(592 days)
A bioclectrical impedance analyzer/monitor for use on adult human patients, utilizing impedance ratios that are displayed as an L-Dex ratio that supports the measurement of extra cellular fluid volume differences between the limbs and is presented to the clinician on an L-Dex scale as an aid to their clinical assessment of unilateral lymphedema of the arm and leg in women and the leg in men.
The device is only indicated for patients who will have or who have had lymph nodes, from the axillary and pelvic regions, either removed, damaged or irradiated.
The device is not intended to diagnose or predict lymphedema of the extremity.
Lymphedema Analysis PC Software - an optional PC software package that is intended to be used only with the ImpediMed L-Dex U400 analyzer/monitor for uploading data on to the PC from the L-Dex U400, processing and analyzing of bioimpedance measurements.
The L-Dex® U400 ExtraCellular Fluid Analyzer like its predicate is a multi-frequency bioelectrical impedance analyzer. It is a non-invasive, battery powered extracellular fluid status analyzer.
The L-Dex® U400 accurately measures current, voltage and phase angle, calculates impedance, resistance and reactance as with its predicate. These measurements and calculations are used to estimate extracellular fluid (ECF) allowing for aiding in the assessment of the development of unilateral Lymphedema of the limbs.
The provided text does not contain detailed information about specific acceptance criteria or a dedicated study proving the device meets those criteria. The submission is a 510(k) premarket notification primarily focused on demonstrating substantial equivalence to a predicate device for expanded indications for use.
Here's an analysis based on the available text:
1. Table of Acceptance Criteria and Reported Device Performance:
The document does not specify quantitative acceptance criteria or a direct performance table for the L-Dex® U400 ExtraCellular Fluid Analyzer. Instead, it relies on demonstrating that the device is substantially equivalent to its predicate (L-Dex® U400 ExtraCellular Fluid Analyzer, K080825) in terms of design, construction, hardware, software, operational features, and safety features.
The core performance claim is its ability to "accurately measure current, voltage and phase angle, calculate impedance, resistance and reactance" and use these to "estimate extracellular fluid (ECF) allowing for aiding in the assessment of the development of unilateral Lymphedema of the limbs." However, specific numerical performance metrics (e.g., accuracy, sensitivity, specificity, or inter-rater reliability values) are not provided in this summary.
2. Sample Size Used for the Test Set and Data Provenance:
The document states, "Clinical Performance data in support of the expanded indications for use is included within this submission." However, it does not provide any details about:
- The sample size used for any clinical test set.
- The data provenance (e.g., country of origin, retrospective or prospective nature of the data).
- The type of study design for this clinical performance data.
3. Number of Experts Used to Establish Ground Truth and Qualifications:
The document does not mention using experts to establish ground truth for a test set. This type of detail would typically be found in a more comprehensive clinical study report, which is not included in this 510(k) summary.
4. Adjudication Method for the Test Set:
Since there is no mention of experts or a test set requiring adjudication, there is no information on the adjudication method.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
The document does not mention a multi-reader multi-case (MRMC) comparative effectiveness study or any effect size related to human readers improving with AI assistance. The device is described as "a bioelectrical impedance analyzer/monitor," which suggests a direct measurement device rather than an AI-assisted diagnostic tool for human readers.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study:
The document focuses on the device's ability to measure and calculate, with the output (L-Dex ratio) being presented to a clinician "as an aid to their clinical assessment." This implies a standalone performance of the device's measurements and calculations. However, no specific standalone performance metrics (like accuracy against a gold standard for ECF volume differences) are provided in this summary. The "clinical performance data" mentioned must have related to this, but the details are omitted.
7. Type of Ground Truth Used:
The document does not explicitly state the type of ground truth used for any clinical performance data. Given the device's function to aid in the assessment of lymphedema, potential ground truths could include:
- Physical measurements (e.g., circumference measurements)
- Diagnosis by a specialist physician (e.g., lymphedema specialist)
- Imaging techniques
- Pathology (though less likely for lymphedema diagnosis in this context)
- Outcomes data
However, none of these are confirmed in the provided text.
8. Sample Size for the Training Set:
The document does not mention a training set sample size. This information would typically be relevant for machine learning algorithms, and while the device uses "bioelectrical impedance analyzer/monitor" it is not explicitly stated to be an AI/ML device in the modern sense. It calculates impedance ratios, which implies a pre-defined algorithm rather than one that learns from a training set.
9. How the Ground Truth for the Training Set Was Established:
Since no training set is mentioned, there is no information on how its ground truth was established.
In summary:
This 510(k) summary focuses on demonstrating substantial equivalence to a predicate device for expanded indications, rather than providing detailed acceptance criteria and supporting clinical study results with specific metrics, sample sizes, and ground truth methodologies. The core argument for safety and effectiveness relies on the L-Dex® U400 being identical in design and function to a previously cleared device. Information regarding specific clinical performance data is noted as being included in the full submission, but not detailed in this summary.
§ 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.