Document Revision No.: 1
Revised: 07/31/17
RIT KGCOE MSD Program
P11011 Modular Motion Tracking Knee Device
Sensor Test Plans
By: Brittany Bochette, Maya Ramaswamy, Lindsey Clark, Andrei Stihi and Michael Ostertag
Table of contents
1.
MSD I: WKS 8-10 PRELIMINARY TEST PLAN .......................................... 2
1.1. Introduction; Problem Statement, Objectives/Scope, and Purpose. .................2
1.2. Project Description; Sub-Systems/ Critical Components Being Tested ...........2
1.3. Approval; Guide, Sponsor: Pending Approval ....................................................4
1.4. Test Strategy ...........................................................................................................4
RIT KGCOE MSD Program
Page 1
Document Revision No.: 1
Revised: 07/31/17
RIT KGCOE MSD Program
P11011: Modular Motion Tracking Sensors
Knee Motion Tracking Subteam
Sensor Test Plans & Test Results
1. MSD I: WKS 8-10 PRELIMINARY TEST PLAN
1.1.
Introduction; Problem Statement, Objectives/Scope, and Purpose.
1.1.1. Problem Statement
1.1.1.1.
P11011 will create a series of sensors that will measure
the flexion of the knee.
1.1.2. Objectives/Scope
1.1.2.1.
Identify sensor solutions for portable motion tracking of
the knee.
1.1.2.2.
Identify microcontroller and auxiliary component solutions
for portable motion tracking system.
1.1.2.3.
Identify and employ test methods to quantitatively
validate system performance
1.1.3. Purpose
1.1.3.1.
Dr. JJ Mowder-Tinney is the Director of Clinical Education at Nazareth College. Dr.
Mowder will primarily be using this device with stroke victims to track and ensure
their increased range of motion after physical therapy treatments.
1.2.
Project Description; Sub-Systems/ Critical Components Being Tested
Figure 1: P10011 Knee Flexion Sensor Block Diagram
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Document Revision No.: 1
Revised: 07/31/17
RIT KGCOE MSD Program
1.2.1. Sensor Subsystem
1.2.1.1.
The critical objectives of sensor testing are validation of
published accuracy and precision.
1.2.1.2.
The second aspect of sensor testing is verifying
successful interface circuitry between the sensor and
microcontroller.
1.2.1.3.
Sensor dimensions and weight will also be evaluated for
compliance with customer ideal and marginal values.
1.2.2. Microcontroller Subsystem
1.2.2.1.
Data acquisition, analysis and conversion, A/D
Conversion and transmission of data to the base unit are
the four primary objectives of the microcontroller unit, and
will be the focus of our microcontroller testing.
1.2.2.2.
The second aspect of microcontroller testing is ensuring
the compatibility and functionality of peripheral devices,
including batteries, zero mechanisms and communication
interfaces, when appropriate.
1.2.2.3.
Microcontroller dimensions and weight will also be
evaluated for compliance with customer ideal and marginal
values.
1.2.3. Software Subsystem
1.2.3.1.
Non Functional Software Testing
Software load testing
-
Perform testing to ensure the software can
be loaded onto the microcontroller.
Stability testing
-
Test software with erroneous data to
determine bugs and correct behavior
Usability testing
-
Test user interface and output medium to
make sure system delivers usable results
Security testing
-
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Test system against overflows and data
corruption
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1.2.3.2.
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Divide software design testing into 4 steps:
-
Data acquisition
a. Test ADC channels
b. Test channel between sensor and
microcontroller
c. Test sampling speed and precision
d. Test precision
1.3.
Approval; Guide, Sponsor: Pending Approval
1.4.
Test Strategy
1.4.1. Product Specifications and Pass/ Fail Criteria
Note: Pass/Fail Criteria is determined by Marginal Value, where:
For values where a high number is desirable: Pass >MarginalValue; Fail < Marginal Value
For values where a low number is desirable: Pass <MarginalValue; Fail > Marginal Value
Engineering
Spec.
Precision
Range of Motion
Derives from
Customer
Needs
CN3, CN4
CN2, CN5
Relative
Importance
9
Description
Measure of
Performance
Units
Angle that the
device is able to
measure.
Ability of
device to
measure
consistently
within a
certain degree.
(degrees)
Marginal
value
Ideal
Value
+/- 5-10
+/-5
3
Ability of device to
measure knee
flexion.
Angle that the
unit is able to
measure.
(degrees)
X: +/- 60
Y: +/- 60
Z: +/- 60
X: +/100
Y: +/100
Z: +/100
How far the
device shifted
or rotated
during use.
(cm,
degrees)
cm: 1.3
deg: 5
cm: 0
deg: 0
Displacement
from attachment
point on body.
CN3
9
Ability of the
device to remain
stationary during
use.
Speed of
attachment
CN7, CN8,
CN12
3
The time it takes to
place the device on
the patient and set it
up.
Time it takes
to put on the
patient and
activate.
(minutes)
3
2
Speed of removal
CN7, CN8,
CN12
1
The time it takes to
take the device off
of the patient.
Time it takes
to remove
device.
(minutes)
2-3
1
Protective
enclosures
CN1, CN9,
CN11
3
Keeping the
sensitive devices
properly protected.
Force of
impact that it
can withstand.
(m of drop)
2.5
6
3
Device still allows
patient to move
knee joint naturally.
Surveying
patients to
determine
level of
obstruction to
(survey)
marginal
None
Does not impede
natural motion
CN2, CN6,
CN10
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RIT KGCOE MSD Program
knee.
3
Ensuring that the
patient is as
comfortable as
possible.
Surveying
patients to
determine
level of
discomfort.
(survey)
marginal
none
CN1
9
Keeping the cost of
the device down as
much as possible.
The cost of all
of the
components.
($)
$300
$200
Weight
CN9, CN10
3
Keep the weight of
the device down.
The weight of
the final
device.
(kg)
1
0.5
Device must be
sanitizable
CN13
3
The device needs to
be sanitizable.
The device
needs to be
washable.
(T/F)
True
True
Size
CN9
9
Keep the size of the
device down.
How far the
device sticks
outside of the
leg.
(mm)
50
70
Minimize patient
discomfort
CN6, CN10
Cost of
components
1.4.2. Test Equipment available
1.4.2.1.
EE Lab: Oscilloscopes, Multimeters, varied resistors and
capacitors, Soldering irons, Excel, Circuitry Software,
PSpice, Altera, Breadboard, PC, Power Supply, Signal
Generator, MATLAB
1.4.2.2.
ME Machine Shop: Mills, Lathes, Drill Presses,
SolidWorks.
1.4.3. Phases of Testing
1.4.3.1. Device Acquisition (wks 10-11)


Finalize Bill of Materials upon meeting with EE Advisors,
order all final components as soon as possible.
Identify other needed laboratories, equipment, or auxiliary
devices, and ensure that RIT has a presence of needed
items.
1.4.3.2. Component/ Device (wks 12-13) (1-2, MSDII)

RIT KGCOE MSD Program
Sensors: Receive sensor, solder and prepare sensor for
evaluation. Measure dimensions and weight of sensor,
connect sensor to standard EE laboratory equipment to
evaluate for basic power/signal metrics. Ensure sensor is in
full working order. Mate with needed auxiliary items such as
buffers, diodes, as needed. (T)
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Document Revision No.: 1
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
RIT KGCOE MSD Program
Microcontrollers: Receive microcontroller, record weight and
dimension metrics. Prepare needed interface circuitry and
filtering with sensors. Employ EE laboratory to test for basic
signal metrics, ensure microcontrollers are in full working
order. (T)
1.4.3.3. Integration (wks 14-15) (3-4, MSDII)

System: Evaluate power distribution between sensors and
microcontrollers. Ensure signal strength and quality are up to
par, and interface circuitry is functional. Test data acquisition
and analysis metrics. (T)
1.4.3.4. System Performance (wks 16-19)(5-8, MSDII)

System:
o Mate sensor with attachment method and ensure full
functionality. (T)
o Work with P10010 to test the sensor system with the
base unit system. (T)
1.4.3.5. Final Evaluation (wks 20-22)(9-11, MSDII)
RIT KGCOE MSD Program

Redo any erroneous tests; explore random results that
deviate from the norm to ensure measurements were correct.

Complete Final Publication outlining final decision and
components for future RIT MSD Motion Tracking Projects.

Complete Final Spreadsheet containing technical information,
including available vendors, for all components.
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Document Revision No.: 1
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RIT KGCOE MSD Program
1.4.4. List of Test Methods:
Test
Category
Spec
Component
Measurement of
Interest
T1
EE
E1
Sensors
Output Signal
T2
EE
E1
Sensors
Power
T3
EE
E1
Sensors
Output Signal Quality
EE
E1
Sensors
Precision of Individual
Measurements
EE
E1
Sensors
Precision over Time
EE
E2
Sensors
T7
EE
E1, E2, E3,
E4, E5, E6
Sensors
T8
EE
E1, E2
Microcontroller
Read
T9
EE
E1, E2
Microcontroller
Precision
T10
EE
E1, E2
Microcontroller
Functionality
T11
EE
E1, E2
Microcontroller
Data Format
T12
EE
E1, E2
Microcontroller
Data
T13
EE
E7, E8,
E10, E12,
T14
EE
E1
Sensors &
Microcontrollers
Microcontroller
/Sensor
T15
EE
E1
Microcontroller
/Sensor
Filter
T16
EE
E1
Microcontroller
/Sensor
Power
T4
T5
T6
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Degrees of Freedom &
Range
Precision with
Enclosures
Dimensions, Weight
Amplify Signal
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Test Description
Connect the sensors to an Oscilloscope and
do basic testing
Test that the sensors are being powered
correctly.
Test signal quality using an oscilloscope and
perform basic filtering if necessary.
Compare sensor measurements to known
values.
Compare sensor measurements over time to
known values.
Compare sensor degrees of freedom and
range measurements to known values.
Test effect of sensor enclosures on
prerecorded sensor accuracy
Test the functionality of being able to read
raw data from ADCs
Calibrate the ADC
Ensure basic functions-being able to
program, load a file, timing, sampling
frequency, I/O, etc., can be performed
Test the ability to convert the data acquired
into USB.
Test data acquisition using microcontroller
programming and sample data
Record weight and dimensions of sensors
and microcontrollers.
Test signal strength and apply amplifiers
where necessary.
Test signal quality and add filters where
necessary with regarding to the
microcontroller being used.
Test the ability to power the sensors through
the base unit (microcontroller as a backup
before base unit is complete)