(211 days)
The CipherOx CRI Tablet is indicated for continuous noninvasive monitoring of functional oxygen saturation of arterial hemoglobin (SpO2), pulse rate (measured by an SpO2 sensor), and the Compensatory Reserve Index (CRI), which trends changes in intravascular volume relative to the individual patient's response to hypovolemia.
For patients with a finger thickness of 0.3" to 1" in hospital and pre-hospital settings.
CRI trends with changes in intravascular volume relative to the individual patient's response to hypovolemia, and should only be used by qualified medical providers as an adjunct to rather than as a replacement for traditional hemodynamic measures. CRI is indicated for adults (19-36 years old) in the supine position under non-motion conditions and without cardiovascular disease. CRI has not been studied in trauma patients.
The CipherOx CRI Tablet consists of a Nonin Onyx II Model 9560 finger pulse oximeter (previously cleared under K081285) that communicates by Bluetooth with a Cybernet CyberMed T10 tablet PC. The CipherOx CRI Tablet is a continuous, multi-parameter monitor that displays SpO2, Heart Rate (HR), photoplethysmograph (PPG) waveform images, and the Compensatory Reserve Index (CRI) value and historical trend-line.
CRI is an index related to the physiologic changes induced by intravascular fluid loss and ranges from 0 to 1, where 1 indicates a normal subject and 0 indicates a subject who has undergone significant physiological effects from loss of fluid volume.
Here's a breakdown of the acceptance criteria and study information for the CipherOx CRI Tablet, based on the provided text:
Acceptance Criteria and Device Performance
The core acceptance criterion for the CipherOx CRI Tablet appears to be the accurate estimation of CRI values, specifically the root-mean-squared error (RMSE) between estimated and reference CRI.
| Acceptance Criteria | Reported Device Performance |
|---|---|
| RMSE between estimated CRI and reference CRI should be less than 0.1 | The verification study showed the root-mean-squared error between the estimated CRI and reference CRI according to the LBNP level to be less than 0.1. |
| CRI estimates are statistically similar across multiple devices | Each of four CipherOx CRI Tablets gave statistically similar CRI estimates. |
| Turning the device on/off has no significant effect on CRI estimates | Turning the CipherOx CRI Tablets on and off during the study had no significant effect on CRI estimates. |
| High correlation between CRI and volume of blood removed during a blood draw study | It was shown that there was a high correlation between CRI and volume of blood removed. |
| Symptomatic subjects reaching lower CRI values during blood loss | The symptomatic group of subjects reached much lower CRI values than those who completed the blood removal without symptoms. |
Study Information
2. Sample size used for the test set and the data provenance:
- LBNP Verification Study: 20 healthy participants.
- Data Provenance: The text does not explicitly state the country of origin, but the development and studies seem to be conducted by Flashback Technologies in Boulder, Colorado. The data is prospective, gathered specifically for the study.
- Blood Draw Validation Study: 42 healthy participants (ages 19 to 36).
- Data Provenance: Similar to the LBNP study, the country of origin is not explicitly stated but implied to be the US. The data is prospective, gathered specifically for the study.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
The text does not mention the use of experts to establish a "ground truth" in the traditional sense (e.g., diagnosis by radiologists). Instead, the ground truth for CRI was established physiologically:
- LBNP Study: Reference CRI values were defined as CRI = 1 - LBNPcurrent / LBNPcollapse, where LBNPcollapse refers to the LBNP pressure level at the point a subject either had a precipitous fall in systolic blood pressure below 80 mmHg and/or voluntary subject termination due to discomfort or expression of presyncopal symptoms (or until completion of -100 mmHg). This relies on objective physiological measurements (blood pressure) and subjective patient reporting (presyncopal symptoms).
- Blood Draw Study: The "ground truth" for the blood draw study was the actual volume of blood removed and the observation of symptoms (e.g., systolic blood pressure
§ 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.