(100 days)
The device is a digital monitor intended for use in measuring blood pressure and pulse rate in adult patient population with wrist circumference ranging from 13.5cm to 21.5cm in home and hospital facilities by using a non-invasive oscillometric technique. The device detects the appearance of irregular heartbeats 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 12 or above) by using a non-invasive technique in which an inflatable cuff is wrapped around the wrist. 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 wrist circumference approximately between 135 and 215 mm, includes the inflatable bladder and PU shell. All models of the wrist 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 two AAA alkaline batteries or adatpter.
The device has irregular 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.
This document describes the FDA 510(k) clearance for the Digital Blood Pressure Monitor WBP Series (K231542) by Weony (Shenzhen) Technology Co., Ltd. The information provided focuses on demonstrating substantial equivalence to predicate devices, particularly regarding performance and accuracy.
Here is an analysis of the requested information based on the provided text:
1. A table of acceptance criteria and the reported device performance
The primary acceptance criteria for blood pressure monitors is typically defined by the ISO 81060-2 standard for clinical validation of automated measurement type. This standard specifies limits for the difference between the device's measurements and reference measurements. The document states the device was tested against this standard and the results show the accuracy is "within acceptable scope specified in ISO 81060-2."
While the document references the standard for acceptance, it does not provide a specific table of numerical acceptance criteria alongside the actual reported device performance (e.g., mean difference and standard deviation). However, the "SE Comparison" table includes:
| Characteristic | Acceptance Criteria (Implied by Predicates) | Reported Performance (Subject Device) |
|---|---|---|
| Accuracy (Pressure) | ±3mmHg or 2% of reading (Predicate K131742) / ±3mmHg (Predicate K210671) | ±3mmHg |
| Accuracy (Pulse) | ±5% (Both Predicates) | ±5% |
| Measuring Range (Pressure) | 0 to 299 mmHg (Both Predicates) | 0 to 299 mmHg |
| Measuring Range (Pulse) | 40 to 180 beat/minute (Both Predicates) | 40 to 180 beat/minute |
| Measuring Resolution | 1 mmHg (Both Predicates) | 1 mmHg |
2. Sample size used for the test set and the data provenance
- Sample Size for Test Set: 85 patients (41 males and 44 females)
- Data Provenance: The document does not explicitly state the country of origin. However, the manufacturer is Weony (Shenzhen) Technology Co., Ltd. in China, and the study was likely conducted in China. The study was a prospective clinical validation as it involved patients participating in a new study.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
The document states that a "manual Mercury Sphygmomanometer was used as a reference device" for ground truth. It does not mention the number of experts or their qualifications for establishing this ground truth. Typically, for such studies, trained clinical personnel (e.g., doctors, nurses) would perform the manual measurements.
4. Adjudication method for the test set
The document does not describe any specific adjudication method for the test set. The ground truth was established by direct comparison to a manual mercury sphygmomanometer.
5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done
No, an MRMC comparative effectiveness study was not conducted. This refers to studies where multiple human readers assess cases with and without AI assistance. The device is a direct measurement device (blood pressure monitor), not an AI-assisted diagnostic imaging tool.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, the primary clinical validation described is a standalone performance study. The device, as an automated non-invasive sphygmomanometer, inherently performs its measurements and calculations without human intervention in the core measurement process. The study validates the device's accuracy against a gold standard (manual mercury sphygmomanometer).
7. The type of ground truth used
The ground truth used was reference measurements from a manual Mercury Sphygmomanometer.
8. The sample size for the training set
The document does not specify a separate "training set" sample size. For medical devices like blood pressure monitors, the validation typically involves extensive bench testing and a clinical validation study (as described) rather than a machine learning "training set" in the conventional AI sense. If there was any internal algorithm development or calibration, the data used for that is not detailed.
9. How the ground truth for the training set was established
As there's no explicitly mentioned "training set" in the AI sense, this information is not applicable. The device's underlying "algorithm" is the oscillometric method, which is a well-established physiological principle, not a machine learning model that requires a distinct, labeled training dataset from scratch. The performance is validated through the clinical study against a gold standard.
§ 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).