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

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

3. Equipment

4. Equipment - Homemade ECG Circuit

5. Equipment – MDA300CA Data Capture Device

6. Equipment – MicaZ Wireless Motes

7. Equipment - MIB600CA Base Station

8. Equipment – Laptop Running Microsoft SQL Server

9. 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

10. Software

11. 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

12. 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

13. 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

14. 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

15. 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

16. Demonstration
Demonstration of the ECG circuit

17. Demonstration
Demonstration of the wireless remote patient monitoring

18. 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

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

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

21. 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

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

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

24. 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

25. 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

26. 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 June 2000.
[3] Mica2 Data Acquistion Module (MDA300) Product Information
[4] MDA300CA Picture
[5] MicaZ ZigBee Series (MPR2400) Product Information
[6] MicaZ Picture

27. References [7] Ethernet Gateway (MIB600)
[8] Wireless Sensor Networks Seminar Course book, Crossbow Technology Inc
November 2005
[9] MIB600CA Picture
[10] TinyOS Mission Statement
[11] Tutorial Lesson 1: Getting Started with TinyOS and nesC
[12] MTS/MDA Sensor and Data Acquisition Board User’s Manual
Document , January 2006

28. References [13] MicaZ Datasheet