Multi-Disciplinary Senior Design Conference
Kate Gleason College of Engineering
Rochester Institute of Technology
Rochester, New York 14623
Project Number: 10007
MECHANICAL SPINE TEST PLATFORM
Irma Bocova (EE)
Jeff Rebmann (ISE)
Rob Bowman (ISE)
ABSTRACT
The intent of this project is to design and build a test
platform that will mimic the actions of a human spine.
The platform will replicate a fixed pelvis, lower
lumbar, and upper lumbar segment. This design will
incorporate and measure positions in three dimensions
(roll, pitch, yaw), and allow horizontal and vertical
segment adjustability. The purpose of developing this
platform is to validate the existing motion capture
measuring device in use at the Nazareth College
Physical Therapy Clinic located in Pittsford, NY. The
spinal platform allows room for reflective marker
attachment for external measuring by the motion
capture device.
The project incorporates mechanical, electrical, and
software components that ultimately provide an
electronic output of Euler angle measurements. The
spine is built of an aluminum structure in order to not
interfere with the electromagnetic limitations of the
sensors. The structure consists of three segments
separated by ball joints that have the ability to lock
into a static position. The entire structure has a nonreflective coating to ensure no reflectivity interference
of Nazareth’s motion capture system.
The orientation sensors are mounted to the spinal
structure and linked with a National Instruments
LabVIEW application. This application allows the
user to read angles in real time from both sensors
simultaneously, and allows for the capture of
information in any static position. The sensors work
in unison with one another so that each sensor
measures relative to the one below it.
Kyle Pilote (ME)
Chris Rowles (ME)
Phetphouvanh “Awt” Phommahaxay (ME)
DAQ: Data Acquisition
LL: Lower Lumbar
UL: Upper Lumbar
Pitch: Rotation in Sagittal Plane
Roll: Rotation in Frontal Plane
Yaw: Rotation in Transverse Plane
CNC: Computer Numerical Control
INTRODUCTION
The Nazareth College Physical Therapy Clinic has
been conducting research to measure the spinal
column in order to help patients with lower back pain.
To validate the data taken by their Motion Capture
System a mechanical spine analog was needed that
would mimic the movement of a human spinal
column. The mechanical spine would have to measure
angle deviation between consecutive spinal segments.
The human spine consists of 5 different sections: a
fixed pelvis, a lower and upper lumbar, a thoracic, and
a cervical region. In order to track the progress of
people with lower back pain Nazareth Physical
Therapy Clinic uses a motion tracking system.
Markers, coated with retroreflective material, are
placed on the surface of muscles corresponding to the
spinal column. Multiple different cameras capture the
image, and then the angle between the two adjoining
sections is calculated using motion capture software.
Figure 1 shows the location of the retroreflective
markers on a human spine.
NOMENCLATURE
A/D: Analog to Digital Converter
DCM: Duty Cycle Modulation
Copyright © 2010 Rochester Institute of Technology
Proceedings of the Multi-Disciplinary Senior Design Conference
Page 2
should be easy to set up, to adjust, and to use. It must
be light weight, stable, and portable. Moreover, the
budget for this project is $2000.
Issues and Risks
One of the major issues and risks with this project is
choosing the correct sensor to meet customer needs.
The sensor has to be precise and accurate up to 1º for
all angle measurements. The small size of the
mechanical design requires a sensor with small
dimensions and light weight. Due to time constraints,
the possibility of building a custom sensor was
eliminated. The sensor has to integrate easily with the
user interface, which would minimize the
programming time.
Figure 1: Spinal Sensor Placement
Previous designs provided a simplified mechanical
spinal representation which consisted of two rigid
segments, moving only in a single plane [1].
Electrogoniometers were used to measure this angle
which was then compared against the motion tracking
software. This method provided accurate results,
however it was not capable of measuring angles in
more than one plane due to its simple design.
The mechanical spinal platform provides the Physical
Therapy Clinic with a device that is able to move in
three different planes while simultaneously being able
to measure all angles of movement. A user friendly
interface helps the customer gather data and save the
output in an MS Excel spreadsheet.
DESIGN PROCESS
One of the issues and risks foreseen in the mechanical
design is instability. The small size of the upper and
lower lumbar sections, which correlate to the human
spine, require a small and durable ball joint that can
hold the spine in place and minimize unneeded height.
The large vertical height variation also is an issue. The
spine segments must be rigid and straight at all lengths
to allow accurate readings of angle measurements.
This becomes increasingly difficult as the maximum
lengths are reached. As the height and angle increase
the spine runs the risk of becoming overly top heavy
causing the device to tip over. Another key factor is
the material of the mechanical spine. The outer surface
must be antireflective for risk of distorting the motion
capturing cameras and the material itself cannot
provide any magnetic interference and skewing the
sensor measurements.
Concept Generation
Needs and Specifications
One of the major customer needs is the adjustability of
the mechanical spine horizontally and vertically in
order to fit the 5th percentile female up to the 95th
percentile male. This adjustability should be discrete.
The final product must consist of a fixed pelvis and
two distinct movable sections: the lower lumbar and
the upper lumbar. The lower lumbar and the upper
lumbar have to move in all three planes (sagittal plane,
frontal plane, and transverse plane) and measure a
combination of static positions which include flexion
or extension, lateral bending, and axial rotation.
Therefore, simultaneous measurements for pitch, roll,
and yaw must be measured. Also, measurements for
the angle deviation relative to the section below are to
be provided. There should be a minimum of 15 degree
movement at each joint.
The customer requests high precision and accuracy in
angle measurements using lockable positions.
Moreover, the mechanical spine has to be
antireflective to eliminate infrared interference. It
Electrical:
Accuracy, cost, electromagnetic and infrared
interference played a major part in sensor selection.
During the design process Analog Devices
accelerometers were considered as a means to measure
angular position [2]. However, preliminary testing
showed that the accelerometer chips were not accurate
enough to meet design criteria.
ADXL202
accelerometer chips were tested and data was gathered
for an input voltage, VDD=3V, and filtering capacitors
of 0.5μF. Figure 2 shows the output of a single chip
double axis ADXL202 accelerometer with its y-axis
oriented perpendicular to gravity and the x-axis
parallel to Earth’s surface. The oscilloscope capture
shows clearly that the period of the DCM is less than
0.88 s. This would result in a highly significant error
in the tilt angle. Also, the same level of precision was
difficult to maintain throughout the testing. Through
further research, it was found that accelerometers
alone are incapable of measuring yaw rotations.
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Proceedings of the Multi-Disciplinary Senior Design Conference
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infeasible to meet the minimum and maximum height
range required. Another option that could meet these
height extremes would be a telescoping segment.
However, it became apparent that this would provide
other problems such as mountings for the sensors and
horizontal members. A telescope also lacked stability.
The best concept for vertical adjustability was discrete
segments using multiple, stackable pieces. This would
allow an increase of one inch increments and use of a
dedicated base for each segment to allow the mounting
of the sensors and the horizontal members.
Figure 2: Oscilloscope capture of DCM for X and Y
outputs. (X-channel 1, Y-channel 2)
Another concept involved a combination of two-axis
tilt sensors and rotational inductors to measure angles
of tilt and rotation, respectively. The sensor’s voltage
output would have to be passed through a multi
channel DAQ and then analyzed. Extensive amounts
of programming and calculations would have to be
performed to translate the voltage outputs into
simultaneous measurements for pitch, roll, and yaw. It
was impossible to incorporate the rotational inductors
in the mechanical design due to the small size of the
ball joints.
Mechanical:
The concepts were selected while taking into
consideration all of the needs, risks and the final
budget. However, cost did not play a large role as
compared to sensor selection. For the joint selection it
was important to find something preferably premade,
small, and durable. The 3-directional maneuverability
requires either a split or regular ball joint. The only
available premade option was a steel ball joint. Due to
magnetic interference it did not fit the specifications.
Therefore a custom aluminum split ball joint was
chosen due to the fact that it provided no
electromagnetic interference and could be easily
locked in place with a thumb screw.
To accommodate the horizontal adjustability, several
options were considered. The options were to use a
rack and pinion, continuous slot/slide adjustment,
discreet peg adjustment, a folding side panel, or
simply a fixed piece. It was necessary for the
adjustability to maintain a horizontal position and be
symmetrical on either side of the spine. Due to the
complexity the rack and pinion was not a viable
option. While the rest of these options were potentially
viable concepts they were not necessary. Simple fixed
horizontal bars met the requirements, therefore this
concept was selected.
Ideally, continuous adjustability would be used for the
vertical adjustment of the mechanical spine segments
as it would incorporate all heights. The main difficulty
with the continuous adjustability was the large
variation in height of each spine segment. It was
It was a goal to have a stable and secure base with
continuous vertical adjustability. It was also required
to hold its position under a relatively light weight
without tipping. A premade option was ideal as it
saved time, therefore the initial options available were
three or four legged tables, a tripod, or a microphone
stand. The tables did not provide vertical adjustability
and were not very stable. After preliminary research
and minor testing of the tripod and microphone stand
it became apparent that these options were very costly
and also unstable. They had numerous components, all
possessing too much freedom of movement. This left
the option of building a custom stand enabling the
vertical adjustability to be set within the correct range
and also provided the tight tolerances needed for a
stable and secure base. Casters were considered for
easier transportation, but would result in excessive
movement.
Final Concept
Selected Sensor
A MicroStrain 3DM was the sensor selected to
perform measurements for pitch, roll, and yaw for
each segment. This 3-axis orientation sensor consists
of an orthogonal array of DC accelerometers and
magnetometers. The DC accelerometers provide roll
and pitch measurements with respect to Earth’s
gravity. The magnetometers use Earth’s magnetic field
vector to compute yaw.
The 3DM sensor is capable of measuring a wide range
of motion in both dynamic and static positions. Its 12
bit A/D converter provides an angle resolution of less
then 0.1 degrees [3]. The output is transmitted at a rate
of 9600 bits/sec and linked to a computer through an
RS-232 serial cable.
One of the major advantages in using 3DM is the
partial LabVIEW programming supplied. It allows the
user to output the orientation information in numerous
formats. It can output raw magnetic field and
accelerometer data, or it can process data to give Euler
Angels, Quaternion, or a coordinate transformation
matrix.
Copyright © 2010 Rochester Institute of Technology
Proceedings of the Multi-Disciplinary Senior Design Conference
Page 4
Moreover, the use of a 3DM sensor eliminates the
need for a data acquisition board and extensive
programming.
Selected Mechanical Design
The final mechanical design consists of a fixed pelvis
and two movable sections, lower lumbar and upper
lumbar, joined by two ball joints. The final product is
constructed of aluminum to eliminate any magnetic
interference with the 3DM sensors. The extruded
aluminum stock is manually machined to create upper
and lower lumbar sections, which are vertically
adjusted by adding 1 inch aluminum blocks. The
range of vertical adjustability is 2” to 5”. The
rectangular shape will prevent rotation between the 1
inch blocks, giving more precise sensor readings for
yaw. Brass screws were used to secure the aluminum
blocks into place. The screw’s non-ferrous material
would eliminate even the slightest magnetic
interference with the sensors.
To further prevent magnetic interference a small 5/8”
diameter, durable and easily lockable aluminum ball
joint was manually machined due to its unavailability
to purchase.
The fixed horizontal members are marked in halfcentimeter increments for accurate marker placement.
The base is constructed out of wood and is adjusted
vertically by two telescoping rectangular aluminum
bars, to fit all anthropometric constraints. Figure 3
shows a picture of the mechanical design.
Figure 3: Mechanical spine design rendering
Selected User Interface
After acquiring written permission from National
Instruments, LabVIEW was chosen for coding and
customer interface purposes.
The interface the
customer will see is shown in Figure 4.
Figure 4: User Interface - Front Panel
According to specifications defined by the customer,
values for roll, pitch, and yaw for both lower lumbar
and upper lumbar are simultaneously displayed in real
time. The front panel also contains a value that
describes the deviation of the sensors from magnetic
north when the program begins its session. This value
is then stored and subtracted from both yaw readings
so that absolute deviation can be measured from the
starting point.
Process:
The user begins the application by running the
program. They are prompted with a dialog box that
asks them to title the spreadsheet where all
measurements will be collected (This is compatible
with version 2003 and 2007 of MS Excel). The
program then begins real time movement data
streaming. When the spinal platform is set to the
desired position, the user clicks the “Capture” button,
and that set of data points is collected in the
spreadsheet. The user now moves onto the next
position, and the process is repeated. Once all desired
measurements are collected, the user will then click
the “End Session” button, which will cease data
collection and the session. The user will then open the
saved spreadsheet, where all values that were stored
are arranged for further analysis.
Coding:
The coding associated with the 3DM sensors works as
a serial data collection device. The program initializes
both serial ports for each sensor, and then sends a
signal to begin collecting data at the specified sample
rate. This data is transferred to the program in bit
form where a set of code translates that data from bits
into degrees [4]. Each measurement (roll, pitch, and
yaw) is outputted to the next block of code in three
separate integer values for each sensor.
The integer values then enter a while loop where the
program runs at a continuous rate until stopped by the
user. The corresponding lower and upper lumbar
values are combined and analyzed in their own block
Project P10007
Proceedings of the Multi-Disciplinary Senior Design Conference
of coding. Each block subtracts the lower lumbar
value from upper lumbar value so that the readings are
respective to one another beginning with the upper
lumbar and ending with the fixed pelvis.
The initial yaw heading is stored in a shift register and
cycled through each iteration of the while loop for
subtraction purposes described previously. The while
loop also contains a case structure controlled by the
“Capture” button. Each time the case structure is true,
the roll, pitch, and yaw data are converted into string
format and sent to a matrix to be stored until the end of
the session. Multiple samples can be collected and
stored in this matrix. Once the session is terminated,
data from the matrix is exported to a spreadsheet with
a 0.1 precision, floating point format as dictated by the
needs.
Building
The wooden block of the stand is machined into a
round base. There are two rectangular aluminum tubes
that slide, one over the other, that make up the
adjustability in the stand. These are machined from 1"
SQR x .125" 6061 T6 Tube Extruded Aluminum Bare
Square Tube 6061 T6, 24" and 1.25" SQR x .125"
6061 T6 Tube Extruded Aluminum Bare Square Tube
6061 T6, 24". First, both rectangular tubes are cut to
length using a band saw. Then the remaining material
is milled out of the outer tube using an end mill. The
holes are also drilled out of the outer tube using an end
mill.
The ball joint studs are machined from 0.5" DIA 6061
T6 Extruded Aluminum Bare Round 6061 T6, 12".
First the stud is cut to length using a band saw. Then a
lathe is used reduce the diameters to their set lengths
and then thread the one side into a male part. An end
mill is then used to drill the hole.
Page 5
The joint receptacle is machined from 1" SQR 6061
Bar Extruded Aluminum Bare Square 6061 T6, 3'
Length. First the joint receptacle is cut to length using
a band saw. Then an end mill is used to mill out the
remaining material as well as drill the holes.
The sensor mount is machined from 1.25" x .125"
6061 T6 Extruded Aluminum Bare Rectangle 6061
T6, 12". First the sensor mount is cut to length using a
band saw. Then an end mill is used to mill out the
remaining material as well as drill out the holes.
The left and right pelvises are machined from 1.25" x
.125" 6061 T6 Extruded Aluminum Bare Rectangle
6061 T6, 12". First the pelvises are cut to length using
a band saw. Then an end mill is used to mill out the
remaining material as well as drill out the hole. The
hash marks indicating measurement are made in a
CNC machine.
The mounting arms are machined from 0.5" DIA 6061
T6 Extruded Aluminum Bare Round 6061 T6, 12".
First the mounting arms are cut to length using a band
saw. Then an end mill is used to mill out the
remaining material.
The base plug is machined from 1" SQR 6061 Bar
Extruded Aluminum Bare Square 6061 T6, 3' Length.
First the base plug is cut to length using the band saw.
Then an end mill is used to drill out the holes.
The horizontal bars are made from .75" x .25" 6061 T6
Extruded Aluminum Bare Rectangle 6061 T6, 48".
First the horizontal bars are cut to length using a band
saw. Then they are cut to shape and the hash marks
indicating measurement are made in a CNC machine.
Testing
Sensor testing
The mounting pad is machined from 1" SQR 6061 Bar
Extruded Aluminum Bare Square 6061 T6, 3' Length.
First the mounting pad is cut to length using the band
saw. Then an end mill is used to fillet the edges and
then drill the hole in the center.
The collars are machined from 1.25" SQR x .125"
6061 T6 Tube Extruded Aluminum Bare Square Tube
6061 T6, 24". First the collar is cut to length using a
band saw. Then an end mill is used to mill out the
remaining material as well as drill the hole.
The one inch vertical segments are machined from 1"
SQR 6061 Bar Extruded Aluminum Bare Square 6061
T6, 3' Length. First the vertical segment is cut to
length using a band saw. Then an end mill is used to
mill out the remaining material as well as drill the
holes.
A set of tests were performed to verify the accuracy of
the 3DM sensor. The first set of tests was performed
in an environment where the magnetic interference
caused by ferromagnetic materials was considerably
large. In order to compare the performance of the
sensor at different locations, a second set of identical
tests were performed at Nazareth Physical Therapy
Clinic (motion capture room).
A mechanical test fixture was build in order to record
measurements for both rotation and tilt. A picture of
this test fixture is shown if Figure 5.
Copyright © 2010 Rochester Institute of Technology
Proceedings of the Multi-Disciplinary Senior Design Conference
Page 6
The mechanical test-set-up did not provide tilt in both
directions for the pitch and roll; therefore in order to
gather the necessary data, the sensor was rotated 180
degrees about its z-axis.
Mechanical testing
The vertical adjustability was tested using calipers to
verify the height of the 1” aluminum blocks. All
blacks were within specification. All other size
measurements for each block were within tolerance of
the machine drawing. Testing using a scale verified
that all three horizontal members were machined
correctly to half centimeter increments as specified.
The next test performed validated the range motion
required between each lumbar segment. The structure
exceeds all specifications set at ± 20 degrees.
Figure 5: Mechanical Test Fixture for MicroStrain
3DM sensor
The results of this set of tests showed that the tests
performed under the influence of large ferromagnetic
constraints, and the tests performed at the customer
site generated similar results. This verified that the
sensors perform equally under both conditions.
The aforementioned tests were set up in the following
manner. First, the roll and pitch were kept constant
(approximately 0º). The 3DM sensor was rotated
clockwise and then counter-clockwise about the zaxes. The yaw angle was varied from 0 to 21 degrees.
In order to test both accuracy and precision of the
3DM sensor, three trials of measurements were taken
for both clockwise and counter-clockwise directions.
Next, the yaw and roll were kept constant and the
pitch was varied from 0 to 20 degrees. Again, three
sets of trials were taken to prove the sensor’s accuracy
and precision. The data shows that the sensor pitch
measurements are very close to the actual tilt angle. A
slight change in the yaw and roll measurements as the
pitch angle is varied is seen. Knowing how sensitive
the sensor is, even to the slightest movements, it was
predicted that the yaw and roll values would not stay
100% constant. It was difficult to maintain the yaw
and roll the same because the force applied to change
the pitch angle would cause the mechanical test fixture
to move more or less than 1 degree. Moreover, it was
noticed that the table used to place the mechanical test
fixture was not perfectly horizontal.
During the testing for roll, the yaw and pitch were kept
constant and the roll angle was varied from 0 to 20
degrees. The 3DM sensor recorded the slightest
movements in the yaw and pitch.
The entire spinal structure also was tested to verify no
infrared interference (no reflectivity). The surface is
coated with flat black enamel eliminating any
reflectivity. The structure was tested at the motion
capture site and succeeded. Any future concerns are
eliminated by providing the customer with additional
enamel to repair any worn areas.
The joint holding strengths were tested using
suspended weights from the sensor mounts. This
provides the maximum torque on the ball joints due to
the distance away from rotation. The upper lumbar
segment was tested using a 1 lb weight at the zero
degree angle position (vertical). A similar test was
performed on the lower lumbar segment. Both joints
held without movement. This verifies that the joints
possess a satisfactory joint strength, exceeding the
value needed for the weight of the sensors. The test
also verified the worst case scenario by withstanding
suspended weights at 20 degrees of tilt. Both ball
joints successfully passed this test, verifying joint
strengths. Figure 6 shows a depiction of the testing.
Figure 6: Joint Strength Test
Project P10007
Proceedings of the Multi-Disciplinary Senior Design Conference
The entire spinal structure weighs less than 10 lbs.
This satisfies the requirement for weight and
portability for the user.
The horizontal members of the lower and upper
lumbar provide a ridge for the reflective markers to sit
upon, guaranteeing repeatable placement across testing
sessions. They also supply enough room (0.75 sq. in.)
for placement of the marker, satisfying the size
requirement.
Due to the 3DM Orientation sensor utilizing a
gravitational reference for the pitch and roll axis,
movement in these directions is permanently
referenced to a “home” position and do not require a
mechanical zero. The mechanical zero device has
therefore been modified to only constrain yaw
movements so that the magnetometer can be zeroed in
relation to the Earth’s magnetic field and the spine
position. The test has been modified to reflect these
changes.
RESULTS AND INTERPRETATION
All engineering specifications and aspects of the
design have been tested and are a success. Figure 7
shows the final design.
Page 7
anthropometric data ranges requested by the customer.
It is able to support the retrorefelective markers and
simulates the human marker placement the physical
therapy clinic uses in practice. The structure is
antireflective as to satisfy the infrared interference
requirement. The precision of the welding of all
attached members leaves room for improvement. The
lack of precision affects the perpendicular angles
required for attaining the absolute zero positions of the
structure.
The sensor readings and mechanical
members must match exactly in order to obtain the
specified accuracy tolerance. Because of the extreme
sensitivity of the magnetometer in the 3DM sensors, it
is imperative that no ferrous materials are within the
immediate vicinity of the structure. If so, the yaw
readings will become skewed.
User Interface – Final Design
The user interface was created using LabVIEW by
National Instruments™. It meets all specified
requirements as well as including additional features
to increase user functionality. The sensors are read
into the computer via a serial to USB compound hub
creating virtual COM ports for each. The program is
designed to allow the user flexibility to change which
COM ports are used based on availability. The user is
able to read Roll (frontal), pitch (sagittal), and yaw
(transverse) angular positions of the spine in real time
of each spinal segment. When the spinal structure is
moved to the desired location, the user is able to
capture the angular readings by clicking the capture
button. This feature sends all measurements to an
output spreadsheet in MS Excel format, therefore
allowing the user to reference the data at a later date.
Because of the functionality of the magnetometer, the
deviation from magnetic north is subtracted from both
yaw measurements. This allows the readings to start
at zero in order to measure deviation from the starting
point of the session.
CONCLUSIONS AND RECOMMENDATIONS
Figure 7: Final Design
Spinal Structure – Final Design
The spinal structure, including the 3DM sensors,
meets all desired specifications. Mechanically, the
structure is built with all three segments as specified,
with a greater than ± 20 degree angular position
between each segment.
Horizontal and vertical
adjustability ranges are met according to customer
specifications. The structure is able to deliver all
From a mechanical standpoint, the specifications were
met however there is room for improvement. The
welding is a critical part of the design, and the
accuracy was underestimated. Therefore a more
experienced welder should be brought in for a future
iteration. Also, some of the mechanical components
were manually machined and some were CNC
machined. For further accuracy all parts should be
CNC machined. To meet the non ferrous requirement,
aluminum was chosen as the principle building
material. To cut cost and weight, a hardened plastic
would be a better option for the next iteration.
The 3DM sensors performed exactly as expected,
meeting all requirements.
Be sure not to
Copyright © 2010 Rochester Institute of Technology
Proceedings of the Multi-Disciplinary Senior Design Conference
underestimate the sensitivity of the magnetometer in
proximity to ferrous materials.
The final user interface granted the customer the
desired features and functionality. LabVIEW allowed
for flexibility in the programming and design as
needed [5]. It assisted with creating an installer and
executable to run on the customer computer without a
cost to the customer. It is important to possess general
knowledge regarding hardware/software integration.
This will eliminate unnecessary programming time for
future iterations.
Page 8
[4] 3DM Data Acquisition & Display Software,
MicroStrain Inc. [CD-ROM], Williston, VT:
MicroStrain Inc. 2007
[5] “NI LabVIEW - The Software That Powers
Virtual Instrumentation,” National Instruments
[Online]. Available: http://www.ni.com/labview/
[Accessed: Jan. 10, 2010].
[6] http://edge.rit.edu/content/P10007/public/Home.
[Online]
ACKNOWLEDGMENTS
REFERENCES
[1] S.P. Gombatto, PhD, PT; J.W. Klaesner, PhD; B.
J. Norton, PhD, PT; S. D. Minor, PhD, PT; L. R.
Van Dillen, PhD, PT, “Validity and reliability of a
system to measure passive tissue characteristics of
the lumbar region during trunk lateral bending in
people with and people without low back pain,”
Journal
of
Rehabilitation
Research
&
Development, vol. 45 num. 9, pp. 1415-1430, 2008.
[2] “Low Cost 62 g/610 g Dual Axis iMEMS®
Accelerometers with Digital Output.” Analog
Devices.
[Online].
Available:
http://www.analog.com/static/importedfiles/data_sheets/ADXL202_210.pdf
[Accessed:
Oct. 12, 2009].
[3] "3DM Flier" MicroStain Inc. [Online]. Available:
http://www.microstrain.com/pdf/3dmflier.pdf
[Accessed: Jan. 6, 2010].
The team would like to extend a special thank you to
Dr. Sara Gombatto and the Nazareth College Physical
Therapy Department. They were extremely helpful
and professional in all interactions. Also, thank you to
all Rochester Institute of Technology faculty and staff
who assisted in the completion of the project. Dr.
Elizabeth DeBartolo as our faculty guide and mentor
was supportive and resourceful during the design and
fabrication processes. The team would like to thank
Dr. Robert Bowman for sensor/electrical advisement
and assistance. Thank you to both Professor Madhu
Nair and Professor John Wellin for assisting with
LabVIEW portion of the project. For helping with
fabrication, the team thanks the RIT machine shop
staff. Finally, thank you to the National Science
Foundation for their sponsorship of the project. See
the P10007 website for further details as desired [6].
Project P10007