Changes in Regional Lung Ventilation Following Mechanical Insufflation-Exsufflation

"Patients will be set up onto their Non Invasive Ventilator and assessed for an hour prior to, during and following secretion clearance and will have the following assessed:~* Electrical impedance tomography (EIT)~* EMGpara~* SpO2~* tcCO2~* Respiratory inductance plethysmography~* EIT will be performed as 2 to 10-minutes recording of quiet breathing before and after each intervention~Interventions will be set as follows with a 30 minute washout period between modes:~* Manual techniques only~* MIE at low pressure (+30 to -30)~* MIE at high pressure (+60 to -60)"

"Patients will be set up onto their Non Invasive Ventilator and assessed for an hour prior to, during and following secretion clearance and will have the following assessed:~* Electrical impedance tomography (EIT)~* EMGpara~* SpO2~* tcCO2~* Respiratory inductance plethysmography~* EIT will be performed as 2 to 10-minutes recording of quiet breathing before and after each intervention~Interventions will be set as follows with a 30 minute washout period between modes:~* Manual techniques only~* MIE at low pressure (+30 to -30)~* MIE at high pressure (+60 to -60)"