(128 days)
The VO200 - NeurOs Cerebral Oximetry is intended for use as an adjunct trend monitor of regional hemoglobin oxygen saturation of blood in the brain tissue beneath the sensor. The prospective clinical value of data from the VO200 - NeurOs Cerebral Oximetry has not been demonstrated in disease states. The VO200 - NeurOs Cerebral Oximetry should not be used as the sole basis for diagnosis or therapy.
The Mesepre VO 200 - NeurOs Cerebral Oximetry System is based on the same optical operating principles of multi-distance diffuse reflectance spectroscopy as the predicate device. It measures oxygenated and de-oxygenated hemoglobin content underneath the sensor probe and allows clinicians to monitor the blood oxygenation level of cerebral tissue. The VO 200 - NeurOs Cerebral Oximetry System consists of a reusable sensor, a single use disposable adhesive, and a display software. The sensor uses two wavelengths within the range from 660nm to 905nm to measure light absorption of tissue, with one wavelength is more sensitive to deoxygenated hemoglobin, the other is more sensitive to oxygenated hemoglobin. Regional cerebral tissue oxygen saturation is calculated through the ratio of tissue absorption to the two wavelengths and validated aqainst blood sample testing through the blood gas analyzer. Sensors are sized to provide desired depth and area coverage for the measurement. The sensor consists of LEDs, photo detectors, pre-amplifier, analogue to digital convertor, and a CUP for controlling the light emission and detection sequence, auto power adjustment for LED, gain adjustment for photo detectors to ensure optimized signal to noise ratio, and data processing and calculations. It also has an isolator between the monitor and the sensor to ensure the electric safety of the sensor. The enclosure of the sensor is made of medical grade ABS. The single use sensor adhesive is made of a soft foam with medical grade adhesives. The Mespere Display Software can be loaded to a tablet, laptop, or stationary PC. The sensor is then connected through a standard USB connector. It displays the measurement through the computer user interface at a refresh rate of approximately one second. Screenshots of the measurement can be saved to a user specified file and can be exported through USB ports or the internet.
Here's a summary of the acceptance criteria and the study that proves the device meets the acceptance criteria for the VO200 - NeurOs Cerebral Oximetry System, based on the provided text:
Acceptance Criteria and Reported Device Performance
| Parameter | Acceptance Criteria (Specification) | Reported Device Performance | Notes |
|---|---|---|---|
| StO2 Measurement Range | 0 - 100% | 0 - 100% | |
| StO2 Validated Measurement Range | 40 - 80% | 40 - 80% | Validation was performed on this specific measurement range. |
| Trending Accuracy of StO2 (40%-80%) | ± 1.5% | ± 1.5% | Accuracy is based on a validation study comparing to venous jugular bulb and radial arterial blood samples and a Co-Oximeter on healthy volunteers. |
| Absolute Accuracy of StO2 (40%-80%) | ± 4.9% | ± 4.9% | Accuracy is based on a validation study comparing to venous jugular bulb and radial arterial blood samples and a Co-Oximeter on healthy volunteers. |
| Resolution of StO2 | 1% | 1% |
Study Details
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Sample Size used for the test set and the data provenance:
- Sample Size: 12 healthy subjects. A total of 284 paired venous and arterial blood sample readings and 284 VO200 - NeurOs Cerebral Oximetry system readings were used for comparison and statistical analysis.
- Data Provenance: Prospective clinical study conducted at the University of California San Francisco (UCSF) Hypoxia Labs, San Francisco, California, USA. The subjects were healthy, non-smoking individuals aged 21-49 years old.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
The document does not explicitly state the number or qualifications of experts involved in establishing the ground truth measurements. The ground truth was established through invasive blood samples analyzed by a Co-Oximeter, which implies highly trained medical and laboratory professionals were involved in the process, but their specific roles or qualifications are not detailed. -
Adjudication method for the test set:
The document does not mention an explicit adjudication method (e.g., 2+1, 3+1). The ground truth was established by simultaneously drawing invasive blood samples (from jugular bulb and radial artery) and immediately analyzing them with a Co-Oximeter. This suggests a direct measurement approach rather than an expert consensus/adjudication process on interpretations. -
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. This was not an MRMC comparative effectiveness study involving human readers and AI assistance. The study focused on validating the accuracy of the device against direct physiological measurements. -
If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
Yes, a standalone performance study was done for the device. The clinical study aimed to validate the accuracy of the VO200 - NeurOs Cerebral Oximetry system's measurements directly against invasive blood samples, without human interpretation of the device's output to determine the primary outcome. -
The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
The ground truth was established through invasive physiological measurements (venous jugular bulb and radial arterial blood samples) directly analyzed by a Co-Oximeter. -
The sample size for the training set:
The document does not provide information about a separate training set. The descriptions focus on the clinical validation study (test set). For medical devices, particularly those based on established physiological principles like oximetry, the "training" (calibration) might be integrated into the device's design and manufacturing process rather than through a distinct, large-scale clinical training dataset as would be common for AI/ML algorithms. -
How the ground truth for the training set was established:
As no separate training set is explicitly mentioned, the method for establishing ground truth for a training set is not provided. The accuracy and trending accuracy (which could be considered performance, not training data) values were derived from the validation study described above, where ground truth was established by Co-Oximeter analysis of invasive blood samples.
§ 870.2700 Oximeter.
(a)
Identification. An oximeter is a device used to transmit radiation at a known wavelength(s) through blood and to measure the blood oxygen saturation based on the amount of reflected or scattered radiation. It may be used alone or in conjunction with a fiberoptic oximeter catheter.(b)
Classification. Class II (performance standards).