I’m a healthy, active adult, but my doctor insists that I monitor my heart rate when I exercise. Why? Because I have a congenital heart defect that puts me at risk for atrial fibrillation, or Afib. This abnormal heart rhythm affects an estimated 33.5 million people worldwide and can lead to dangerous cardiovascular complications. Samsung Electronics has added an electrocardiogram (ECG) function to the new Samsung Health Monitor app to make it easier for consumers to monitor their heart rates during exercise and daily activities.
Because Afib can contribute to blood clots, stroke, and heart failure, early detection and treatment are critical. The ECG feature of the Health Monitor app, now approved by South Korea’s Ministry of Food and Drug Safety (MFDS), uses a sensor on Samsung’s Galaxy Watch Active2 to detect electrical heart activity. The user places a fingertip on top of the watch for 30 seconds, and the app then measures and analyzes the heart rate and rhythm, and tags the results as normal or Afib.
In addition to heart conditions, a wide variety of factors can cause Afib, including viral infections, sleep apnea, and thyroid disorders. A primary cause — high blood pressure — rarely has symptoms of its own and can itself lead to stroke and other complications. The Health Monitor app features a blood pressure (BP) monitor, also cleared by MFDS, which could make the user aware of high blood pressure before a potentially fatal event occurs.
The BP monitor currently requires an initial calibration with a traditional BP cuff. In February, Health Tech Insider reported that biometric sensor company Valencell announced a new blood pressure sensor system for hearables and wearables that doesn’t require an initial calibration. Valencell has licensed its other sensor technology to Samsung in the past, suggesting that a future edition of the Galaxy Watch might include the new calibration-free sensor.
The Active2 features sleep tracking and analytics. It also tracks up to 39 fitness activities, including walking, running, cycling, elliptical trainer, rowing, and swimming. Golfers can up their game with distance readings, touch-targeting, and shot history. Even users who don’t have specific concerns about Afib can use the watch and the Health Monitor app to obtain a clearer picture of their overall health.
cleared for ECG, but not for BP?
Must be calibrated how many times per week?
How accurate for what BP range?
PPG BPM need cal every two days and are only relatively accurate in the normal BP range, not in the hypertensive range !!!
Johan, in our article it states “The Health Monitor app features a blood pressure (BP) monitor, also cleared by MFDS…” so yes, it is cleared (in South Korea) for both ECG and BP.
According to this article, Samsung recommends monthly recalibration. I don’t have a primary source for that information, however. All the Samsung documents I find refer to an “initial calibration.”
For the watch’s accuracy, you will have to ask Samsung as I don’t have that information.
As for your blanket statement about PPG BPM, I believe that this is not true for Valencell’s technology. It does not require calibration at all, and meets the ISO 81060-2:2018 standard. Here’s a link to more detail about their research data supporting their claims: https://valencell.com/blog/2020/01/validation-data-for-valencell-calibration-free-blood-pressure-technology/
I hope that this is helpful.
Alfred Poor, Editor
Health Tech Insider
Has Samsung released the documents submitted to the South Korean Health authorities and FDA in the U.S.A? I think the users of these new appliances should have free access to:
(1) the documents that have led to approval, and,
(2) the raw data that are invoked.
Furthermore, It would be interesting to know which preliminary and post-.studies have been sponsored by Samsung (as Apple has done), to investigate the reliability of the smartwatch ECG to detect, e.g., atrial fibrillation. Also, I would like to know if comparative studies have been carried out between, e.g., Apple Watch. Fitbit Sense, and Samsung Galaxy Watch 3.
In any case, the documents which have led to the clearing of ECG monitoring by FDA and South Korean using 1-led ECG monitoring on Samsung watches should be released for the general public and research community. Where are these data?
Finally, full exportability of the data **in a simple way** should be ensured from the smartwatches to pull these out.
These are certainly great questions. I don’t know the policies and practices of the South Korean agency, but I do know that the FDA publishes information about 510(k) clearances. I don’t believe that they publish the specific study results, but this might be the place to start to get answers to your questions: https://www.fda.gov/medical-devices/510k-clearances/search-releasable-510k-database
All the best,
Alfred Poor, Editor
Health Tech Insider
Thanks for the quick feedback. Here is the FDA clearance at:
which includes a link to the Clearance Letter and a Summary issued by the FDA’s Division of Cardiac Electrophysiology, Diagnostics and Monitoring Devices, Office of Cardiovascular Devices downloadable at https://www.accessdata.fda.gov/cdrh_docs/pdf20/K201168.pdf. From page 3 this document offers a summative (and not very detailed) comparison of AppleWatch with the new Samsung appliance.
Most interestingly is the performance evaluation of “Rhythm Classification” rating Apple Watch Atrial Fibrillation Sensitivity (98.3%) and Sinus Rhythm Specificity (99.6%) against Samsung’ Atrial Fibrillation Sensitivity (98.1%) and Sinus Rhythm Specificity (100%). These result are impressive, taking into account that FDA has carried out an independant testing og both devices and software presented on pages 6 and 7. This is, in my opinion, the most interesting part of the document. It states that: Clinical validation showing non-inferiority to the predicate in clinical performance in terms of (1) ECG signal quality sufficiency (2) Rhythm classification accuracy (2) Human Factors Validation,(3) IEC 60601-2-47 ECG Database Testing and (4) Heart Rate Accuracy Bench Testing, and (5) SW Verification Testing. On the hardware side, it is worth noting that the FDA has tested ECG Signal Quality and Lead Detection through Bench Testing (but no description of the benchmarking methods used is given).
A study sponsored by Samsung (I presume) enrolled 544 subjects, among whom 268 were AFib patients, 261 had sinus rhythm (SR), and 15 had other arrhythmias. The FDA states (repeating verbatim Samsung’s documents?) that:
“The Samsung ECG Monitor App was proven to be non-inferior to the predicate in terms of rhythm classification accuracy and ECG signal quality sufficiency. No adverse events were observed. The study enrolled 544 subjects, among whom 268 were AFib patients, 261 had sinus rhythm (SR), and 15 had other arrhythmias. The ECG App algorithm detection of AFib and SR was compared to cardiologists’ read of 12-lead ECG reference strip. Among the recordings where the algorithm output a rhythm classification, AFib was correctly indicated with 98.1% sensitivity (95%CI: 96.3%, 99.9%) and 100% specificity (95% CI: 100%, 100%) in the Samsung ECG Monitor App, while the predicate showed 99.6% sensitivity (95% CI: 98.7%, 100%) and 99.6% specificity (95% CI: 98.8%, 100%) in the comparison study. As a result, the sensitivity and specificity of the Samsung ECG Monitor App were within the pre-determined non-inferiority margin, thus the primary endpoint was met. The ratio of readings that were deemed inconclusive (or unclassifiable) by the Samsung ECG Monitor App when the truth was either AFib or SR was 2.9% (95% CI: 1.1%, 4.7%) while the predicate was 2.2% (95% CI: 0.7%, 3.7%), which met the non-inferiority margin. To assess the signal quality of the ECG Monitor App recording, cardiologists’ interpretation of the ECG Monitor App strips was compared to the paired reference 12-lead ECG. Cardiologists were able to interpret 98.5% (95% CI: 97.4%, 99.5%) of ECG recordings on the Samsung ECG Monitor App and 99.4% (95% CI: 98.8%, 100%) on the predicate App. The results showed good concordance between the interpretation of the ECG Monitor App strip and the reference 12-lead ECG, 99.4% (95%CI: 98.7%, K201168 Page 7 of 7 100%) on Samsung ECG Monitor App and 99.8% (95%CI: 99.4%, 100%) on the predicate ECG App. Both of the interpretation and agreement met the pre-determined non-inferiority margin. To further assess the ECG waveform accuracy, a total of 140 subjects (AFib cohort: 70, SR cohort: 70) were randomly selected for fiducial point annotation. Three blinded, independent ECG technicians marked the fiducial points for key ECG features (QRS amplitude, RR interval, QRS duration, PR interval) in comparison between the ECG Monitor App strip and the reference 12-lead ECG. The key ECG features of Samsung ECG Monitor App were all within non-inferiority margin with statistical significance. Thus the secondary endpoints were met.”
This study can be compared with the Apple-sponsored study involving “226 participants aged 22 years or older who had received an AF notification while wearing Apple Watch and subsequently wore an electrocardiogram (ECG) patch for approximately one week, 41.6% (94/226) had AF detected by ECG patch. During concurrent wear of Apple Watch and an ECG patch, 57/226 participants received an AF notification. Of those, 78.9% (45/57) showed concordant AF on the ECG patch and 98.2% (56/57) showed AF and other clinically relevant arrhythmias. A total of 370 irregular rhythm notifications with readable ECG patch data was received by the 57 participants. Of those 370 notifications, 322 (87.0%) were assessed to be AF, 47 (12.7%) were arrhythmias other than AF and 1 (0.3%) was sinus rhythm. These results demonstrate that, while in the majority of cases the notification will accurately represent the presence of AF, in some instances, a notification may indicate the presence of an arrhythmia other than AF. No serious device adverse effects were observed.”
This is at a first glance most impressive. However, a more reserved appraisal of Samsung’s (and Apple’s) ECG monitoring has. been offered by Dr. Anthony Pearsn at his website “the Skeptical Cardiologist”. See e.g., https://theskepticalcardiologist.com/2018/09/13/the-new-apple-watch-4-cardiac-accuracy-unknown-game-changing-benefits-overblown/ and https://theskepticalcardiologist.com/2020/09/27/apple-watch-versus-kardia-to-monitor-atrial-fibrillation-from-home-a-case-study/.
Thanks for sharing all that detail. One thing that many people don’t realize is that a 510(k) clearance is granted if you can prove that your device is no worse than another device that has already been cleared. It doesn’t really address whether or not the comparison device is effective.
All the best,
Alfred Poor, Editor
Health Tech Insider