Team Pacemaker

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Team Pacemaker
Luke Philips Ryan Laterza Min Dong Bian Sarah
Makhija

• Apparatus for the Analysis of Heart Sounds
• Electronic Stethoscope / EKG Device

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Project Objectives

• Provide objective means of analyzing cardiac
  acoustics
• Aid in diagnosis of heart murmurs
• Amplified signal from stethoscope, EKG
• Synchronized signals
• Handheld device, portable memory, graphical
  display

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Design Summary
Current Domain Model
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Design Summary (cont.)
Future Domain Model
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Project Diagram
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Preliminary Graphical Displays

• Dr. Weinbergers data files
• No accompanied EKG data

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EKG Triggering Averaging
10 sec. FFT of Filtered Stethoscope Data
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Mixed Signal Microcontroller TI MSP430F1611
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MSP430F1611 Features

• Program Memory Type Flash  
• Program Memory 48 kB
• RAM 10 kB
• I/O Pins 48  
• ADC 12-bit SAR 
• 8 Software Programmable Input Channels
• 200 ksps Maximum Conversion Rate
• Integrated Peripherals DMA, 2 12-bit DAC
• Interface 2 Hardware SPI or UART
• Pin/Package 64LQFP

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Programming the Microcontroller

• MSPGCC
• Free C Compiler TI MSP430 Family
• Windows and Unix Compatible
• Supports the MSP430F1611 MCU
• Supports JTAG Interfacing
• Interface Used to Download Code from the PC to
  the MCU via a Serial/Parallel/USB Adapter

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Example C CodeBlinking Lights

• include "hardware.h"
• void delay(unsigned int d)
• int i
• for (i 0 iltd i)
• nop()
• nop()
• int main(void)
• int i
• int o 0
• WDTCTL WDTCTL_INIT
• P1OUT P1OUT_INIT
• P2OUT P2OUT_INIT
• P1SEL P1SEL_INIT

P2SEL P2SEL_INIT P1DIR P1DIR_INIT P2DIR
P2DIR_INIT P1IES P1IES_INIT
P2IES P2IES_INIT P1IE
P1IE_INIT P2IE P2IE_INIT while (1)
//main loop, never ends.. for (i0 ilt8 i,
o) P1OUT (1ltlti) (0x80gtgt(o7)) dela
y(0x4fff)
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EKG

• Amplifier Circuit Design

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Amplifier Implementation

• LF155/LF156./LF356 JFET input Operational
  Amplifiers

• Applications
• Precision High Speed Integrators
• Fast D/A A/D Converters
• High Impedance Buffers
• Wideband, low noise, low drift amplifiers

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• Advantages

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OR

• 2. Single-Supply CMOS Operational Amplifiers

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Features
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Applications
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Simple Circuit Testing for Optimal Design
OPA 335
LF356

• Bypass Capacitors
• 0.1 nF 4.7 nF

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Before After Adding Amplifier
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EKG Schematic
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Power User Interface
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Power

• Power Supply
• wall wart interface
• Supplies up to 9VDC/300mA
• Regulated 5V/3.3V
• Stand alone Battery Charger
• AC12050615A-01 single cell charger
• Numerous Adjustable Voltage Regulators

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Power

• Battery
• ED053455-2C
• 860mAh Polymer Lithium Ion Battery
• High Energy Density
• Low Cost
• 3.7V Nominal Working Voltage
• Low Weight - 0.65oz (18.5g)
• Excellent Temperature Performance
• Self-Discharge lt8 (per month)

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Power

• Intelligence
• TI-TPS65011
• Multi-Channel 1-cell Li-Ion Power Mgmt IC
• 2DC/DC, 2 LDOs, I2C interface

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UI

• LCD, two stages
• Hantronix HDM08216L
• 8x2

• Seiko Backlight Graphic LCD

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UI

• Low power Keypad Interface With the MSP430
• interrupt driven
• Low power if all keys are pressed and held
  simultaneously
• No crystal required
• Minimal external components
• Suitable for MSP430

• Keypad

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Updated Schedule Division of Labor
Milestone 1 Data sampling Power device EKG
Circuit Milestone 2 UI / Software
Integration Expo Device able to acquire and
display data
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Thank You!
Questions/Comments?