Electromagnetic ventilation: First evaluation of a new method for artificial ventilation in humans

Abstract

Current methods of artificial ventilation cannot prevent diverse problems associated with mechanical ventilation. In contrast to all current forms of mechanical ventilation, electromagnetic stimulation can activate respiratory muscles directly. However, it is not known if and to what extent electromagnetic stimulation can ventilate humans. In 10 volunteers we stimulated the lateral neck using magnetic stimulators. Over 63 s we stimulated nine times with a frequency of 25 HZ for 1.1 s using 600 V, 900 V, and 1,200 V. The minimum stimulation time for each volunteer was 9 min. A Capnomac monitor measured minute ventilation. Electromagnetic stimulation was well tolerated and safe. Bilateral stimulation with 600 V achieved considerable minute ventilation (median +/- SD, 7.2 +/- 3.4 L/min) that increased at higher voltage levels (P < 0.0001). 900 V achieved sufficient minute ventilation in all volunteers (11.5 +/- 5.0 L/min; 1200 V, 14.0 +/- 4.9 L/min). This first evaluation of electromagnetic ventilation demonstrates that it can be used to ventilate humans sufficiently. This method may be developed to a new mode of ventilation.

Comparing phrenic nerve stimulation using three rapid coils: implications for mechanical ventilation

“…Finally, while Sander et al (14) reported no cardiovascular changes (unspecified), the present study showed an increased BP during RMSBAMPS-ventilation, but without changes in HR. Although the increase in BP did not reach an unsafe level in these young subjects and stimulator-output was likely higher than what would be used in patients, it is still suggested that the cardiovascular system is closely monitored during continuous RMS.…”

“…The mean achieved in the present study was similar to the 14.0L/min by Sander et al . (14) with 25Hz at 40% stimulator-output (two MagStim butterfly coils) in 10 healthy volunteers. Their ventilation, however, surpassed the present when stimulator-output was increased to 50% (18.6L/min), but this increase in stimulator-output resulted in only three participants undergoing ventilation due to a largely increased perception of pain and discomfort, similar to our single-train RMS BAMPS responses with maximal stimulator-output.…”

“…The 10-min limit was a result of our protocol rather than equipment overheating or participant intolerance (all that achieved 10min indicated they could go longer). Thus, with proper coil cooling, it is possible to overcome the 5-min limitation seen by Sander et al (14).…”

“…RMS may therefore serve as an ideal candidate for non-invasive treatment. Sander et al (14) showed that rapid bilateral anterior magnetic phrenic nerve stimulation (RMSBAMPS) can produce strong enough diaphragmatic contractions to induce short-term ventilation in healthy subjects for no longer than 5min due to "technical prerequisites." Adler et al (15) sought to determine the optimal combination of stimulation-frequency and stimulatoroutput for tolerable rapid CMS (RMSCMS) in healthy humans, but they were unable to induce inspiratory flow despite sufficient diaphragm contraction.…”

Treatments to restore respiratory function after spinal cord injury and their implications for regeneration, plasticity and adaptation

“…However, there are some limitations. It has been well established by patient models that diaphragm function alone is not enough to sustain life and quality of life in patients with SCI who also have an impaired ability to augment their inspiratory capacity in response to the hypoxic state: individuals are mechanically ventilated which only allows rhythmic activation of diaphragm contractions (DiMarco 2005, Sander et. al., 2010).…”