Revisimo Remote Vital Sign Monitor

About us Dr. Thomas Morris Advisor Cory Zywno EE Data Transmission Matthew Galloway EE ADC & Thermistor Matthew Gallups EE Alarm & ADC Aaron Cheeseman EE Monitor & PCB design Paul Jang CPE Data Transmission & Website

Overview Introduction Problem/Solution Constraints –Technical –Practical Technical Approach Progress Timeline Question

Introduction What is Revisimo? –Digital wireless Thermometer

Current Problem Hospital equipment –Expensive –Difficult to use Market (oral, tympanic, scanning) –Inaccurate –Temporal –No alarm

Solution Bandage –Thermistors –Flex PCB Base station –Alarm –Temperature set by the user –Clear LCD display

System Overview

Constraints Revisimo must meet a set of predetermined technical and practical constraints ensuring that the device will be competitive in the home-healthcare market. Technical Constraints outline Revisimo’s functionality. Practical Constraints define usability.

Technical Constraints Battery Life Revisimo must have a minimum battery life of seven days. Wireless The bandage and monitor must communicate with each other within a 100-foot radius (indoors). Alarm System The alarm must be triggered if a user defined temperature is reached. Also, the alarm must be audible from at least 30 feet away. Temperature Precision Revisimo must calculate the core body temperature within 0.5 °F. Revisimo must read temperatures within the range of 65 °F to 110 °F. Visual Distance The display must present data to the user at a distance of up to 3 feet.

Politics Revisimo must abide by Federal Communications Commission regulations and allocations of the radio spectrum (9kHz to 3THz).

Manufacturability The bandage must fit on the temple and the monitor must be handheld.

Microprocessors NameSizeIntegrated RadioADCResources Available CC24307 mm x 7 mm2.4 GHz DSSS12 bitsPrototyping Boards PIC16F6884 mm x 4 mmNone10 bitsNone

Data Exchange – Success

Data Exchange - Failure

Non-linear Surface Mount Negative Temperature Coefficient (NTC) –Good Stability –No Resistance Spikes Positive Temperature Coefficient (PTC) –Poor Stability –Spikes in Resistance –At High Temperature reverts to NTC Characteristics Modeled using MATLAB Thermistor Photo taken from

Voltage Divider Vin = 3.0V Rref ≈ 200 KΩ Rthrm = Variable Vout = input to ADC

Analog to Digital Converter / Accuracy ADC Characteristics –12-Bit Resolution –Internal Reference of 1.25 V –Each bit represents a change of 305 µV Accuracy –Temperature Range: 65 °F °F –When Temp = 65 °F: Vout = V –When Temp = 115 °F: Vout = V

Progress Data Transmission ADC measurements Temperature Conversion PCB Development

Timeline JanuaryFebruaryMarchApril Research Radio Hardware Assembly Testing

Questions?

References [1] Information Technology Strategic Plan, 02.pdf, Accessed: February 18, 2009 [2] Accessed: February 18, 2009

Thank you!