SaECG: a new FHIR Data format revision to enable continuous ECG storage and monitoring

Information Technologies are enabling integrated healthcare processes with effective information exchange between the patient and the medical professionals. ECG is one of the key human vital signs, used by a vast number of clinicians. Fast Healthcare Interoperability Resources (FHIR) created by Health Level Seven International (HL7), Digital Imaging and Communications in Medicine (DICOM), and Standard communications protocol for computer assisted electrocardiography (SCP-ECG) are representing major digital health-data archiving standards. Most of these standards are using XML-based/JSON-based or binary formats. The interoperability and compatibility between the various ECG formats are valid problems since many years. ECG monitoring is a challenging process due to many factors such as time limitation, data size, or device dependent parameters such as the number of used parallel sampling channels. Nowadays' portable and wearable devices with non-invasive single-lead ECG capability are able to provide continuous long-term ECG data streaming that can last for many hours or even for weeks of monitoring. Available standards enable ECG data storage for a limited time, lasting from 30 seconds up to few minutes. FHIR is a medical data storage standard by HL7 for health data storage and exchange. In this paper, we propose a new FHIR (HL7-aECG) extension format for stream-like ECG, namely Stream-enabled annotated ECG (SaECG). The new format is validated successfully in our living lab and is capable to be used easily both by clinicians and researchers.