This study will be conducted as a pilot trial of the TransAeris system for the prevention and treatment of ventilator-induced diaphragm dysfunction (VIDD) in patients identified prior to surgery to be at greater risk of prolonged mechanical ventilation (PMV).

This pilot study is an open label observational study in adult open cardiac surgery patients. Eligible patients from whom informed consent is obtained and electrodes are successfully implanted are enrolled in the study. All subjects will be implanted with the TransLoc electrodes during their primary surgery. Following admission to the ICU, diaphragm EMG recording will begin and continue until TransAeris use begins or until discharge from the ICU. TransAeris stimulation therapy adjunctive to continued MV will begin 24 hours after leaving the operating room. TransAeris stimulator settings (stimulus intensity, stimulus frequency, and burst on/off) will be programmed to optimize diaphragm recruitment without compromising patient comfort.

When deemed ready by the physician, the subject will perform a spontaneous breathing trial (SBT). Diaphragm EMG will be recorded for the first 15 minutes of an SBT, when performed with study staff available, then TransAeris therapy will continue. If an SBT is not performed on a day or performed when study staff is not available, a diaphragm EMG will be recorded for 15 minutes and then TransAeris therapy will be resumed. If the subject fails the SBT or the physician determines the subject is inappropriate for extubation, TransAeris stimulation therapy will continue. Prior to leaving the ICU, diaphragm EMG will be recorded for 15 minutes and the TransLoc electrodes will be removed. Subjects that reach Day 30 after implantation will stop TransAeris therapy. Diaphragm EMG will be recorded for 15 minutes and the TransLoc electrodes will be removed prior to the end of Day 30.

Inclusion Criteria:

1. Subject is undergoing an open cardiac procedure by median sternotomy
2. Subject is at risk of prolonged mechanical ventilation ≥ 24H
3. Subject is at least 22 years of age
4. Informed consent has been obtained from the subject or designated representative

Exclusion Criteria:

1. Subject is on invasive mechanical ventilation prior to procedure
2. Subject has known or pre-existing phrenic nerve paralysis
3. Subject has progressive, non-reversible neuromuscular disease affecting the diaphragm
4. Subject is pregnant or lactating
5. Subject is actively participating in another clinical study which could affect outcomes in this study