YY/T 1709-2020Evaluation of measurement uncertainty of calibrators for in vitro diagnostic kits (English PDF)

3.1 Product calibrator; calibrator

The calibrator intended for the manufacturer's final product.

3.2 Working calibrator; master calibrator

Measurement standard used for calibration of manufacturer's permanent measurement procedures.

3.3 Metrological traceability

The characteristic of linking measurement results with references through a documented uninterrupted calibration chain. Every calibration introduces measurement uncertainty.

3.4 Measurement uncertainty; uncertainty

Non-negative parameter that characterize the dispersion given to measured value, according to the information used. [GB/T 29791.1-2013, definition A.3.35]

3.5 Target uncertainty; maximum allowable measurement uncertainty

The specified upper limit of the measurement uncertainty based on the intended use of the measurement result.

4.1 General

4.1.1 Basic flow

According to the flow shown in Figure 1, evaluate the measurement uncertainty of in vitro diagnostic calibrator.

4.1.2 Amount of being measured and target uncertainty

The manufacturer shall specify the amount of being measured, including the intended use of the amount in a specific medical decision, biological sample matrix and any type and unit of measurement related to the analyzed component, amount.

4.1.3 Sources of uncertainty

See Figure 2 for evaluation of measurement uncertainty sources of calibrators for in vitro diagnostic kits. The measurement uncertainty introduced by uniformity and stability as well as the uncertainty related to the setting process together constitute the main component of the measurement uncertainty of the calibrator.

4.1.4 Uncertainty evaluation strategy

The scheme proposed in this Standard is a non-restrictive scheme. Other reasonable schemes can be used to evaluate the uncertainty of the calibrator.

4.2 Measurement uncertainty introduced by uniformity, ubb

4.2.1 General

The product calibrators for in vitro diagnostic kits are usually produced in batches. The measurement uncertainty ubb introduced by the uniformity between bottles within a batch, constitutes an important component of the uncertainty of the calibrator.

4.2.2 Test scheme

4.2.2.1 Test method

The test method shall meet the following requirements.

4.2.2.2 Sample extraction

According to random stratification method, extract the calibrator from the smallest packaging unit for uniformity inspection. Number the samples in sequence, for example, 1, 2,..., 15.

4.2.2.3 Testing

Each packaging unit is respectively measured at least 3 times. Considering the fluctuation of the measurement system over time and other factors, it needs to reverse the sequence of samples between 3 measurements, for example, 1-3- 5-7-9-11-13-15-2-4-6-8-10-12-14-15-14-13-12-11-10-9-8-7-6-5-4-3-2-1-2-4-6- 8-10-12-14-1-3-5-7-9-11-13-15.

4.3 Measurement uncertainty introduced by stability, us

4.3.1 General

The stability of the calibrator includes long-term stability and short-term stability.

Long-term stability is the storage stability under the conditions specified by the manufacturer. Short-term stability includes transportation stability and use stability (for example, involving multiple sampling). Generally, the measurement uncertainty introduced by long-term stability, ults, constitutes an important component of the uncertainty of the calibrator. The measurement uncertainty introduced by short-term stability, usts, shall also be considered when it is not negligible.

4.6 Uncertainty reporting and evaluation

When the user needs it, the manufacturer shall provide the user with the uncertainty of the calibrator assignment and be able to provide the uncertainty component results and uncertainty evaluation process.