Transfer learning in spirometry: CNN models for automated flow-volume curve quality control in paediatric populations

Problem

Current spirometers face challenges in evaluating acceptability criteria, often requiring manual visual inspection by trained specialists. Automating this process could improve diagnostic workflows and reduce variability in test assessments.

Aim

This study aimed to apply transfer learning to convolutional neural networks (CNNs) to automate the classification of spirometry flow-volume curves based on acceptability criteria.

Methods

A total of 5287 spirometry flow-volume curves were divided into three categories: (A) all criteria met, (B) early termination, and (C) non-acceptable results. Six CNN models (VGG16, InceptionV3, Xception, ResNet152V2, InceptionResNetV2, DenseNet121) were trained using a balanced dataset after data augmentation. The models' performance was evaluated on part of the original unbalanced dataset with accuracy, precision, recall, and F1-score metrics.

Results

VGG16 achieved the highest accuracy at 93.9 %, while ResNet152V2 had the lowest at 83.0 %. Non-acceptable curves (Group C) were the easiest to classify, with precision reaching at least 87.7 %. Early termination curves (Group B) were the most challenging, with precision ranging from 75.0 % to 90.3 %.

Conclusion

CNN models, particularly VGG16, show promise in automating spirometry quality control, potentially reducing the need for manual inspection by specialized technicians. This approach can streamline spirometry assessments, offering consistent, high-quality diagnostics even in non-specialized or low-resource environments.