(161 days)
The device intended to measure the diastolic, systolic blood pressures and pulse rate for adult population in home and hospital facilities by using a non-invasive oscillometric technique with a single upper arm cuff (22-36 cm). The device detects the appearance of irregular heats during measurement and gives a warning signal with readings.
Weony Digital Blood Pressure Monitor WBP Series are designed to measure the systolic and diastolic blood pressure and pulse rate of an individual (at least 18 or above) by using a non-invasive technique in which an inflatable cuff is wrapped around the upper arm. Our method to define systolic and diastolic pressure is similar to the auscultatory method but uses an electronic pressure sensor rather than a stethoscope and mercury manometer. The sensor converts tiny alterations in cuff pressure to electrical signals, by analyzing those signals to define the systolic and diastolic blood pressure and calculating pulse rate, which is a well-known technique in the market called the "oscillometric method".
The main components of the Blood Pressure Monitor are the main unit and cuff unit. ABS is used to outer housing of the main unit. The preformed cuff unit, which is applicable to arm circumference approximately between 220 and 360 mm, includes the inflatable bladder and nylon shell. All models of the arm blood pressure monitor use a single size of cuff. The device consists of the microprocessor, the pressure sensor, the operation keys, the pump, the electromagnetic deflation control valve, and the LCD. The subject devices are powered by four AA alkaline batteries or adatpter.
The device has irreqular heart beat (IHB) indicator which compares the longest and the shortest time intervals of detected pulse waves to mean time interval and displays a warning signal with the reading to indicate the detection of irregular pulse rhythm when the difference of the time intervals is over a specified range.
The provided text describes the 510(k) summary for the Digital Blood Pressure Monitor WBP Series. It details the device, its intended use, comparison to a predicate device, and the non-clinical and clinical tests performed to support substantial equivalence.
Here's an analysis of the provided information regarding acceptance criteria and study proving adherence to them:
1. A table of acceptance criteria and the reported device performance
The primary standard for clinical validation of automated non-invasive sphygmomanometers, ISO 81060-2:2018, sets the acceptance criteria for accuracy.
| Acceptance Criteria (Based on ISO 81060-2:2018) | Reported Device Performance (from text) |
|---|---|
| Mean difference between the device and reference method is ≤ ±5 mmHg | "The results showed the accuracy of the blood pressure monitor is within acceptable scope specified in ISO 81060-2." (This is a summary statement, the precise mean difference values are not provided in the text but are implied to be within the standard's limits for both systolic and diastolic pressure.) |
| Standard deviation of the differences between the device and reference method is ≤ 8 mmHg | (Not explicitly stated in the provided text, but implied by "within acceptable scope specified in ISO 81060-2.") |
2. Sample size used for the test set and the data provenance
- Sample Size: 85 patients (47 males and 38 females)
- Data Provenance: Not explicitly stated, but the submission is from a Chinese manufacturer (WEONY (SHENZHEN) TECHNOLOGY CO., LTD.), so it is highly probable the data was collected in China. The text does not specify if the study was retrospective or prospective, but clinical validation studies for device approval are almost always prospective.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
The ground truth for blood pressure measurements in this context is established by a reference method, not by individual experts' interpretation of images or other subjective data.
- Reference Method: "The manual Mercury Sphygmomanometer was used as a reference device."
- Number of Experts/Operators: While not explicitly stated, clinical validation of automated sphygmomanometers according to ISO 81060-2 typically requires measurements by trained observers using the reference method. The standard mandates specific procedures for these measurements to ensure accuracy and minimize bias, often involving at least two trained observers taking simultaneous or sequential measurements. The document does not specify the number or qualifications of these observers.
4. Adjudication method for the test set
- Adjudication Method: "Same arm sequential method was adopted during the clinical testing." This indicates a direct comparison of the device's reading against the reference standard on the same arm, likely following strict protocols to minimize errors. This isn't an "adjudication" in the sense of resolving conflicting expert opinions, but rather a direct comparison to a gold standard.
5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
- No, an MRMC comparative effectiveness study was not done. This device is a blood pressure monitor, not an AI-powered diagnostic imaging tool that would typically involve human readers interpreting data with or without AI assistance. The study is a direct clinical validation of the device's accuracy against a known reference standard (manual mercury sphygmomanometer).
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Yes, in spirit. The device itself is an automated system based on the oscillometric method. Its primary function is to measure blood pressure without direct human interpretation of raw signals; humans only read the displayed results. The clinical study validates the performance of this automated algorithm in measuring blood pressure. However, the term "standalone" usually refers to AI algorithms in diagnostic contexts. In this case, the device essentially functions as a "standalone" measurement system.
7. The type of ground truth used
- Expert Consensus / Reference Standard: The ground truth was established using a manual Mercury Sphygmomanometer, which is considered the gold standard (or a highly accurate reference method) for blood pressure measurement in clinical validation studies. The measurements taken with this reference device are performed by trained personnel, effectively serving as an "expert consensus" or highly accurate reference.
8. The sample size for the training set
- Not applicable. This document describes the validation of a traditional medical device (blood pressure monitor) that operates on an established oscillometric principle, not an AI/machine learning model that would require a separate "training set" and "test set" in the conventional sense. The device's algorithm is based on well-understood physiological principles and signal processing, not on learning from a large dataset.
9. How the ground truth for the training set was established
- Not applicable. As stated above, this device does not utilize a machine learning model that requires a "training set" with ground truth established for learning. Its operational principles are fixed and based on physics and established medical techniques.
§ 870.1130 Noninvasive blood pressure measurement system.
(a)
Identification. A noninvasive blood pressure measurement system is a device that provides a signal from which systolic, diastolic, mean, or any combination of the three pressures can be derived through the use of tranducers placed on the surface of the body.(b)
Classification. Class II (performance standards).