Portable Respiratory Monitor segmentation by type dissects demand across handheld pulse oximeters, capnography devices, peak-flow meters, and spirometers. Handheld oximeters dominate unit share owing to low cost and instant SpO₂ readouts, yet average selling prices below US$160 cap their revenue contribution at roughly 35 % of the 2023 market. Capnography-enabled units, although representing <20 % of volume, command ASPs above US$1.1 k and generate >30 % of dollar sales as clinicians adopt portable CO₂ monitoring for post-op transport and home-COPD titration. Peak-flow meters, priced near US$60, remain a paediatric asthma mainstay but are structurally mature; growth is tethered to emerging-market access programmes rather than technology refresh. Portable spirometers occupy a mid-tier niche, balancing smartphone connectivity with ATS/ERS accuracy; their value is amplified in occupational health screening where mobility and diagnostic-grade tracings justify a US$400–700 price band.