(73 days)
The noninvasive INVOS 5100C is intended for use as an adjunct monitor of regional hemoglobin oxygen saturation of blood in the brain or in other tissue beneath the sensor. It is intended for use in individuals greater than 2.5 kg at risk for reduced-flow or no-flow ischemic states. It is also intended for use as an adjunct trend monitor of regional hemoglobin oxygen saturation of blood in the brain or in other tissue beneath the sensor in any individual.
The INVOS 5100C is a 2 wavelength, diffuse reflectance spectroscopy system employing near infrared light to estimate the percentage of hemoglobin saturated with oxygen in tissue underneath the sensor. An adhesive sensor containing a light source and 2 photodiodes is applied to the skin over the tissue of interest and the returning light is analyzed for oxyhemoglobin and deoxyhemoglobin light absorption. Absorption signals from the photodiode closer to the light source are subtracted from those from the farther photodiode where the returning photons penetrate more deeply in the tissue. This suppresses absorption events originating in the outer layers of tissue that are common to both photodiodes, including the effects of skin pigmentation and subcutaneous tissues. This method of "spatial resolution" also allows estimation of scattering to improve measurement accuracy.
The provided text describes a 510(k) premarket notification for the SOMANETICS OxyAlert NIRSensors (models IS-C and IS-S accessories) for use with the INVOS 5100C System.
Here's an analysis of the acceptance criteria and the study that proves the device meets them, based on the provided information:
1. Table of Acceptance Criteria and Reported Device Performance:
The document primarily focuses on demonstrating substantial equivalence to a predicate device, rather than explicit performance acceptance criteria in terms of specific numerical thresholds (e.g., accuracy, sensitivity, specificity). The core acceptance criterion is that the new sensors are as safe and effective as the predicate device.
| Acceptance Criterion | Reported Device Performance |
|---|---|
| Substantial Equivalence to Predicate Device (INVOS® 5100C Cerebral/Somatic Oximeter System, K082327) | "Performance data demonstrates that the new photodiodes are as safe and effective as the predicate." |
| No New Questions of Safety or Effectiveness | "The change in photodiodes does not raise any new questions of safety or effectiveness." |
| Same Intended Use and Indications | Explicitly stated: "The new sensors have the same intended use and indications..." |
| Same Principles of Operation | Explicitly stated: "...principles of operation..." |
| Same Technological Characteristics | Explicitly stated: "...and technological characteristics as the predicate device." |
2. Sample Size Used for the Test Set and Data Provenance:
- Sample Size: Not explicitly stated in the provided text. The document only mentions "Bench testing." There's no information on the number of subjects or samples used in this bench testing.
- Data Provenance: Not explicitly stated. The nature of "bench testing" suggests it was likely controlled laboratory testing. There's no mention of country of origin, nor whether the data was retrospective or prospective.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of Those Experts:
- Number of Experts: Not mentioned.
- Qualifications of Experts: Not mentioned.
Given that the study was "bench testing" for a device measuring regional hemoglobin oxygen saturation, the ground truth would likely involve a validated reference measurement instrument or method, rather than expert interpretation of images or clinical assessments by human experts in the typical sense.
4. Adjudication Method for the Test Set:
- Adjudication Method: Not mentioned. The nature of "bench testing" typically involves direct comparison to a reference standard, rather than adjudication of human interpretations.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size of Improvement with AI vs. Without AI Assistance:
- MRMC Study: No, an MRMC comparative effectiveness study was not conducted. This is not an AI-assisted diagnostic or interpretative device; it's a physiological monitoring sensor.
- Effect Size of AI Improvement: Not applicable, as this is not an AI device designed to assist human readers in interpretation.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done:
- This device is a sensor and monitoring system. Its primary function is to measure physiological parameters directly. The "performance data" mentioned refers to the device's ability to accurately measure these parameters. As such, the performance described is akin to a standalone performance for the sensor, comparing its output to a known reference. However, it's not an "algorithm only" device in the sense of image analysis software; it's a hardware sensor that produces data based on its measurement principles.
7. The Type of Ground Truth Used:
- Ground Truth: The document states "Bench testing is submitted demonstrating the substantial equivalence of the new sensors with modified photodiodes for the stated indication." For a "two wavelength, diffuse reflectance spectroscopy system employing near infrared light to estimate the percentage of hemoglobin saturated with oxygen in tissue," the ground truth for "performance data" would typically involve:
- Reference Oximetry or Spectroscopy: Comparison against a gold standard or a highly accurate reference oximeter/spectrometer under controlled conditions.
- Simulated Tissues or Phantoms: Use of known optical properties in phantoms to verify measurement accuracy.
- In-vitro testing: Testing under laboratory conditions with known concentrations of oxyhemoglobin and deoxyhemoglobin.
The document does not specify which type of ground truth was used, only that performance data was submitted from "bench testing."
8. The Sample Size for the Training Set:
- Training Set Sample Size: Not applicable/not mentioned. This device is not described as using a machine learning or AI model that requires a "training set" in the conventional sense. The "bench testing" described is for validation and verification against a predicate device and known measurement principles, not for algorithm training.
9. How the Ground Truth for the Training Set Was Established:
- Ground Truth for Training Set: Not applicable, as there is no mention of a training set or machine learning algorithm.
§ 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).