(35 days)
The HCG method for the Dimension® RxL clinical chemistry system with the heterogeneous immunoassay module is used to quantitatively measure intact hCG in serum and plasma, for the early detection of pregnancy.
The HCG method for the Dimension® RxL system with the heterogeneous immunoassay module is a two-step enzyme immunoassay based on the "sandwich" principle. Sample is incubated with chromium dioxide particles coated with monoclonal antibodies specific for the hCG alpha subunit to form a particle/hCG complex. Particles are separated magnetically and the supernatant removed. The particle/hCG complex is incubated with conjugate reagent (β-galactosidase labeled monoclonal antibodies specific for the hCG beta subunit) to form a particle/hCG/conjugate sandwich. Unbound conjugate and analyte are removed by magnetic separation and washing. The sandwich bound ß-galactosidase is combined with the chromogenic substrate chlorophenol red-ß-d-galactopyranoside (CPRG) and catalyzes the hydrolysis of CPRG to the chromophore chlorophenol red (CPR). The concentration of hCG in the patient sample is directly proportional to the rate of color change measured at 577nm due to formation of CPR.
The provided text is a 510(k) summary for a medical device (Human Chorionic Gonadotropin Method for the Dimension RxL system) and does not describe acceptance criteria for performance, nor does it detail a study proving the device meets specific acceptance criteria in the way a clinical trial or a more extensive validation report would.
The document focuses on demonstrating substantial equivalence to a predicate device, the Abbott IMx® hCG. This is a common regulatory pathway for medical devices seeking FDA clearance.
Here's an analysis based on the information provided, framed to address your questions where possible, and noting where information is absent:
1. Table of Acceptance Criteria and Reported Device Performance:
The document does not explicitly state pre-defined acceptance criteria in terms of sensitivity, specificity, accuracy, or other performance metrics. Instead, it presents a comparison to a predicate device as the primary measure of performance and equivalence.
| Acceptance Criteria (Implied by Substantial Equivalence Goal) | Reported Device Performance (vs. Predicate) |
|---|---|
| Strong correlation with predicate device | Correlation Coefficient: 0.986 |
| Slope and intercept indicating similar analytical measurement | Slope: 1.270 |
| Intercept: 2.87 mIU/mL |
2. Sample Size Used for the Test Set and Data Provenance:
- Sample Size for Test Set: 134 clinical patient samples.
- Data Provenance: The text states "clinical patient samples." It does not specify the country of origin. It is a retrospective comparison, as samples were collected and then split for testing on both devices.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications:
- This information is not provided. The "ground truth" in this context is implicitly the measurement from the predicate device (Abbott IMx® hCG), as the study aims to show equivalence to it, not an absolute truth established by external experts or pathology.
4. Adjudication Method for the Test Set:
- This information is not applicable/provided in the context of this type of comparison study. There was no adjudication process described for establishing ground truth; the predicate device's result was the comparison standard.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size:
- No, an MRMC comparative effectiveness study was not done. This study is an analytical performance comparison between two diagnostic assays, not an assessment of human reader performance with or without AI assistance. The device is an automated chemistry system, not an AI-assisted diagnostic tool for human interpretation.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done:
- Yes, effectively. The study described is a comparison of the automated performance of the "HCG method for the Dimension® RxL system" in a standalone capacity (algorithm only, as it's an automated immunoassay) against another automated system (Abbott IMx® hCG). There is no "human-in-the-loop" component in the direct operation or result generation of these chemistry systems.
7. The Type of Ground Truth Used:
- The "ground truth" for the comparison in this study was the measurement obtained from the predicate device (Abbott IMx® hCG) for the same split patient samples. The study's goal was to demonstrate that the new device's measurements correlated strongly with those of the established predicate device.
8. The Sample Size for the Training Set:
- Not provided. This document describes a validation study (comparison to predicate), not the development of a machine learning model, which would typically involve a training set. The HCG method for the Dimension® RxL system is an immunoassay, not an AI/ML algorithm that requires a "training set" in the computational sense.
9. How the Ground Truth for the Training Set Was Established:
- Not applicable. As stated above, this is not an AI/ML device, so there is no "training set" in that context.
§ 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.