(56 days)
IMMULITE Turbo HCG is a solid-phase, two-site chemiluminescent enzyme immunometric assay for use with the IMMULITE Automated Analyzer and designed for the quantitative measurement of human chorionic gonadotropin (HCG) in serum, and Heparinized or EDTA plasma. It is intended strictly for in vitro use as an aid in the detection of pregnancy.
IMMULITE® Turbo HCG is a two-site chemiluminescent enzyme immunometric assay for use with the IMMULITE® Automated Analyzer.
IMMULITE Turbo HCG is a solid-phase, two-site chemiluminescent immunometric assay. The solid phase, a polystyrene bead enclosed within an IMMULITE Test Unit, coated with a monoclonal antibody specific for HCG beta subunit. While the patient sample and alkaline phospatase-conjugated polyclonal antibody are incubated for approximately 6 minutes at 37°C In the Test Unit with intermittent agitation, HCG in the sample is bound to form an antibody sandwich complex. Unbound conjugate is then removed by a centrifugal wash, after which substrate is added and the Test Unit is incubated for a further 4 minutes. The chemiluminescent substrate, a phosphate ester of adamantyl dioxetane, undergoes hydrolysis in the presence of alkaline phosphatase to yield an unstable intermediate. The continuous production of this intermediate results in the sustained emission of light, thus improving precision by providing a window for multiple readings. The bound complex - and thus also the photon output, as measured by the luminometer - is proportional to the concentration of HCG in the sample.
The provided K994085 document describes the IMMULITE® Turbo HCG device, an in vitro diagnostic assay for the quantitative measurement of Human Chorionic Gonadotropin (HCG) in serum or plasma, intended as an aid in detecting pregnancy. The study detailed is a method comparison study between the IMMULITE® Turbo HCG and the predicate device, DPC's IMMULITE® HCG Kit.
Here's an analysis of the acceptance criteria and the study that proves the device meets them:
1. A table of acceptance criteria and the reported device performance
The document does not explicitly state pre-defined acceptance criteria in terms of numerical thresholds for method comparison. Instead, it presents the results of the comparison and implies that these results demonstrate substantial equivalence. However, based on the provided data, we can infer the performance metrics and their achieved values. The primary metric used is linear regression analysis for method comparison.
| Acceptance Criteria (Inferred) | Reported Device Performance |
|---|---|
| Strong linear correlation (r value close to 1) between the new device and the predicate device. | r = 0.999 for HCG concentrations from 8 mIU/mL to 3,000 mIU/mL |
| Slope of linear regression close to 1. | Slope = 1.0 |
| Y-intercept of linear regression close to 0. | Y-intercept = 12 mIU/mL |
| Close agreement between mean HCG concentrations. | IMMULITE® Turbo HCG Mean: 439 mIU/mL |
| IMMULITE® HCG Mean: 445 mIU/mL |
2. Sample size used for the test set and the data provenance
- Sample Size: 60 patient serum samples.
- Data Provenance: The document does not explicitly state the country of origin. It indicates that the samples were "patient serum samples," implying they were clinical samples. The study is retrospective, as it involves existing patient samples being tested on two different assays.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
This type of information is not applicable to this study. For an in vitro diagnostic device like IMMULITE® Turbo HCG, the "ground truth" for HCG concentration is established by the reference method itself (in this case, the predicate device, IMMULITE® HCG) or a gold standard method. It does not involve human expert interpretation of images or clinical data in the same way an imaging device might. Therefore, no experts were used to establish ground truth in this context.
4. Adjudication method for the test set
This is not applicable. The study is a quantitative method comparison, not one that requires adjudication of subjective measurements or interpretations by multiple readers. The output of both devices is a quantitative HCG concentration.
5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
This is not applicable. The device is an in vitro diagnostic assay, not an AI-assisted diagnostic tool that aids human readers. Therefore, an MRMC study and the concept of human reader improvement with AI assistance are not relevant to this submission.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, this study is inherently a standalone (algorithm only) performance evaluation. The IMMULITE® Turbo HCG is an automated immunometric assay. The study compares its quantitative results directly against another automated assay (the predicate device) without human interpretation being part of the measurement process itself. Human interpretation comes into play for clinical decision-making based on the quantitative result, but the device performance itself is standalone.
7. The type of ground truth used
The "ground truth" for this method comparison study is established by the predicate device's measurement (IMMULITE® HCG). The goal is to show substantial equivalence of the new device to an already legally marketed device, implying the predicate device's measurements serve as the accepted standard for comparison.
8. The sample size for the training set
The document does not mention a training set or any machine learning/AI components. The device is a traditional laboratory assay, and its development would typically involve optimization and validation runs, but not in the sense of a machine learning training set with labeled data for algorithm learning.
9. How the ground truth for the training set was established
As there is no explicit training set for a machine learning algorithm, this question is not applicable. For the assay's development, the "ground truth" during optimization would involve using known HCG standards and calibrators, and possibly characterized patient samples, to ensure accurate and precise measurements.
§ 862.1155 Human chorionic gonadotropin (HCG) test system.
(a)
Human chorionic gonadotropin (HCG) test system intended for the early detection of pregnancy —(1)Identification. A human chorionic gonadotropin (HCG) test system is a device intended for the early detection of pregnancy is intended to measure HCG, a placental hormone, in plasma or urine.(2)
Classification. Class II.(b)
Human chorionic gonadotropin (HCG) test system intended for any uses other than early detection of pregnancy —(1)Identification. A human chorionic goadotropin (HCG) test system is a device intended for any uses other than early detection of pregnancy (such as an aid in the diagnosis, prognosis, and management of treatment of persons with certain tumors or carcinomas) is intended to measure HCG, a placental hormone, in plasma or urine.(2)
Classification. Class III.(3)
Date PMA or notice of completion of a PDP is required. As of the enactment date of the amendments, May 28, 1976, an approval under section 515 of the act is required before the device described in paragraph (b)(1) may be commercially distributed. See § 862.3.