaneous taking less than 2 seconds for calculations on 400 samples.
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Clinical Trials To assess the efficacy of the iHD
To obtain the statistical data of the area and concentration of hemoglobin
Subjects : patients undergoing surgery due to IH.
Scheduled on 23rd May, at National Hospital, accident ward
Testing duration : 5 minutes
Procedure: Scanning before undergoing the surgery and a follow up trial after the surgery is conducted with a duration of another 5 minutes, when possible. 2 areal scans done in each side of the head of the patient, and another 8 single scans on specific locations.
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Financial Statement
Prototype cost
Item Cost
Bluetooth module 7000
Microcontroller 500
Sensor and LED 2000
Components 300
PCB 300
Dual cell 1500
Enclosure 16000
Miscellaneous 1000
28600
Total R&D cost
Item Cost
Components 5000
Enclosure 25000
Imported components 20000
Optical filters 55000
Miscellaneous 5000
110000
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Problems faced
Power and safety
FDA regulations
Hair absorption
Ambient noise
Compactness of the device
Detection and false alarm
Field testing
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Future directions
2D solution : Using an array of LEDs and sensors
Compact design : Using surface mount components and aluminum body
Modulated signal and matched filter : To improve accuracy
Quick results : Performing basic calculations in the microcontroller
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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Glimpses
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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DISCUSSION
Department of Electronic and Telecommunication Engineering, University of Moratuwa
Final Year Project Presentation – Y05 May 22, 2009
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THANK YOU
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