Human cord derived MSC cell(Asia Stem Cell Regenerative Pharmaceutical)

The goal of this clinical trial is to evaluate the safety and tolerability of multiple doses of human umbilical cord mesenchymal stem cell injection in patients with Mild to Moderate Acute Respiratory Distress Syndrome (ARDS), and to further explore the efficacy, pharmacodynamic profile and appropriate dose of administration to provide a basis for the use of safer and more effective treatments for patients with Mild to Moderate Acute Respiratory Distress Syndrome (ARDS).
Participants are required to sign an informed consent form and, after undergoing a series of tests and meeting the protocol's entry and exclusion criteria, are assigned to a dose group for intravenous infusion of human umbilical cord mesenchymal stem cells. Each subject will receive three infusions.