Wearable Sensors Final Presentation

Problem Background Inferred Transmission (short range) Bulky Design, hard to wear 20 Samples per second MIT Research Affective Wearable Computers

Goals and Objectives To create a wearable device that reads temperature, skin conductance, and blood volume pulse and transmits data wirelessly to a computer, where it will be displayed in real time.

Expected Product Layout Lapaic Wireless Transmitter Blood Volume Pulse (BVP) Galvanic Skin Conductor Temperature Sensors Team Transmission Board Team Software Team Lapaic Wireless Receiver Microcontroller GUI

Team Overview Sensors Team –Phillip Hay –Rosy Logioia –Gouri Shintri Transmission / Microcontroller Board Team –Christina Hernandez –Clayton Smith –Adam Stevenson Software Team –Daniel Bishop –Josh Handley

Sensors BVP Detection and Filtering Temperature BVP Subtraction and Offsetting Galvanic Skin Conductance

Sensors (Design Specs) Strengths Compact Wearable Low power Weaknesses Poor quality board and parts Sensitive signals Inconsistent signals (BVP)

Transmission Board Layout Schematic PCB Layout

Transmission Board (Design Specs) Strengths Size (1.8” square) Potential wireless transceiver and microcontroller on same board Weaknesses Wasted space where Chipcon was originally soldered onto board Separate transceiver / microcontroller boards

Software Overview Divided into 2 programs that run concurrently: Cygnal microcontroller PC: The Wearable Sensor Display Utility (WeaSeL) Connected through a USB Connection

Microcontroller Software Microcontroller Code: Interrupt Driven Polls data from A/D converter every X seconds. Transmits it to PC via USB using a custom packet protocol.

Used to connect the microcontroller to the computer The device uses a simple FIFO interface The high data speed rate coupled with a ~64k byte buffer on the computer, allows for our sensor technology to quickly send large amounts of data points to the computer for processing The device is powered by the computer through the USB connection and therefore no additional power constraints are added to the project MCU to Computer USB Connection From:

Microcontroller / USB Connection (Design Specs) Strengths C-based IDE Interrupt Driven  No wasted clock cycles  Easier to maintain code USB  High Data Rate  Built in Buffering System  Easy to integrate w/.NET C#  1.1 Compliant Weaknesses Microcontroller clock somewhat erratic ADC has some spill over

WeaSeL Reads data from the USB port “Real time” display of sensor readings, similar to oscilloscope Can save readings to a file for future comparison

WeaSeL (Design Specs) Strengths Easy to visualize changes in data User-friendly Weaknesses USB buffering may cause WeaSeL to lag or stall

Final Product Layout Blood Volume Pulse (BVP) Galvanic Skin Conductor Temperature Sensors Team Software Team Microcontroller GUI Lapaic Wireless Transmitter Transmission / Microcontroller Board Team Lapaic Wireless Receiver

Project Status Due to lack of time and equipment, our team was not able to complete wireless transmission of data. The transmission code is currently being reviewed by Laipac Corporation.

Project Integration Sensor board hooked up to user and microcontroller Microcontroller on evaluation board hooked up to USB

Team Management Issues Schedule Conflicts Areas of Expertise Time Management (other classes, work, graduation, etc) Resolving the Issues Communication Division of Work Weekly Team Meetings

Budget USB Software$ Lapaic Transmission$ Transmission / Microcontroller Board Parts $ Board FabricationFree Sensor Board Parts$ Fabrication of Sensor Boards$ Total~ $512.95

Engineering Standards and Safety Easy to produce because of availability of parts Product is for medical purposes Product is powered by batteries at low voltage Batteries must be disposed of properly to prevent environmental harm

Project Sponsors This project was completed with the help of the Computer Science Department at Texas A&M University, especially Dr. Ricardo Gutierrez, Dr. Steve Liu, and Dr. Cote from the Biomedical Engineering Department. The project was financially sponsored by Applied Materials and the National Science Foundation.

Demonstration – Double-click to Play