Tidal Volume (TV) post-process obtained with electrical impedance tomography on a group of chronic obstructive pulmonary disease (COPD) patients. Use of adjust equations
Document typeConference report
Rights accessOpen Access
Equations used to estimate ventilation out of EIT images, validated on healthy volunteers show a significant bias and a larger variance when were applied on a COPD patients group. The differences in estimation values were found to be highly correlated with anthropometric parameters. Two groups of 13 and 4 COPD male patients (FEV1/FVC<70% and FVC ≥ 80%) were used in this study. We have measured different anthropometric parameters like age, weight, height and skinfolds. The EIT system (TIE4sys) and a pneumotach were simultaneously connected to monitor tidal volume. The main anthropometric parameters values of 13 COPD patients were: age: 67±9 years, height: 1.65±0.05 m, weight: 72±11 kg, BMI: 26.4±3.3; and the subscapular skinfold thickness was 23±9mm. The mean tidal volume estimated with TIE4sys and the pneumotach were: 0.580±0.212 L and 0.774±0.173 L r = 0.861 (p<0.01). The mean difference was 0.196±0.096 L (p<0.01). On this group we have found out an adjust equation and we have validated it on an independent group of 4 COPD patients. The equation was Diff=-1478+15.6(weight). The mean tidal volume values obtained with pneumotach and TIE4sys on the second group of COPD patients (M:4) were: 0.798±0.395 L and 0.732±0.327 L. The mean of the differences was 0.066±0.114L. The differences of determinations estimated with pneumotach and TIE4sys can be attributed to changes of anthropometric characteristics like subscapular skinfold.
CitationBalleza, M. [et al.]. Tidal Volume (TV) post-process obtained with electrical impedance tomography on a group of chronic obstructive pulmonary disease (COPD) patients. Use of adjust equations. A: International Conference on Electrical Bioimpedance. "XIVth International Conference on Electrical Bioimpedance and the 11th Conference on Biomedical Applications of EIT". Gainesville, Florida: 2010, p. 1-4.