''The WhaleTeq device is specifically constructed to reproduce ECG records faithfully and noise free.''
－ Supplementary information of ''Performance of seven ECG interpretation programs in identifying arrhythmia and acute cardiovascular syndrome''
The interpretation algorithm of an electrocardiograph (ECG) machine is the core of its functionality, as it requires accurate interpretations of the possible symptoms represented by the ECG signals. Similar to other electronic devices, different manufacturers develop various ECG machines with respective algorithm designs. However, when selecting a device, unlike common electronic devices with numerous users who can share their experiences, ECG machines are specialized medical devices that require objective and real interpretation results to determine the accuracy and clinical usability of the ECG interpretation algorithm, in addition to the users' personal experiences.
Therefore, research on ECG interpretation algorithms has emerged, aiming to evaluate their performance. However, previous studies have mostly evaluated single algorithms without comparing the results with each other, or they have had limitations such as insufficient sample size of ECG recordings during testing or the use of non-12-lead ECG machines. Furthermore, some studies have only utilized two less common ECG symptoms, which are inadequate to reflect common clinical conditions and provide a comprehensive assessment of algorithm performance.
Considering the aforementioned reasons, and with no direct comparison studies on ECG interpretation algorithms for over 25 years, Mortara Instrument Europe s.r.l., an Italian company, and the Department of Experimental, Diagnostic and Specialty Medicine at the University of Bologna jointly published a study in 2020 on the performance of seven ECG interpretation algorithms in identifying arrhythmia and acute coronary syndrome (ACS). The study employed the WhaleTeq MECG 2.0 ECG Database Player as the testing tool to convert and play ECG signals for the ECG machines to assess the algorithm's performance.
Organizations
(1) Mortara Instrument Europe s.r.l., Bologna, Italy
(2) Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy
Challenges
(1) Conversion of ECG signals into analog format
(2) Processing and filtering of signals, as well as slight variations in electronic amplification and sampling circuits, which may impact the test results
Solutions
WhaleTeq MECG 2.0
(1) Simultaneously outputs analog signals to 8 channels, supporting testing with 12-lead ECG machines
(2) Captures ECG signals at a sampling rate of 1kHz and provides an output signal resolution of up to 0.15μV using a 16-bit DAC, ensuring the faithful reproduction of the original ECG recording*
*Note: During the experimental process, the printed ECGs from the tested ECG machines were visually checked periodically to assure that they were consistent with the original ECG recordings.
Research Findings
(1) Different interpretation algorithms showed significant differences in determining abnormal rhythms and flagging possible ACS cases.
(2) Most algorithms demonstrated low false-negative and false-positive rates in identifying atrial fibrillation and atrial flutter. After 12-lead ECG machines automatically identify atrial fibrillation, further confirmation by cardiologists is an effective validation method.
(3) In the identification of ACS, cardiologists leaned toward flagging ECGs for further review than the interpretation algorithms. However, both algorithm and cardiologist interpretations exhibited high variability in false-negative rates. Therefore, in the cases of critical test results or acute infarction statements, relying solely on a single criterion should not be used to determine the priority for further ECG review.
It is recommended that when setting the threshold for the "critical results" statement, ECG machine manufacturers align their judgment criteria with the opinions of cardiologists to improve the relevance to expert opinions and determine when ECGs should be reviewed promptly.
As real-time and non-invasive equipment for monitoring users' rhythms, ECG machines play a crucial role in assisting health professionals in assessing users' physiological status. Therefore, the stability and reliability of their interpretation algorithms are of utmost importance. By reducing the rate of misinterpretation, the occurrences of delayed identification of serious conditions and inappropriate medical treatments caused by misinterpretations can be minimized, thereby improving the efficiency of health professionals and enhancing the quality of medical care.
In this study, the WhaleTeq MECG 2.0 converted the original ECG data into the analog format, providing the researchers with lossless signals necessary for testing and assisting in obtaining the test results for various interpretation algorithms. Despite not providing a medical device used in the front line of healthcare, WhaleTeq is committed to developing precise testing equipment to aid medical device manufacturers and laboratories in validating their products and safeguarding users' health by enhancing the performance of medical devices.
• Product Information: MECG 2.0 ECG Database Player
• Research Paper: Performance of seven ECG interpretation programs in identifying arrhythmia and acute cardiovascular syndrome. Journal of Electrocardiology, 58 (2020), 143-149