Clinical neurophysiology examinations include electroencephalography, sleep and vigilance studies, as well as nerve conduction recordings. Interpretation of these recordings is largely taught during clinical work, using the same devices and software that are employed in everyday practice. Browser‑based applications offer an easy, secure and cost‑effective way to conduct unsupervised teaching remotely. The same datasets can be used both for educational purposes and for scientific research.
Sampsa Lohi, a Doctoral Researcher at the University of Eastern Finland has developed an open‑source JavaScript library, Epicurrents, that enables users to view several types of clinical neurophysiology recordings directly in a web browser. The application has already been used in teaching, including at European Academy of Neurology congresses. A description of the application has now been published in the open‑access journal Clinical Neurophysiology Practice.
Easy access through a web‑based application
One of the key strengths of browser‑based applications is their high accessibility. The Epicurrents application can be used on any device capable of running a Chromium‑based web browser. No additional software needs to be installed, as the application runs directly in the browser. Because the application supports opening files both locally and over the network, pseudonymised recording datasets can be shared and viewed in a secondary‑use context, such as in scientific research, through the browser. Web browsers also enable reliable user authentication if access restrictions are necessary.
Advanced tools for scientific research
As a JavaScript‑based application, Epicurrents is not particularly optimised for heavy numerical computation. To support advanced analysis, the application allows running Python code and ONNX‑based machine‑learning models for signal data processing.
“These additional features increase memory requirements and are therefore primarily suitable for desktop computers or higher-performance laptops,” Lohi notes.
Openness increases trust
In line with open‑source principles, the source code of Epicurrents is not only publicly viewable but also freely available for use, modification and redistribution. “Open source typically increases trust in a project – not only due to transparency but also because it supports long‑term sustainability. It also enables contributions from other individuals interested in the topic,” Lohi adds.
For further information, please contact:
Doctoral Researcher, Specialist in Neurology and Clinical Neurophysiology
Sampsa Lohi, University of Eastern Finland, [email protected]
Professor Petro Julkunen, University of Eastern Finland, Department of Technical Physics, [email protected]
Professor Reetta Kälviäinen, University of Eastern Finland, Neurology, [email protected]
Professor emeritus Esa Mervaala, University of Eastern Finland, Clinical neurophysiology, [email protected]
Research article:
Sampsa Lohi, Petro Julkunen, Reetta Kälviäinen, Esa Mervaala. An open‑source JavaScript clinical neurophysiology library for education and clinical research. Clinical Neurophysiology Practice; 2026. https://doi.org/10.1016/j.cnp.2026.02.001.
