(127 days)
The X4 System is intended for prescription use in the home, healthcare facility, or clinical research environment to acquire, record, transmit and display physiological signals from adult patients. The X4 System acquires, records, transmits and displays electroencephalogram (EEG), electrooculogram (EOG), electrocardiogram (ECG), and/or electromyogram (EMG), accelerometer, acoustical and photoplethesmographic signals. The X4 system only acquires and displays physiological signals, no claims are being made for analysis of the acquired signals with respect to the accuracy, precision and reliability.
The X4 system is used for configurable acquisition of physiological signals. Model X4-E provides for acquisition of three channels of electroencephalography (EEG) and one photoplethesmographic (PPG) signal from a head strip, with an optional channel connected to two sensors via a dual-lead connector with twice the gain. Model X4-M provides four channels of EEG with the dual-lead connector providing the input for reference sensors. Both models measure sound via an acoustic microphone, and movement and position measured via a 3-D accelerometer. The device is designed so it can be affixed by the patient and to record data. Alternatively, a technician can affix the device and display the signals via a wireless connection during acquisition. The X4 system firmware monitors signal quality to ensure that the sensors are properly applied and that high quality signals are being acquired.
The X4 software provides a means to: a) initiate a study and track patient information, b) acquire and save signals to the memory of the device, c) acquire and wirelessly transmit signals from the device, d) upload data saved in the memory of the device to a PC, and e) visually inspect the signal quality.
The acquired signals are saved in a universal data format (European Data Format – EDF) that is intended to be analyzed with third party software, including Advanced Brain Monitoring's Sleep Profile Software (K120450).
The provided text describes the X4 System, a device for acquiring physiological signals. The 510(k) summary focuses on demonstrating substantial equivalence to predicate devices through non-clinical testing and a limited clinical study.
Here's an analysis of the acceptance criteria and study information provided:
Acceptance Criteria and Reported Device Performance
The core acceptance criterion for the X4 System, as articulated in the clinical tests, is based on the interpretability of the acquired signals and the ease of device application.
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Non-Clinical: | |
| Compliance with system-level requirements | All features of the X4 System were compliant with the system level requirements. |
| Electrical, biological safety, performance, and software tests | Confirmation of conformity to FDA recognized consensus standards and voluntary standards (IEC 60601-1-1, IEC 60601-1-2, ISO 10993-1, IEC 60601-1-11, IEC 60601-2-26). |
| Signals provide similar information to predicate device for physician interpretation | Signals acquired with the X4 System provide similar information as compared to the predicate device that would allow a physician to interpret the signals. (Specific metrics or comparison data are not provided in this summary.) |
| Clinical: | |
| Over 90% of overnight studies recorded with the X4 are interpretable and behave as expected | Result: Over 90% of studies recorded overnight with the X4 are interpretable and behave as expected. |
| Device instructions can be applied without difficulty by patients in the home | Result: The X4 instructions were applied without difficulty, allowing all subjects to properly apply the device so that it remained in the proper position and allowing any problems that triggered an audio alarm to be properly resolved. (No specific quantitative metric for "difficulty" or "proper application" is given beyond the qualitative statement.) |
Study Details for Acceptance Criteria
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- Test set sample size: While a specific number for the sample size for the clinical test is not explicitly stated, it refers to "all subjects" and "over 90% of studies recorded overnight." This suggests a prospective clinical study involving multiple subjects.
- Data provenance: Not explicitly stated, but the context of a 510(k) submission to the FDA for a US company suggests it would likely involve data from the US, potentially a prospective clinical trial.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)
- The summary states that "signals acquired with the X4 System provide similar information as compared to the predicate device that would allow a physician to interpret the signals." and that "over 90% of studies recorded overnight with the X4 are interpretable."
- This implies that physicians are the experts who would interpret the signals to determine interpretability. However, the number of experts and their specific qualifications (e.g., board-certified sleep physicians, neurologists, years of experience) are not specified in the provided text.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- The text does not specify an adjudication method. It mentions that "physicians" would interpret the signals, but it does not detail how potential disagreements among interpreters would be resolved or if multiple interpreters were used for each case.
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
- No, an MRMC comparative effectiveness study was not done.
- The X4 System is described as a device for acquiring, recording, transmitting, and displaying physiological signals, with "no claims being made for analysis of the acquired signals with respect to the accuracy, precision and reliability." This indicates that the device itself does not perform AI-assisted analysis and therefore, a study on human reader improvement with AI assistance would not be applicable to this submission.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- No, a standalone (algorithm only) performance study was not done.
- The device's intended use is to acquire, record, transmit, and display physiological signals. It explicitly states "no claims are being made for analysis of the acquired signals." Thus, there is no standalone algorithm being evaluated for diagnostic or analytical performance.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
- The ground truth for the clinical study appears to be expert interpretation (physician interpretability) of the acquired signals. The study aimed to demonstrate that the signals are "interpretable" and "behave as expected," which would rely on a physician's assessment.
8. The sample size for the training set
- Not applicable / Not provided. The X4 System is a signal acquisition and display device, not an analytical or AI-driven system. Therefore, it does not involve a "training set" in the context of machine learning algorithms.
9. How the ground truth for the training set was established
- Not applicable. As a signal acquisition device without analytical claims, there is no training set or associated ground truth establishment process for algorithm training.
§ 882.1400 Electroencephalograph.
(a)
Identification. An electroencephalograph is a device used to measure and record the electrical activity of the patient's brain obtained by placing two or more electrodes on the head.(b)
Classification. Class II (performance standards).