Functional magnetic stimulation of expiratory muscles: a noninvasive and new method for restoring cough. J. Appl. Physiol. 84(4): 1144-1150, 1998.-The purpose of this study was to assess the effectiveness of functional magnetic stimulation (FMS) for producing expiratory function in normal human subjects. Twelve able-bodied normal subjects were recruited for this study. FMS of the expiratory muscles was performed by using a magnetic stimulator and placing the magnetic coil along the lower

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... c spine. Results showed that peak expired pressure, volume, and flow rate generated by FMS at the end of normal inspiration (102.5 Ϯ 13.62 cmH 2 O, 1.6 Ϯ 0.16 liters, and 4.8 Ϯ 0.35 l/s, respectively) were comparable to their voluntary maximal levels (P Ͼ 0.1). The optimal coil placement was between T7 and T11, and the optimal stimulation parameters were a frequency of 25 Hz and 70-80% of maximal intensity. We conclude that 1) FMS of the lower thoracic nerves in normal subjects resulted in a significant expiratory function comparable to their voluntary maximum; 2) FMS was noninvasive and was well tolerated by all subjects; and 3) FMS may be useful to produce cough in patients in critical care or perioperative settings, or in patients with neurological disorders.