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Abdominal FES to assist ventilator weaning

At Anatomical Concepts we view FES (Functional Electrical Stimulation) as a very powerful and flexible tool for rehabilitation. We have used it in some ways that you may not have thought of and this article is to alert you to a recent paper using FES to assist tetraplegic patients to wean from a mechanical ventilator. The application uses a RehaStim 1 unit from our partners Hasomed GmbH to both process signals from the user as well as trigger stimulation of the abdominal muscles.

A system diagram with the RehaStim 1 FES Unit from Hasomed GmbH

An injury to the cervical region of the spinal cord can cause paralysis affecting all four limbs and the trunk, termed tetraplegia.  People with tetraplegia have paralysis and impaired function of the major respiratory muscles, namely the diaphragm and the intercostal and abdominal muscles. This reduces respiratory function, resulting in up to 40% of these individuals requiring mechanical ventilation in the acute stage of injury.  While approximately 75% of these patients will wean from mechanical ventilation, its use is associated with increased likelihood of respiratory infection and a three and a half fold increase in mortality rate compared to the general spinal cord injured population.  Ventilator dependence also reduces quality of life, delays rehabilitation and increases costs for the local health care provider (by approximately $1500 per day). Any improvement in respiratory function that reduces the time dependent on mechanical ventilation will have numerous benefits.

Electrode placement for AFES

The authors (see below) applied Abdominal FES for 20 to 40 minutes per day for 5 days per week with a group of 10 acute ventilator dependent tetraplegic patients. The results show very high compliance and an average of 11 days less on the ventilator compared with a control group.

The RehaStim 1 unit is popular with researchers due to its flexibility for control purposes and fast response.

You can read and download the paper from this link

"Abdominal Functional Electrical Stimulation to Assist Ventilator Weaning in Acute Tetraplegia: A Cohort Study"
Euan J. McCaughley, Helen R. Berry, Alan N. McLean, David B. Allan, Henrik Gollee
PLoS ONE 10(6): e0128589. doi:10.1371/journal.pone.0128589