(112 days)
The TANITA Ironman Innerscan Body Composition Monitor measures body weight, impedance and estimates total and segmental body fat percentage, body water, total and segmental muscle mass, physique rating, bone mass, visceral fat rating with healthy range, basal metabolic rate(BMR), daily caloric intake(DCI) and metabolic age using BIA (Bioelectrical Impedance Analysis). The device is intended to be used by generally healthy children 7-17 years old and generally healthy adults with active, moderately active, to inactive lifestyles for body composition assessment in the home environment. Actual measurements made by the BC-558 include weight and impedance. Based upon these measured values, values are calculated for: total and segmental body fat percentage, body water, total and segmental muscle mass, physique rating, bone mass, visceral fat rating with healthy range, basal metabolic rate (BMR), daily caloric intake (DCI) and metabolic age.
The TANTA Ironman Innerscan Body Composition Monitor BC-558 are a computer-operated body composition analyzer that utilizes BlA (bigledrical impedance analysis) to determine body fat percent, muscle mass, bone weight, visceral fat rating, Basal Metabolic Rate (BMR), metabolism age, physique rating, daily calorie intake (DCI), body water percent and segmental fat percent.
Here's a breakdown of the acceptance criteria and study information based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The provided text does not explicitly state acceptance criteria in terms of specific performance metrics or thresholds the device needed to meet. Instead, it relies on a comparison to predicate devices, asserting "substantial equivalence." The "Predicate Devices" section in the summary provides a side-by-side comparison of specifications and functions, implying that matching or exceeding these characteristics (particularly for the new functionalities) constituted meeting the "acceptance criteria" for substantial equivalence.
Since precise quantitative acceptance criteria are not given, the table below will present the comparative specifications as performance indicators for the subject device (BC-558) and its predicates.
| Feature | Acceptance Criteria (Implied by Predicate) | Reported Device Performance (TANITA Ironman Innerscan Body Composition Monitor: Model BC-558) |
|---|---|---|
| Analytical Method | Segmental BIA or Foot-to-Foot BIA with In-house BIA and DXEA/Deuterium Dilution reference | Segmental BIA with In-house BIA and DXEA reference |
| Measurement Frequency | 50kHz | 50kHz |
| Measurement Current | Max. 500μA or Max. 90μA | Max. 500μA |
| Number of Electrodes | 4 or 8 | 8 |
| Capacity | 150 kg / 330 lb or 200 kg / 440 lb | 150 kg / 330 lb |
| Increments | 100 g / 0.2 lb or 50 g / 0.1 lb | 100 g / 0.2 lb or 50 g / 0.1 lb |
| Body Fat % Increment | 0.1% | 0.1% |
| User Memory | 4 | 4 |
| Input Age Range | 7-99 (Child: 7-17, Adult: 18-99) | 7-99 (Child: 7-17, Adult: 18-99) |
| Input Height Range | 100 cm - 220 cm or 90 cm - 249 cm | 90 cm - 220 cm |
| Input Activity Level | 1-3 | 1-3 |
| Input Body Type | Standard / Athlete | Standard / Athlete |
| Data Memory | 4 weeks / 1 week average, 2 months / 1 month average (Predicate K040778) | 31 days / 1 day average, 52 weeks / 1 week average, 36 months / 1 month average |
| Power Supply | AA Batteries or AC Adapter / DC5V 3.5A | AA Batteries |
| Printer Function | Present on one predicate | Not present |
| Computer Interface | Present on one predicate | Not present |
| Weight Measurement | ✓ | ✓ |
| Full Body Fat % | ✓ | ✓ |
| Segmental Body Fat % | ✓ (Right arm, Left arm, Right feet, Left feet, Trunk present on predicate K033157) | ✓ (Right arm, Left arm, Right feet, Left feet, Trunk) |
| Body Water % | ✓ | ✓ |
| Full Body Muscle Mass | ✓ | ✓ |
| Segmental Muscle Mass | ✓ (Right arm, Left arm, Right feet, Left feet, Trunk present on predicate K033157) | ✓ (Right arm, Left arm, Right feet, Left feet, Trunk) |
| Physique Rating | ✓ | ✓ |
| Bone Mass | ✓ | ✓ |
| Visceral Fat | ✓ | ✓ |
| Visceral Fat Judge | ✓ for one predicate, not for another | ✓ |
| BMR | ✓ | ✓ |
| DCI | ✓ | ✓ |
| Metabolic Age | ✓ | ✓ |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: This document does not specify a sample size for any test set. It refers to "the results of using the previously approved BIA methodology with our whole body BIA," suggesting general validation, but no specific number of subjects is mentioned for a test set.
- Data Provenance: Not specified. There is no mention of the country of origin or whether the data was retrospective or prospective.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
- Number of Experts: Not specified.
- Qualifications of Experts: Not specified.
4. Adjudication Method for the Test Set
- Not specified. The document does not describe any expert adjudication process.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- Was it done?: No. The document does not describe an MRMC study comparing human readers with and without AI assistance. The evaluation is based on "substantial equivalence" to predicate devices and the performance of the BIA methodology itself, not on human-in-the-loop performance.
- Effect size of improvement: Not applicable, as no MRMC study was conducted.
6. Standalone (Algorithm Only) Performance Study
- Was it done?: Yes, implicitly. The document states, "Based on the results of using the previously approved BIA methodology with our whole body BIA, it was concluded that the TANITA Ironman Innerscan Body Composition Monitor BC-558 performs as well as the predicate devices and therefore have proven its safety and efficacy." This indicates that the device's algorithmic performance in estimating body composition was evaluated in comparison to the established BIA methodology and predicate devices. However, details of this standalone performance are limited to the comparative specifications provided.
7. Type of Ground Truth Used
- The document states the analytical method for the BC-558 and its predicates uses "In house BIA and DXEA reference" or "In house BIA and DXEA/Deuterium Dilution reference."
- DXEA (Dual-energy X-ray absorptiometry): This is a widely accepted and highly accurate method for measuring body composition (bone mineral density, fat mass, and lean mass) and is considered a "gold standard" for body composition analysis in research and clinical settings.
- Deuterium Dilution: Another reference method, particularly for total body water, which can be used to derive fat-free mass.
- Therefore, the ground truth used appears to be objective reference methods (DXEA, Deuterium Dilution), which are considered highly accurate and reliable measures of body composition.
8. Sample Size for the Training Set
- Not specified. The document does not provide details about a specific training set or its size. The device likely relies on algorithms and equations derived from extensive prior research and data (implied by "previously approved BIA methodology"), rather than a newly trained model for this specific submission.
9. How the Ground Truth for the Training Set Was Established
- Not specified. Given the reliance on "previously approved BIA methodology" and "in house BIA and DXEA reference," it is inferred that the underlying BIA algorithms and their derived equations were developed and validated using data where ground truth was established by highly accurate methods like DXEA and potentially Deuterium Dilution. However, the specific process for the training set of this particular device (if a separate training phase was conducted beyond the general BIA methodology development) is not described.
§ 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.