(135 days)
The Study Watch with Irregular Pulse Monitor is indicated for use by adult patients (22 years and older) who have been diagnosed with, or are susceptible to developing, atrial fibrillation enabling them to monitor and record their heart rhythms. Study Watch is also intended to record, store, transfer, and display single-channel electrocardiogram (ECG) rhythms. The Irregular Pulse Monitor is indicated for use in professional healthcare facility environments, while worn as a wrist watch.
The Study Watch with Irregular Pulse Monitor is a miniaturized physiological data monitoring device that is intended to record, store, transfer and display single-channel electrocardiogram (ECG) rhythms. The Study Watch with Irregular Pulse Monitor is intended to notify the user in the event of irregular pulse, such as atrial fibrillation (AF), and recommend acquisition of an ECG. The device utilizes a band and proprietary watch that incorporates two dedicated sensing electrodes to obtain a single-channel ECG measurement. In practice, a healthcare professional (HCP) may prescribe the Study Watch with Irregular Pulse Monitor to a patient and recommend the capture and transmission of one or more ECG rhythms on a daily basis for analysis by the HCP. The patient uses prompts provided on the graphical user interface (GUI) of the watch to collect a realtime 60-second ECG measurement. The patient is able to capture an ECG rhythm on-demand by navigation to the ECG menu, in response to a daily ECG reminder, or upon receipt of an irregular pulse notification. While an animated ECG waveform is briefly displayed on the GUI of the watch, the patient will not have direct access to the collected wave form. Using the provided charging dock (Cradle) and Verily's Study Hub device, the ECG measurements are securely transferred to Verily's cloud server and are viewed by the HCP using a web portal. The web portal is solely intended for use by the HCP to view time-stamped ECG waveforms collected by the patient and does not include any analysis features. Collectively, the Study Watch consists of the wearable watch and band, the Study Hub (used to transfer data from the watch to the cloud), a Cradle, and the web portal.
The document describes the Study Watch with Irregular Pulse Monitor, focusing on its ability to detect irregular pulses, particularly atrial fibrillation (AF). The performance data presented primarily relates to the Irregular Pulse Monitor algorithm, which uses photoplethysmogram (PPG) data as input.
Here's a breakdown of the acceptance criteria and study findings:
1. Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Requirement (Implicit) | Reported Device Performance (PPG-based Irregular Pulse Monitor algorithm) |
|---|---|---|
| Sensitivity (Per-interval) | Not explicitly stated as a numerical acceptance criterion, but the text states the algorithm "exceeds the pre-specified per-interval performance thresholds for sensitivity." | 0.85 (85%) with a confidence interval of (0.79-0.90) |
| Specificity (Per-interval) | Not explicitly stated as a numerical acceptance criterion, but the text states the algorithm "exceeds the pre-specified per-interval performance thresholds for specificity." | 0.96 (96%) with a confidence interval of (0.93-0.99) |
Note: The document does not provide explicit numerical acceptance criteria values, only that the reported performance exceeds them. These reported values are for the PPG-based irregular pulse monitor algorithm, not necessarily the ECG functionality of the watch which is for recording, storing, transfer, and display.
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: The document does not explicitly state a numerical sample size for the test set of the clinical study. It mentions the study "collected Study Watch PPG waveform (Test) data in clinic from patients with a history of AF."
- Data Provenance: The document does not specify the country of origin. It indicates the data was collected "in clinic," implying a prospective clinical study specifically for this device's performance validation.
3. Number of Experts Used to Establish Ground Truth and Qualifications
- The document states that "contemporaneous Holter ECG (Reference) data" was used as "ground truth." It does not mention the use of human experts to establish this ground truth for the test set. Holter ECG data is considered an objective gold standard for rhythm analysis.
4. Adjudication Method for the Test Set
- The document implies that the ground truth was established by "contemporaneous Holter ECG (Reference) data," which would not require a human adjudication method in the traditional sense (e.g., 2+1, 3+1). The Holter ECG itself serves as the reference.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- The document does not describe an MRMC comparative effectiveness study where human readers improve with AI vs. without AI assistance. The study focuses purely on the standalone performance of the irregular pulse monitor algorithm against a clinical reference standard (Holter ECG).
6. Standalone (Algorithm Only) Performance
- Yes, a standalone performance evaluation was done. The reported sensitivity and specificity values of 85% and 96%, respectively, are for the "PPG-based Irregular Pulse Monitor algorithm" operating on the Study Watch PPG data, with Holter ECG as the ground truth. This indicates algorithm-only performance.
7. Type of Ground Truth Used
- The ground truth used for the clinical study was contemporaneous Holter ECG data. This is a clinical gold standard for continuous heart rhythm monitoring.
8. Sample Size for the Training Set
- The document does not provide information regarding the sample size used for the training set of the algorithm.
9. How the Ground Truth for the Training Set Was Established
- The document does not provide information on how the ground truth for the training set was established. Given the nature of a machine learning algorithm for pulse monitoring, it's highly probable that ground truth for training data would also have been established using reference ECGs or similar clinical gold standards.
§ 870.2920 Telephone electrocardiograph transmitter and receiver.
(a)
Identification. A telephone electrocardiograph transmitter and receiver is a device used to condition an electrocardiograph signal so that it can be transmitted via a telephone line to another location. This device also includes a receiver that reconditions the received signal into its original format so that it can be displayed. The device includes devices used to transmit and receive pacemaker signals.(b)
Classification. Class II (performance standards).