(220 days)
The non-invasive Adult Cerebral Oximeter Model 2040 should be used as an adjunct monitor of regional hemoglobin oxygen saturation of blood in the brain of an adult. The Cerebral Oximeter Monitor System should not be used as the sole basis for decisions as to the diagnosis or therapy. The value of data from the Cerebral Oximeter Monitoring System has not been demonstrated in disease states.
The Adult Cerebral Oximeter, model 2040 measures brain oxygenation allowing the clinician to accurately determine absolute levels of tissue and venous oxygenation in the brain. This measurement can be of significant value in numerous acute care (OR, ICU, ER) situations, providing health care professionals with information to guard against neurological injuries due to compromised brain oxygenation, which can occur during many surgical and clinical situations. The 2040 Cerebral Oximeter consists of an optical transducer containing a laser light source and photodiode detectors, and a graphic display monitor with user interface. The non-invasive, reflection mode, optical transducer is placed on the forehead of the subject via a disposable probe attachment to determine cerebral oxygenation. The 2040 Cerebral Oximeter will be safe to use, since it is designed to operate as a Class I laser product, the safest FDA laser classification. Additional safety features include a laser interlock system designed to prevent laser operation in case the optical transducer is not securely attached to the subject. A patent-protected algorithm optimizes accuracy of the device in measurements of absolute brain tissue oxygen saturation and, in conjunction with pulse oximetry, in providing absolute readings of brain venous oxygen saturation.
Here's a breakdown of the acceptance criteria and study information for the CAS Medical Systems, Inc. Adult Cerebral Oximeter Monitor (Model 2040) based on the provided text:
Acceptance Criteria and Reported Device Performance
The document doesn't explicitly state formal "acceptance criteria" but rather reports the device's performance metrics (bias and precision) in comparison to a reference standard derived from co-oximetry. We can infer that the reported values met the internal performance specifications that CAS Medical Systems deemed acceptable for substantial equivalence.
| Performance Metric | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Bias (Model 2040 StO2 vs. Reference StO2) | (Not explicitly stated) | 0.43 |
| Precision (Model 2040 StO2 vs. Reference StO2) | (Not explicitly stated) | ± 3.78 (1 standard deviation) |
| Bias (Model 2040 SvO2 vs. Reference SjbO2) | (Not explicitly stated) | 0.63 |
| Precision (Model 2040 SvO2 vs. Reference SjbO2) | (Not explicitly stated) | ± 5.38 (1 standard deviation) |
Study Information
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Sample Size used for the Test Set and Data Provenance:
- Sample Size: Not explicitly stated, but the study involved "healthy adult volunteers."
- Data Provenance: Prospective clinical study conducted at Duke University Medical Center in Durham, North Carolina, USA.
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Number of Experts used to establish the ground truth for the test set and the qualifications of those experts:
- The ground truth was established through direct physiological measurements (blood samples analyzed by co-oximetry), not by expert interpretation. Therefore, the concept of "experts establishing ground truth" in the interpretive sense does not apply here. The expertise lies in the medical professionals performing the procedures (e.g., placing catheters, drawing blood) and the laboratory personnel operating the co-oximeter.
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Adjudication method for the test set:
- Not applicable. The ground truth was based on objective physiological measurements from blood samples, not subjective interpretations requiring adjudication.
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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 a standalone performance study of the device against a reference standard, not a comparative effectiveness study involving human readers or AI assistance.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Yes, this was a standalone performance study. The device's algorithm, which calculates cerebral oxygenation values, was directly compared to the reference standard. There was no human-in-the-loop component in the performance evaluation described.
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The type of ground truth used:
- Outcomes Data/Physiological Measurement: The ground truth was established using co-oximetry analysis of arterial (SaO2) and jugular bulb (SjbO2) blood samples, considered a direct physiological measurement of oxygen saturation in the bloodstream. These values were then used to calculate a "Reference StO2%" and "Reference SjbO2."
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The sample size for the training set:
- Not explicitly stated. The document describes the clinical testing for showing substantial equivalence, which appears to be a validation/test set for the already developed device. It does not provide details about a separate training set used during the algorithm development phase.
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How the ground truth for the training set was established:
- Not explicitly stated, as details regarding a distinct training set are absent. However, it can be inferred that similar physiological measurement methods (blood sampling, co-oximetry) would likely have been used during the development and initial calibration of the proprietary algorithm if a separate training set was utilized.
§ 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).