변수 중요도를 이용한 설명 가능한 인공지능 기법의 시각화에 대한 고찰과 보건정보 자료에의 응용

Abstract

Objectives: Deep learning techniques have been actively used in the medical field where precise diagnosis and results are very important. Deep neural network-based models utilizing big data from medical records are supporting medical opinions and are revolutionizing the medical industry. In addition, the convolutional neural network model shows excellent performance in analyzing image data and are used for image classification and X-ray/CT image reconstruction. Methods: In this paper, we conducted a visualization study using structured and unstructured data in the medical field. Results: In order to determine input variables affecting mortality and to evaluate their importance, a total of five techniques, namely, the augmented neural network model with multi-task learning, random forest, extra tree, gradient boosting and xgboost are applied to the intensive care unit data. Variable importance is calculated for each technique, and these indicators are all converted to ratios in consideration of the differences considering the patient group as a stratification variable. The converted values are shown in three graphs, a lollipop graph, a bubble chart graph, and a heat map graph. Through the visualization, it was easy to see which variables were relatively important for each technique and to what extent. InceptionResnetV2 was used as a classification model for skin cancer image data, and LIME and Grad-CAM were applied to the model to easily identify the characteristics of each cancer. Conclusions: Through this study, we apply several explainable artificial intelligence techniques to medical data to enhance understanding of the results of analysis and to help identify and visualize important input variables and features.