Lower Extremity Functional Electrical Stimulation

Lower extremity functional electrical stimulation is a type of neuromuscular electrical stimulation in which long-term embedded prosthetics electrically generate the same neural signals the brain would normally use to control the muscles in a person's legs, and transmit them into the trunk nerves heading into those muscles.

This type of Functional Electrical Stimulation (FES) is used when the spinal cord or a major trunk nerve in the leg has been severed. The resulting paralysis renders the limb non-functional even though there is nothing wrong with the muscles. As the brain's own signals cannot get through, they must be artificially generated instead.

In cases of severe damage, the severed nerves are highly unlikely to reconnect, and so an implant is placed into the affected nerve bundles just after the break. Its job is to use electrode arrays to transmit the neural codes – the brain's equivalent of function calls to control the muscles of the body – into these bundles, and restore function.

The opposite number of FES or a procedure known as TMR or Targeted Muscle Re-enervation. This process uses a similar electrode array setup to read the neural codes as they transmit down the nerve bundle, by picking up minute changes in the electrical activity of the muscles they are embedded in.

In an ideal situation, a lower extremity functional electrical stimulation prosthetic would have both parts: TMR before the damaged area, to detect what signals the brain is trying to send, and FES after the damaged area to relay those signals back into the target muscles. In theory this setup could render nerve damage invisible, bypassing the damaged area completely.

In practice, both TMR and FES are presently inexact sciences, with the current impossibility of directly tapping into every individual neuron in the bundle directly, and the multitude of neural codes whose full effects remain unknown to us.

Work is continually proceeding to address both issues, however for the moment, a lower extremity FES prosthetic is typically controlled by a control console operated by the patient's hands. Different controls thus ordering their own legs to begin specific preset series of muscle movements. This allows the individual to perform tasks such as walking, climbing stairs, descending stairs, standing up and sitting down. This type of interface does not allow much in the way of individual customisation or spontaneous action, still it prevents the muscles in the legs from atrophying due to disuse and gives the individual back some degree of independence.

See Also: NMES, Neural Coding, TMR, BMI

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Lower Extremity Functional Electrical Stimulation

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Home Stroke Rehabilitation ? 2014?

Its early 2009, and the University of Southampton, in the UK, is developing electrical stimulation technology, designed to help stroke patients relearn movement, by duplicating the natural, original nerve impulses. The technology is a direct offshoot of work to decode the electrical signals of the peripheral nervous system.

Prosthetics and Orthotics: Lower Limb and Spine

This book is predominately a medical textbook, designed for students. However, it is a heavily illustrated tome, with detailed diagrams and explanations of lower body prosthetics lavishly slapped over a great many of its pages. It looks at when prosthetics might be necessary, and how they would be integrated into the body.

VR Interfaces: Vivid Cyber Sex Suit

A mis-fire in the teledildonics industry, this early attempt at sexual stimulation in VR fell short after it was discovered it had a minor side effect - bodily secretions caused a lethal electrical discharge.

Self-Charging Power Cell converts Mechanical Energy into Stored Chemical Energy
A different paradigm in power generation for implants and prosthetics, combines electrical generation and storage in a single thin three-layer flexible ribbon. Piezoelectric in nature, it builds long-term storage into the electrical ggeneration process. No other battery or powersource required.

Bypassing the Uncanny Valley with Hands
In August 2008, the first hand and forearm pairing was achieved which realistically bypasses the uncanny valley for the lower arm, and allows completely realistic movement of the wrist and hand.

MUD Pies: Part 2
Part two of this series takes you through everything you need, to turn your initial code into a functional chat server ? the bare-bones basics for any world.

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