Pulmonary ventilation distribution with low-cost and commercial incentive spirometers measured by electrical impedance tomography in a randomized clinical trial

The Incentive Spirometer (IS) encourages deep breaths to improve lung volume and prevent respiratory complications, but its cost limits some populations. The low-cost "modified Pachon Incentive Spirometer (mPIS)" was developed, and this study aims to compare the distribution of pulmonary ventilation between a low-cost IS named mPIS and another commercial flow-based IS using electrical impedance tomography (EIT). A randomized clinical trial that includes healthy volunteers aged 18-65 years. Responses obtained with the mPIS, and a branded IS were compared. Randomization was used to assign treatments. Spirometry was performed to rule out chronic lung disease, and EIT was used to evaluate the distribution of pulmonary ventilation, measuring variables such as Tidal Variation Minute and End-expiratory lung volume. When comparing the %TVM in the different regions of interest (ROIs) before and after using the mPIS and the branded IS, no changes were found in any of the ROIs for both devices. However, when comparing the global ΔEELIT3-T1 change, the mPIS showed a increase compared to the branded IS (p = 0.049). Additionally, in ROI1 (right anterior), the mPIS showed a increase in ΔEELIT3-T1 (p = 0.000), while in the other ROIs no differences were identified with the use of both incentives. The study demonstrated that the mPIS, is a valid option to improve pulmonary ventilation, as it showed a significant increase in global ΔEELIT3-T1 compared to a commercial device. This suggests that the mPIS can be as effective as more expensive options, representing an accessible alternative in resource-limited settings.