Functional and Biological Test of a 20 Channel Implantable Stimulator in Sheep in View of Functional Electrical Stimulation Walking for Spinal Cord Injured Persons

: A newly developed implantable stimulator with 20 output channels, mainly intended for the stimulation of lower extremities in paraplegics, was implanted in 6 sheep over a time period of 26 weeks. Five epineural electrodes each were used to contact various nerves at different locations to elicit hi...

Full description

Saved in:
Bibliographic Details
Published in:Artificial organs 2001-06, Vol.25 (6), p.467-474
Main Authors: Bijak, Manfred, Mayr, Winfried, Girsch, Werner, Lanmüller, Hermann, Unger, Ewald, Stöhr, Hans, Thoma, Herwig, Plenk Jr, Hanns
Format: Article
Language:English
Subjects:
Animal experiments
Animals
Electric Stimulation Therapy - instrumentation
Electrodes
Implantable stimulator
Leg - physiology
Lower extremities
Muscle, Skeletal - physiology
Selectivity
Sheep
Spinal Cord Injuries - physiopathology
Spinal Cord Injuries - therapy
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:: A newly developed implantable stimulator with 20 output channels, mainly intended for the stimulation of lower extremities in paraplegics, was implanted in 6 sheep over a time period of 26 weeks. Five epineural electrodes each were used to contact various nerves at different locations to elicit hip and knee extension and flexion and to make carrousel and selective stimulation possible. Different electrode application strategies in view of paraplegic standing and walking were investigated. Additional implanted electrodes allowed M‐wave monitoring for selectivity investigations in 3 sheep. Stimulator, electrode leads, and electrodes proved to be reliable. Selective stimulation with electrodes placed on the trunk of the sciatic nerve could be demonstrated but with bad reproducibility. Histological investigation of the tissues surrounding electrodes and leads showed the expected stable foreign body response. Strong hip and knee extension could be gained in all cases while only weak flexion forces could be elicited in most cases. Muscle biopsies showed that daily stimulation for 8 h at threshold level caused an increase in muscle Type I fibers and a decrease in Type IIc fibers. Implants and electrodes fulfill the most important functional and biological criteria for their clinical application for paraplegic walking. The intention to provide selective flexion functions via epineural stimulation could not be demonstrated sufficiently in this animal model.
ISSN:0160-564X
1525-1594
DOI:10.1046/j.1525-1594.2001.025006467.x