(15 days)
The DS-181 system is intended 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 Nissei Model DS-181 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, a six-digit LCD display of systolic and diastolic pressure readings and heart rate; a memory function that stores the seven most recent measurement results plus the computed average of the stored readings; error displays; a standard arm cuff; and an optional large arm cuff.
Acceptance Criteria and Device Performance Study for Nihon Seimitsu Sokki Co., Ltd. Model DS-181 Noninvasive Blood Pressure Measurement System
This document outlines the acceptance criteria and details of the study proving the Nihon Seimitsu Sokki Co., Ltd. Model DS-181 Digital Blood Pressure Monitor meets these criteria.
1. Acceptance Criteria and Reported Device Performance
The Model DS-181 system was evaluated against the accuracy criteria established in the ANSI/AAMI Standard SP10-1992. The document states that the device was "found to comply fully with the accuracy criteria established in the standard."
| Acceptance Criteria (ANSI/AAMI Standard SP10-1992) | Reported Device Performance (Model DS-181) |
|---|---|
| Accuracy criteria as defined by ANSI/AAMI Standard SP10-1992 for noninvasive blood pressure measurement devices. (Specific numerical criteria are not detailed in the provided text but are implied by adherence to the standard). | Complies fully with the accuracy criteria established in the standard. |
Note: The provided text does not explicitly state the numerical accuracy criteria from the ANSI/AAMI Standard SP10-1992. However, the FDA's acceptance of the 510(k) submission confirms that the device met the required accuracy for its intended use.
2. Sample Size and Data Provenance for the Test Set
- Sample Size for Test Set: The document indicates "clinical studies conducted in accordance with ANSI/AAMI Standard SP10-1992." While the exact number of subjects in the test set is not explicitly stated, adherence to this standard implies a sufficiently robust sample size as per the standard's requirements for clinical validation of blood pressure devices.
- Data Provenance: The studies were described as "clinical studies," implying human subjects. The country of origin of the data is not explicitly stated in the provided text, but the company is based in Japan. It is not specified whether the studies were retrospective or prospective; however, clinical validation studies for medical devices are typically prospective.
3. Number and Qualifications of Experts for Ground Truth
The mechanism for establishing ground truth in clinical studies for blood pressure monitors typically involves comparison against a reference standard, often auscultation performed by trained clinicians.
- Number of Experts: Not explicitly stated, but standard practice for ANSI/AAMI SP10-1992 compliance involves multiple trained observers to mitigate inter-observer variability.
- Qualifications of Experts: Not explicitly stated. However, for blood pressure measurement validation, experts would typically be medical professionals (e.g., physicians, nurses, or trained technicians) with experience in accurate auscultatory blood pressure measurement using a mercury sphygmomanometer, often with specific training for validation studies.
4. Adjudication Method for the Test Set
The adjudication method is not explicitly described in the provided text. In a typical ANSI/AAMI SP10-1992 validation, multiple observers would take reference measurements, and the results would be averaged or reconciled to establish a robust ground truth, reducing individual observer bias.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
An MRMC comparative effectiveness study, which typically evaluates the improvement of human readers with AI assistance versus without AI assistance, was not indicated. This device is a standalone blood pressure monitor, not an AI-assisted diagnostic imaging or interpretation tool that would involve human readers.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
Yes, a standalone study was performed. The "measurement performance of the DS-181 system has been evaluated in clinical studies... and found to comply fully with the accuracy criteria established in the standard." This confirms the device's ability to accurately measure blood pressure independently of human interpretation of readings, demonstrating its standalone performance.
7. Type of Ground Truth Used
The ground truth used for the clinical validation of blood pressure monitors typically involves a reference method, such as:
- Simultaneous auscultatory measurements performed by trained observers using a mercury sphygmomanometer (or other validated reference devices), which is considered the gold standard for non-invasive blood pressure measurement.
- The ANSI/AAMI Standard SP10-1992 specifically outlines requirements for the reference method.
8. Sample Size for the Training Set
The document does not provide details about a separate "training set" in the context of machine learning. The Model DS-181 uses "fuzzy logic to regulate opening cuff pressure" and "a pressure measurement algorithm designed to detect, filter, process, and store pressure readings." While these algorithms would have been developed and refined, the text specifically focuses on the clinical studies for performance evaluation, which are typically validation studies rather than training set evaluations. If an internal training process using data was performed for the fuzzy logic or algorithms, its sample size is not disclosed.
9. How the Ground Truth for the Training Set Was Established
As noted above, details about a distinct "training set" for the fuzzy logic or algorithms are not provided. However, generally, the ground truth for developing such algorithms would be established through:
- Extensive experimental data collection, potentially involving human volunteers, alongside established reference blood pressure measurement methods.
- Data could be derived from engineering tests, simulated physiological conditions, and early human subject measurements to optimize the algorithm's performance before final clinical validation.
§ 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).