GastroscopeGastroscopeAdvisor:Advisor:Dr. Ata AkinDr. Ata Akin

Design Team:Design Team:Casey GavinskiCasey Gavinski

Kenneth HoytKenneth Hoyt

Ashish PatelAshish Patel

Kalpesh TrivediKalpesh Trivedi

Problem BackgroundProblem Background

Diabetes Mellitus Gastroparesis Techniques for Diagnosis

InvasiveNon-invasive

Methods of DiagnosisMethods of Diagnosis

Nuclear Medicine TestPatient consumes small amount of radioactive materialScanner monitors amount of radioactivity in stomach

Upper Gastrointestinal (GI) Endoscopy TestCamera inserted into digestive tractVisually examines stomach

Intraluminal ManometryBaloon inserted into stomachMeasures pressure generated by stomach contractions

Electrogastrography (EGG)

Invasive

ElectrogastrographyElectrogastrography Measurement of Gastric Myoelectrical

Potential SignalsElectrodes placed on abdominal surfaceTesting performed during states of

Fasting and PostprandialCorrelation between EGG signals

and gastric motility

Non-Invasive !!

EGG SignalEGG Signal

Gastric Myoelectrical Signals (500μV)

0 20 40 60 80 100 120

-0.2

-0.1

0

0.1

0.2

0.3

0.4

Time (sec)

Am

plit

ud

e (

mV

)

Internal EGG Measurement

0 20 40 60 80 100 120

-0.2

-0.1

0

0.1

0.2

0.3

0.4

Time (sec)

Am

plit

ud

e (

mV

)

Surface EGG Measurement

EGG SignalEGG Signal

Primary Frequency Component3 cpm (0.05 Hz)

0 50 100 1500

1

2

3

4

5

6

7

8

9

Ma

gn

itu

de

Frequency (cpm)

Existing EGG SystemsExisting EGG Systems Signal Measurement Bandwidth

1-18 cpm (0.02-0.3 Hz)Primary Frequency

Stand AloneMobility Limited

PortableNo Graphical DisplayNot Stand Alone

GastroscopeGastroscope

Portable Stand Alone System Graphical Display Increased Bandwidth

0 50 100 1500

1

2

3

4

5

6

7

8

9

Ma

gn

itu

de

Frequency (cpm)

EGG SignalEGG Signal

Secondary Frequency Component50 – 80 cpm (0.8 – 1.3 Hz)

Why the 50 to 80 cpm ?Why the 50 to 80 cpm ?

3cpm range requires monitoring throughout fasting and postprandial states. (Differential Comparisons)

50 to 80 cpm range provides consistent results with a short time reading.

50 to 80 cpm range closely correlated to Intraluminal Manometry Test in dogs. (Diagnostic Charts Available)

Create look-up charts for faster more accurate diagnosis.

Gastroscope System ArchitectureGastroscope System Architecture

Laptop(LabVIEW)

Spreadsheet(Excel)

Amplifier FiterFunction

Generator

DAQ

Analog Signal ProcessingAnalog Signal Processing

DC AmplifierInstrumentation AmplifierGain > 10,000Low Noise

FilterLow PassFlat ResponseSharp Roll-off

Amplifier SchematicAmplifier Schematic

     

kR

FC

Hzfc

RCfc

2.8

1

20

2

1

VV

VV

RcRc

kGain

15

15

510

10050

1

OUTPUT

V -

V + V +

V -

+ INA121

_Rc

+ INA121

_RcINPUT

V +

V -

C

+ OPA2131A

_R

R

C

V +

V -

C

+ OPA2131A

_

R

C

ROUTPUT

Printed Circuit Board (PCB)Printed Circuit Board (PCB)

Amplifier ResponseAmplifier Response

Amplifier and filter response to an input of 100 μv at 1 Hz

 

 

Amplifier Response (Cont’d)Amplifier Response (Cont’d)

Amplifier and filter response to an input of 100 μv at 15 Hz

Amplifier Response (Cont’d)Amplifier Response (Cont’d)

Amplifier and filter response to an input of 1 mv at 1 Hz

Amplifier Response (Cont’d)Amplifier Response (Cont’d)

Amplifier and filter response to an input of 1 mv at 15 Hz

DSP Flow ChartDSP Flow Chart

Hanning Windowing

Mean Subtraction

Power

Peak Detectionand

CorrespondingFrequency

Display and Memory

Primary Signal3 cpm

(0.05 Hz)

Secondary Signal50 - 80 cpm

(0.83 - 1.33 Hz)

Fast FourierTransform

Window Averaging

EGG Signal

Data Windowing

Matlab SimulationMatlab Simulation

10 20 30 40 50 60 70 80 90 100 110 1200

5

10

15

Frequency (cpm)

Ma

gn

itu

de

Fasting State Postprandial State

Matlab Simulation (Cont’d)Matlab Simulation (Cont’d)

0 50 100 1500

0.5

1

1.5

2

2.5

3M

ag

nit

ud

e

Frequency (cpm)

Fasting State Postprandial State

Laptop Based DesignNear Real Time Data AnalysisLabVIEW SoftwareData Storage in Spreadsheet FormatGUI InterfacePortableResearch Applications

• IRB Approved

Alternative System DesignAlternative System Design

Future WorkFuture Work

Integrated System DSP Based Architecture Properly Configured ADC Touchscreen Display (LCD)

Senior Design ExpendituresSenior Design Expenditures

Component CostPrinted Circuit Board (PCB) $20

Integrated Circuits NAShielded Electrode Lead Assembly $125

Large Electrodes (50) $35DSP Workshop/Starter Kits $700

Misc. Hardware $40Labtop Computer NA

LabVIEW Software NADAQ Card-AI-16E-4 NA

Total Cost $920

4 Year Financial Estimation4 Year Financial Estimation

Role Appoint Effort Year 1 Year 2 Year 3 Year4 TotalEngineer 4 100% $30,000 $31,500 $33,075 $34,729 $129,304Subtotal $120,000 $126,000 $132,300 $138,915 $517,215

Overhead and Benefits @ 100% 100.00% $120,000 $126,000 $132,300 $138,915 $517,215Product Manufacturing ($600/unit) $12,000 $18,000 $24,000 $30,000 $84,000Supplies $500 $500 $500 $500 $2,000Equipment $15,000 $2,000 $2,000 $2,000 $21,000Travel $5,000 $5,000 $5,000 $5,000 $20,000Total Cost for Production $272,500 $277,500 $296,100 $315,330 $1,161,430

Unit Price $13,625 $9,250 $7,403 $6,307

Note: Production at $600 per unit is assumed as follows Year 1 – 20 units Year 2 – 30 units Year 3 – 40 units Year 4 – 50 units

National InstrumentsDAQ AI 16EAmplifier Fiter

EGG SYSTEM

0 50 100 1500

1

2

3

4

5

6

7

8

9

Mag

nitu

de

Frequency (cpm)

START

Freq =

Mag =

Power =

Laptop

STOP RESETSUMMARY

Summary of System DesignSummary of System Design