Diaphragm and accessory respiratory muscle stimulation using intramuscular electrodes.
We tested the hypothesis that electrical stimulation of respiratory muscles can be obtained from intramuscular electrodes. In acute anesthetized dogs, suture-type intramuscular electrodes were placed in each hemidiaphragm and needle electrodes were placed in various intercostal regions of the thorax. During a hyperventilation induced period of apnea a 2-second stimulation was applied to the diaphragm or to the thoracic electrodes, followed by a combined thoracic-diaphragm stimulation period. Thoracic expansion and tidal volumes were measured as indices of inspiratory effort. We found that diaphragm stimulation produced tidal volumes between 104% and 180% of spontaneous breathing. Electrodes in the upper thorax produced chest expansion and when combined with diaphragm stimulation increased tidal volumes (p < .05). We conclude that intramuscular electrodes represent a feasible method for long-term electrogenic ventilation. Also, thoracic support for diaphragm pacing in quadriplegics could produce a more effective long-term system that is less prone to fatigue and failure.
Dunn
R B
RB
Rehabilitation Research and Development Center, VA Hines Hospital, IL 60141, USA.
Walter
J S
JS
Walsh
J
J
D000818:Animals; D001049:Apnea / Q000503:physiopathology / Q000628:therapy; D004195:Disease Models, Animal; D004285:Dogs; D004558:Electric Stimulation / Q000295:instrumentation*; D004567:Electrodes, Implanted; D005240:Feasibility Studies; D012121:Respiration, Artificial / Q000295:instrumentation; D012132:Respiratory Muscles / Q000502:physiology*; D013990:Tidal Volume