Medical WSNs

Challenges

• reliability
• privacy and security
• power management - not all devices are battery powered
• diversity - both a challenge and an opportunity
• fast deployment - disaster recovery scenarios

Medical devices

• ECG
• SpO2
• Blood pressure (CardGuard)
• Motion analysis board
  • for Parkinson's, to identify uncontrolled shaking and fine-tune dosage -- Code blue
  • for detecting falls -- UVA

Groups

• University of Virginia: Alarm-NET
• Intel Research Seattle
• University of Washington
• University of Rochester
• Harvard University
• John Hopkins: AID-N
• University of Alabama at Birmingham: Advanced Network Infrastructure for Health and Disaster Management

Projects

Overview

Project	Domain	Network Architecture	Devices	Sensors	Provides
Code Blue	Patient monitoring	Flat architecture, just looks at collection	Motes	SpO2, HR, EKG, motion	Patient monitoring, Reliable Routing, Localization
AID-N	Disaster recovery - Triage	Two-tier architecture, 802.15.4 and 802.11	Motes, PDAs	SpO2, HR, ECG	Patient monitoring, Continuous monitoring of triage levels

CodeBlue

• AMDR Routing:
  • support for pub/sub
  • routing state proportional to the # of publishers (an entry in the table for each publisher)
  • route discovery initiated when a device requests to publish data, requires flooding
  • a subscriber that wants to receive data from a channel sends a route reply on the reverse path (handles asymmetric links)
  • routes are updated through periodic floods (every 15s)
  • negative results on mobility
  • path metric (PDR)
    • for each link, estimate LDR by mapping the measured LQI to a link delivery estimator. This model is determined empirically.
    • PDR is the product of all LDRs of the links along the path
  • see CodeBlue Technical Report

SMART (Scalable Medeical Alert Response Technology)

• Domain: disaster recovery, triage
• Network architecture: 802.11b
  • Two types of devices: patient monitoring and caregiver
• Devices: PDAs
• Sensors:
  • medical: SpO2, ECG from MIT
• Functions:
  • vital sign monitoring
  • vital sign analysis & alarms
  • localization

Notes:

Good background section.

References:

1. Curtis DW, Pino EJ, Bailey JM, Shih EI, Waterman J, Vinterbo SA, Stair TO, Guttag JV, Greenes RA, Ohno-Machado L, SMART An Integrated Wireless System for Monitoring Unattended Patients. J Am Med Inform Assoc 2008 January-February; 15(1):44-53.

AID-N

• AID-N(Advanced Health and Disaster Network)
• Domain: disaster recovery, triage
• Network architecture:
  • 802.11 -- one hop
  • 802.15.4 -- seems one hop
• Devices: motes, PDAs, PCs
• Sensors:
  • medical
  • non-medical: GPS
• Functions:
  • monitoring and alarm
  • vital sign analysis & alarms

References:

1. Tia Gao; D. Greenspan; M. Welsh; R.R. Juang; A. Alm, "Vital Signs Monitoring and Patient Tracking Over a Wireless Network," Engineering in Medicine and Biology Society, 2005. IEEE-EMBS 2005. 27th Annual International Conference of the , vol., no., pp.102-105, 2005

Alarm-NET

• Domain: assisted living, circadian activity rhythms (CAR)
• Network architecture:
  • Spans body networks, sensor networks and IP networks
  • Query service to collect data
  • Emphasis on dynamic security
  • Use CAR information for security and power management
• Devices: heterogeneous - motes, PDAs and PCs
• Sensors:
  • medical: pulse, blood oxygenaton
  • non-medical: temperature, light, infrared motion

References:

1. A. Wood, G. Virone, T. Doan, Q. Cao, L. Selavo, Y. Wu, L. Fang, Z. He, S. Lin, J. Stankovic, “ALARM-NET: Wireless Sensor Networks for Assisted-Living and Residential Monitoring,” Technical Report

News

Band-aids