Parts to be Added
List of concerns from Fall Design Review and how we addressed or plan on
Faculty concerns to be addressed later by our team:
o How will the FIT System deal with the issue of the last lap?
Will allow the user a choice to delete it.
o Look into using a 2 electrode heart rate system instead of a 3 electrode
This is no longer an issue due to the purchased heart rate monitor.
o Look into using conductive rubber electrodes for the heart rate monitor
This is no longer an issue due to the purchased heart rate monitor.
o Must TEST how perspiration changes the electrode conductivity.
This is no longer an issue because the heart rate monitor was
Polar does recommend pre-moistening the chest strap prior to each
workout with saline solution or electrode gel.
Sweat inhibits bacterial growth (due to its salt content), therefore,
this is probably not a big issue.
Users will be asked to wipe down the chest strap after use (same as
current Kern center equipment policy).
Due to the low cost ($6.95), each user will be encouraged to buy
their own elastic strap (for sanitation and sizing reasons).
• This cost may even be cheaper if it is possible to buy the
elastic straps in bulk and re-sell them to the users at the
o Look into the effects that Magnetic fields may have on people.
Based on prior research, it is believed that magnetic fields
produced by the RFID system will not cause any harm to people.
The FIT System team will be doing research on this to verify this
o How are the amplifiers in the FIT System going to be powered?
• For the RFID Amplifier, for a proof of concept, the power
supply from Tech Support at MSOE will be used.
• The RFID Amplifier could be powered by the power
supply listed in the Budget section of this report for an
additional 150 dollars.
HR Monitor amplifiers
• Heart rate monitor amplifiers are no longer being used, but
all components of the purchased heart rate monitor system
use standard watch batteries, which are replaceable.
o Address issues involved in lane changes.
Due to the fact that the RFID lap tracking system uses a fixed lap
distance and the measured time to calculate speed of the lap,
intralap lane changes could easily become an issue.
• The first solution to this is that each user will be instructed
to stay in lane one. This will work because the FIT System
is not being used for a competition.
• All users will be informed that if they do change lanes
during their lap, the distance traveled will be slightly
inaccurate, causing their speed to also be inaccurate. (both
inaccuracies should be negligible).
o Can you simultaneously read two different RFID tags?
The 13.56 MHz antenna/reader will allow two tags to be read
It takes 20ms to read a tag
• This was tested, and it was determined that no runner could
possibly close the following distance of a foot or two in
20ms. Therefore, this is a mute point.
o Calculate how many people can be in the antenna at the same time.
People can’t run two side-by-side in one lane, and it takes more
than 20ms to close the gap between two runners one behind the
We will instruct users not to pass each other for at least 3 feet
before and after the antenna.
• This distance was verified through testing to find the
readable area of the antenna. See the System Component
Testing section of this paper for further details.
Business Student Collaboration Results
During the Fall of 2006 the FIT System team collaborated with a group of MSOE
business students. The business collaboration led to an understanding of how the FIT
System could be made more marketable. The business team provided the idea of
marketing the FIT System on several different levels: the primary level would include
only basic parts of the system, and increasing levels would increase the complexity and
cost of the overall system leading up to the complete system with the main program,
RFID system, heart rate monitoring system, and large display screen.
Note about funding
Thorough research and application has not yielded any funding from companies or
grants. All of the necessary FIT System components have been purchased, and the team
is currently applying for reimbursement from the Keen Grant.
System Component Testing
Determination of Readable range of the RFID antenna and the maximum readable speed.
The goal of the study was to determine the usable range of the Radio Frequency
Identification (RFID) antenna and the maximum speed at which the transponder must
cross the antenna’s range. First, the transponder was slowly moved in the three-
dimensional space surrounding the horizontal antenna in order to determine the range of
readability for a stationary transponder. Then, the antenna was placed on the floor in a
horizontal position and a pendulum was swung over it in a variety of positions at
different speeds in order to determine the maximum swing speed at which the
transponder could be detected.
In order to determine the usable range of the antenna, the reader was first connected to
the antenna and power supply as shown in FIGURE 1. The range in the vertical
dimension was determined by bracing the antenna on top of two poster paper easels. The
transponder was dragged along the paper from top to bottom, until the reader no longer
detected it. Once the transponder was no longer detected, a point was drawn on the
paper. Five points were drawn for each side that the antenna was resting on. Then, the
easels were moved closer to each other such that the antenna was still centered about it.
The process of detecting readability and drawing points was repeated. Then, the poster
paper was placed horizontally and the antenna was placed on top of it. The transponder
was dragged along the two-dimensional plane of the antenna in order to detect readability
and the points were marked as before. Matlab will be used to enter the data in order to
create a diagram indicating the three-dimensional range of readability of the reader.
Power Supply RFID Reader
FIGURE 1: Set-up of RFID Reader and Antenna to Determine Range of Readability
In order to determine the maximum allowable swing speed of the transponder, the
antenna was placed on the floor and the pendulum was swung above it such that when the
pendulum was not moving, the transponder was 22 inches above the antenna. Four
different pendulum orientations were used, as shown in FIGURE 2.
Case A Case B Case C Case D
FIGURE 2: Pendulum Position and Swing Direction with Respect to Antenna for Four
A video camera was used to record the pendulum swings. For each case, three swings
were obtained in which the transponder was read by the reader and one case was obtained
in which the reader did not detect the transponder. Video software will be used to
determine the velocities of each of the swings in order to determine the best position of
the antenna and the maximum allowable swing speed.
Future Experiment plans
Heart rate Monitor
The heart rate monitor and Datalogger have both been activated and found to be
Future testing of the heart rate monitor must be completed to determine the range
limitations because Polar does not publish the range of the b1 heart rate monitor.
Therefore, the first test will involve attaching the chest strap (by using electrodes) to a
function generator with a proper attenuator set so that reasonable human EKG traces can
be simulated and controlled. Through this experimental setup, the minimum and
maximum readable heart rates will be tested. The amplitude and bandwidth limitations of
the Polar b1 will be tested to determine the upper and lower signal amplitude limits by
testing the levels at which the heart rate output appears erratic or flaky.
Finally, the accuracy of the heart rate monitor will be tested by simultaneously
connecting a subject to a standard 3-lead EKG and the Polar b1 chest strap. The EKG
will be recorded using Biopac, and the Polar b1 data will be recorded using the
Datalogger. A comparison of the heart rate data will determine the accuracy of the Polar
b1 heart rate monitor.
Heart rate monitor
o Test accuracy by comparing the monitor’s results to Biopac
o Attach to self
Check placement limitations
o Use function generator with attenuator
Possibly attach electrodes to the strap (using ECG electrodes)
Do slow rate and fast rate and see what rate it won’t capture anymore
• Basically self-test the limitations (bandwidth)
Check the amplitude limitations (what are the upper and lower signal
• Where does it get erratic or flaky for HR
o Pendulum test to check the maximum speed that the reader can still pick up