The main aim of this study is to test spirometry measurements using EIT with a calibration using tidal volume obtained from the simultaneous standard spirometry measurement. Another goal is to compare, based on the calibration, the spirometry parameters obtained from separate measurements using EIT and the standard spirometry using a pneumotachograph.

All spirometry measurements will be conducted in accordance with the latest available standards of the American Thoracic Society (ATS) and European Respiratory Society (ERS) from the year 2005, including their emendation from 2017.

Adding the pneumotachograph and antibacterial filter to the respiratory system can lead to increased dead space, flow resistance, and change the respiratory pattern. All of these negative features and reduced patient co-operation affect the measured results and their interpretation. The aim of this study is to test spirometry measurement using EIT and evaluate such spirometry parameters as forced vital capacity (FVC), forced expiratory volume exhaled in the first second of a forced expiration (FEV1) and ratio of FEV1/FVC called Tiffeneau index (TI) based on recalculation using the calibration constant. The study will be conducted using Ergostik (Geratherm, Germany) spirometer and EIT system Pulmovista 500 (Dräger, Germany).

Inclusion Criteria:

• Healthy males and females > 18 years old
• Signed informed consent has been obtained

Exclusion Criteria:

• Pregnancy
• Cardiac pacemakers
• Electrically active implant
• Critical illness
• Intrathoracic metal implants
• Value of body mass index (BMI)>50

EIT anonymous images and corresponding spirometry data.