(91 days)
The BOD POD® is indicated for measuring the body mass and estimating the body composition (i.e. percent and absolute amounts of fat and lean body mass) of generally healthy individuals. The BOD POD is also indicated for estimating Resting Metabolic Rate (RMR) and Total Energy Expenditure (TEE) in generally healthy individuals aged 18 years or older.
The Sonamet Body Composition System is designed to measure the mass and estimate the body composition of individuals. Once an individual's body composition has been determined, the BOD POD is able to accurately estimate Resting Metabolic Rate (RMR) and total Energy Expenditure (TEE).
The BOD POD estimates body composition using a densiometric approach (i.e. by determining the density of the entire body). A weighing apparatus is used to measure the subject's mass. Air displacement plethysmography is used to measure the subject's volume. Using this data, the subject's density is calculated. The subject's body composition is then estimated using several algorithms derived from scientific research.
An individual's RMR and TEE can also be estimated accurately using values for Fat Mass and Fat Free Mass. Scientifically derived algorithms utilize the Fat Mass and Fat Free mass values determined by the BOD POD to calculate RMR and TEE.
Here's an analysis of the provided 510(k) summary regarding the acceptance criteria and the study conducted for the Sonamet Body Composition Analyzer (BOD POD):
1. Table of Acceptance Criteria and Reported Device Performance
The provided document does not explicitly state specific numerical acceptance criteria for the device's performance. Instead, it makes a general statement about accuracy.
| Acceptance Criteria (Explicitly stated in document) | Reported Device Performance |
|---|---|
| Not explicitly stated as specific numerical thresholds. | "The results of verification testing demonstrate that the RMR and TEE results generated by the BOD POD Body Composition Analyzer are accurate when compared with expected results based on published scientific research..." |
| Not explicitly stated as specific numerical thresholds. | "...and is substantially equivalent to the predicate devices." |
| Not explicitly stated as specific numerical thresholds. | "Test results indicate that the device satisfies functional performance requirements safely and accurately when used as indicated." |
2. Sample Size Used for the Test Set and Data Provenance
The document does not provide information on the sample size used for the test set or the data provenance (e.g., country of origin, retrospective or prospective nature). It only mentions "verification testing."
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
The document does not provide information on the number of experts used or their qualifications for establishing ground truth in any test set.
4. Adjudication Method for the Test Set
The document does not specify any adjudication method used for a test set.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
The document does not mention a multi-reader multi-case (MRMC) comparative effectiveness study. The device is a "Body Composition Analyzer," which typically involves direct measurement rather than interpretation by multiple human readers comparing performance with and without AI assistance.
6. Standalone (Algorithm Only) Performance Study
The entire document describes the performance of the standalone device (algorithm only). The BOD POD itself is the algorithm that measures mass and volume and then calculates body composition, RMR, and TEE. The "verification testing" mentioned would refer to the performance of this algorithm.
7. Type of Ground Truth Used
The ground truth for the device's accuracy appears to be established by:
- Published scientific research: The document states, "RMR and TEE results generated by the BOD POD Body Composition Analyzer are accurate when compared with expected results based on published scientific research." This implies that established scientific models or data serve as the benchmark.
- Substantial equivalence to predicate devices: The comparison to legally marketed predicate devices (Sonamet Body Composition Analyzer K924972 and TANITA Segmental Body Composition Analyzer Model BC-418) implies that their established performance serves as a form of ground truth or benchmark for comparison.
8. Sample Size for the Training Set
The document does not provide information on the sample size used for a "training set." This type of device (Body Composition Analyzer) likely relies on established physical principles and scientific equations rather than a machine learning model that would typically have a distinct "training set." The algorithms are "derived from scientific research."
9. How Ground Truth for the Training Set Was Established
As noted above, the concept of a "training set" in a machine learning sense is not applicable here. The algorithms for calculating body composition, RMR, and TEE are described as being "derived from scientific research." This means the ground truth for establishing these algorithms comes from:
- Scientific literature and models: Previous research on human physiology, energy expenditure, and densitometry would have informed the algorithms.
- Empirical data from prior studies: The original development of these equations would have involved studies where body composition, RMR, and TEE were measured using gold standard methods (e.g., DEXA, indirect calorimetry for RMR) to derive and validate the predictive equations used in the device.
§ 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.