Ravi Chacko CEOChase McCaleb CFO

Walker Plash CMOPerry 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, $800-3,000 with

150x more likely to re-injure3

1. Mayo Clinic Online2. JD Hubbell, MD; E Schwartz, MD; http://emedicine.medscape.com/article/89442-overview3. Dunn et al 2004

Reasons for ACL Tears…Planting and cuttingStraight-knee landings

Causing…Hyperextention of the

kneeExcessive inward

rotation

MarketCDC estimates 7.2 million high school

athletes in the U.S.1

Approximately 4 million professional athletes.

Affects anyone involved in:VolleyballBasketballSoccerFootballGymnasticsAnd more

1. CDC: MMWR; September 29, 2006 / 55(38);1037-1040; http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5538a1.htm

Known Risk FactorsPhysiological FactorsHormones, Sex, Leg Dominance, Joint

Laxity/Recurvation

Behavioral FactorsLanding/Jumping

Torso position and resulting stresses on knee

Toe to heel shock absorptionSide Cut

Quad and Hamstring firing patterns

Risk Factors- ZebisMette 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 - LESSLindsay 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

ComponentsEMG

Vastus Lateralis Semitendinosus

2 IMU 6DOF Sensors3 Gyroscopes3 Accelerometers

4 Pressure SensorsAmplifier

NIDAQ & Arduinos

Force Sensor CaptureOriginal Design 2 sensors

Heel and ToeAnkle 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 AnalysisVertical Jump Test (x2)

Toe (red) is used primarily during takeoff1st (cyan) and 5th metatarsal (green) are

used primarily during landing Heel (blue) is kept off the ground

EMG CaptureEKG electrodes placed

at the VL and STGrounded at the

abdomenSystem contains a

circuit for a DC offset so we can view both positive and negative values

EMG AnalysisPurpose: to

capture the difference in average activity (% of max) in the 10 ms prior to cut.

Method:Sync Filter ThresholdRMS

Motion CaptureInertial 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 PlansFinal PrototypeLightweight and wirelessFree movement

This SemesterStay tethered, but clean up wires to increase

mobilityExpand to include multiple testsMultiple test subjects

Development TimelineInterpret data

collected from gyros/accelerometers

Increase mobilityImprove EMG

analysisConnect mechanical

to bioelectric dataCreate GUI for data

collection and analysis

Future Business PlanPhase II: Research and Development

Distribute to athletic teams for data collectionProve that we can actually predict risk factors

Phase III: Initial ReleaseTarget athletic teams, gyms, and physical

therapists.Projected cost of use:

$250 initial startup fee $50 per athlete per analysis

Phase IV: Review and ExpansionUltimately target home users

Thank youKeith YeagerAaron KyleProf. Gordana Vunjak-NovakovicProf. Elizabeth HillmanProf. Paul Sadja

Project AdvisorMatthew Bouchard & Ick BhumiratanaLauren GrosbergJim Gossett

Associate Athletics Director for Sports MedicinePaige Plash

Physical Therapist, COO Encore Rehabilitation

Questions?