The study has two parts, which patients can participate in either or both. The first part is a self-controlled study which will enroll 40 patients from the ALS clinic. On the day of their clinical visit, study participants will perform both a standard PFT as well as a simulated rPFT, both generating three valid repetitions of forced vital capacity (FVC) and maximal inspiratory pressure (MIP) procedures. The simulated rPFT will mimic the practice of home telemonitoring by having patients be instructed by a respiratory therapist over the telemanagement portal while in a research room within the ALS clinic. The primary hypothesis is that there is no difference in the results of PFT and rPFT for respiratory assessment of FVC and MIP.