This document discusses various orthotic and rehabilitation devices including: 1. Adjustable ankle-foot orthoses (AFOs) that can correct for plantar flexion and provide knee stability. 2. Powered gait orthoses that use hydraulic or electric actuation to power hip and knee joints during walking, though early designs were bulky. 3. Functional electrical stimulation (FES) technologies like BION microstimulators that can be implanted to reanimate paralyzed muscles through electrical pulses controlled externally.

1. Wednesday, November 18Orthoses : passive, poweredHand movers Ankle rehabilitatorsWalking Lab

3. AFO adjustable for PF correctionDAAJ

4. Knee stability in an AFO Standard MetalAFO: 375 in. lbs.60% reductionIn Quad torque

5. Types of ankle bracing

6. More types

7. Powered Gait OrthosesHydraulic Actuation (Seireg et al 1981)Five DOFs (2 at hip, 1 at knee, 2 at ankle)Good and simple design and analysisBulky and unusable because of the current state of technologylinear DC motor (Ruthenberg et al 1997) 4 bar linkage and CAM systemOne DOF run by a Battery pack and control system Mechanized hip and knee with cam-modulated linkage for knee functionPeak power usage ~ human walkingMay be a practical means for paraplegic gait?

8. Powered anklehttp://www.ossur.com/prostheticshttp://www.ossur.com/bionictechnology/propriofoot

9. Functional Electrical StimulationCan re-animate paralyzed musclesExternal or internal electrodesUser triggered with switches. How else?Most are open loop, but reflexes not necessary for rhythmic motions. Problem because cutaneous nerves are stimulated first. Also larger motoneurons have lower threshold.

10. Functional Arm OrthosesSee also pp. 319 yellow

11. FES

12. Correcting muscle AtrophyAtrophy is the loss of muscle mass Present methods for preventing atrophy Myoplasty Myodesis Implantable devicesContinuation of Class 5 on muscles

13. Elasticity (All or none)Time scale

14. Muscle adaptationTwo types : fast and slowor twitch and tonicwhite and redInterchangeableFibers extend full length of muscle

15. Bion (Loeb et al.) BIONs are individually addressable, single channel stimulators that can be injected in or near muscles and nerves to treat paralysis, spasticity and other neurological dysfunctions. BIONs receive power and digital commands from an externally worn RF transmitter coil and generate precisely timed, current-regulated electrical stimulus pulses.

16. System for functional electrical stimulationNon-polarizableHigh surface areaPrototypes of Bion2 have sensing capability for acceleration, & proximity. Galvani discovery of electricity

17. The BION™A system using BIONs consists of a personal computer, a transduction coil, and the associated implantable BIONsA computer can control up to 256 BIONs at a timeWhat are present uses for the BION?560 KHz carrier, need 20 Hz stimE Storage in body’s capacitance

18. Flow Charts of BION OperationImplantable Device

19. Comparison of Std. FES and the BION™ SystemSimilaritiesBoth use magnetic fields to activate the implants

20. Both are used to stimulate muscle contractionDifferencesImplantable FESBION™ Not battery powered

21. External computer controls BION™ activationBattery PoweredSwitch to turn power on or off

22. Idea for Bion in Preventing Atrophy Currently bions are controlled by an outside source, the personal trainerGoal would be to have the body control the computer that controls the bions.The trick would be creating a component that would be able to sense/detect an action potential along the severed nerve and use that signal to activate the bions.

23. Some ApplicationsShoulder Subluxation

24. Hand assist devices

25. Without a gloveMay be difficult for a paralytic hand to don.

27. Ankle ExercisorDrop foot is due to central paralysis; injury, I.e. PTT; osteoarthritis; Charcot foot.

28. Range of Motion Ankle RehabilitatorAn inverted joystick interface to computer.