Global Gas Exchange Pulmonary Function Testing Market By Product Type (Cardiopulmonary Exercise Testing Systems, Diffusing Capacity Lung Transfer Systems, Metabolic Carts, Oxygen Uptake Measurement Systems, Respiratory Gas Analyzers, Others) By Technology (Open Circuit, Closed Circuit) By End User (Hospitals & Clinics, Diagnostic Laboratories, Academic & Research Institutes, Home Care Settings, Others), Region and Companies – Industry Segment Outlook, Market Assessment, Competition Scenario, Trends and Forecast 2026-2035