(243 days)
This device is intended to provide a means for sampling end tidal carbon dioxide with the option to deliver supplemental O2 therapy to patients for up to 24 hours.
Southmedic's CO2/02 Nasal Cannula incorporates sampling nares that channel expired carbon dioxide to a capnograph. A port located between the two nares is used to deliver oxygen to the patient as needed from an oxygen source. Its unique design delivers 02 to both the nose and mouth area. This device when in use involves surface contact to the patient's intact skin. There is also gas pathway contact between patient and tubing/nasal cannula. Contact is considered limited exposure (up to 24 hours).
The provided text describes several studies conducted to support the substantial equivalence of the Southmedic CO2/O2 Nasal Cannula. The studies focus on biocompatibility and performance.
1. Table of Acceptance Criteria and Reported Device Performance
| Test/Study Attribute | Acceptance Criteria | Reported Device Performance |
|---|---|---|
| Biocompatibility - Cytotoxicity (Agar Overlay) | The United States Pharmacopeia & National Formulary (USP 87) states that the test article meets criteria if the reactivity grade is not greater than 2 or a mild reactivity. The ANSI/AAMI/ISO 10993-5 standard states the achievement of a numerical grade greater than 2 is considered a cytotoxic effect. | Three samples were investigated obtaining an average score of 1. Results were compared to both positive and negative controls (average scores of 4 and 0 respectively). |
| Conclusion: Southmedic's CO2/O2 Nasal Cannula is composed of materials that do not have a cytotoxic effect. | ||
| Biocompatibility - Sensitization (Guinea Pig Buehler) | Test results were based on incidence and severity of the sensitization reaction. Incidence was defined as the percentage of animals exhibiting a sensitization reaction at each observation time point (24 and 48 hours) post challenge. Severity was calculated by dividing the sum of the scores of one (1) or greater in the test group generally indicated sensitization, provided grades of less than one (1) were observed in the control animals. If severity of one (1) or greater was noted on the controls, then the reaction of the test animals exceeded the most severe control reaction to be considered due to sensitization. In the final analysis of data consideration was given to overall patterns, intensity, duration and character of reactions of the test as compared to the control animal. | No sensitization reaction was observed in either the control or test group. |
| Conclusion: Southmedic's CO2/O2 Nasal Cannula is composed of materials that do not have a sensitization effect. | ||
| Biocompatibility - Primary Skin Irritation (Rabbits) | After the 72 hour scoring, all erythema plus edema scores generated during the 24±2, 48±2, and 72±2 hour observations were totaled separately for each test sample and control for each animal. The resulting totals for each animal were divided by 6 (two tests/observation site, three time points) to determine separate test article and control primary irritation scores for each animal. The primary irritation index is characterized by the number (score) and description (response category) given: |
- Negligible: >0 to 0.4
- Slight: 0.5 to 1.9
- Moderate: 2 to 4.9
- Severe: 5 to 8 | The test subject received a Primary Irritation Index Score of 0 in all areas.
Conclusion: Since no skin irritation was observed in the test subjects, this test demonstrates that Southmedic's CO2/O2 Nasal Cannula is composed of materials that are a non-irritant to skin. |
| Performance - End Tidal CO2 Measurement | End tidal CO2 values for Southmedic Nasal Cannula shall not be statistically different, or shall vary less from the true end tidal CO2 value than the predicate products. | The end-tidal CO2 values for the Southmedic CO2/O2 Nasal Cannula was not statistically different, or varied less from the true end tidal CO2 value than predicate products. A comparison of variances of the end tidal CO2 measurements from the actual value for all four devices indicates that the Southmedic nasal cannula has the least variance from true value when compared to the three predicate devices within 95% confidence intervals.
Conclusion: The Southmedic CO2/O2 Nasal Cannula met the predetermined acceptance criteria of the test and performs equally to, or better than, the predicate devices. |
2. Sample Size Used for the Test Set and Data Provenance
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Biocompatibility Studies (Cytotoxicity, Sensitization, Irritation):
- Cytotoxicity: Three samples of the Southmedic device were tested. Control samples (positive and negative) were also used.
- Sensitization (Guinea Pig Buehler): Involved Guinea Pigs (number not explicitly stated, but implied to be sufficient for control and test groups). Data provenance is from Nelson Labs (an independent laboratory).
- Irritation (Rabbits): Involved Rabbits (number not explicitly stated, but implied to be sufficient for control and test subjects). Data provenance is from Nelson Labs (an independent laboratory).
- Provenance: All biocompatibility testing was "contracted to an independent laboratory" (Nelson Labs). The nature of these tests (animal models) implies prospective testing under controlled lab conditions.
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Performance Study (End Tidal CO2 Measurement):
- Test Subjects: Southmedic's CO2/O2 Nasal Cannula and three predicate devices (Salter Labs #4706, Hudson RCI BiFlow 1850, UnoMedical/Hospitak 368E).
- Sample Size: "4 samples x 4 tests per sample x 3 respiratory settings x 4 oxygen flow rate settings = 144 tests total." This refers to testing configurations rather than biological subjects.
- Provenance: "comparative performance bench test against predicate devices was contracted from an independent laboratory" (Piper Laboratory). This is a prospective bench study using a "Harvard Respiratory pump and mannequin head to simulate patient conditions."
3. Number of Experts and Qualifications for Ground Truth
- Biocompatibility Studies: The ground truth for these studies (e.g., cytotoxicity score, presence/absence of sensitization, irritation index) is established by the methods and observations of the independent laboratory (Nelson Labs) performing the tests according to recognized standards (USP 87, ANSI/AAMI/ISO 10993-5, ISO 10993 Part 10). The qualifications of the personnel performing these lab tests are implied by their adherence to these standards, but specific expert qualifications (e.g., 'toxicologist with 10 years of experience') are not provided.
- Performance Study: The "true end tidal CO2 value" in the performance study refers to the simulated CO2 value set by the test apparatus with the Harvard Respiratory pump. The accuracy of measurements against this simulated "true value" is the ground truth. There is no mention of human experts establishing this ground truth, rather it's based on the controlled parameters of the simulation.
4. Adjudication Method for the Test Set
- Biocompatibility Studies: The adjudication method for these studies involves direct measurement and assessment of biological reactions (scores for cytotoxicity, observation for sensitization, irritation index calculation) as per the specified ISO and USP standards. This typically involves trained lab personnel following standardized protocols, not necessarily an "adjudication panel" in the clinical sense.
- Performance Study: The performance study measured end-tidal CO2 values against a simulated "true" value. There is no mention of an adjudication method involving experts for this test. The statistical analysis of the variance of measurements directly against the known simulated value served as the comparison.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No MRMC comparative effectiveness study was done. The device is a nasal cannula, and the studies performed are bench and biocompatibility tests, not clinical or diagnostic interpretation studies involving human readers.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
The device (CO2/O2 Nasal Cannula) is a physical medical device, not an algorithm or AI system. Therefore, the concept of a "standalone (algorithm only without human-in-the-loop performance)" study is not applicable. The performance study evaluates the physical device's ability to accurately sample CO2 and deliver O2 under simulated conditions.
7. Type of Ground Truth Used
- Biocompatibility Studies: Ground truth is based on standardized biological assays (e.g., cell culture reactions for cytotoxicity, animal responses for sensitization and irritation) interpreted against established regulatory and scientific criteria (USP, ISO standards).
- Performance Study: Ground truth is based on controlled simulated conditions using a mechanical respiratory pump and a mannequin head, where the "true end tidal CO2 value" is a predefined parameter of the simulation.
8. Sample Size for the Training Set
The concept of a "training set" is not applicable as this is a physical medical device and not an AI/ML model for which data models are trained. The studies described are for verification and validation of the device's physical properties and performance.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no training set for an AI/ML model.
§ 868.1400 Carbon dioxide gas analyzer.
(a)
Identification. A carbon dioxide gas analyzer is a device intended to measure the concentration of carbon dioxide in a gas mixture to aid in determining the patient's ventilatory, circulatory, and metabolic status. The device may use techniques such as chemical titration, absorption of infrared radiation, gas chromatography, or mass spectrometry.(b)
Classification. Class II (performance standards).