Design Problem

Knee related injuries: • Most common sports-career ending

injury

Post-ACL Surgery: • Pain, scar tissue, muscle atrophy,

decreased proprioception

Physical therapy: • Important for full recovery

Problem

Difficult and expensive to restore injured

knee to pre-injury functionality.

http://www.leefalin.com/wp-images/acl.jpg

Background & Demographics

Background

• The average cost of ACL reconstruction ~$11,500

• Total cost of recovery ~ $30,000

• Recovery time can be up to 6 months

• Out-patient physical therapy 1-2 visits/week• Check progress, review and modify program

• Patient Overexertion/Non-Compliance• Poor results• Re-injury

http://tinyurl.com/3dzgqt

Jerry Rice

Rice's 2nd Knee InjuryEnds a Lost Season

The New York Times

Rice's 2nd Knee InjuryEnds a Lost Season

The New York Times

MethodProvide an suitable exercise regimen coupled with sensors to:

• Display physiological measurements for real-time biofeedback• Record these signals for later evaluation by health care

providers

Design Brief

SolutionDevelop an integrated exercise

device for a more autonomous rehabilitation.

Basic Principles

• 6-8 weeks• Control swelling• Regain R.O.M., muscle strength• PT visits few times per week• Exercise 30-60 minutes per day

• 2-4 months• Stability and balance training• Less frequent PT sessions• Weight machines, exercise bicycles or treadmills

• Several months• Full R.O.M.• Normal muscle strength, no swelling• Continue stability, balance and strength training

Phase 1 Phase 2 Phase 3

General Rehab Process

http://tinyurl.com/2gxw2l

Target Muscle Groups Rehabilitation Metrics

• Qualitative assessment• Cincinnati Knee Rating System • QOL Questionnaire for ACL Deficiency• Manual manipulation

• Quantitative assessment • Surface/Needle EMG• Range of Motion• Volume of exercise

http://www.orthoassociates.com/ACL_Rehab_protocol.htm

Delsys Myomonitor®

Competing Products

Biodex System 4®

Reliability & Accuracy• Must collect EMG data reliably and accurately enough to distinguish

between a functioning knee and a sub-functioning knee

Usability• Must be intuitive, accessible, and attractive to use

Simple User Interface• User interface/data output must be easy to understand and analyze by

both the user and the professional

Cost • Must not be prohibitively expensive - $5000 or less to build / $10,000 or

less to purchase (to be subsidized by insurance company)

Business Model• Initially sold to physical therapy facilities or doctor’s offices, possibly rented

out for home use• Potential for partnership with an exercise equipment company• Disposables - Electrodes

Constraints & Specifications

Components

Exercise equipment

Sensors

Display

Data transfer

Bike EllipticalLeg press

Surface EMG Goniometer Knee cuff

Exercise data

Waist pack

Muscle firing (EMG)

Bluetooth

Idea 1

Components• Elliptical trainer• Surface EMG• Bluetooth

Targeted Muscles• Calves• Gluteal• Hamstrings• Quadriceps

Partial-weight bearing• Lower joint loading

Drawbacks• Less common

ORTHOMETRICSSmart Elliptical Trainer 2007®

Idea 2

*Serrão F, et al. “Effect of tibia rotation on the electromyographical activity of the vastus medialis oblique and vastus lateralis longus muscles during isometric leg press.” Physical Therapy in Sport. 6(1) 15-23 (2005).

Components• Leg press• Surface EMG• Goniometry • Bluetooth/Wifi

Targeted Muscles• Quadriceps• Gluteus Maximus• Hamstrings

Physical Therapy • Phase II and later• Drawbacks*

ORTHOMETRICSLeg Press Trainer 2007®

Idea 3

ORTHOMETRICSBike Trainer 2007®

surface EMG electrodesurface EMG electrode

user interfaceuser interface

Idea 3

ORTHOMETRICSBike Trainer 2007®

bluetooth/wifi antennabluetooth/wifi antenna

Exercise equipmentExercise equipment

Summary

BiosensorsBiosensors

Data processingData processing

User friendly efficientguided

rehab program

User friendly efficientguided

rehab program

Dr. William MacaulayOrthopedic Surgeon, Columbia University Medical CenterDirector of Center for Hip and Knee Replacement

Dr. Ranjan GuptaDepartment Chair of Orthopaedic Surgery, UC Irvine Professor of Orthopaedics, Anatomy & Neurobiology, and

BME

James GossettAssociate Athletic Director, Columbia University

Dr. Evan JohnsonDirector of Physical Therapy at the Spine CenterAdministrative Director of the Spine Center

Julianne CostaOccupational Therapist RegisteredPhysical Therapist

Dr. Tim WrightOrthopaedic Biomechanics and Biomaterials Hospital of Special Surgery

Thank You

Dr. Clark HungAssociate Professor of Biomedical

Engineering

Dr. Elizabeth HillmanAssistant Professor of Biomedical

Engineering

Keith YeagerSenior Staff Associate, Laboratory

Manager