Search Results
Found 1 results
510(k) Data Aggregation
(277 days)
The B.R.A.H.M.S.PCT LIA is an immunoluminometric assay (ILMA) used to determine the concentration of PCT (procalcitonin) in human serum and plasma.
The B.R.A.H.M.S PCT LIA is intended for use in conjunction with other laboratory findings and clinical assessments to aid in the risk assessment of critically ill patients on their first day of ICU admission for progression to severe sepsis and septic shock.
B-R A-H-S PCT LIA is an immunoluminometric assay (ILMA) used to determine the concentration of Procalcitonin (PCT) in human serum and plasma. Two antigen-specific monoclonal antibodies that bind PCT (the antigen) at two different binding sites (the calcitonin and katacalcin segments) are added in excess. One of these antibodies is luminescence labeled (the tracer), and the other is fixed to the inner walls of the tube (coated tube system). During the course of incubation, both antibodies react with PCT molecules in the sample to form "sandwich complexes". As result the luminescence labeled antibody is bound to the inner surface of the tube. Once the reaction is completed, the excess tracer is completely removed from the tube and discarded. Then, the amount of residual tracer on the test-tube wall is quantified by measuring the luminescence signal using a suitable luminometer and the B·R·A·H·M·S Basiskit LIA reagents. The intensity of the luminescence signal (RLU) is directly proportional to the PCT concentration in the sample. After a standard curve has been established using standards with known antigen concentrations (calibrated against recombinant intact human PCT), the unknown PCT concentrations in patient serum or plasma samples can then be quantitated by comparison of test values with the curve.
Here's a breakdown of the acceptance criteria and the study details for the B·R·A·H·M·S PCT LIA device, based on the provided 510(k) summary:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state "acceptance criteria" in a codified format with target values. Instead, it presents performance characteristics and clinical study results that demonstrate the device's utility for its intended use. I will present the performance characteristics provided as "reported device performance."
| Performance Characteristic | Reported Device Performance |
|---|---|
| Analytical Sensitivity | 0.1 ng/ml |
| Functional Assay Sensitivity (FAS) | 0.3 ng/ml |
| Total Precision (%CV) | 5.3 - 16.6 % CV |
| Within Run Precision (%CV) | 2.4 - 10 % CV |
| High Dose Hook Effect | Does not have an effect on patient assignment to reference ranges for PCT concentrations up to 4000 ng/ml. (If a PCT result above the highest standard is obtained, samples should be diluted and re-run.) |
| Interference | No interference from tested substances at specified concentrations (Bilirubin, Triglyceride, Hemoglobin, Protein (Albumin), Imipenem, Cefotaxim, Vancomycin, Dopamine, Noradrenaline, Dobutamine, Heparin, Furosemide, Calcitonin, Katacalcin, a-CGRP, β-CGRP, Calcitonin Salmon, Calcitonin Eel). |
| Clinical Interpretation (PCT > 2.0 ng/ml) | Represents a high risk for progression to severe sepsis and/or septic shock on the first day of ICU admission. |
| Clinical Interpretation (PCT < 0.5 ng/ml) | Represents a low risk for progression to severe sepsis and/or septic shock on the first day of ICU admission. (Does not exclude infection, especially localized or very early infections). |
| Clinical Interpretation (PCT 0.5-2.0 ng/ml) | Should be reviewed carefully considering clinical background. |
| Expected Values | In normal subjects, PCT concentrations are < 0.3 ng/ml (143 out of 144 healthy subjects had values < 0.3 ng/ml). |
2. Sample Size for the Test Set and Data Provenance
The "test set" in this context refers to the clinical study populations.
- Study 1:
- Sample Size: 101 consecutive critically ill patients.
- Data Provenance: Medical ICU in Switzerland. Retrospective or prospective is not explicitly stated in the summary itself, but the reference "Müller B. et al., Crit. Care Med. 2000; 28(4): 977-983" suggests it's a published, likely prospective, clinical study. The summary explicitly states "controlled prospective studies."
- Study 2:
- Sample Size: 78 consecutive critically ill patients.
- Data Provenance: Medical and surgical ICU in Switzerland. Prospective.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
The document does not provide details on the number or qualifications of experts used to establish the "ground truth" for the clinical classifications (SIRS/Sepsis, Severe Sepsis, Septic Shock). The classification of patients into these categories would typically be based on established clinical criteria and diagnosis by attending physicians or critical care specialists. The referenced studies (Müller et al. and Harbarth et al.) would have detailed their methodology for patient classification.
4. Adjudication Method for the Test Set
The document does not describe a formal "adjudication method" for the clinical classifications. Patient classification into SIRS/Sepsis, Severe Sepsis, or Septic Shock was presumably done according to standard clinical diagnostic criteria at the time of the studies, likely by the clinicians managing the patients.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done
No. This was not an MRMC comparative effectiveness study. This device is an in vitro diagnostic assay that provides a quantitative measurement (PCT concentration). The studies evaluated the diagnostic utility of this quantitative measurement in aiding risk assessment, not the performance improvement of human readers with or without AI assistance.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, in essence. The B·R·A·H·M·S PCT LIA is a standalone diagnostic assay. Its performance output is the PCT concentration, which is then interpreted by clinicians based on established thresholds and along with other clinical findings. The studies presented demonstrate the performance of the assay results in correlation with clinical outcomes (progression to severe sepsis/septic shock).
7. The Type of Ground Truth Used
The ground truth used for the clinical studies was clinical diagnosis and patient outcomes as defined by:
- SIRS (Systemic Inflammatory Response Syndrome), Sepsis, Severe Sepsis, and Septic Shock based on established clinical criteria at the time of the studies.
- Progression to severe sepsis and septic shock as observed in the critically ill patient populations.
8. The Sample Size for the Training Set
The document does not specify a separate "training set" for the clinical performance evaluation. The two studies (Study 1 with 101 patients and Study 2 with 78 patients) are presented as the clinical validation for the device's intended use.
For the assay's technical performance (e.g., sensitivity, precision, interference), these types of studies typically involve a series of laboratory experiments using controlled samples (e.g., spiked samples, known concentrations), rather than a "training set" in the machine learning sense. The "standards" (S1-S6) and "controls" (K1, K2) mentioned in the reagents section are used for calibrating and quality control of the assay itself.
9. How the Ground Truth for the Training Set was Established
As there is no distinct "training set" identified for clinical performance in the machine learning sense, this question is not fully applicable. For the technical performance aspects (e.g., calibration, linearity, precision), the ground truth is established through:
- Known concentrations of PCT (recombinant PCT used for standards S1-S6).
- Controlled spiking of interfering substances at defined concentrations.
- NCCLS testing guidelines for analytical and functional sensitivity, and precision, which involve standardized procedures and reference materials.
Ask a specific question about this device
Page 1 of 1