(51 days)
The Philips disposable SpO₂ Sensor is intended for non-Indications for Ober 14th oxygen saturation (SpO2) and pulse rate. Indicated for adult/pediatric patients.
The Philips SpO2 devices measure, non-Device invasively, the arterial oxygen saturation of Description blood. The measurement method is based on the red and infrared light absorption of hemoglobin and oxyhemoqlobin. Light of a red and infrared light source is emitted through human tissue and received by a photodiode. The measurement is based on the absorption of light, which is emitted through human tissue (for example through the index finger). The light comes from two sources (red LED and infrared LED) with different wavelengths and is received by a photodiode. Out of the different absorption behavior of the red and infrared light a so-called Ratio can be calculated. The saturation value is defined by the percentage ratio of the oxygenated hemoglobin [HbO₂] to the total amount of hemoglobin [Hb]. SpO2 = [HbO2] / ( [Hb] + [HbO2] ) Out of calibration curves, which are based on controlled hypoxia studies with healthy nonsmoking adult volunteers over a specified saturation range (SaO2 from 100%-70%), the Ratio can be related to a SpO₂ value. The devices contain a red and infrared light source and a photodiode receiving the nonabsorbed red and infrared light. The received signals are forwarded to a measurement device that amplifies the acquired signal and an algorithm that calculates the ratio and converts via a validated calibration table the ratio to a saturation value.
The provided document, K042306, describes the 510(k) summary for the Philips Disposable SpO2 Sensor M1131A. Here's a breakdown of the acceptance criteria and study details based on the information provided:
1. Table of Acceptance Criteria and Reported Device Performance
The document states: "Pass/Fail criteria were based on standards, where applicable, and on the specifications cleared for the predicate device. Test results showed substantial equivalence." However, a specific table detailing numerical acceptance criteria (e.g., accuracy range for SpO2 values) and the M1131A's performance against those criteria is not explicitly provided in the given text.
The primary performance metric mentioned for SpO2 sensors is accuracy against controlled hypoxia studies. The summary describes the general method:
| Acceptance Criteria Category | Reported Device Performance (M1131A) |
|---|---|
| SpO2 Accuracy (General) | Demonstrated through clinical evaluations and comparison to predicate device specifications. Test results showed substantial equivalence. |
| Environmental Testing | Pass/Fail criteria based on standards. |
| Safety Testing | Pass/Fail criteria based on hazard analysis. |
| Interference Testing | Pass/Fail criteria based on standards. |
| Hardware Verification | Pass/Fail criteria based on standards. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: The document mentions "controlled hypoxia studies with healthy nonsmoking adult volunteers," but it does not specify the number of volunteers (sample size) used for the clinical evaluation of the M1131A or its predicate devices.
- Data Provenance: The studies were prospective (controlled hypoxia studies). The country of origin of the data is not explicitly stated, but the submitter is based in Germany (Philips Medizin Systeme Boeblingen GmbH). Given the 510(k) submission to the FDA, it's likely the studies aimed to meet US regulatory requirements.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
The document describes "controlled hypoxia studies" with "healthy nonsmoking adult volunteers" where "calibration curves" are generated. This implies direct measurement of arterial oxygen saturation (SaO2) as the gold standard.
- The ground truth (SaO2) in these hypoxia studies is typically established by arterial blood gas analysis, performed by trained medical professionals (e.g., lab technicians, respiratory therapists, physicians). The document does not specify the number of experts or their exact qualifications, but it implicitly relies on standard clinical laboratory practices for blood gas analysis.
4. Adjudication Method for the Test Set
The concept of "adjudication" (e.g., 2+1, 3+1 for expert review) is typically used for subjective assessments, particularly in imaging or clinical diagnosis where there's room for interpretation. For physiological measurements like SpO2, where the ground truth is established through a direct, objective method (arterial blood gas analysis), an adjudication method in the traditional sense is not applicable or mentioned. The comparison is made directly between the device's SpO2 reading and the simultaneously measured SaO2 from the blood gas.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- No, an MRMC comparative effectiveness study was not done. The device (SpO2 sensor) is a standalone measurement tool, not an AI-assisted diagnostic system that aids human readers in interpreting complex cases. Therefore, the concept of improving human readers with AI assistance does not apply here.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
- Yes, a standalone study was done. The entire clinical evaluation, where the device's SpO2 readings are compared directly to arterial blood gas measurements, represents the standalone performance of the algorithm and sensor. The document states: "The received signals are forwarded to a measurement device that amplifies the acquired signal and an algorithm that calculates the ratio and converts via a validated calibration table the ratio to a saturation value." The clinical evaluations for accuracy directly assess this algorithm-only performance.
7. Type of Ground Truth Used
- The type of ground truth used is objective physiological measurement data, specifically arterial blood gas analysis (SaO2), obtained during controlled hypoxia studies. This is considered the "gold standard" for determining arterial oxygen saturation.
8. Sample Size for the Training Set
The document refers to "calibration curves, which are based on controlled hypoxia studies." These studies are used to "train" or establish the relationship between the light absorption ratio and the SpO2 value.
- The document does not specify the sample size (number of volunteers) used to generate these calibration curves (the "training set"). It only states "healthy nonsmoking adult volunteers."
9. How the Ground Truth for the Training Set Was Established
- As mentioned above, the ground truth for establishing the calibration curves (training set) was established through direct arterial blood gas analysis (SaO2) obtained during "controlled hypoxia studies" with healthy non-smoking adult volunteers. Participants' oxygen levels are systematically lowered over a specified saturation range (SaO2 from 100%-70%), and simultaneous SpO2 readings from the device are correlated with the SaO2 values from 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).