(1025 days)
The ORi feature is intended to be used in patients undergoing surgery as an adjunct to SpO2 for increased monitoring resolution of elevated hemoglobin oxygen saturation levels (e.g., due to the administration of supplemental oxygen).
The ORi feature is indicated for the monitoring of hemoglobin oxygen saturation levels in patients 18 years and older (adults and transitional adolescents) on supplemental oxygen during no-motion conditions perioperatively in hospital environments.
ORi is a device that provides an adjunct oximeter function that extends the monitoring resolution of hemoglobin oxygen saturation at elevated oxygen levels (e.g., due to the administration of supplemental oxygen). The feature is intended to be used in conjunction with SpO2 monitoring provided by a pulse oximeter. The ORi feature utilizes the similar principles of operation as pulse oximetry, utilizing hemoglobin wavelength absorption characteristics to determine relative blood oxygen saturation. Whereas SpO2 monitoring provides visibility to blood oxygen saturation in the transition from normoxia to hypoxia on the hemoglobin oxygen disassociation curve, ORi provides visibility to the transition from normoxia to hyperoxia.
Here's an analysis of the acceptance criteria and the study that proves the device meets them, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria for the ORi device are not explicitly laid out in a pass/fail table with specific metrics. Instead, the document discusses various performance aspects and mitigation measures for identified risks. However, we can infer some criteria from the "Risks to Health" and "Special Controls" sections, specifically focusing on the clinical performance aspect. The most direct performance claim for ORi is its ability to monitor hyperoxia.
| Acceptance Criterion (Inferred from Risks/Controls) | Reported Device Performance / Study Finding |
|---|---|
| Accuracy of hyperoxia monitoring (Clinical performance testing to evaluate accuracy) | - Adjunct to SpO2 for increased monitoring resolution of elevated hemoglobin oxygen saturation levels (PaO2 100 to 250 mmHg). |
| - AUC > 0.8 in determination of PaO2 for the range 100-250mmHg when compared to SpO2. | |
| - Benefits for detection of changing PaO2 in the range of 100 to 250mmHg better than pulse oximetry alone. | |
| - The trend of ORi values is beneficial to titrate O2 delivery in surgical patients receiving supplemental O2 therapy. | |
| - Labeling mitigates the high intra- and inter-subject ORi variability with respect to PaO2. | |
| No adverse events with concomitant SpO2 monitoring | - No adverse events when the device was used with concomitant SpO2 monitoring in the operating room environment on patients receiving supplemental oxygen. |
| Demonstrated benefits for intended patient populations | - Benefit-risk profile was determined to be favorable for the intended patient populations (adults and transitional adolescents, 18 years and older under surgery with supplemental oxygen). |
| Human factors/usability testing | - Human factors/usability testing must demonstrate that the user can correctly use the device, based solely on reading the instructions for use. (No specific performance metric mentioned beyond this general statement, but it's a requirement). |
| Software verification and validation | - Software documentation for ORi was provided according to the FDA Guidance Document... The software was found to have a Moderate Level of Concern. |
| - ORi validation testing was performed to demonstrate the device software meets its performance requirements using patient data. (Specific performance details of software not quantified in this summary, but overall successful.) | |
| Biocompatibility | - Leveraged from previously cleared device (Masimo Root Monitoring System and Accessories K171121); patient contacting components are identical. (Implies it meets the criterion by proxy). |
| Reprocessing/Cleaning | - Leveraged from previously cleared device (Masimo Root Monitoring System and Accessories K171121). (Implies it meets the criterion by proxy). |
| Electromagnetic Capability & Safety | - Leveraged from a prior 510K submitted for the subject device (Masimo Root Monitoring System and Accessories K171121). (Implies it meets the criterion by proxy). |
| Compatibility with pulse oximeter devices | - Performance testing must demonstrate compatibility with pulse oximeter devices labeled to be compatible with the device. (No specific performance study mentioned for this, but it's a requirement and implies it was met). |
2. Sample Sizes Used for the Test Set and Data Provenance
The clinical studies involved a total of 206 subjects and 2330 data pairs (SpO2, SaO2) used for calculating ORi values.
- Masimo Clinical Lab Study:
- Sample Size (Subjects): 52 healthy volunteers
- Data Pairs: 939
- Provenance: Retrospective (Masimo desaturation laboratory study)
- Ground Truth: Reference PaO2 blood gas values from an ABL blood gas analyzer.
- Loma Linda University Study:
- Sample Size (Subjects): 126 hospitalized participants
- Data Pairs: 1251
- Provenance: Retrospective (Data previously collected prospectively)
- Ground Truth: ABG convenience samples obtained as part of standard of care.
- UC Davis Study:
- Sample Size (Subjects): 28 hospitalized patients
- Data Pairs: 140
- Provenance: Prospective
- Ground Truth: ABG (Arterial Blood Gas) drawn at specific time points.
Overall Data Provenance:
- Country of Origin: Not explicitly stated, but the institutions (Masimo, Loma Linda University, UC Davis) suggest United States.
- Retrospective/Prospective: Two studies were retrospective (Masimo Clinical Lab and Loma Linda), and one was prospective (UC Davis). The retrospective studies utilized data previously collected prospectively.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
The document does not specify the number of experts or their qualifications used to establish the ground truth. It states that:
- For the Masimo Clinical Lab study and UC Davis study, the reference PaO2 blood gas values were collected by an ABL blood gas analyzer and ABG, respectively. This implies that the ground truth for PaO2 was based on laboratory analysis of arterial blood samples, which is the gold standard, rather than expert consensus on image interpretation or clinical diagnosis.
- For the Loma Linda University study, ABG convenience samples were obtained as part of standard of care.
Therefore, the ground truth was primarily objective physiological measurement via ABG analysis, not expert interpretation.
4. Adjudication Method for the Test Set
There was no "adjudication method" in the sense of multiple experts reviewing and reaching a consensus clinical diagnosis. The ground truth was established by direct physiological measurement (Arterial Blood Gas analysis), which is considered objective and definitive for blood gas values.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not explicitly described for evaluating human reader improvement with AI vs. without AI assistance. The study focused on the performance of the ORi device itself in relation to PaO2, and its benefit as an "adjunct" to SpO2, implying general clinical utility rather than a direct comparison of human performance with and without ORi assistance. The statement "benefits for detection of changing PaO2 in the range of 100 to 250mmHg better than pulse oximetry alone" suggests a comparison between ORi + SpO2 vs. SpO2 alone, but not specifically quantified for human reader improvement.
6. Standalone (Algorithm Only) Performance Study
Yes, a standalone study was performed. The studies evaluated the performance of the ORi algorithm by comparing its output directly to the reference standard (PaO2 from ABG analysis). This is evidenced by:
- "ORi validation testing was performed to demonstrate the device software meets its performance requirements using patient data."
- "The pooled data demonstrated an AUC >0.8 in determination of PaO2 for the range 100-250mmHg when compared to SpO2." (This is a statistical assessment of the algorithm's output).
- "The percentage of ORi was greater than that of SpO2 for the same PaO2 values."
The device's mechanism of action and the way its output (a numeric index on a 0-1 scale) is calculated based on light absorption implies an algorithm-only function. The ORi is intended to be an adjunct to SpO2 and not a stand-alone diagnostic device, but its performance was evaluated as a standalone output (an index related to PaO2).
7. Type of Ground Truth Used
The primary type of ground truth used was Arterial Blood Gas (ABG) analysis, specifically PaO2 values. This is an objective, physiological measurement and is explicitly referred to as the "gold standard in diagnosis of hypoxemia."
8. Sample Size for the Training Set
The document does not explicitly state the sample size for a separate training set. The studies described are presented as evaluations of the device, implying they are test sets for validation. It is common for device algorithms to be developed and refined using internal datasets before these validation studies are performed, but details of such a training set are not provided here. The 206 subjects and 2330 data pairs are described as being "submitted by the sponsor for calculation of the ORi values," which might imply they were used in part for validating the final algorithm, but not necessarily for initial training.
9. How the Ground Truth for the Training Set was Established
Since a dedicated training set is not explicitly described, the method for establishing its ground truth is also not mentioned. If the validation data itself (or portions of it) was also used for initial algorithm development or parameter tuning, then the ground truth would have been established by Arterial Blood Gas (ABG) analysis as described for the test set.
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