(15 days)
The Actiheart is an ambulatory Heart Rate and Activity Recorder. Actiheart may be used to quantifiably measure Heart Rate, Activity, and estimates of Caloric Expenditure. This device is not intended for use as an ECG monitor.
Actiheart is a compact, ambulatory, physiological Heart Rate and Activity data recorder. Actiheart may be attached to the chest surface through the use of standard ECG electrodes. Recorded data may be transferred later to a PC for display and conversion for export to other programs.
The document provides details of the Actiheart device, an ambulatory Heart Rate and Activity Recorder. It includes information on its substantial equivalence to a predicate device, indications for use, device description, and performance testing results against acceptance criteria.
1. Table of Acceptance Criteria and Reported Device Performance
| Figure of Merit | Requirement | Actiheart Performance |
|---|---|---|
| Tall T-wave Rejection Capability | Reject Tall T-Waves up to 1.2 mV with ±10% accuracy or ±5 BPM (greater of two) | Sensitivity is better than 98% |
| Specificity is 100% | ||
| MIT-BIH Normal Sinus Rhythm waveform library | Detect HR with accuracy of ±10% or ±5 BPM (greater of two) | Sensitivity is better than 99% |
| Specificity is better than 98% | ||
| European ST-T waveform library | Detect HR with accuracy of ±10% or ±5 BPM (greater of two) | Sensitivity is better than 99% |
| Specificity is better than 97% | ||
| AAMI Normal Sinus Rhythm waveform library | Detect HR with accuracy of ±10% or ±5 BPM (greater of two) | Sensitivity is better than 99% |
| Specificity is better than 99% | ||
| Line frequency tolerance and drift tolerance | Detect HR with accuracy of ±10% or ±5 BPM (greater of two) when drift or line noise present | No difference between HR measurement for waveforms with and without superimposed noise |
| Range and accuracy of HR meter | Detect HR with accuracy of ±10% or ±5 BPM (greater of two) over specified range of 32 to 255 BPM | Within limits for all values of HR |
| Amplitude of QRS waveform | Detect HR with accuracy of ±10% or ±5 BPM (greater of two) for amplitudes 0.5 mV to 5 mV | Within limits for all values of amplitude between 0.45 mV and 9 mV. |
2. Sample Size Used for the Test Set and Data Provenance
The document does not explicitly state the sample size of unique patients or recordings for the test sets. Instead, it refers to "libraries of ECG waveforms" such as the MIT-BIH Normal Sinus Rhythm waveform library, European ST-T waveform library, and AAMI Normal Sinus Rhythm waveform library. These are standardized, publicly available databases of ECG recordings, often used for testing algorithms and devices. The provenance of these publicly available libraries is generally known, but not detailed in this document. The testing described is a "bench test comparison report" and relies on "library recordings of known Heart Rate." This suggests a retrospective analysis using pre-recorded data.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
The document does not specify the number or qualifications of experts used to establish the ground truth for the test set. Ground truth for these waveform libraries is typically established through a combination of expert cardiological review and often includes reference annotations that have been meticulously validated.
4. Adjudication Method for the Test Set
The document does not specify an adjudication method for the test set. Given that it relies on established ECG waveform libraries, the ground truth (e.g., true heart rate, QRS complex locations) from these libraries would serve as the reference, precluding the need for real-time expert adjudication of the device's output.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No multi-reader multi-case (MRMC) comparative effectiveness study is mentioned. The study focuses purely on the standalone performance of the Actiheart device against established benchmarks and in comparison to a predicate device in a bench test setting. It does not evaluate human readers' improvement with or without AI assistance.
6. Standalone Performance
Yes, a standalone performance study was conducted. The "Actiheart to Mini Logger Series 2000 bench test comparison report" directly assesses "the Heart Rate detection performance characteristics of both devices side-by-side against a set of library recordings of known Heart Rate." This is further supported by "Additional testing with the use of simulated recordings per ASTM EC13:2002," and the detailed "Assessment of non-clinical performance data" which lists various tests applied to the "submitted Recorder" (Actiheart) against specific performance requirements. These tests evaluate the device's ability to detect and measure heart rate independently.
7. Type of Ground Truth Used
The ground truth used for the performance testing cited in Table 10D is based on "known Heart Rate" from "libraries of ECG waveforms" such as MIT-BIH, European ST-T, and AAMI Normal Sinus Rhythm waveform libraries. These libraries contain reference annotations (e.g., R-peak locations, true heart rates) typically established through expert consensus and automated validation. The document also mentions testing with "simulated recordings per ASTM EC13:2002," implying a ground truth derived from controlled, simulated ECG signals.
8. Sample Size for the Training Set
The document does not provide information on the sample size used for the training set for any algorithms within the Actiheart device. It mentions "proprietary code transforms digitized signal and detects location of features in ECG complex" and "proprietary algorithms to detect motion" and "proprietary algorithm" for caloric expenditure, but does not detail the development or training of these algorithms.
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 (if any was used for the proprietary algorithms) was established.
§ 882.1845 Physiological signal conditioner.
(a)
Identification. A physiological signal conditioner is a device such as an integrator or differentiator used to modify physiological signals for recording and processing.(b)
Classification. Class II (performance standards).