A device operates for secretion clearance and cough assistance by means of transdermal stimulation of muscle groups including the pectoralis majoris, the serratus anterior, and the abdominal muscles. The various muscle groups may be stimulated in different ways: not just different pulse trains but in addition, different stimulations to accomplish different phases of clearance or cough assistance. In a first phase a vibration action provided by the muscles (for example the pectoralis and serratus) is used to encourage the motion of mucus and other secretions within airways. In a second phase, the abdominal muscles for example might be stimulated differently so as to cause not a vibration but instead a coughing action, especially to detect and assist a natural cough. The invention further teaches a zone stimulator large enough to span and stimulate major muscles or groups of large muscles effectively.
