Transcript ACL Prevention - Columbia University

Ravi Chacko CEO
Chase McCaleb CFO
Walker Plash CMO
Perry Yin CTO
George Zhou CRO
ACL Injury Background…
 100,000 -200,000 ruptured per
year1
 60,000-75,000 ACL
reconstructions annually2
 Costs range from $20-50k
without insurance, $8003,000 with
 150x more likely to re-injure3
1. Mayo Clinic Online
2. JD Hubbell, MD; E Schwartz, MD; http://emedicine.medscape.com/article/89442-overview
3. Dunn et al 2004
Reasons for ACL Tears…
 Planting and cutting
 Straight-knee landings
Causing…
 Hyperextention of the knee
 Excessive inward rotation
Market
 CDC estimates 7.2 million high school athletes in
the U.S.1
 Approximately 4 million professional athletes.
 Affects anyone involved in:
 Volleyball
 Basketball
 Soccer
 Football
 Gymnastics
 And more
1. CDC: MMWR; September 29, 2006 / 55(38);1037-1040; http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5538a1.htm
Known Risk Factors
 Physiological Factors
 Hormones, Sex, Leg Dominance, Joint
Laxity/Recurvation
 Behavioral Factors
 Landing/Jumping
 Torso position and resulting stresses on knee
 Toe to heel shock absorption
 Side Cut
 Quad and Hamstring firing patterns
Risk Factors- Zebis
Mette K. Zebis (7/09)
 Found that a
difference in Vastus
Lateralis and
Semitendinosus
firing 10ms before a
side cut led to a
significantly
increased chance for
ACL rupture.
Risk Factors - LESS
Lindsay J. DiStefano (2009)
 Used Landing Error Scoring System (LESS) before and
after training to show that landing errors can be
improved with training.
 Current prototype can capture knee flexion and
displacement
 May Prototype will include a hip component that will
capture trunk flexion
Components
 EMG
 Vastus Lateralis
 Semitendinosus
 2 IMU 6DOF Sensors
 3 Gyroscopes
 3 Accelerometers
 4 Pressure Sensors
 Amplifier
 NIDAQ & Arduinos
Force Sensor Capture
 Original Design 2 sensors
 Heel and Toe
 Ankle pronation and impact time
 1st Prototype 4 Sensors
 1st and 5th metatarsal, heel and big toe
 Time of impact, ankle and foot pronation
Force Sensor Analysis
 Vertical Jump Test (x2)
 Toe (red) is used primarily during takeoff
 1st (cyan) and 5th metatarsal (green) are used
primarily during landing
 Heel (blue) is kept off the ground
EMG Capture
 EKG electrodes placed at the
VL and ST
 Grounded at the abdomen
 System contains a circuit for a
DC offset so we can view both
positive and negative values
EMG Analysis
 Purpose: to capture
the difference in
average activity (%
of max) in the 10 ms
prior to cut.
 Method:
 Sync
 Filter
 Threshold
 RMS
Motion Capture
 Inertial Measurement Units (IMU) consist
of 4 perpendicular accelerometers and 4
perpendicular gyroscopes
 IMUs attached to brace at the calf and
thigh
 Record linear acceleration and rotational
velocity, each in 3 dimensions at each point
Motion Capture Analysis
Motion Capture Analysis
Side Cut
Side Cut
Future Plans
Final Prototype
 Lightweight and wireless
 Free movement
This Semester
 Stay tethered, but clean up wires to increase mobility
 Expand to include multiple tests
 Multiple test subjects
Development Timeline
 Interpret data collected
from gyros/accelerometers
 Increase mobility
 Improve EMG analysis
 Connect mechanical to
bioelectric data
 Create GUI for data
collection and analysis
Future Business Plan
 Phase II: Research and Development
 Distribute to athletic teams for data collection
 Prove that we can actually predict risk factors
 Phase III: Initial Release
 Target athletic teams, gyms, and physical therapists.
 Projected cost of use:


$250 initial startup fee
$50 per athlete per analysis
 Phase IV: Review and Expansion
 Ultimately target home users
Thank you
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Keith Yeager
Aaron Kyle
Prof. Gordana Vunjak-Novakovic
Prof. Elizabeth Hillman
Prof. Paul Sadja
 Project Advisor
 Matthew Bouchard & Ick Bhumiratana
 Lauren Grosberg
 Jim Gossett
 Associate Athletics Director for Sports Medicine
 Paige Plash
 Physical Therapist, COO Encore Rehabilitation
Questions?