(110 days)
For use only in healthy subjects for Measurement of:
Estimated: Skeletal Muscle Mass, Extra-Cellular Water (ICW), Total Body Water (ICW), Total Body Water (TBW), ECW/TBW, Body Fat, Percentage of Body Fat (PBF), Body Lean + Dry Lean, Metabolic Rates), Segmental Lean Mass, Segmental Fat Mass, % Segmental Body Fat, Energy Expenditure of Activity, Visceral Fat Area (VFA), Visceral Fat Level, Segmental Body Water, Percent Body Shape Graph, Weight Control, Fat Control, Muscle Control, Segmental ECW/TBW, Segmental ICW, TBW/LBM, Leg Lean Mass, Fitness Score, AC (Arm Circumference)
Actual: Weight, Body Mass Index (BMI) and Impedance Values, Height [which can require the entry of Height], Resistance Values [only for InBody S10], Reactance Values [only for InBody770, InBody S10], Phase Angle [only for InBody770, InBody S10]
Impedance plethysmographic devices are used to estimate peripheral blood flow by measuring electrical impedance changes in a region of the body such as the arms and legs. Multi-frequency and segmental bioelectrical impedance analysis can estimate the distribution of body water (total body water; intra-cellular water), and can correlate with fluid compartmentalization. Assuming that body lean mass is hydrated in a constant and uniform manner; bioelectrical impedance analysis can be used to estimate body lean mass and fat mass.
These devices are impedance plethysmograph body composition analyzers. These devices determine body composition parameters based on bioelectrical impedance analysis (BIA). BIA relies on the differing behavior of biological tissues in response to an applied electrical current. Lean tissue is generally highly conductive because it contains large amounts of bound water and electrolytes, while fat tissue and bone are relatively poor conductors. By analyzing the response to electrical signals, BIA thereby permits differentiation of lean tissue, fat, and water and, in some instances, derivation of related body composition parameters. The total impedance resulting from BIA incorporates both resistance and capacitance components. Impedance plethysmographic devices are used to estimate peripheral blood flow by measuring electrical impedance changes in a region of the body such as the arms and legs. Multi-frequency and segmental bioelectrical impedance analysis can estimate the distribution of body water (total body water; intra-cellular water; extra-cellular water), and can correlate with fluid compartmentalization. Assuming that body lean mass is hydrated in a constant and uniform manner; bioelectrical impedance analysis can be used to estimate body lean mass and fat mass. Body composition analysis results may be of value to health care professionals in their management of the relative balance and levels of fat and lean tissue
The Biospace Body Composition Analyzers (Models InBody770, InBody570, InBody S10, InBody230) were evaluated through a clinical study to demonstrate substantial equivalence to previously cleared predicate devices. The primary method of evaluation involved comparing the performance of the new devices against predicate devices across a range of body composition metrics.
1. Table of Acceptance Criteria and Reported Device Performance:
The document does not explicitly state "acceptance criteria" with numerical thresholds for performance. Instead, it relies on demonstrating comparable performance to predicate devices already cleared by the FDA, with "very nearly 1.00" correlation coefficients between the new devices and predicates as the key performance indicator.
| Metric | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Correlation Coefficient with Predicate Devices | Close to 1.00 | Very nearly 1.00 for all four new units |
2. Sample Size and Data Provenance:
- Test Set Sample Size: Approximately 80 patients.
- Data Provenance: The document does not explicitly state the country of origin. Given Biospace Corporation Limited is based in Seoul, Korea, it is highly probable the data originated from Korea. The study appears to be prospective as it states "We conducted clinical testing on each model."
3. Number and Qualifications of Experts for Ground Truth:
The document does not mention using experts to establish ground truth for the test set in the traditional sense (e.g., radiologists interpreting images). The study focuses on comparing the output of the new devices against predicate devices, implying that the predicate devices themselves serve as a form of "reference" or "ground truth" for comparative effectiveness in this context.
4. Adjudication Method:
Given that the ground truth appears to be based on the output of predicate devices, an adjudication method in the form of expert consensus is not applicable or mentioned in the document.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
An MRMC study was not conducted as this device does not involve human readers interpreting diagnostic images. The study compared device outputs directly. Therefore, there is no effect size of human improvement with or without AI assistance to report.
6. Standalone Performance Study:
A standalone performance study of the algorithm (if "algorithm" refers to the core BIA calculation logic) was implicitly done in the context of comparing the new devices against predicates. The reported "very nearly 1.00" correlation coefficients represent the standalone performance of the new devices relative to the established performance of the predicate devices. The study compares the device's measurement capabilities rather than an AI algorithm without human intervention.
7. Type of Ground Truth Used:
The primary "ground truth" for comparison was the measurements obtained from predicate devices. This is a form of comparative validation against established medical devices with a known performance profile.
8. Sample Size for the Training Set:
The document does not provide information regarding a separate training set or its sample size. As a medical device based on bioelectrical impedance analysis, its underlying principles and algorithms might be well-established, potentially requiring calibration and validation rather than extensive machine learning-style "training" on a specific dataset for output generation in the same way an AI image classification model would.
9. How Ground Truth for the Training Set Was Established:
As no explicit training set is mentioned in the provided text, the method for establishing its ground truth 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.