7. Powered Gait Orthoses Hydraulic Actuation (Seireg et al 1981) Five DOFs (2 at hip, 1 at knee, 2 at ankle) Good and simple design and analysis Bulky and unusable because of the current state of technology linear DC motor (Ruthenberg et al 1997) 4 bar linkage and CAM system One DOF run by a Battery pack and control system Mechanized hip and knee with cam-modulated linkage for knee function Peak power usage ~ human walking May be a practical means for paraplegic gait?
9. Functional Electrical Stimulation Can re-animate paralyzed muscles External or internal electrodes User 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.
12. Correcting muscle Atrophy Atrophy is the loss of muscle mass Present methods for preventing atrophy Myoplasty Myodesis Implantable devices Continuation of Class 5 on muscles
14. Muscle adaptation Two types : fast and slow or twitch and tonic white and red Interchangeable Fibers 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 stimulation Non-polarizable High surface area Prototypes 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 BIONs A computer can control up to 256 BIONs at a time What are present uses for the BION? 560 KHz carrier, need 20 Hz stim E Storage in body’s capacitance
22. Idea for Bion in Preventing Atrophy Currently bions are controlled by an outside source, the personal trainer Goal 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.
