Spirometry is the most commonly used modality for measuring lung function. However,
spirometry is a coordination-dependent test and may lead to erroneous results if subjects are
unable to fully comply with the instructions. It also lacks the capability for regional
assessment of pulmonary functions.
Electrical impedance tomography (EIT) is a potential alternative test to spirometry. EIT has
been employed in clinical use to provide qualitative and quantitative measurements of
ventilation in patients on mechanical ventilators to prevent lung damage or
patient-ventilator desynchronies.
In this study, we aim to utilize EIT lung device to study EIT-derived indicators in pulmonary
functional assessment and develop novel biomarkers for detecting and monitoring pulmonary
diseases. This is a non-interventional clinical study on patients with chronic lung diseases,
to establish the feasibility of using EIT-lung device in detecting lung functional changes.
Specifically, we will establish the relationship between EIT-derived functional indicators
and spirometry results. Furthermore, we will explore, develop, and establish EIT-derived
regional lung functional indicators in healthy and chronic diseased states.
Subjects with underlying lung disease, and age- and gender-matched healthy control subjects
will be recruited in this study. They will perform spirometry and EIT examination, as well as
an interview with a structured questionnaire.
The results from spirometry and EIT test will be correlated and compared to identify the
feasibility and accuracy of EIT lung device. Lung function parameters (e.g. FEV1, FVC, and
FEV1/FVC ratio) measured using a spirometer would also be calculated from lung flow-volume
curves derived from continuous EIT functional images. Regional lung function assessment will
also be explored using EIT, and establish regional EIT features that could assist in
screening and evaluating different chronic lung diseases. The EIT-derived indicators will be
finally analyzed together with demographics, clinical assessments and patient history to
derive fine grained insights and elucidate the effect of demographics and biometrics on EIT
lung data. The parameters include, but not limited to, age, chest size, gender, weight,
height, BMI, smoking habits and ethnicity. The analysis will improve the stability of the EIT
indicators, and ultimately increase their predictive power towards diseased lung regions.
With the availability of the EIT device on lung function assessment, which was validated with
spirometry findings, patients who are unable to perform spirometry but need a proper lung
function assessment can benefit by having the EIT test. These patients include but not
limited to those who need major lung resection and interstitial lung diseases on
anti-fibrotic. EIT can also be a more comfortable alternative to spirometry for patients who
need lung function assessment.
