2003 News

The Long-Term ST Database has been updated with the addition of detailed clinical notes and ST deviation trend plots for all 86 records of the database.

A beta release of the WFDB_tools package is now available for testing. This package allows Matlab R13 users to use the WFDB library to read and write digitized signals and annotations such as those available from PhysioNet. The WFDB_tools functions are wrappers for the WFDB library, so that Matlab users can access the full range of capabilities offered by current and future versions of the WFDB library, including transparent access to data in a large and growing number of formats, whether stored locally or on remote web servers. The package was written and contributed by Jonas Carlson. It has been tested successfully under GNU/Linux and MS-Windows, and it should be portable to MacOS X and other platforms supported by Matlab R13.

Patrick McSharry and Gari Clifford have contributed ECGSYN, software for generating a realistic ECG signal with a wide variety of user-settable parameters. The package includes C, Java, and Matlab/Octave implementations, together with a paper describing the model.

The NHLBI-sponsored multi-center Sleep Heart Health Study has contributed the first of a planned set of 1000 overnight polysomnograms to PhysioBank. The study has investigated the relationship between sleep disordered breathing and cardiovascular disease since 1995. The data include EEG, EOG, EMG, ECG, nasal airflow and respiratory effort signals, SaO2 and heart rate measurements, and annotated sleep stages, respiratory events, EEG arousals, and more.

Version 10.3.11 of the WFDB software package incorporates many improvements over previous versions; a summary of recent changes is available here. Sources, GNU/Linux and MS-Windows binaries, and revised manuals are now available.

The PhysioNet/Computers in Cardiology Challenge 2004 is underway! The topic is spontaneous termination of atrial fibrillation. The challenge dataset is available now; further details about the challenge will be posted shortly.

The master PhysioNet server has been replaced by a new server with greater capacity and speed. Please report any problems you encounter by clicking on the comments link at the bottom of most pages (or to webmaster@physionet.org).

Among the new features of this server are significantly improved Advanced Search and Chart-O-Matic facilities, and the complete MGH/MF Waveform Database.

A two-lead ECG recording that was selected for inclusion in the AHA Database for Evaluation of Ventricular Arrhythmia Detectors, but eventually excluded, is now available here.

Participants in the PhysioNet/Computers in Cardiology Challenge 2003 have an extra week to submit abstracts describing their work, since the conference has extended the abstract deadline to Thursday, 8 May.

Robert Tratnig and Klaus Rheinberger have contributed a Matlab viewer that reads and displays many PhysioNet records, the latest in a collection of software for Matlab and Octave contributed by PhysioNet users.

An effort is now underway to create a set of Matlab wrappers for the WFDB library. Such wrappers would allow Matlab applications to make use of the full range of capabilities offered by the WFDB library, including direct access to records stored on PhysioNet and other web servers in addition to local disk files, support for a wide and growing variety of data formats using a uniform API, resampling on-the-fly, and much more. If you are interested in contributing to this project, whether as a developer, a tester, or a documentation writer, please write and let us know how you would like to participate.

The creators of the Long-Term ST Database have contributed a paper describing the database (available as HTML or PDF).

Several of the participants in the first PhysioNet/Computers in Cardiology Challenge, together with the organizers, have published a joint paper that compares the methods used in the challenge and investigates how to combine several of the most successful strategies for detecting and quantifying sleep apnea based on the ECG. This paper appeared last year in Medical & Biological Engineering & Computing, and it can now be read on-line [external link, PDF].

PhysioNet is made possible by the generous contributions of a worldwide community of researchers. We are pleased to inaugurate the PhysioNet Contributors Page, a who's who of those who have made this resource what it is.

A heartprint is a novel way of visualizing the dynamics of ventricular ectopy. Software for creating heartprints from beat annotation files or RR interval lists has been contributed to PhysioNet.

A pair of papers discussing the effects of trends and nonstationarities on detrended fluctuation analysis (DFA), together with the surrogate data on which these studies were based, have been contributed to PhysioBank.

The fourth annual PhysioNet/Computers in Cardiology Challenge has begun. Is it possible to tell the difference between transient ST changes in the ECG that are due to myocardial ischemia, and those that are not? We invite you to participate in this challenge, making use of the recently completed Long-Term ST Database to study this provocative question.

A new tutorial, RR Intervals, Heart Rate, and HRV, provides a brief overview of how to obtain inter-beat (RR) interval and heart rate time series, and of some basic methods for characterizing heart rate variability, using freely available PhysioNet software.

The Intracardiac Atrial Fibrillation Database is a new collection of high-resolution recordings from eight subjects in atrial fibrillation or flutter. Each recording includes three surface ECG signals and five intracardiac signals, all simultaneously recorded. These are the first freely available recordings of their type.

Software for measuring pNNx, a family of time-domain heart rate variability statistics of which the widely-used pNN50 is a member, has been contributed to PhysioNet. The study that introduced pNNx made use of several PhysioNet databases as well as additional data that have also been contributed to PhysioNet, including the Congestive Heart Failure RR Interval Database, the Normal Sinus Rhythm RR Interval Database, and the remainder of the Fantasia Database (see the news item for 2 March below).

The Congestive Heart Failure RR Interval Database includes beat annotations (about 24 hours each, no ECGs) for 29 subjects with congestive heart failure (NYHA classes 1, 2, and 3).

The Normal Sinus Rhythm RR Interval Database also includes 24-hour beat annotation files for 54 subjects in normal sinus rhythm.

A subset of data from the Fantasia Database has been available here for several years; the remainder of the database is now available. It consists of ECG and respiration recordings, with beat annotations, from 20 young and 20 elderly subjects, all rigorously screened as healthy, in sinus rhythm during a resting state (two hours each). Half of the recordings also include (uncalibrated) continuous noninvasive blood pressure signals.

The creators of the Long-Term ST Database have contributed half of it (43 of 86 complete records) to PhysioNet. Each record is 21 to 24 hours long, and contains 2 or 3 ECG signals, annotated beat-by-beat and with respect to ST episodes, rhythm changes, and signal quality changes; each record also includes ST level time series based on 16-second averages centered on each beat.

Version 10.3.2 of the WFDB Software Package has just been released, with new several new applications and numerous updates; see the release notes for details.

A standard set of test waveforms, as specified by ANSI/AAMI EC13 (the American National Standard for cardiac monitors, heart rate meters, and alarms), is now available in PhysioNet.