Flexible and Efficient Retrieval of Hemodialysis Time Series

The problem of retrieving time series similar to a specified query pattern has been recently addressed within the Case Based Reasoning (CBR) literature. Providing a flexible and efficient way of dealing with such an issue would be of paramount importance in medical domains, where many patient parameters are often collected in the form of time series. In this paper, we describe a novel framework for retrieving cases with time series features, relying on Temporal Abstractions. With respect to more classical (mathematical) approaches, our framework provides significant advantages. In particular, multi-level abstraction mechanisms and proper indexing techniques allow for flexible query issuing, and for efficient and interactive query answering. The framework is currently being applied to the hemodialysis domain. In this field, experimental results have shown the superiority of our approach with respect to the use of a classical mathematical technique in flexibility, user friendliness, and also quality of results. Tests in other application domains, as well as further enhancements, are foreseen in our future work.