(86 days)
Truly Automatic Wrist Blood Pressure Monitor DW series, Models DW801, DW802, DW803, DW805, DW806, DW807, DW808, DW901, DW902, DW903 are a series devices intended to measure the systolic and diastolic blood pressure and pulse rate of an adult individual by using a non-invasive technique in which an inflatable cuff is wrapped around the wrist.
The devices features include irregular pulse rhythm detection during measurement, and display a warning signal with the reading once the irregular heartbeat is detected.
Truly Automatic Wrist Blood Pressure Monitor DW series, Models DW801, DW802, DW803, DW805, DW806, DW807, DW808, DW901, DW902, DW903 are designed to measure the systolic and diastolic blood pressure and pulse rate of an individual 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 Truly Automatic Wrist Blood Pressure Monitor DW series 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 135 and 220 mm, includes the inflatable bladder and nylon 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.
The device also 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 25%.
Here's a summary of the acceptance criteria and the study proving the device meets them, based on the provided text:
Acceptance Criteria and Device Performance Study
The Truly Automatic Wrist Blood Pressure Monitor (Models DW801, DW802, DW803, DW805, DW806, DW807, DW808, DW901, DW902, DW903) conducted a clinical study to demonstrate its accuracy in measuring systolic and diastolic blood pressure.
1. Table of Acceptance Criteria and Reported Device Performance
| Criteria (ANSI/AAMI SP10 Standard) | Systolic Pressure Performance | Diastolic Pressure Performance |
|---|---|---|
| Mean difference ≤ ±5mmHg | -3.5 mmHg (meets criteria) | -3.2 mmHg (meets criteria) |
| SD differences ≤ 8 mmHg | 3.5 mmHg (meets criteria) | 3.5 mmHg (meets criteria) |
| Between-observer agreement: 95% or more readings agree to within ±10mmHg | 100% (meets criteria) | 100% (meets criteria) |
| Between-observer agreement: 85% or more readings agree to within ±5 mmHg | 99% (meets criteria) | 99% (meets criteria) |
2. Sample Size and Data Provenance
- Sample Size (Test Set): 90 subjects, including 15 hypertensive patients.
- Data Provenance: The document does not explicitly state the country of origin, but the submitter's address is in Guangdong Province, China, suggesting the study was likely conducted there. The study appears to be prospective, as it involved actively recruiting subjects and performing blood pressure determinations.
3. Number and Qualifications of Experts for Ground Truth
- Number of Experts: Two doctors.
- Qualifications of Experts: The document does not specify their exact qualifications (e.g., "radiologist with 10 years of experience"). It only mentions they are "two doctors" who performed simultaneous and blinded blood pressure determinations.
4. Adjudication Method
The adjudication method used was paired, simultaneous, and blinded reference measurements by two observers against the test device. This implies a 2-reader, 1-device comparison method:
* The two observers ("doctors") simultaneously and independently measured blood pressure using a standard mercury sphygmomanometer (the reference standard).
* The agreement between these two observers also had its own acceptance criteria (95% within ±10mmHg, 85% within ±5mmHg).
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not explicitly conducted as described for AI-assisted human readers. The study focused on the standalone accuracy of the device itself compared to a reference standard with human observers. There is no mention of a scenario where human readers' performance was compared with and without AI assistance from this device.
6. Standalone Performance Study
Yes, a standalone performance study was conducted. The entire clinical study described is a demonstration of the device's accuracy in measuring blood pressure and pulse rate (algorithm only/standalone without human-in-the-loop performance, beyond interacting with the device itself) compared to a reference standard.
7. Type of Ground Truth Used
The ground truth used was expert consensus / reference standard comparison using a standard mercury sphygmomanometer. The "between-observer agreement" criteria also implies the ground truth for the reference measurements themselves was established by agreement between the two doctors.
8. Sample Size for the Training Set
The document does not specify a sample size for a training set. This is typical for a traditional medical device (like a blood pressure monitor) which relies on established physical principles (oscillometric method) and calibration rather than machine learning models that require distinct training data.
9. How Ground Truth for the Training Set Was Established
As no specific "training set" for an AI/machine learning model is mentioned, this information is not applicable to this device's development as described. The device's measurement algorithm ("oscillometric method") is a well-established technique that would have been developed and validated through general engineering and physiological principles rather than a distinct machine learning training phase.
§ 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).