Respiratory rate measurement device

A respiratory rate measurement device comprising:

• a detection unit that detects an in-tube pressure and/or an in-tube gas flow rate in a tube supplying concentrated oxygen gas to a patient from a pressure swing adsorption oxygen concentration device connected to the patient and concentrating oxygen in the air by periodically repeating pressurization and depressurization, and outputs pressure data and/or gas flow rate data;
• an arithmetic operation unit that extracts patient respiratory information data, based on the pressure data and/or the gas flow rate data;
• and
• an estimation unit that estimates a respiratory rate per predetermined time, based on the patient respiratory information data,
• wherein the estimation unit calculates an autocorrelation coefficient between the patient respiratory information data and data shifted from the patient respiratory information data by a time Δt, while changing the time Δt, and estimates the respiratory rate using, as a respiratory interval, a time Δt in which the autocorrelation coefficient takes a peak.