Motion Tracking Technology Evaluation 1Motion Tracking Technology Evaluation

Motion Tracking Technology Evaluation

1Motion Tracking Technology Evaluation

David Monahan- Project Manager (ME)Brian Glod- Data Lead (CE)Assis Ngolo – Communication Lead (CE) Jahanavi Gauthaman- Sensor Technology

Lead (EE)Cory Laudenslager- Sensor- MCU Interface

Lead (EE) James Stern- Sensor- Human Interface Lead

(ME)Motion Tracking Technology Evaluation 2

Motion Tracking Technology Evaluation 3

Research Clinic: Dr. Sara Gombatto Lower back pain: Lumbar area

Neuro Clinic: Dr. JJ Mowder- Tinney Rehabilitation: Limbs

Desire for a portable motion tracking device has long been expressed P08006


• Measured patient’s angles of the hip, knee, and ankle joints, as well as track progression of gait

• Utilized Gyroscopes with mixed results▪ Outputted pattern of motion but not angle measurements▪ Erratic if more than 1 cycle performed▪ Ultimately never given to Nazareth

• Lessons Learned: ▪ Pattern-Recognition Algorithm▪ Low Pass Filters▪ Faster Sampling Rate▪ Two-Leg System ▪ Need for separate Human Interface team


Proposed projects for Winter-Spring 2009: P10009: Portable Spinal Motion Tracker P10010: Portable Limb Motion Tracker P10011: Motion Tracking Human Interface

Due to resource allocation and technical challenges: Motion Tracking teams were combined Shift of focus: More research-oriented


Nazareth College Physical Therapy Clinic Currently Uses an optical Motion Tracking System.

Video of Vicon Motion Tracking System Optical Cameras pick up Reflective points

placed on patient. Necessary for patient to be in clinic for

testing. Expensive. Give Doctor large amounts of data over a

small amount of time.Motion Tracking Technology Evaluation 7

http://www.youtube.com/watch?v=sA3Kkq9kEiM&feature=player_embedded


The primary ranges of motion of interest: Motion of a human limb, where a limb is defined as a 3-bar linkage, for example: upper leg, lower leg, and foot.

Motion of a human's lower back, where lower back is defined as the lumbar region, with 3 points of contact: sacrum, L1-L2, L3-L5.


Design concepts ranked according to customer needs for use by future MSD projects.

Analysis of possible solutions for: Sensors, MCUs, ICs, circuitry, communication devices.

Work with P10011 to research compatible enclosures for the system.

Testing methods/ fixtures to test future systems.

Test several prototype sensors and systems (MSDII)


Sanitary Portable Comfortable Durable Accurate Provide reasonable Ease of Use Test Methods should

Numerically Validate Results [Refer to: P10010PDF, Page 4]



CUSTOMER

Specification Number

Customer Need

Design Specification Importance Unit of Measure Marginal Value Ideal ValueMarginal

ValueIdeal Value

1 CN14 Accuracy of Angles High Degrees ±10 ±1 ±2 ±1

2 CN16 Range of Angles High Degrees 270 360 90 180

3 CN6 Size of Sensor Medium mm x mm x mm 60x60x30 30x30x15 60x60x30 30x30x15

4 CN13 Degrees of Freedom Medium Axis 1 3 1 3

5 CN23 Size of Data Storage High GB 3 5

6 CN15 Sampling Frequency High Hz 100 100

7 CN3 Input Voltage High V 9 9

8 CN6 Range of Data Transmission High Ft 2 5

9 CN7 Weight of Data Logger/Micro Controller High kg 1 <.5 Cell Phone Wt

10 CN21 Set-up Time Low Minutes 20 10 30 10

11 CN3 Battery Life of the system High Hours 12 24 6 12

12 CN7 Weight of Sensors High g 20 10

13 CN5 Time to transfer data from device to computer Low Minutes 5 3 15 5

14 CN19 Angles are displayed for user High N/A text box C3D Format text box C3D Format

15 CN19 Comparison of Data High N/A text box C3D Format text box C3D Format

16 Wirefree Solution Medium N/A Wired Wireless Wired Wireless

17 CN7 Comfortablility of Sensors on Person High Subjective Yes Yes

18 CN28 Attachment Safety High Subjective Patient is Safe Patient is Safe

19 CN28 Patient Safety High Subjective Patient is Safe Patient is Safe

20 Budget High Dollars 1000 1000

P10010 Motion Tracking Systems 14

Human Interface(P10011

)

SensorsInterfac

e Circuitry

Microcontroller Unit

Communications Interface

Analog-Digital

Conversion

Active Filtering

Instr. Amplifier

Buffering

Storage Interface

[www.serverlab.net]

[www.laptoping.com]

- 360 Degree Orientation - Integrated 3D Gyroscopes,

Accelerometers and Magnetometers

- On board DSP with real-time sensor fusion algorithm

- Gyroscopes enable high-frequencyorientation tracking

- Individually calibrated for temperature,

- 3D misalignment and sensorcross-sensitivity

- Accepts and generates synchronization pulses

-Very Bulky and Heavy-Very Expensive…Cost:

$2500.00 15Motion Tracking Technology Evaluation

[http://www.xsens.com/images/stories/products/PDF_Brochures/mti%20leaflet%2009.pdf]

-6 DOF -10 Bit ADC on

Board -Operating voltage

3.4V to 10V (onboard regulator)

-Uses MMA7260Q accelerometer

-Draws 24mA -Cost: $124.95


http://www.sparkfun.com/commerce/product_info.php?products_id=9184

- Low Current Consumption: 500 μA

-Sleep Mode: 3 μA -Low Voltage Operation:

2.2 V -3.6 V -6mm x 6mm x 1.45mm -High Sensitivity (800

mV/g @1.5 g) -Fast Turn On Time -Integral Signal

Conditioning with Low Pass Filter

-Robust Design, High Shocks Survivability

-Cost: $11.8017Motion Tracking Technology Evaluation

http://www.freescale.com/files/abstract/event/MMA7260QPK.html?tid=tslp

-Triple axis ±2g sense range

-Up to 720mV/g sensitivity

-Operating voltage 3.5V to 15V (onboard regulator)

-3.3V regulator can power external microcontroller

-Output short protected -Standard DIP-16 form

factor -Draws 0.9mA -Cost: $36.50


http://www.dimensionengineering.com/datasheets/DE-ACCM3D2.pdf

-Low Voltage Operation: 5V Regulated

- Highly Accurate/High Sensitity

-Rated Analog Output -Self Test For Both

Sensors -25mm x 20mm x

2mm -Cost: $125.00


http://www.sparkfun.com/datasheets/Accelerometers/IMU_Combo_Board-v2.pdf

- 2.16 V to 3.6 V supply voltage

- <1 mW power consumption

- ± 2g/± 8g dynamically selectable full-scale

- I2C/SPI digital output interface

- Embedded high pass filter

- 10000g high shock survivability

- Cost: $9.3020Motion Tracking Technology Evaluation

http://sites.google.com/site/hardwaremonkey/lis302dlaccelerometer

- 1 DOF (Elbow/Knee Joint)

-Variable Lengths Available

-Light Weight -Robust Design (> 1

Million Life Cycles) -Easy To Correlate

to Relative Angle -Very Inexpensive -Cost: $11.95


http://itp.nyu.edu/physcomp/sensors/Reports/Flex


CONCEPT SELECTION-SENSOR TECHNOLOGY

Sensor/Micro Chip Sensor Combo Board Sensor

Model Units Atomic SEN-

09184MMA7260

QSEN-

08606(Flex) LIS302DL DE-ACCM3D2IMU

ADXL203/ADXR5614Min Input

Voltage Volts 3.4 2.2 5 2.1 3.5 5Max Input

Votlage Volts 10 3.6 12 3.6 15 5

Current Draw mA 24 .5 N/A .4 .9 N/ADegrees of Freedom Degrees 6 3 1 3 3 3

Interface UART Analog Analog Digital Analog Analog

Angle Range Degrees 0-180 0-180 0-180 0-180 0-180 0-180

Sensitivty mV/g N/A 800 N/A N/A 600 1000

Operating Temp °C N/A -20-85 -35-80 -40-85 -40-85 -40-85

Dimensions mm 47X37X25 6X6X1.45 5inX.28X.1 3X5X1 10X21X8 25X20.4X2

Weight g Approx 15 .5 0.5 .5 2 2

Sampling rate Hz 350-150 NONE Resistance CLK N/A N/A

Wired/Wireless Wired/Wireless Wired Wired Wired Wired Wired

Price $ 125 11.8 11.95 9.30 36.50 125

Link LINK LINK LINK LINK LINK LINK

http://www.sparkfun.com/commerce/product_info.php?products_id=9184

http://www.sparkfun.com/datasheets/Accelerometers/MMA7260Q-Rev1.pdf

http://itp.nyu.edu/physcomp/sensors/Reports/Flex

http://www.st.com/stonline/products/literature/ds/12726.pdf

http://www.dimensionengineering.com/datasheets/DE-ACCM3D2.pdf

http://www.sparkfun.com/datasheets/Accelerometers/IMU_Combo_Board-v2.pdf

P10010 Motion Tracking Systems 23

[TI AppNote SLOA058]

[TI AppNote SLOA058]

[The Art of Electronics, 2nd Ed.]

Size: 2.60” x 3.65” x 0.45” Power consumption

<20mA at 7.4 MHz <100µA sleep mode

ADC inputs Differential mode

▪ 4 channels▪ 12-bit (9-bit accuracy)

Single-ended▪ 8 channels▪ 11-bit (8-bit accuracy)

Up to 200 samples/sec Flash: 512K SRAM: 512K Digital inputs: 16 Digital outputs: 10 Cost: $199 for board;

$399 for starter kit

LP3500[www.rabbit.com]

RCM3900[www.rabbit.com]

SD or microSD Raw data – initial FAT Filesystem – time permitting

C3D File Format [www.c3d.org]

Main Sections▪ Header▪ Parameters▪ 3D data

Binary, not ASCII Coordinate data To be interpreted by C-

Motion Visual3D software

[www.c-motion.com]

[http://www.digitalmobile.co.nz]

MSP430FG47x by TI is optimized for portable medical applications and features 48 I/O pins



-The MSP430 has an SPI interface

- Allows communication to an MMC or SD card.

- Serial data is transmitted to MSP430 using USART module in SPI mode.

Customer requirement: transfer 1 GB in 5 – 15 minutes

Bluetooth 2.1 + EDR Maximum theoretical throughput: 3 Mbit/s Maximum transfer time = (1 GB) / (3 Mbit/s) ≈ 45

mins▪ Does not meet requirements!

USB 2.0 Maximum theoretical throughput: 480 Mbit/s

▪ In reality, closer to 40-80 Mbit/s

Assuming 40 Mbit/s, transfer time ≈ 3.5 mins

Assume: 6 sensors, 3 analog signals each (X, Y, Z axes) Sample rate: 60 Hz 10-bit ADC 24-hour constant data collection

▪ Customer only requires 12 hours 120 Mbytes Increase to 16-bit ADC = 190 Mbyte 12 sensors , 16-bit ADC = 375 Mbyte 24 sensors, 16-bit ADC = 750 Mbyte Result: standard 1-GB, 2-GB, 4-GB SD cards

will be more than adequate for data storage

Sanitary Regulations: Biomedical Engineering Society FDA has tons of restrictions

It appears that products for physical therapy devices usually fall under the Consumer Product Safety Commission (CPSC)

Sara has expressed that we don't need to directly concern ourselves with FDA regulations and such, however, it appears that many enclosures on the market are designed for medical applications- may be a good idea to kill 2 birds with 1 stone


Some already in use motion tracking devices are strapped on the subject externally.

Another aspect to look at is the application of the sensor to the patient. Like previously mentioned most current models use straps. But Dr. G. asked us to apply the sensor directly to the skin of the patient with some type of adhesive.

[Source: http://www.xsens.com]


Xsens has created full body suits to completely cover the sensors. This would make the risk of sensors being knocked off less likely.

This aspect of enclosures would fall under the Human Interface Team P10011.

[Source: http://www.xsens.com]


The sensors themselves are usually enclosed in a box like structure.

[Source: http://www.xsens.com] Sensor enclosures on the market come in various

sizes based on the chip set inside. For our project the smaller the better. With smaller sensors and enclosures it will create less discomfort for the patient.


More R&D than concept selection due to customer’s desired model

Goals: Identify typical human ranges of motion Identify ideal placement of sensors

Current concern: Lumbar Kinematics Placement of sensors? Multiple sensors? Size restrictions? Accuracy v. Comfort?

Model of the Human Spine Desired: 3 points of interest

▪ Sacrum▪ L4-L5▪ L1-L2-L3

Need effective placement▪ Counter skin movement▪ Correct for curvature of spine▪ Correct for curvature of back

“Lumbar region angle was defined as the relative angle between the lumbar region segment and the superior-inferior (z) axis of a local pelvic coordinate system”

All information from: Gombatto SP et al 2008

Lordosis: Curvature of spineAdjustable plastic wedges utilized by

Van Herp, Rowe, Salter..

Model: Spinal triangles Three 3DOF sensors

per point of interest Translation:

Added sensors = complexity of system

Added bulk = complicates comfort of patient

Plan up to week 11Emphasis on Customer needsTasks assigned through WBSWeekly risk assessmentPreparation for MSD II

[Refer to: P10010 PDF, page 9]




Motion Tracking Technology Evaluation 41[Refer to: P10010 PDF, page 16]






What to expect in Detailed Design Review (Week 11):

Feasibility Analysis for possible systems

Testing Methods Ordering parts before MSDII (BOM) Detailed architectural design

(schematics, datasheets, design concepts)

More Market EvaluationMotion Tracking Technology Evaluation 45

Questions? Ideas? Concerns?

[Source: http://mossrivers.com/images/GyroscopeC.jpg]


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Motion Tracking Technology Evaluation 1Motion Tracking Technology Evaluation