01-10-2012, 04:32 PM
BODY SENSOR NETWORKS
[attachment=34952]
Inductive Coupling
transfer of energy without any electrical contact
Requires no internal battery
Long-term communication
Applications
Artificial heart system
Cochlear implant
Electromagnetic communication is typically 13.56 MHz or 26 MHz
Problems
Space is an issue
Impractical when implant is in deep
Doesn’t support a very high data rate
Can’t initiate a communication from inside of body
RF Communication in Body
Compare with inductive coupling
Increases bandwidth
Two-way data link to initiate communications
Greater distance
Short time
Requires an implanted battery and antenna
Frequency band
403 MHz to 405 MHz
Wireless transmission challenges in human body
Human body is composed of varied components
Each individual is different
Location of implant
Antenna design
Surrounding medium is very different
Location of the implant
Antenna needs to tunable with transceiver
Type of antenna
Monopole antenna
Dipole antenna
Helical antenna
Patch antenna
Bow-tie antenna
Transmitter tuning
Output signal
2v peak-peak maximum
Maximum peak current of about 10mA
Maximum efficiency is obtained when output devices are with purely resistive
RF output power
Required radiated power
Less the antenna gain
Matching circuit loss
[attachment=34952]
Inductive Coupling
transfer of energy without any electrical contact
Requires no internal battery
Long-term communication
Applications
Artificial heart system
Cochlear implant
Electromagnetic communication is typically 13.56 MHz or 26 MHz
Problems
Space is an issue
Impractical when implant is in deep
Doesn’t support a very high data rate
Can’t initiate a communication from inside of body
RF Communication in Body
Compare with inductive coupling
Increases bandwidth
Two-way data link to initiate communications
Greater distance
Short time
Requires an implanted battery and antenna
Frequency band
403 MHz to 405 MHz
Wireless transmission challenges in human body
Human body is composed of varied components
Each individual is different
Location of implant
Antenna design
Surrounding medium is very different
Location of the implant
Antenna needs to tunable with transceiver
Type of antenna
Monopole antenna
Dipole antenna
Helical antenna
Patch antenna
Bow-tie antenna
Transmitter tuning
Output signal
2v peak-peak maximum
Maximum peak current of about 10mA
Maximum efficiency is obtained when output devices are with purely resistive
RF output power
Required radiated power
Less the antenna gain
Matching circuit loss