This study compares a handheld ultrasonic spirometer with a standard hospital spirometer in adults with chronic respiratory diseases. Each participant will complete lung function tests using both devices. The study aims to determine whether the ultrasonic device provides accurate and reliable measurements for use in clinical or home settings.

This study aims to compare a new ultrasonic handheld spirometer with the standard hospital spirometer used in lung function testing. We want to find out whether the ultrasonic device can measure breathing strength and lung capacity as accurately and reliably as the traditional machine.

Adults with chronic respiratory diseases-including COPD, asthma, bronchiectasis, and interstitial lung disease-will participate. Each participant will perform lung function tests using both devices in a randomized order. The results from the two methods will then be compared to see how closely they match.

The goal of this study is to determine whether the ultrasonic spirometer can be used as a convenient alternative tool for lung function monitoring in clinics, community settings, or at home.

Inclusion Criteria:

• Adults aged 18 to 80 years.
• Diagnosed with a chronic respiratory disease (e.g., COPD, asthma, bronchiectasis, or interstitial lung disease).
• Willing to follow the instructions for using the ultrasonic spirometer.
• Clinically stable and able to understand the study purpose and procedures, and who provide informed consent.

Exclusion Criteria:

• Individuals who, after explanation, are still unable to properly perform the ultrasonic spirometry procedure.
• Individuals who, after explanation, refuse to participate in the study.
• Patients with unstable vital signs.
• Pregnant or suspected pregnant women.