This is an unblinded pilot study to investigate the technical feasibility of using an electrical impedance tomography device for noninvasive pulmonary function monitoring in ALS patients. The study will enroll patients with ALS in one cohort and healthy volunteers in a second cohort that will both undergo EIT imaging with the investigational device prior to and while performing a standard PFT procedure.

This is an unblinded pilot study to investigate the technical feasibility of using an electrical impedance tomography device for noninvasive pulmonary function monitoring in ALS patients.

For both Cohort I and II, subject participation will require two visits (initial and 3-4 month follow up), which are expected to last approximately 30 minutes. Subjects will undergo EIT imaging with the investigational device prior to and while performing a standard PFT procedure. The actual EIT imaging will last for 10 to 15 minutes.

Cohort I

Inclusion Criteria:

1. ALS patients able to perform PFT.
2. ALS patients recommended for PFT.
3. Subjects capable of giving written informed consent.
4. Adult, age ≥ 18 years old.

Exclusion Criteria:

1. Serious psychiatric illnesses.
2. Presence of an implanted electronic device (e.g. pacemaker, vagal stimulator, deep brain stimulator) or electrodes or electrical wires.
3. Skin lesions at chest belt placement sites.
4. Pregnant women.
5. Patients with primary lung disease, at the discretion of the Investigator.

Cohort II

1. Subjects capable of giving written informed consent; 2. Subjects capable of performing a PFT; 3. Adult, age ≥ 18 years old 10.2.2 Exclusion Criteria

1. Serious psychiatric illnesses.
2. Presence of an implanted electronic device (e.g. pacemaker, vagal stimulator, deep brain stimulator) or electrodes or electrical wires.
3. Skin lesions at chest belt placement sites.
4. Pregnant women.
5. Subjects with primary lung disease, at the discretion of the Investigator.

Patients clinically diagnosed with ALS