(39 days)
The quantitative determination of total thyroxine concentration in human serum or plasma by a microplate enzymeimmunoassay.Measurements obtained from this device are used in the diagnosis and treatment of thyroid diseases.
Monobind Inc. , registration number 2020726, plans to introduce into commercial distribution an enzymelmmunoassay (EIA) kit for the determination of total thyroxine (T4) In human serum or plasma. The proprietary name is Total Thyroxine (T4) Microplate EIA and the usual name is T4 EIA. This device classification name is - enzyme immunoassay, non-radiolabeled, total thyroxine - product code 75KLI (per 21 CRF section 862.1700). The Monobind microplate EIA utilizes anti-thyroxine antibody immobilized on the surface of plastic wells of a microtiterplate. Specimens, calibrators or controls are then added followed by the enzyme-T4 conjugate. A competition reaction results between the native thyroxine in the sample and the added enzyme-T4 conjugate for a limited number of antibody combining sites. After the completion of the incubation period, the enzyme-T4 conlugate is separated from unreacted material by decantation. The activity of the enzyme on the well is quantitated by reaction with suitable substrate to produce color.
Here's a breakdown of the acceptance criteria and study details for the Total Thyroxine (T4) Microplate EIA device, based on the provided text:
Acceptance Criteria and Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Correlation Coefficient (r) indicating good method agreement | 0.934 |
| Equation to a straight line (linear regression) | y = 0.39 + 0.952x |
| Average recovery for exogenous added thyroxine | 101.1% |
| Average linearity for diluted specimens | 101.2% |
| Mean value for reference method (coated tube RIA) | 8.07 |
| Mean value for new method (microplate EIA) | 8.06 |
Study Details
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Sample size used for the test set and the data provenance:
- Sample Size: 131 specimens
- Data Provenance: The specimens were from "hypothyroid, euthyroid and hyperthyroid populations." The country of origin is not specified, nor is whether the data was retrospective or prospective.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g., radiologist with 10 years of experience):
- Not applicable. The ground truth was established by a predicate device, not human experts for this specific comparison.
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Adjudication method (e.g., 2+1, 3+1, none) for the test set:
- Not applicable. The comparison was against a predicate device, not through human expert adjudication.
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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:
- Not applicable. This is not an AI device, and no MRMC study was conducted. The study was a "clinical comparison (linear regression)" against a predicate device.
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If a standalone (i.e. algorithm only without human-in-the loop performance) was done:
- Yes, in a sense. The device itself (the microplate EIA) was evaluated in comparison to a predicate device (coated tube RIA) to establish substantial equivalence. Human involvement is primarily in performing the lab test, not in interpreting AI output.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- The ground truth was established by a predicate device: the Monobind total thyroxine (T4) coated tube radioimmunoassay (RIA).
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The sample size for the training set:
- Not explicitly mentioned. This is a traditional immunoassay device, not a machine learning or AI algorithm that typically uses a "training set" in the same way. The development of such assays involves optimization and validation steps, but not a distinct "training set" as understood in AI/ML context.
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How the ground truth for the training set was established:
- Not applicable, as there isn't a traditional "training set" for AI/ML in this context. The underlying principles and performance of immunoassays are established through biochemical and analytical validation, not through ground truthing of a data set in the AI sense.
§ 862.1700 Total thyroxine test system.
(a)
Identification. A total thyroxine test system is a device intended to measure total (free and protein bound) thyroxine (thyroid hormone) in serum and plasma. Measurements obtained by this device are used in the diagnosis and treatment of thyroid diseases.(b)
Classification. Class II (special controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 862.9.