P11011: MOTION-TRACKING SYSTEMDETAILED DESIGN REVIEWBrittany BochetteLindsey ClarkMike OstertagMaya RamaswamyAndrei Stihi
AGENDA• Project Background• Knee Flexion System
– Updated Customer Needs– Updated Engineering Specs– Sensor and Attachment Choices– Test Plans
• Head Tilt System– Updated Customer Needs– Updated Engineering Specs– Sensor and Attachment Choices– Test Plans
• Project Budget• Risks• Project Plan• Questions for Audience
PROJECT BACKGROUND Motion-tracking system that measures knee
flexion and head-tilt Continuation of past senior design groups
P10010 Sensors P10011 Attachment Methods
Customers are Nazareth Physical Therapy Clinic and Rochester General Hospital
KNEE FLEXION Clinicians and students work with patients
recovering from strokes
Goal is to see improvement in flexion
Sessions are short
Measuring is done by goniometers
UPDATED CUSTOMER NEEDS
Sanitation
Cost
UPDATED ENGINEERING SPECSTwo new engineering specs were added to address issues of the device needing to be sanitizable, as well as not impeding patients by its size.
-The final device will need to either be wipe able, or have removable sleeves that can be washed about once a week.
-The outwards size of the device will need to be minimized so that patients are not impeded or hit the device against something.
SENSOR SELECTION CRITERIA Cost Ease of Use Durability Precision Ease of Attachment to the Rest of the System Size – To Fit Into Attachment Method (Low
Profile)
BENDSHORT FLEX SENSOR
Pros:•Size •Ease of Use
Cons:•Cost•Durability•Precision•Ease of Attachment
INCLINOMETER
Durability Precision Size
Cons:
Pros:
• Cost• Ease of Use• Ease of Attachment
HONEYWELL 785-381L25K POTENTIOMETER
Pros: Cost Ease of Use Precision Ease of Attachment Size
Cons: Durability
BI TECHNOLOGIES POTENTIOMETER
Pros: Ease of Use Durability Precision Ease of Attachment
Cons: Cost Size
HONEYWELL 785-380C3100K POTENTIOMETER (Used as Baseline)
Cost Ease of Use Durability Precision Ease of Attachment
Pros:
Cons: Size
DETAILED SCHEMATIC
ATTACHMENT SELECTION Utilizing the potentiometer sensor, two
arms need to extend from either side of it to measure knee flexion.
Slide a neoprene sleeve up the leg with the device attached to the outside of it.
Typical knee brace with Velcro straps around the upper and lower legs.
Wrapping leg in Ace bandages.
ATTACHMENT SCHEMATIC
Designed to be incorporated into existing knee braces
TEST PLANS Included in packet
Based heavily off of last years test plans (same needs apply for most part)
Includes impact testing on enclosure and maximum torque required to impede motion
HEAD TILT Studying movement of patients with cervical
dystonia
Primarily a research setting
Goal is to see accurate measurement of several movements
Measuring is done by goniometers
UPDATED CUSTOMER NEEDS
Sanitation
Ability to walk around while using the device
UPDATED ENGINEERING SPECS Ability to measure shift of head
Measured in centimeters
Ability to measure while walking Measured as error to expected value
Ability to be sterilized Materials must be able to be cleaned by alcohol
wipes Examination for level of sterilization, not required
SENSOR SELECTION CRITERIA
Cost
Ease of Use
Weight/Size
SENSOR SELECTION
Atomic IMULarge form factor6 degrees of freedomExpensive
Razor Ultra-ThinNo on-board regulation6 degrees of freedom
AccelerometerCan’t measure all directionsNo on-board regulationVery inexpensiveLarge form factor
SENSOR SELECTION
Razor IMU9 degrees of freedomSingle, flat boardOn-board microcontroller
DETAILED SCHEMATIC
SCHEMATIC
ATTACHMENT SELECTION Utilizing the 9DOF sensor, it needs to be
securely held to the top of the head. A second sensor will need to be fastened to the body.
Baseball cap with the sensor box placed on top. Headlamp style strap. Wrestling style head strap.
The body sensor will need to be securely held to the upper chest or back.
ATTACHMENT SCHEMATIC
A head strap will be custom sewn from existing headlamp style straps, with an electronics enclosure box on top housing the sensor package.
TEST PLANSIncluded in packet
Will be based largely off last year’s teams testing methods.
Both the enclosure and the sensor itself have a list of tests to be performed
CONNECTION INTERFACE Arduino Pro Mini (5V) was selected for the
following reasons: Programmable configurations Future expandability Ease of Use Size Cost
http://www.sparkfun.com/commerce/product_info.php?products_id=9218
INTERFACE AGREEMENT Selected USB as top choice
Speed Signal Integrity Universal use
Personal Healthcare USB Device Standardizes protocol for personal healthcare
devices
http://www.tomsguide.com/us/pictures-story/12-USB-peripherals-accessories.html
SCHEMATIC
PROJECT BUDGET
RISK MANAGEMENT UPDATES
PROJECT PLAN UPDATES Updates to the work breakdown structure Critical path:
1. Research sensors2. Select sensors3. Research attachments4. Select attachments5. Design detailed schematics6. Finalize design
QUESTIONS FDA approval? Following standards? How do you think the attachment methods
can be improved? Are the test methods adequate?
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