(273 days)
The IMED-Z Fluid Status Monitor is intended for patients:
- With fluid management problems
- Taking diuretic medication
- Living with Heart Failure ●
- Living with End-stage Renal Disease ●
- Recovering from Coronary artery Disease related event ●
- o Suffering from Recurrent Dehydration
This device is intended for use, under the direction of a physician, for the noninvasive monitoring and management of patients with fluid management problems in a variety of medically accepted clinical applications.
The IMED-Z Fluid Status Monitor is a non-invasive, battery-powered impedance monitor designed as an "early warning" monitor for determining changes in the fluid status of patients with fluid management problems. The IMED-Z Fluid Status Monitor works by applying a low-amplitude, high frequency electrical current to the body and measuring the electrical impedance using a four-point measurement technique through hydrogel (ECG style) electrode contacts. Base Impedance, also known as Zo, decreases when fluid increases and increases when fluid decreases. The Fluid Status Monitor is designed for use with disposable, self-adhesive silver / silver chloride electrodes that are readily available from Intersection Medical, Inc. IMED-approved electrodes must be used with the IMED-Z Fluid Status Monitor. Zo reading obtained from unapproved electrodes may not be accurate.
The provided text describes the IMED-Z Fluid Status Monitor and its substantial equivalence to a predicate device, the ZOE Fluid Status Monitor. However, it does not contain a detailed study proving the device meets specific acceptance criteria in the way a clinical performance study would typically be presented. Instead, it focuses on bench testing and comparisons to the predicate device's performance.
Based on the information provided, here's a breakdown:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly present a table of acceptance criteria with corresponding performance metrics for a clinical study. Instead, it describes various types of testing and their outcomes aimed at demonstrating substantial equivalence. The core performance "acceptance criteria" appear to be related to matching the measurement linearity and accuracy of the predicate device for impedance measurements in a bench setting.
| Acceptance Criteria (Inferred from Performance Bench Testing) | Reported Device Performance |
|---|---|
| Measurement linearity of impedance on simulated thoracic impedances | IMED-Z device demonstrated linearity matching the predicate ZOE device. |
| Measurement accuracy of impedance on simulated thoracic impedances | IMED-Z device demonstrated accuracy matching the predicate ZOE device. |
| Biocompatibility (cytotoxicity, sensitization, irritation) | Fulfilled, in accordance with ISO-10993. |
| Electrical Safety (IEC 60601-1 Ed 3.1) | Fulfilled requirements (Report Number: 101945161LAX-001). |
| Electromagnetic Compatibility (IEC 60601-1-2 Ed 3.0) | Complies with requirements (Report Number: 101754547BOX-001). |
| Design Specification Requirements | All design requirements, including impedance measurement accuracy, were met (via Design Verification and Validation Activities). |
| Shelf-life | Validated for up to 24 months (via accelerated shelf-life testing). |
| Usability | Healthcare workers validated human interface design and instructions for use, ensuring safe and effective device interactions. |
2. Sample Size Used for the Test Set and Data Provenance
The document describes performance bench testing using a "calibrated precision resistor array." This means the "test set" was not human physiological data, but rather a set of known electrical impedances.
- Sample size for test set: Not explicitly stated as a number of "cases" but implies a range of impedance loads from the precision resistor array.
- Data provenance: Bench simulated data, not from human subjects or specific countries.
- Retrospective/Prospective: Not applicable, as it's bench testing.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
- Number of experts: Not applicable. The "ground truth" for the bench testing was the known values of the "calibrated precision resistor array."
- Qualifications of experts: Not applicable.
4. Adjudication Method for the Test Set
- Adjudication method: Not applicable. The "ground truth" was instrumental (calibrated resistor values), not based on expert opinion.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
- No, an MRMC comparative effectiveness study was not done. The document describes a "head-to-head performance bench test" comparing the IMED-Z device to the predicate ZOE device using a resistor array. It does not involve human readers interpreting output or measuring their improvement with or without AI assistance.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
- Yes, a standalone performance assessment was done in the context of the bench testing. The device (algorithm and hardware) was tested on its own to measure impedance values against known resistor values, demonstrating its function without a human interpreter in the loop for that specific measurement. However, this is for the technical performance of measuring impedance, not a clinical diagnostic performance in a standalone AI context.
7. The Type of Ground Truth Used
- Bench Testing: The ground truth for the performance bench testing was the known, calibrated electrical impedance values presented by the precision resistor array.
- Other Testing:
- Biocompatibility: Established through standardized laboratory tests.
- Electrical Safety and EMC: Established through compliance with international standards (IEC 60601-1, IEC 60601-1-2).
- Design Verification/Validation: Established against internal design specifications.
- Usability: Established through observation and feedback from healthcare workers.
8. The Sample Size for the Training Set
- Not applicable / Not explicitly mentioned. This document describes premarket notification for a medical device (Impedance Plethysmograph), not an AI/ML algorithm that typically requires a large training set of labeled data. The IMED-Z device functions by directly measuring electrical impedance, not by pattern recognition or learning from a dataset in the way a modern AI would. It is a measurement device.
9. How the Ground Truth for the Training Set Was Established
- Not applicable / Not explicitly mentioned. As there's no indication of an AI/ML component requiring a "training set" in the conventional sense, the establishment of ground truth for such a set is not discussed.
§ 870.2770 Impedance plethysmograph.
(a)
Identification. An impedance plethysmograph is a device used to estimate peripheral blood flow by measuring electrical impedance changes in a region of the body such as the arms and legs.(b)
Classification. Class II (special controls). The device, when it is a body composition analyzer which is not intended to diagnose or treat any medical condition, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 870.9.