Patients will be implanted with 4 intramuscular electrodes, 2 in each hemi-diaphragm, using laparoscopic techniques.

The abdominal cavity is inflated with CO2 and 4 ports are inserted: one for optics, 2 for a probe containing a temporary electrode for mapping the diaphragm and the electrode insertion tool, and a smaller one for the output wires of the electrodes of the abdominal cavity. The intra-abdominal pressure variation during the stimulation test (mapping) will be measured externally by one of the ports.

Sites that provide the optimal response (greater region and magnitude) are noted.

Once the optimal site for electrode placement is identified two intramuscular electrodes are deployed in each hemi-diaphragm. The guide wires will come out of the peritoneum through the port placed in the xiphoid region. An additional electrode is placed subcutaneously in the upper abdomen. The instruments and ports are then removed and the incision sites closed.

The ability of the NeuRx RA / 4 to obtain clinically acceptable tidal volume during a period of 4 continuous hours will be evaluated by spirometry. Clinically acceptable volume is defined as a volume in excess of 15% above the basal metabolic requirements of the particular patient. For a male patient, the flow volume to meet the basal metabolic requirement is set at 7 ml/kg body weight, while for a female patient, it is defined in 6ml/Kg body weight.

Using spreadsheets to patients and caregivers, will collect information related to the use of the device, such as total usage time, the preference to use it both day and night instead of a mechanical ventilator, or to use it partial time to perform any activity or acquire independence that would otherwise be difficult with mechanical ventilation.