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Hand-held Breast Cancer Detector
J. Miguel OrtigosaElectrical Engineering
Advised by Dr. Britton Chance
Inexpensive and
convenient!
Breast cancer and methods for its detection
Breast cancer is the most commonly diagnosed cancer: 40,000 women in the U.S. died from the disease in 2002.
Early detection essential for reducing chance of death.
Most common methods of detection:
X-Ray Mammography.MRI Mammography.Ultra-sound Mammography.
Device Look… Probe: Light and detector
Objective for Hand-Held Breast Cancer Device
Detect a tumor of a few millimeters in size at a distance of up to 3 cm from the breast surface.
Commercial uses would include:Tumor Localization.Preliminary Screening.
• Mass and Home Screening.
Detection Method…
Null Plane
L1 L2D
Photon Density Waves
Object
2 cm 2 cm
Amplitude Cancellation in the Null Plane
Photomultiplier Tube Detector
(PMT)
Light emitting diode (LED):- 0 degree phase
LED at 180 degrees
Detection Method…Monitor Display
Y=Voltage
X=Time
L1
L2
Middle
Plot: Tumor Location
Block Diagram Analysis
PMTPMT
BPFBPFMonitorMonitor SplitterSplitterSwitchSwitch0℃
180℃
1st Section
2nd Section
3000 Hz3000 HzOscillatorOscillator
SplitterSplitterObjectLED1
LED2
Problem and Resolution: 1stSection
8
1
4
3
2U1ALF353N
10KR4
24KR6
10K R3
53k R1
53K
R2
12KR5
-5V
+5V
1nF
C1
1nF
C2
D1Diode 1N5400
D2
Diode 1N5400
T?
Trans CT
200
R13
200
R14
D1Diode
D2Diode
10
R15
10
R16
+5V +5V
Problem: Insufficient Intensityand Modulation.
Resolution: Added Transistor with high base resistance.
Results:20-100 mA swing.Clearer signal.
TX1
kbreak
R2
Q1
Q2N3904
0
0
0Q2
Q2N3904
LED
0
V2
0
R3
V1
LED
V4
0
V5
R4
R1
0
V3
Problem and Resolution: 2ndSection
Problem: Noise.Resolution:
Replaced noisy transformer.Implemented higher order bandpass filter.
Frequency
100Hz 300Hz 1.0KHz 3.0KHz 10KHzV(out3) V(out2)
0V
40V
80V
120VPLOT: Frequency Response
Room for ImprovementI. Protect PMT from light overexposure.
II. Make better contact during breast navigation andphysically protect PMT.
III. Eliminate Noise from LED sources themselves.
Innovations in Breast Cancer DetectorI. Shut-off Protection System.
PMT Voltage Input
Supply Voltage
Innovations in Breast Cancer DetectorII. New Case Design Idea:
Better design for navigation.Physically Protect PMT by using Fiber Optics.
PMT Computer Mouse Design
Steps for Completion
Assemble new system on Circuit Board or PC Board.
Finish program for Time-Shared System.
Test new completed system on Breast phantom.
Q & A
Innovations in Breast Cancer Detector
I. Time-Shared System
LED1
LED3
LED2
LED4
object
Time shared 10HzCONTROL
DAQ cable
How we can detect tumors…
High Absorption in Tumors
Block Diagram Analysis
PMTPMT
BPFBPFMonitorMonitor SplitterSplitterSwitchSwitch0℃
180℃
1st Section
2nd Section
3000 Hz3000 HzOscillatorOscillator
SplitterSplitterObject
300 Hz300 Hz SplitterSplitter
LED1
LED2
LED3
LED4
LED1
LED4
LED3
LED2
Shut-off Schematic
5V5V
0-5V
0
R3
1k
Q1
Q2N3904
0
R1
1k
0
V out
U1
3
27
46
1
5+
-V+
V-OUT
OS1
OS2
0
Photodiode
V12V
0
0
Relay
V source
PMTVoltage Input
Problem discovered
LED performance:
Low Intensity.Low Modulation swing.
3000 Hz3000 HzOscillatorOscillator SplitterSplitter Object
PMTPMT
LED1
LED2LED1
LED4
How it works …
II. Photomultiplier Tube (PMT)
PhotocathodeDynodesAnode
How it works…I. Light Emitting Diodes (LED)
Near Infrared Light (780 nm wavelength).
High Scattering and Low Absorption mediums:
Microscopically, a random walk.
Macroscopically, outgoing spherical wave referred to as the diffuse photon density wave (DPDW).
PMT Output Signal Filtering Circuit
0
0
out2
0
V1-15
0
R1
10k
R2
100
0
0
R7
1k
R3
750
R6
1k
C3
0.1u
V510
0
R5
750
V410
R8
750
U4
uA741
3
2
74
6
1
5+
-
V+
V-
OUT
OS1
OS2
0
V3-10
C4
0.1u
R11
1k
0
0
out3
R9
750
U3
uA741
3
2
74
6
1
5+
-
V+
V-
OUT
OS1
OS2
V6-10
out1
R12
1k
0
0
I2
0Adc1Aac
V215
C2
0.1u
0
R4
750
C1
0.1u
R10
750
U2A
LM324
1
3
2
41
1
OUT
+
-
V+
V-
0
Frequency Response
Frequency
100Hz 300Hz 1.0KHz 3.0KHz 10KHzV(out3) V(out2)
0V
40V
80V
120V