(282 days)
The Vivio® System is indicated to non-invasively estimate left ventricular end-diastolic pressure (LVEDP) is above or below 18mmHg. This measurement can aid in the diagnosis of heart failure when used by qualified healthcare professionals as an adjunct alongside other clinically relevant information. For use in adults only.
The Vivio System consists of an Arm Cuff system (BP cuff electronics, connection tubinq), EKG patch, and a software application that runs on an off-the-shelf computer tablet. Data is collected non-invasively at the brachial artery and via a single-lead EKG Patch. An off-the-shelf blood pressure arm cuff is attached to the patient's upper arm as if taking a blood pressure measurement. The Arm Cuff is attached to the blood pressure cuff with the quick connect end connected to the pneumatic pump within the Arm Cuff Electronics Enclosure. Two off-the-shelf electrodes are attached to the snap connections on the bottom of the EKG Patch and then connected on the left side of the patient's chest. Both the pneumatic pump attached to the Arm Cuff and EKG Patch are then powered on by pressing and releasing their respective power buttons. The Vivio App is opened on an off-the shelf computer tablet, and the on-screen prompts are followed to connect the Arm Cuff and the EKG Patch. The user is prompted to enter required patient and user data, initiating a patient recording session. Data from the recording session is processed by a proprietary algorithm and results reported on the computer tablet.
The provided document focuses on the 510(k) summary for the Vivio® System, which is an "Adjunctive Cardiovascular Status Indicator" device. It outlines the regulatory classification, device description, indications for use, technological characteristics, and summaries of non-clinical and clinical tests.
Here's an analysis of the acceptance criteria and the study that proves the device meets them, based on the provided text:
Indications for Use: The Vivio® System is indicated to non-invasively estimate left ventricular end-diastolic pressure (LVEDP) as above or below 18mmHg. This measurement aids in the diagnosis of heart failure when used by qualified healthcare professionals as an adjunct alongside other clinically relevant information, for use in adults only.
1. Table of Acceptance Criteria and Reported Device Performance
The document states "The primary efficacy objectives for the study were met." The acceptance criteria for efficacy are directly linked to diagnostic performance metrics:
| Acceptance Criteria (Performance Metric) | Reported Device Performance (95% Confidence Interval) |
|---|---|
| Sensitivity | 80% (64-91) |
| Specificity | 80% (73-86) |
Note: The document does not explicitly state these as acceptance criteria but rather as "primary efficacy objectives for the study." In the context of a 510(k) submission, meeting these pre-specified performance thresholds demonstrates the device's ability to achieve its intended use. The LVEDP threshold for diagnosis is 18mmHg.
2. Sample Size Used for the Test Set and Data Provenance
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Sample Size (Test Set):
- Cath Lab Cohort: 195 subjects scheduled for non-emergent left heart catheterization.
- Non-Aged Healthy Cohort: 101 subjects.
- Aged Healthy Cohort: 40 subjects.
- Total Enrolled: 195 + 101 + 40 = 336 subjects.
- However, the statistical analysis was performed on a "subset of validation data that had passed the completeness and quality requirements outlined in the data management plan and procedure." The exact size of this final validation subset, specifically used for the reported sensitivity and specificity, is not explicitly stated, but it would be derived from the 195 subjects in the "Cath Lab Cohort" used for comparison to invasive LVEDP. The sensitivity and specificity numbers are specifically tied to the LVEDP estimate, which would rely on the cohort with ground truth LVEDP measurements (Cath Lab Cohort).
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Data Provenance:
- Geographic Origin: The Cath Lab Cohort was enrolled "across 9 sites" (locations not specified, assuming within the US for FDA clearance), and the two Healthy Cohorts were enrolled "at a single site" (location not specified).
- Nature of Data: Prospective validation study.
3. Number of Experts Used to Establish Ground Truth for Test Set and Qualifications
- The document states that the ground truth for the Cath Lab Cohort was "gold-standard invasive LVEDP obtained via the Millar Mikro-Cath." This is a direct physiological measurement, not established by human experts in a subjective reading context.
- For the "reference-standard non-invasive echocardiographic indices" used for the Aged Healthy Cohort, the document does not specify the number or qualifications of experts involved in establishing these indices. However, echocardiographic indices are objective measurements and calculations, typically performed by trained sonographers and interpreted by cardiologists/echocardiographers.
4. Adjudication Method for the Test Set
- Since the primary ground truth for LVEDP was an invasive, objective measurement (Millar Mikro-Cath), no expert adjudication method (like 2+1 or 3+1) would have been necessary for this part of the ground truth establishment.
- For the echocardiographic indices, the document does not provide details on adjudication, but as noted above, these are typically objective measurements.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- The document does not indicate that an MRMC comparative effectiveness study was done to show how human readers improve with AI vs. without AI assistance.
- The Vivio System is described as a device that "estimates LVEDP" and "aids in the diagnosis of heart failure when used by qualified healthcare professionals as an adjunct." It provides a calculated clinical parameter, not necessarily an AI-driven image interpretation system that assists human readers.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
- Yes, the reported "sensitivity of 80% (64-91), and specificity of 80% (73-86)" appear to be a measure of the Vivio System's (algorithm's) standalone performance in classifying LVEDP as above or below 18mmHg against the invasive gold standard. The device generates the estimate, and these metrics directly assess its accuracy.
7. Type of Ground Truth Used
- Primary Ground Truth: "Gold-standard invasive LVEDP obtained via the Millar Mikro-Cath" for the Cath Lab Cohort. This is direct physiological outcomes data.
- Reference Standard: "Reference-standard non-invasive echocardiographic indices" for the Aged Healthy Cohort. This relies on established clinical measurements, not subjective expert consensus.
8. Sample Size for the Training Set
- The document does not specify the sample size used for the training set. It mentions a "proprietary algorithm" and a "fixed parameter model" (as opposed to AI/machine learning), but no details on its development data are provided.
9. How the Ground Truth for the Training Set Was Established
- The document does not specify how the ground truth for the training set was established. Given the device uses a "fixed parameter model" rather than a machine learning model, it implies that the algorithm's parameters were likely determined based on physiological principles and pre-existing clinical data/models, rather than a large-scale data-driven training process with established ground truth labels in the same way as an AI model.
§ 870.2200 Adjunctive cardiovascular status indicator.
(a)
Identification. The adjunctive cardiovascular status indicator is a prescription device based on sensor technology for the measurement of a physical parameter(s). This device is intended for adjunctive use with other physical vital sign parameters and patient information and is not intended to independently direct therapy.(b)
Classification. Class II (special controls). The special controls for this device are:(1) Software description, verification, and validation based on comprehensive hazard analysis must be provided, including:
(i) Full characterization of technical parameters of the software, including any proprietary algorithm(s);
(ii) Description of the expected impact of all applicable sensor acquisition hardware characteristics on performance and any associated hardware specifications;
(iii) Specification of acceptable incoming sensor data quality control measures; and
(iv) Mitigation of impact of user error or failure of any subsystem components (signal detection and analysis, data display, and storage) on accuracy of patient reports.
(2) Scientific justification for the validity of the status indicator algorithm(s) must be provided. Verification of algorithm calculations and validation testing of the algorithm using a data set separate from the training data must demonstrate the validity of modeling.
(3) Usability assessment must be provided to demonstrate that risk of misinterpretation of the status indicator is appropriately mitigated.
(4) Clinical data must be provided in support of the intended use and include the following:
(i) Output measure(s) must be compared to an acceptable reference method to demonstrate that the output measure(s) represent(s) the predictive measure(s) that the device provides in an accurate and reproducible manner;
(ii) The data set must be representative of the intended use population for the device. Any selection criteria or limitations of the samples must be fully described and justified;
(iii) Agreement of the measure(s) with the reference measure(s) must be assessed across the full measurement range; and
(iv) Data must be provided within the clinical validation study or using equivalent datasets to demonstrate the consistency of the output and be representative of the range of data sources and data quality likely to be encountered in the intended use population and relevant use conditions in the intended use environment.
(5) Labeling must include the following:
(i) The type of sensor data used, including specification of compatible sensors for data acquisition;
(ii) A description of what the device measures and outputs to the user;
(iii) Warnings identifying sensor reading acquisition factors that may impact measurement results;
(iv) Guidance for interpretation of the measurements, including warning(s) specifying adjunctive use of the measurements;
(v) Key assumptions made in the calculation and determination of measurements;
(vi) The measurement performance of the device for all presented parameters, with appropriate confidence intervals, and the supporting evidence for this performance; and
(vii) A detailed description of the patients studied in the clinical validation (
e.g., age, gender, race/ethnicity, clinical stability) as well as procedural details of the clinical study.