This prospective, single-arm, self-controlled validation study aims to evaluate the accuracy and safety of the Spirometry Test System (STS) handheld device in measuring pulmonary parameters in pediatric subjects aged 7-17 years.

Each participant will undergo pulmonary function testing using both conventional laboratory methods (spirometry and body plethysmography) and the STS device in randomized order. Agreement between methods, repeatability of measurements, and device safety will be assessed. The study will be conducted at Children's National Hospital, Washington, USA

Pulmonary function testing (PFT) is essential for diagnosing and monitoring respiratory diseases in pediatric patients. Conventional PFT requires body plethysmography and laboratory spirometry, which can be time-consuming and challenging for children.

The Spirometry Test System (STS) is a portable handheld device capable of measuring spirometry parameters and lung volumes without the need for a plethysmograph chamber. The STS device is FDA cleared for use in adult patients (FDA 510(k) K240293). However, its performance has not yet been validated in the pediatric population.

This study aims to evaluate the accuracy and safety of the STS device in pediatric subjects aged 7-17 years.

Pediatric patients referred for clinically required pulmonary function testing will perform lung function testing using both conventional laboratory methods (spirometry and body plethysmography) and the STS device. The testing order will be randomized to minimize order bias. Each test will be performed by a different technician, and technicians will remain blinded to the results of the alternate testing method.

The primary objective is to evaluate agreement between STS measurements and conventional pulmonary function testing using Bland-Altman analysis. Secondary objectives include assessment of repeatability and safety evaluation.

The first 10 enrolled subjects will serve as an initial training set and will not be included in the final analysis. Interim analyses will be performed periodically throughout the study to ensure data quality and safety oversight.

The study involves a single visit and no follow-up assessments.

Inclusion Criteria:

• Pediatric subjects aged 7-17 years able to cooperate with testing
• Referred for clinically required pulmonary function testing
• Informed consent obtained from legal guardian

Exclusion Criteria:

• Inability to perform lung function testing
• Inability or unwillingness to provide consent
• Presence of tracheostomy
• Pulmonary edema