(72 days)
Combination unit for measuring systolic and diastolic blood pressures and pulse rates in adult patients with arm circumference between 4.9" to 8" inches as well as body composition, i.e. estimation of body fat, a noninvasive bioimpedance analyzer for use in estimating the human's body fat volume (mass) and percentage by weight. Age range 10-80 years normal subjects, 18-80 years for athletic subjects.
The Model WT-20 Wrist Blood Pressure Monitor & Fat Meter combines the familiar wrist blood pressure monitor found over the counter in drug stores with a body composition/body fat meter.
Here's an analysis of the provided text to extract the requested information about acceptance criteria and the study proving the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance:
The document describes the device, the Nissei WT-20 Wrist Blood Pressure Monitor & Fat Meter, as substantially equivalent to predicate devices. This implies that the 'acceptance criteria' for the Nissei WT-20 are that its performance is comparable to or meets the specifications of the predicate devices. The study provided focuses on this comparison rather than defining explicit numerical acceptance criteria for a new, unique performance claim.
| Characteristic | Predicate Device (OMRON Body Fat Analyzer HBF-306) | Nissei WT-20 (Reported Performance) | Acceptance Criteria (Implied) |
|---|---|---|---|
| Operating Principle | Bioelectrical Impedance Analysis (BIA) | SAME (Also measures blood pressure) | Must be BIA for fat measurement |
| Display (Body Fat %) | 4.0 to 50.0% | 5.0 to 50.0% | Functionally similar range (within acceptable variance) |
| Display (BMI) | 7.0 to 90.0 | 5 to 100 | Functionally similar range (within acceptable variance) |
| BMI Classification | 4 levels | 4 levels | Same number of classification levels |
| Measurement Time | 7 Seconds | 5 to 10 seconds | Similar measurement time frame |
| Height Range | 3'4" to 6'6" (101cm. to 198cm.) | 36 to 79 inches (appears to be a slightly wider range: 3 ft to 6ft 7in) | Covers a similar range of heights |
| Weight Range | 23lbs. to 440 1/2 lbs (10kg.to220kg.) | 22 to 440 pounds (appears slightly different at the lower end) | Covers a similar range of weights |
| Age Range (Normal) | 10 to 80 years old | 10 to 80 (age) | Covers the same age range |
| Age Range (Athlete) | 18 to 60 years old | Indicated 18-80 years for athletic subjects in Indications for Use. The table only says "10 to 80 (age)". | Covers the same or broader age range |
| Gender | Male / Female | Male or female (sex) | Supports both genders |
| Power Supply | 2 AAA batteries (R03) | SAME (Alkaline recommended) | Uses 2 AAA batteries |
| Memory | 9 personal profile memories | 4 sets of weight, height, age, sex and 10 measurement results of blood pressure and body fat | Provides memory for user profiles and historical measurements |
| Indications for Use | Not explicitly stated for HBF-306, but implied for body fat estimation. | Measuring systolic and diastolic blood pressures and pulse rates, and body composition (body fat volume and percentage). | Performance for body fat: comparable to predicate. Blood pressure: comparable to WS-500 |
2. Sample Size Used for the Test Set and Data Provenance:
The document mentions "clinical testing data" but does not explicitly state the sample size (number of participants) used for the test set for the body fat measurement or blood pressure features. The provenance of the data (country of origin, retrospective or prospective) is also not specified.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:
The document does not provide information on the number or qualifications of experts used to establish ground truth for the test set. Given the nature of a 510(k) submission for substantial equivalence, the "ground truth" for the body fat measurement would likely be established through comparison to a well-accepted clinical standard (e.g., DEXA or underwater weighing), and for blood pressure, comparison to a validated manual sphygmomanometer. However, the details of these comparisons are not in the provided text.
4. Adjudication Method for the Test Set:
The document does not describe any adjudication method for the test set.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
No MRMC comparative effectiveness study is mentioned. The device is a direct measurement tool, not an interpretive one typically evaluated by MRMC studies (which often involve human readers interpreting images, for example).
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study:
The provided text details a comparison of the device's technical specifications and intended use against predicate devices. The "Summary of Safety and Effectiveness" states that "The results of bench and user testing indicate that the new device is as safe and effective as the predicate devices." This implies a standalone performance evaluation of the device itself (without human interpretation of results, beyond the user reading the display), but the details of this study are not elaborated. The comparison matrix directly addresses the device's inherent capabilities against the predicate.
7. Type of Ground Truth Used:
For the body fat measurement component, the ground truth would typically be established against a recognized gold standard for body composition (e.g., DEXA scan, hydrostatic weighing, or a dual-energy X-ray absorptiometry). For the blood pressure measurement component, the ground truth would typically be established against a medical-grade, validated oscillometric or auscultatory blood pressure measurement device. However, the document does not explicitly state which methods were used as ground truth. It focuses on comparison to a legally marketed predicate device rather than an ultimate gold standard.
8. Sample Size for the Training Set:
The document does not mention the use of a "training set" in the context of an algorithm or AI. This device appears to be based on established bioelectrical impedance analysis (BIA) and oscillometric blood pressure measurement principles, likely using pre-defined algorithms rather than machine learning models that require a distinct training phase.
9. How the Ground Truth for the Training Set Was Established:
As no training set is indicated, this information is not applicable and is not provided in the document.
§ 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.