(191 days)
A body composition analyzer that measures body weight and impedance and estimates total and segmental body fat percent, body mass index (BMI), fat mass, fat-free mass, regional muscle mass, basal metabolic rate, and total body water using BIA (bioelectrical impedance analysis) in healthy children (7-17 years old) and healthy adults.
The TANITA BC-418, Segmental Body Composition Analyzer is a computer-operated body composition analyzer that utilizes BIA (bioelectrical impedance analysis) to determine body fat percent and regional muscle mass.
Here's an analysis of the provided text, focusing on the acceptance criteria and the study that proves the device meets those criteria:
1. Table of Acceptance Criteria and Reported Device Performance
The provided 510(k) summary does not explicitly state quantitative acceptance criteria in a dedicated section. Instead, it relies on a comparison to a predicate device to establish substantial equivalence.
| Characteristic / Performance Metric | Acceptance Criteria (Implied by Predicate) | Reported Device Performance |
|---|---|---|
| Intended Use | A combination non-invasive device, which determines weight and estimates body fat composition using BIA (bioelectrical impedance analysis). | A combination non-invasive device, which determines weight and estimates body fat composition and muscle mass using BIA (bioelectrical impedance analysis). (Note: Applicant device adds "muscle mass" and "segmental" BIA, which is a key differentiator). |
| Product Description | Body composition analyzer/scale that utilizes a "foot-to-foot" BIA (bio- electrical impedance) technology to determine internal body composition. | Body composition analyzer/scale that utilizes segmental BIA (bio- electrical impedance) technology to determine internal body composition. |
| Analytical Method/Measurement | • Foot-to-Foot BIA | |
| • In-house BIA and DEXA reference methods | • Segmental BIA | |
| • In-house BIA and DEXA reference methods | ||
| Safety and Efficacy | Safe and effective as demonstrated by the predicate device's prior approval. | "Performs as well as the predicate device and therefore have proven its safety and efficacy." |
Explanation of "Acceptance Criteria" in this context: For a 510(k), the primary "acceptance criterion" is often that the new device is "substantially equivalent" to a legally marketed predicate device. This means it has the same intended use, and the same technological characteristics, or if it has different technological characteristics, it does not raise different questions of safety and effectiveness, and the information submitted demonstrates that the device is as safe and effective as the predicate device. The document implies that the performance of the predicate (Model TBF-410) serves as the benchmark for acceptable performance.
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: The document does not specify a sample size for the test set. It mentions "Side by side comparisons" and "results of using the previously approved BIA methodology," but no numerical data for the number of subjects or measurements.
- Data Provenance: The document does not explicitly state the country of origin of the data or whether it was retrospective or prospective. The study appears to be an internal comparison ("in-house BIA and DEXA reference methods") conducted by Tanita.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
The document mentions "in-house BIA and DEXA reference methods" for establishing ground truth, but it does not specify the number of experts or their qualifications who were involved in operating the DEXA or BIA reference methods, or in interpreting the results to establish ground truth for the test set.
4. Adjudication Method for the Test Set
The document does not describe any specific adjudication method (e.g., 2+1, 3+1, none) for the test set. The comparison seems to be direct performance against the predicate and reference methods rather than an expert consensus process on specific cases.
5. If a Multi Reader Multi Case (MRMC) Comparative Effectiveness Study was done
A Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not conducted. The study described is a comparison of the new device to a predicate device and reference methods, not an assessment of human reader performance with or without AI assistance. The device itself is a measurement tool, not an AI for interpretation.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, the study described is essentially a standalone performance assessment of the device (algorithm only). The device is a diagnostic measurement tool. The evaluation focuses on its analytical performance (body composition measurements) compared to reference methods and a predicate, without considering a human-in-the-loop aspect for interpretation or decision-making.
7. The Type of Ground Truth Used
The ground truth was established using:
- "In-house BIA and DEXA reference methods."
- DEXA (Dual-energy X-ray absorptiometry) is widely considered a gold standard for body composition measurement.
- "In-house BIA" (of the predicate device) is used as a reference point for substantial equivalence, implying its output is accepted as valid.
8. The Sample Size for the Training Set
The document does not provide any information about a separate "training set" or its sample size. This type of device relies on established BIA principles and internal calibration, rather than a machine learning model that requires a distinct training set in the typical sense. The "training" here would likely refer to the development and calibration data used to create the BIA algorithms for body composition estimation embedded in the device, which is not detailed.
9. How the Ground Truth for the Training Set was Established
As no separate training set is explicitly mentioned or detailed, there is no information on how its ground truth was established. For BIA devices, the algorithms are typically derived from extensive research correlating impedance measurements with direct body composition methods (like DEXA or hydrostatic weighing) in general populations. The "in-house BIA and DEXA reference methods" mentioned likely refer to the validation of the device's algorithms, not a distinct training process for a machine learning model.
§ 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.