Wearable Wireless Wearable Wireless Physiological Physiological

SensorsSensors

Daniel Bishop Rosy Daniel Bishop Rosy LogioiaLogioia

Josh Handley Josh Handley Gouri ShintriGouri Shintri

Phillip Hay Phillip Hay Clay SmithClay Smith

Christina Hernandez Adam Christina Hernandez Adam StevensonStevenson

Goals and Objectives• Measure blood volume pulse

• Measure skin resistance

• Measure temperature

• Record measurements on wearable device unit

• Transmit measurements wirelessly to a computer

• Display measurements on Graphical User Interface in real time

Recent IssuesRecent Issues BVP Sensor – Correctly amplifying and BVP Sensor – Correctly amplifying and

filtering signalsfiltering signals GSR – Reverse engineering safelyGSR – Reverse engineering safely Convert bulky circuit into small and Convert bulky circuit into small and

wearable devicewearable device Understanding EagleUnderstanding Eagle Size and availability of partsSize and availability of parts Compatible design to Dr.Liu’s Compatible design to Dr.Liu’s

requirementsrequirements Getting Chipcon to process informationGetting Chipcon to process information Debugging hardwareDebugging hardware

Sensors Team - Goals

Objectives – To Do

•Properly filter BVP signal with 2nd order low pass filter

•Reverse engineer GSR sensor

• Condense circuits into wearable item

• Integrate sensors and board

• Test / Debug integration

• Integrate sensors / board with software

• Test / Debug complete configuration

• Present final product

Objectives – Done

• Reverse engineer BVP sensor

• Reverse engineer temperature sensor

• Calibrate and test temperature sensor

Temperature – CircuitTemperature – Circuit

Temperature – Temperature – CalibrationCalibration

Voltage to Tem p Conversion y = 47.985x + 76.513R2 = 0.9229

0

20

40

60

80

100

120

140

0 0.2 0.4 0.6 0.8 1

V2-V1 (V)

Tem

per

atu

re (

F)

Temperature – TestingTemperature – Testing

ThermometerPositions

Temperature◦F

Measured Voltage V

Calculate Voltage V

% Error

Gouri’s palm 91.6 .314 .314 0

Zach’s palm 97.2 .442 .431 2.55

Di’s palm 96.4 .403 .414 2.66

Di’s fingers 94.995.9

.340

.360.383.404

11.2210.89

Pulse Oximetry – Pulse Oximetry – CircuitsCircuits

Photovoltaic Circuit

LED Circuit

Skin ResistanceSkin Resistance

•Waiting on extra samples to arrive

•Reverse engineer sample to learn how GSR sensors work

•Build a working prototype on breadboard using knowledge and information from sample

•Calibrate sensor

•Proposed skin resistance circuit

Board Design Team - Goals

Objectives – To Do

• Test schematic

• Send off schematic for board creation

• Integrate sensors and board

• Test / Debug integration

• Integrate sensors / board with software

• Test / Debug complete configuration

• Present final product

Objectives – Done

• Comprehension of Chipcon 2400 and Microcontroller

• Board Schematic (Eagle)

• Research Parts – Size and $$

Board DesignBoard Design Microcontroller and Chipcon 2400Microcontroller and Chipcon 2400

• Microcontroller

• 32 I/O Pins

• 8 analog inputs pins (100 ksps)

• Max amplification = 16, variable

• UART (Built-In)

• Chipcon CC2400

• 4 pin SPI bus

• 6 optional digital interfaces

• 3 pin antenna connection

• 2.4 GHz transceiver

Custom Circuit BoardCustom Circuit Board

PCB LayoutPCB Layout

Software Team - Goals Objectives – To Do

• Transmission software

•Receiving Software

•USB software

•GUI

• Integrate software with sensors / board configuration

•Test / Debug complete configuration

• Present final product

Objectives – Done

• Comprehension of Chipcon 2400 and Microcontroller

•Analog input software

Analog InputAnalog Input

CodeCode Initialize timerInitialize timer Poll sensors Poll sensors

continuouslycontinuously Convert to digital Convert to digital

signalssignals TestingTesting

Signal generatorSignal generator

CommunicationCommunication

CodeCode Initialize Chipcon Initialize Chipcon

registers/clockregisters/clock Construct/Construct/

Transmit packetsTransmit packets TestingTesting

Writing/Reading Writing/Reading chipcon registerschipcon registers

Set up multiple Set up multiple Chipcon EBsChipcon EBs

Questions?Questions?