A review of ECG storage formats

The interoperability of the Electrocardiogram (ECG) between heterogeneous systems has been facilitated by not one, but a number of predefined open storage formats. To improve the techniques currently used, it is important to define the similarities and the differences between these ECG storage formats.

This paper presents a review of 9 formats used to store the ECG. Three of the predominant formats, namely, SCP-ECG, DICOM-ECG, and HL7 aECG are reviewed in detail along with the undertaking of a SWOT analysis. The remaining formats have been examined to a lesser extent as they are not as predominant in the literature.

This study suggests that a plethora of open ECG formats, all aiming to promote interoperability has the opposite effect of adding more complexity. This paper discusses whether a format supporting a variety of diagnostic modalities is more advantageous than a format that only supports the ECG. It is conclusive that a general purpose format such as DICOM solves more interoperability issues, however, no general purpose format currently exists that fulfils the requirements of all users. As a result, the healthcare industry has been bombarded with custom storage formats, i.e., a format for storing the resting ECG, a format for storing the ambulatory ECG, a format for storing the ECG in clinical trials, a format for storing ECG data on mobile devices etc. This study then examines which implementation method is more suited to encode ECG data, i.e. binary or XML. Binary encoding has been used in the past to store the ECG, however, unlike binary, XML files are human readable, searchable and provide a better form of semantics. Based on analysis within this work it is speculated that XML may overtake binary as the preferred implementation method for encoding ECG data since it has already made a huge impact in the healthcare industry.

It can be concluded that there is a wide range of vastly different techniques used to store the ECG. Although the specifications of these formats are openly available, neither has been internationally adopted to be used with all ECG machines. Therefore, there remains a lack of global interoperability of ECG information.