Search Results

The device is intended to capture, and report symptomatic and asymptomatic cardiac events and continuous electrocardiogram information for long-term monitoring. While continuously recording patient ECG, both patient-triggered and automatically-detected arthythmia events are transmitted to a monitoring center for reporting. After wear, a final report is generated based on the beat information from the entire ECC recording. It is indicated for use on patients 18 years or older who may be asymptomatic or who may suffer from transient symptoms such as palpitations, shortness of breath, dizziness, light-headedness, pre-syncope, fatigue, or anxiety and patients who are asymptomatic. The reports are provided for review by the intended user to render a diagnosis based on clinical judgment and experience. It is not intended for use on critical care patients.

The ZEUS System is an electrocardiogram (ECG) analysis and reporting software system, designed to process continuously recorded, signal-lead ECG data. The ZEUS System downloads, stores, analyzes and sorts the ECG data to allow iRhythm's Certified Cardiographic Technicians (CCTs) to generate and distribute a report of the findings contained within the data, thereby enabling the provision of a complete ECG processing and analysis service.

The provided text describes the 510(k) premarket notification for the Zio AT ECG Monitoring System, specifically focusing on the modifications made to the ZEUS System's rhythm classification algorithm from a rule and machine-learning implementation to a deep-learning basis.

Here's an analysis of the acceptance criteria and the study that proves the device meets them, based on the provided text:

1. A table of acceptance criteria and the reported device performance:

The document states that "Safety and performance of the modified ZEUS System has been evaluated and verified in accordance with design specifications and applicable performance standards." and "The nonclinical verification and performance test results established that the device meets its design requirements and intended use, that the modifications to the originally cleared device do not raise new questions of safety and efficacy."

However, there is no specific table of acceptance criteria with corresponding performance metrics provided in the text. The document broadly refers to compliance with standards like AAMI ANSI EC57: 2012 and IEC 60601-2-47:2012. These standards typically outline performance requirements for ECG analysis systems (e.g., sensitivity, specificity for various arrhythmias), but the specific numerical targets set as acceptance criteria by iRhythm and the reported device performance against those targets are not detailed in this public FDA letter.

2. Sample size used for the test set and the data provenance:

The document mentions that "The modified device's arrhythmia algorithm detection was tested in accordance to AAMI ANSI EC57: 2012". While AAMI ANSI EC57: 2012 provides guidelines for testing and reporting performance, it does not explicitly state the sample size (number of patients or recordings) used for the test set.

Data Provenance: The document does not specify the country of origin of the data, nor does it explicitly state whether the data was retrospective or prospective.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:

The document mentions that the ZEUS System enables "iRhythm's Certified Cardiographic Technicians (CCTs) to generate and distribute a report of the findings contained within the data". However, it does not specify the number of experts used to establish the ground truth for the test set used to validate the deep-learning algorithm, nor does it explicitly state their qualifications (e.g., number of years of experience, specific certifications beyond "Certified Cardiographic Technicians").

4. Adjudication method (e.g., 2+1, 3+1, none) for the test set:

The document does not describe any adjudication method used for the test set to establish ground truth. It implies that CCTs generate reports, but not the process for an independent adjudicated ground truth for testing.

5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance:

The document does not mention an MRMC comparative effectiveness study where human readers' performance with and without AI assistance was evaluated. The focus of this submission is on the technological change to the algorithm itself and demonstrating its substantial equivalence to the predicate device.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:

Yes, the document implies that standalone performance testing of the algorithm was done. It states: "The modified device's arrhythmia algorithm detection was tested in accordance to AAMI ANSI EC57: 2012" and "The ZEUS System is an electrocardiogram (ECG) analysis and reporting software system, designed to process continuously recorded, signal-lead ECG data." This suggests that the algorithm's performance in detecting arrhythmias was evaluated independently.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):

The document indicates that "iRhythm's Certified Cardiographic Technicians (CCTs) generate and distribute a report of the findings contained within the data". This implies that the ground truth for the data used in the system's operation is established by CCTs. For the testing data, it's highly probable that expert review (likely by CCTs, and potentially also by cardiologists as part of a gold standard process not explicitly detailed here) was used to establish ground truth for the arrhythmias. However, it does not explicitly state "expert consensus" or provide details on how many experts.

8. The sample size for the training set:

The document does not specify the sample size for the training set used for the deep-learning algorithm. It only states that the algorithm was updated "from a rule and machine-learning implementation to a deep-learning basis."

9. How the ground truth for the training set was established:

The document does not explicitly state how the ground truth for the training set was established. Given that the "ZEUS System downloads, stores, analyzes and sorts the ECG data to allow iRhythm's Certified Cardiographic Technicians (CCTs) to generate and distribute a report of the findings," it is highly probable that the training data and their corresponding labels (ground truth) were derived from previous ECG recordings marked up by these Certified Cardiographic Technicians or similar qualified personnel.

Ask a specific question about this device