(15 days)
For the noninvasive measurement of systolic and diastolic blood pressure and determination of heart rate in adult patients, i.e. age 18 and above. The product is recommended for use by patients capable of understanding written and/or oral directions in a home care environment.
The Nissei Model DS-1862 is an automatic sphygmomanometer intended for measurement, including self-measurement by the patient, of blood pressure and heart rate. The method of operation is the oscillometric method and the site of measurement is the brachial artery in the arm. The system is microprocessor controlled and includes an air pump for automatic inflation; fuzzy logic to regulate opening cuff pressure, circuitry to detect and process minute pressure oscillations; an electromagnetic deflation-rate control valve, an eleven-digit LCD display of systolic and diastolic pressure readings and heart rate; a memory function that stores the thirty most recent measurement results for two patients plus the computed average of the stored readings; error displays, a standard arm cuff, and an optional large arm cuff.
The provided documents describe the Nihon Seimitsu Sokki Co. Ltd. (Nissei) Model DS-1862 Digital Blood Pressure Monitor and its substantial equivalence to a predicate device, the Nissei DS-181.
Here's the breakdown of the acceptance criteria and the study that proves the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria are essentially the performance specifications of the predicate device, which the new device (DS-1862) aims to match or improve upon. The reported device performance for the DS-1862 is stated as "SAME" across several key metrics, implying it meets or exceeds the predicate's specifications.
| Acceptance Criteria (Predicate Device DS-181) | Reported Device Performance (DS-1862) |
|---|---|
| Operating Principle: Oscillometric method | SAME (Oscillometric method) |
| Indication for use: For noninvasive measurement of systolic and diastolic blood pressure and determination of heart rate in adult patients, i.e., age 18 and above. | SAME |
| Display: 7 Digit LCD | 11 Digit LCD |
| Measurement Range: Sys 50-250 mm Hg (cuff press.) Dia 40 to 180 mm Hg Pulse rate 40 to 160 pulse/min | SAME |
| Accuracy: ±3 mm Hg (cuff press.) ±5% of reading (pulse rate) | SAME |
| Cuff arm circumference: 230 to 320 mm | 170 to 350 mm |
| Power supply: Four AA size batteries | SAME |
| External dimensions: 160mm W x 100mm D x 52mm H | 163mm W x 180mm D x 83mm H |
| Memory: 7 Measurement results, Computation of the average of stored data. | 30 Measurement results x 2, Computation of the average of stored data. |
| Weight: 265 g. w/o batteries | 420 g. w/o batteries |
2. Sample Size Used for the Test Set and Data Provenance
The documents do not explicitly state the sample size used for the test set or the data provenance (e.g., country of origin, retrospective or prospective). They only mention "bench and user testing" and "clinical testing data."
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
This information is not provided in the given text.
4. Adjudication Method for the Test Set
This information is not provided in the given text.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
A multi-reader multi-case (MRMC) comparative effectiveness study was not performed, nor is it applicable in this context. This device is a standalone blood pressure monitor, not an AI-assisted diagnostic tool that would involve human readers interpreting results with and without AI assistance. The study focuses on the device's accuracy compared to a validated predicate.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
A standalone study was effectively performed. The device itself is an automated system for measuring blood pressure. The "bench and user testing" and "clinical testing data" likely refer to the performance of the device's algorithm and hardware in isolation, as well as its use by individuals. The focus is on the device's intrinsic accuracy and functionality.
7. Type of Ground Truth Used
The ground truth for the accuracy assessment (±3 mm Hg for cuff pressure and ±5% for pulse rate) would typically be established by a validated reference measurement method. For blood pressure monitors, this usually involves:
- Auscultation by trained observers: Using a mercury sphygmomanometer and stethoscope, where multiple trained observers independently take readings, and their consensus or average is used as the reference.
- Invasive arterial pressure measurement: In a clinical research setting, direct intra-arterial pressure measurement can be used as the gold standard, though this is less common for routine validation of home-use devices.
The documents do not explicitly state which method was used, but the "Accuracy" specification (±3 mm Hg) is a standard requirement for blood pressure monitors and implies comparison against a highly accurate reference.
8. Sample Size for the Training Set
The concept of a "training set" is relevant for machine learning algorithms. While the device uses a "pressure measurement algorithm designed to detect, filter, process, and store pressure readings," the documents do not provide any information about a specific training set or its size. For older-generation oscillometric devices, the "algorithm" is often based on established mathematical models and signal processing techniques rather than a machine learning model that requires a distinct training phase with labeled data in the same way modern AI systems do.
9. How the Ground Truth for the Training Set Was Established
Given the lack of information on a specific "training set" in the context of modern machine learning, this information is not provided and likely not applicable in the typical sense for this type of device and its submission. The algorithms for oscillometric blood pressure measurement are generally developed and refined based on engineering principles and physiological understanding, and then validated with clinical testing against established reference methods.
§ 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).