(527 days)
The CODMAN Neurotrend Cerebral Tissue Monitoring System measures Intracranial oxygen, carbon dioxide, pH and temperature, and is intended as an indicallarial oxygon, and in these parameters, indicating the perfusion and metabolic acidosis/alkalosis status of cerebral tissue local to sensor placement. metabolic academand values are relative within an individual, the Neurotrend should not be used as the sole basis for decisions as to diagnosis or therapy. It is intended to provide data additional to that obtained by current clinical practice, in cases where hypoxia/ischaemia is a concem.
The Neurotrend Sensor (C7004S) is a modified version of the Fluorescent Paratrend 7 sensor which has been cleared for the US Market (K953893). The measurement parameters for Neurotrend are essentially the same as the Fluorescent Paratrend 7. The sensor does not require a heparin treatment, as a consequence of the application - to monitor cerebral tissue and fluid gas parameters.
The provided text describes the Neurotrend Multiparameter Sensor, a device intended to measure intracranial oxygen, carbon dioxide, pH, and temperature. The submission focuses on demonstrating substantial equivalence to a predicate device by showing that the modification (absence of heparin treatment) does not negatively impact performance.
Here's an analysis of the acceptance criteria and study information based on the provided text:
Acceptance Criteria and Reported Device Performance
The document doesn't explicitly state quantitative acceptance criteria in terms of specific thresholds for bias, precision, or drift. Instead, the "acceptance criteria" appear to be met by demonstrating comparable performance between the modified device (non-heparin treated) and the predicate device (heparin treated) in terms of accuracy characteristics.
| Parameter Measured | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Accuracy (pO₂, pCO₂, pH, Temp) | Demonstrated comparable bias and precision to the predicate heparin-treated sensor. | "The data satisfy product accuracy claims and show comparable results for heparin-treated and non-heparin treated sensors." |
| 90% Step Response Time | Comparable step response times to the predicate heparin-treated sensor. | Step response times were calculated and used in the comparison. No specific values provided, but results were part of the "comparable results." |
| Drift (over 72 hours) | Comparable mean drift to the predicate heparin-treated sensor. | Mean drift was calculated and used in the comparison. No specific values provided, but results were part of the "comparable results." |
Study Information
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Sample Size Used for the Test Set and Data Provenance:
- Test Set Sample Size:
- Heparin-treated sensors (predicate): n = 8
- Non-heparin treated sensors (device under review): n = 7
- Data Provenance: The study was an in vitro test, not involving human data. The devices were manufactured in the UK (based on the submitter's address).
- Test Set Sample Size:
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Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:
- The ground truth for the in vitro test set was established using precision gas mixtures and the Henderson-Hasselbalch equation for pH in tonometers maintained at 37°C. This is a laboratory-based, objective method, so no human experts were used to establish the ground truth for this in vitro study.
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Adjudication Method for the Test Set:
- No adjudication method was mentioned as the ground truth was objectively determined by precision instruments and physical/chemical equations.
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If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done:
- No, a multi-reader, multi-case comparative effectiveness study was not done. This was an in vitro performance study comparing device characteristics.
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If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done:
- This is not applicable in the context of this device. The Neurotrend Sensor directly measures physiological parameters. The "standalone" performance described here is the in vitro performance of the sensor itself, without human interpretation of the raw measurements.
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The Type of Ground Truth Used:
- For the in vitro study, the ground truth was established by precision gas mixtures for partial pressures of O2 and CO2, the Henderson-Hasselbalch equation for pH, and a reference thermometer for temperature within equilibrated tonometers. This is an objective, laboratory-based physical/chemical ground truth.
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The Sample Size for the Training Set:
- The document does not describe the development or training of an algorithm in the traditional sense. It's a sensor device providing direct measurements. Therefore, there's no "training set" for an AI algorithm as typically understood. The sensors themselves are calibrated according to the Instructions For Use (IFU), but this is part of device manufacturing and operational procedure, not an algorithm training process.
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How the Ground Truth for the Training Set Was Established:
- Not applicable as no algorithm training set is described. The "calibration" of the sensors is done against primary standards in a manufacturing/testing environment.
§ 882.1620 Intracranial pressure monitoring device.
(a)
Identification. An intracranial pressure monitoring device is a device used for short-term monitoring and recording of intracranial pressures and pressure trends. The device includes the transducer, monitor, and interconnecting hardware.(b)
Classification. Class II (performance standards).