Page 1
Biosensor Networks
Principal Investigators: Frank Merat, Wen H. Ko, Darrin Young
Case Western Reserve University
NASA SpaceCommunications
Page 2
Biosensor Networks
Project Overview
The goal of this project is to develop a test platform for biomedical monitoring using COTS components and state-of-the-art communications concepts.
Body drawing from Fundamentals of Bioelectrical Impedance Analysis, Rudolph J. Liedtke, RJL Systems, February 1998.
RF SourceSpectrum Analyzer
Biomonitoring NetworkComputer Medical
Data Logger/Analysis Station
Conventional RF Link (BlueTooth?)
IntraBody Wireless Network
IntraBody/Extrabody Wireless Network
Router
Page 3
Biosensor Networks
Relevance
This technology has applications for continuous health monitoring of humans in space and for long duration space experiments involving humans and/or animals.Any wireless solution should interface with existing and future proximity networks.
“A Lightweight Ambulatory Physiological Monitoring System,” NASA Tech Briefs, January 2001.
Page 4
Biosensor Networks
Impact
The major impact of this technology is upon manned missions, e.g., space station and shuttle missions .
Removal of wires and other encumbrances would improve astronaut freedom of movement and increase the system reliability.
Wireless Biosensor Network
Page 5
Biosensor Networks
Feasibility Experiment
Body drawing from Fundamentals of Bioelectrical Impedance Analysis, Rudolph J. Liedtke, RJL Systems, February 1998.
RF SourceSpectrum Analyzer
RF Phantom
Page 6
Biosensor Networks
Characterize human body as rf communications channel
Received Power Through the Body (underside of forearm with 30 cm separation). Antenna dimensions: L =39 mm, W = 42
mm, and h = 0.062” on FR-4 substrate.
Received Power at 50 cm separation.Transmitter antenna: L = 54 mm, W = 48 mm, h = 0.062”; receiver antenna L = 26
mm, W = 38 mm, h = 0.062”, both on FR-4 substrate.
Geometry of Basic Rectangular Patch Antenna
Received Power at 1 m separation. Antenna dimensions are L = 41 mm, W = 38 mm, and h = 0.062” on FR-4 substrate.
Page 7
Biosensor Networks
Prototype sensor node
Typical rectangular center fed patch antenna used for testing.
Bare PC board for prototype
Prototype sensor node with integrated antenna and D-socket for programming
“early” power for prototype
Antenna board for prototype
Page 8
Biosensor Networks
Propagation modeling
Simulation of Transmission Line Model for 0.6 Meters Antenna Separation
Transmission Line Model of Antenna/Human Circuit using experimentally measured antenna parameters and
published values for the electrical parameters of the human body
Page 9
Biosensor Networks
Papers and Awards
[1] M. Dummeruth. Wireless Wearable Health Monitoring System. M.S. Thesis, Case Western Reserve University, August 2002. (Advisor: F. Merat).