(261 days)
The Microlife Upper Arm Automatic Digital Blood Pressure Monitor, Model WatchBP Office Central (TWIN200 CBP) is a device intended to measure the systolic and diastolic blood pressure, pulse rate, Mean Arterial Pressure (MAP), anklearm blood pressure and calculates Pulse Pressure (PP) and Ankle Brachial Index (ABI) of an adult individual with arm circumference sizes ranging from 22-42 cm and ankle circumference sizes ranging from 22-32 cm. It uses a non-invasive oscillometric technique using one (single arm) or two (dual arm measurement) inflatable cuffs wrapped around the upper arms and one inflatable cuff wrapped around the ankle (ABI).
The device provides aortic blood pressure parameters. includes central systolic blood pressure (cSBP), central pulse pressure (cPP) and central diastolic pressure (cDBP), non-invasively through the use of a brachial cuff.
The device detects the appearance of atrial fibrillation during measurement and gives a warning signal together with the measured blood pressure value if atrial fibrillation is detected.
The device can be connected to a personal computer (PC) running the WatchBP Analyzer Office software. The measured patient data can be transferred from the blood pressure monitor to the PC by means of a USB cable connection.
The blood pressure monitor is an automated digital professional clinical device for measuring blood pressure in upper arm and ankle in adults.
The device is for hospital use only.
Microlife Upper Arm Automatic Digital Blood Pressure Monitor, Model WatchBP Office Central (TWIN200 CBP) is designed to measure systolic and diastolic blood pressure, pulse rate and calculate Pulse Pressure (PP), Mean Arterial Pressure (MAP),Ankle Brachial Index (ABI), Central Blood Pressure(CBP) and Central Pulse Pressure(CPP) of an adult individual with arm circumference sizes ranging from 22 -42 cm a (rigid cuff for central BP and a soft cuff for brachial BP measurements) and ankle circumference sizes ranging from 22 -32 cm (using a soft cuff) by using a non-invasive technique in which one (or two) inflatable cuff(s) is (are) wrapped around the single (or dual) upper arm(s) and one inflatable cuff is wrapped around the ankle. Our method to define systolic and diastolic pressure is similar to the auscultatory method but use two resistive pressure sensors rather than a stethoscope and mercury manometer. The sensors convert tiny alterations in cuff pressure to electrical signals, by analyzing those signals to define the systolic and diastolic blood pressure and calculating pulse rate, Pulse Pressure (PP), Mean Arterial Pressure (MAP),Ankle Brachial Index (ABI) Central Blood Pressure(CBP) and Central Pulse Pressure(CPP) which is a well known technique in the market called the "oscillometric method".
The device has >, > and > measurement modes and has atrial fibrillation detection function, inflation pressure setting function, measurement intervals setting function etc. In addition, the device can be used in connection with your personal computer (PC) running the WatchBP Analyzer Office software. The memory data can be transferred to the PC by connecting the monitor with the PC via cable.
The > mode is selected to complete a fully-automated triple measurements on both arms according to recommended ESH/AHA blood pressure measurement protocols for a patient's first office visit.
The > mode is selected to perform central blood pressure measurements on the preferred arm for prompt and accurate office measurements.
The > mode is selected for Ankle Brachial Index pressure measurement. Select the lateral with the higher blood pressure value according to the measurement result of > mode.
The device detects the appearance of atrial fibrillation during measurement and the atrial fibrillation symbol "is displayed on the LCD screen if any atrial fibrillation signal has been detected.
The blood pressure monitor is an automated digital professional clinical device for measuring blood pressure in upper arm and ankle in adults
The Microlife Upper Arm Automatic Digital Blood Pressure Monitor, Model WatchBP Office Central (TWIN200 CBP), demonstrates substantial equivalence to its predicate devices through non-clinical and clinical testing.
Here's an analysis of the provided text, broken down by your requested categories:
1. A table of acceptance criteria and the reported device performance
The provided text doesn't explicitly state "acceptance criteria" in a tabular format with corresponding "reported device performance." However, it does refer to compliance with various standards, which implicitly set the acceptance criteria. The device's performance is affirmed by its clinical validation and demonstration of substantial equivalence.
Based on the information, the primary performance criteria are related to accuracy of blood pressure measurement and detection of Atrial Fibrillation (AFIB) and Ankle Brachial Index (ABI).
| Performance Metric | Acceptance Criteria (Implied by Standards) | Reported Device Performance |
|---|---|---|
| Brachial Blood Pressure Measurement | Compliance with AAMI / ANSI / ISO 81060-2 (accuracy against auscultation reference measurements). | Substantially Equivalent to Predicate: The device's brachial BP measurement algorithm re-uses the validated algorithm from the predicate device (WatchBP Office ABI, K112845). |
| Confirmed Performance with New Cuff: A published clinical study (Cheng et al) "Measurement Accuracy of a Stand-Alone Oscillometric Central Blood Pressure Monitor: A Validation Report for Central Microlife WatchBP Office Central" confirmed the performance of the WatchBP Office Central (TWIN200 CBP) using its WRR conical cuff against auscultation reference measurement for brachial systolic and diastolic blood pressure. | ||
| Atrial Fibrillation (AFIB) Detection | Effectiveness in detecting AFIB during measurement and providing a warning signal. | Substantially Equivalent to Predicate: The AFIB detection function is deemed substantially equivalent to that of the predicate device (WatchBP Office ABI, K112845). No repeated clinical testing was required for AFIB detection as it leverages the predicate's validation. |
| Ankle Brachial Index (ABI) Measurement | Accurate calculation of ABI. | Substantially Equivalent to Predicate: The ABI measurement function is deemed substantially equivalent to that of the predicate device (WatchBP Office ABI, K112845). No repeated clinical testing was required for ABI detection as it leverages the predicate's validation. |
| Central Blood Pressure (CBP) Measurement | Accurate estimation of central systolic blood pressure (cSBP), central pulse pressure (cPP), and central diastolic pressure (cDBP). | Accurately Estimated: The device is stated to "estimate accurately" aortic blood pressure parameters (cSBP, cPP, cDBP). The efficacy of the rigid conical cuff for central BP was "proven clinically," likely through the same Cheng et al. study mentioned. |
| Biocompatibility | Compliance with ISO 10993-1, 10993-5, 10993-10 for materials in contact with skin. | The mutispandex material used for the WRR Conical Cuff is identical to the cuff material of the Microlife BP3AP1-3E (K111652) which meets ISO 10993-1 requirements, thus no new biocompatibility testing was needed. |
| Software Validation | Compliance with FDA guidance for software in medical devices (moderate level of concern) and off-the-shelf software. | Software validation was conducted according to FDA November 2005 guidance for "moderate level of concern" and FDA September 1999 guidance for "Off-The-Shelf Software Use." |
Study Details:
The document describes a clinical study that was used to validate the performance of the device, particularly regarding its brachial blood pressure measurement with the new cuff and its ability to estimate central blood pressure.
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
The document refers to a published clinical study by Cheng et al. titled "Measurement Accuracy of a Stand-Alone Oscillometric Central Blood Pressure Monitor: A Validation Report for Central Microlife WatchBP Office Central." However, it does not specify the sample size used in this study. It also does not explicitly state the country of origin or whether it was retrospective or prospective. Given the nature of a validation report for accuracy, it is highly likely to be a prospective study.
For the brachial blood pressure measurement, AFIB detection, and ABI detection, the device leverages the clinical validation of the predicate device (WatchBP Office ABI, K112845). The specifics of the original predicate validation study (including sample size, provenance, etc.) are not detailed in this 510(k) summary.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
For the validation of brachial systolic and diastolic blood pressure, the standard AAMI / ANSI / ISO 81060-2 dictates specific requirements for the ground truth, typically involving multiple trained observers (experts) using auscultation with a mercury manometer or equivalent standardized reference. The document states that the Cheng et al. study confirmed performance "against auscultation reference measurement," implying that such experts were used. However, the exact number of experts and their specific qualifications are not provided in this document.
For Central Blood Pressure (CBP) parameters, the document states "The efficacy of the use of the rigid conical cuff was proven clinically," likely through the same study. The ground truth for central blood pressure validation typically involves invasive radial artery catheterization and tonometry, or a previously validated non-invasive method often requiring comparison with invasive measurements. The document does not specify the method or the experts involved for CBP ground truth.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
The document does not explicitly state the adjudication method used in the Cheng et al. study for establishing the ground truth, especially for brachial blood pressure measurements. Standard ISO 81060-2 protocols often involve two observers, with a third observer called upon in case of discrepancies, but this is not confirmed here.
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, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done, and this device is not an AI-assisted diagnostic tool for human readers. This device is an automated blood pressure monitor. The evaluation focuses on the device's standalone accuracy against reference methods, not on how it assists human interpretation of images or other data.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, a standalone performance evaluation was done. The device itself is an automated system designed to measure blood pressure, pulse rate, MAP, ABI, and CBP, and detect AFIB. The clinical study (Cheng et al.) directly assesses the accuracy of the device's measurements against reference methods, which is a standalone performance evaluation. The statement "Measurement Accuracy of a Stand-Alone Oscillometric Central Blood Pressure Monitor" directly supports this.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- For Brachial Blood Pressure (Systolic and Diastolic): Auscultation reference measurement is stated as the ground truth, which relies on expert observers (human experts) listening to Korotkoff sounds. This falls under a form of "expert consensus/reference standard."
- For Atrial Fibrillation (AFIB) Detection and Ankle Brachial Index (ABI): The device leverages the validation of the predicate device (K112845). While not explicitly stated here, the ground truth for these would typically involve comparison to an ECG for AFIB and Doppler assessment for ABI, overseen by medical professionals.
- For Central Blood Pressure (CBP) Parameters: The document states the efficacy was "proven clinically," but does not specify the ground truth method. For CBP, this typically involves invasive catheterization or a validated non-invasive method that itself was validated against invasive measurements.
8. The sample size for the training set
The document does not provide information on the sample size used for the training set of the device's algorithms. As the core algorithms for brachial BP, AFIB, and ABI are inherited from a predicate device, their "training" would have occurred with the predicate device's development. For the CBP estimation, if it involves a model trained on data distinct from the predicate's main algorithm, the training set size is not disclosed.
9. How the ground truth for the training set was established
The document does not provide information on how the ground truth for any potential training set was established. Since the device leverages an existing oscillometric algorithm from a predicate device, its fundamental "training" would likely have been established during the development and validation of that earlier device. For the novel CBP functionality, if a machine learning model was used, the method for establishing ground truth for its training data is not mentioned. Typically, this would involve paired measurements (e.g., non-invasive device reading vs. invasive central arterial pressure).
§ 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).