Telemedicine: Issues in Mote Based Remote Patient Monitoring Thesis Defense Erik Hadley Advisor: Dr. Patrick Bobbie

Purpose To explore issues in creating a reliable remote patient ECG monitoring system How to maintain a data stream of the ECG signal

Equipment

Equipment - Homemade ECG Circuit

Equipment – MDA300CA Data Capture Device

Equipment – MicaZ Wireless Motes

Equipment - MIB600CA Base Station

Equipment – Laptop Running Microsoft SQL Server

The System Block diagram of the remote patient monitoring system Electrodes amplifier and filter Analog to digital converter MicaZ MicaZ Network MIB600 Base Station Computer and Database

Software

Software TinyOS Open source OS developed specifically for wireless sensor devices Everything is component based Task based concurrency model Tasks cannot preempt each other Hardware events can preempt tasks

Software nesC C like language that all TinyOS components are written in nesC programs have “modules” and “configurations” Modules contain the application code and module interfaces Configurations connect the modules through their interfaces

Software XSensorMDA300 Sample software from Crossbow Technologies Inc for using the MDA300CA Polls all sensors and transmits the data back to the base station with four packets

Software Modified XSensorMDA300 Only polls the analog to digital channel that has the ECG connected Each packet only contains data for the ECG channel to improve data throughput

Software MoteListener Client application written in C# Creates TCP connection to the MIB600CA Receives the packet stream from the MIB600CA Parses the packets and inserts the ECG data into a database

Demonstration Demonstration of the ECG circuit

Demonstration Demonstration of the wireless remote patient monitoring

Limitations Packet transmission rate is not fast enough to produce an accurate ECG representation on the laptop If the sampling rate is 100Hz then there would have to be 100 packets per second

Limitations Multihopping across nodes does not currently work with the MDA300CA software Mobility is currently limited to the range of the MicaZ

Limitations Skin connectivity with the electrodes can be a problem The electrodes pull away from the skin after a while

Improvements for the Next Implementation How to deal with packet transmission rate A data buffer system to store data on the mote and then send a burst signal to the base station

Improvements for the Next Implementation Develop software supported multihopping to increase the range of transmission

Improvements for the Next Implementation Use some form of elastic material to press the electrodes against the skin to maintain better conductivity

Extensibilities Add additional sensors like an oximeter to monitor oxygen in the bloodstream Add temperature and humidity sensors to correlate environmental conditions with heart conditions Limited only to the ideas you can come up with

Conclusion This thesis has created a prototype that demonstrates the ability to use motes for telemedicine We have only begun to scratch the surface of the potential for telemedicine As discussed in the extensibilities, the sky is the limit

References [1] Chaudary Zeeshan Arif. “Wi-Fi Compatible ECG Monitoring & Interpretive Assistant”, Masters Thesis, Southern Polytechnic State University, August 2004 [2] Carlson, Shawn. “Home is Where the ECG is”, Scientific American http://www.sciam.com/article.cfm?articleID=000C74E4-5172-1C74-9B81809EC588EF21, June 2000. [3] Mica2 Data Acquistion Module (MDA300) Product Information http://www.xbow.com/Products/productsdetails.aspx?sid=77 [4] MDA300CA Picture http://www.xbow.com/Products/productsdetails.aspx?sid=77 [5] MicaZ ZigBee Series (MPR2400) Product Information http://www.xbow.com/Products/productsdetails.aspx?sid=101 [6] MicaZ Picture http://www.xbow.com/Products/productsdetails.aspx?sid=101 

References [7] Ethernet Gateway (MIB600) http://www.xbow.com/Products/productsdetails.aspx?sid=90 [8] Wireless Sensor Networks Seminar Course book, Crossbow Technology Inc November 2005 [9] MIB600CA Picture [10] TinyOS Mission Statement http://www.tinyos.net/special/mission [11] Tutorial Lesson 1: Getting Started with TinyOS and nesC http://www.tinyos.net/tinyos-1.x/doc/tutorial/lesson1.html [12] MTS/MDA Sensor and Data Acquisition Board User’s Manual Document 7430-0020-04, January 2006 http://www.xbow.com/Support/Support_pdf_files/MTS-MDA_Series_Users_Manual.pdf

References [13] MicaZ Datasheet http://www.xbow.com/Products/Product_pdf_files/Wireless_pdf/MICAz_Datasheet.pdf