Transcript Presentation

Group #15
Matt Frank
Russell Geschrey
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This project was chosen
because of an interest in
wireless communication
systems, namely BAN's
(body area networks)
and their recent
integration with flexible
electronics research here
at the University of
Illinois. This area of
research, if successful,
has the potential to
greatly change health
care and advance the
field of bioinformatics.
Pictured above: A flexible
electronics project created by
Rogers Research Group.
The goal is to create a small flexible electronics
vitals sensor, about the size of an average bandage,
which can measure a person's vitals such as ECG
(heart rate), body movement and core body
temperature. It will relay this information over the
air in real time to a receiver, where it will be
displayed in a graph format and stored for later
analysis (such as for medical studies).
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Allows for mobility while still being able to
monitor patients.
Less intrusive and more seamlessly integrated
into everyday tasks.
Capable of being used where previous rigid
devices were unable to operate.
Allows for studies that could not normally be
performed with wired devices.
Does not require battery replacement, which
means it is reusable and not harmful to the
environment.
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Major components
PaLFI/Microcontroller Development Board
 Power Supply RF harvesting system
 Accelerometer
 Temperature Sensor
 ECG
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Once RF power is transmitted via the “battery
charge” command, the device will make sensor
measurements using the harvested energy
continuously until another command is
received. All devices wait in their lowest power
mode until addressed and turned on by the
microcontroller.
When the “MSP access” command is received,
the microcontroller will stop measurements,
and transmit the latest sensor measurements to
the RFID transponder.
REQUIREMENTS
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The Base Station Reader
can communicate
required commands to
the development board
in battery-less mode.
VERIFICATION PROCEDURE
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With the software and
firmware installed for
the device, the base
station demo program
reports a CRC correct
after receiving data
from the EZ430 PaLFI
development board
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The development board’s self test command is
able to flash it’s LED’s without a battery.
PaLFI memory can be remotely read and
written to without a battery by test code in the
microcontroller. This was tested through the
RFID demo software command to read the raw
transponder memory.
REQUIREMENTS
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The diode and DC/DC
converter must be able
to convert the rectified
RF signal from the
antenna to a constant
3.3 V DC.
VERIFICATION PROCEDURE
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When the battery check
confirms the device is in
range, a "charge"
command will be given
and a voltmeter will be
used to measure the
potential across the
capacitor to ensure a
voltage of 3.4V with no
more than a 10% error.
Power Supply System Quantitative
Verification
At a distance of 1 cm, we see that the time constant of the capacitor
is 290ms.
At a distance of 4 cm, we see that the time constant of the
capacitor is 236ms.
Currently, measurements are being taken, alternating every
200ms.
One measurement takes a maximum of 2.4ms, with a maximum
voltage drop of 200mV.
REQUIREMENTS
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The sensor must be able
to determine the
acceleration within 10%
accuracy and transmit
the data along the I2c
bus
VERIFICATION PROCEDURE
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Test by recording data
over time when
accelerating the sensor.
Be sure the time,
magnitude, and
direction of the
acceleration reported is
accurate.
REQUIREMENTS
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The sensor must be able
to determine the
temperature within 10%
accuracy and transmit
the data along the I2c
Bus
VERIFICATION PROCEDURE
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Test by recording data
over time when
changing the
temperature using a
soldering iron. Be sure
the time and magnitude
of the temperature data
reported is accurate.
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Using the RF harvesting and capacitor storage
to power the sensor system, the same distances
of communication and reliability were possible
as the datasheet indicates for an unloaded
RFID transponder.
Reliability was 87% over 100 measurements at
4cm distance.
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Due to time constraints, we were unable to
successfully solder, mount and test ECG.
Communication with the RFID reader over
USB was not possible due to lack of software
support for this device.
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Development of ECG sensor
PCB development and mounting
Embedded software to interface with USB
reader directly (as compared to the current GUI
script method currently employed).
Purchase and test of a high power reader
Development of hardware on flexible substrate.
Questions?