Glossary of terms

A premarket submission made to the FDA to demonstrate that a device is substantially equivalent to a legally marketed predicate device.

How close a test result is to the true value. Accuracy combines trueness, meaning freedom from systematic bias, with precision, and is usually assessed by comparing results against a reference method or reference material.

Software that uses artificial intelligence or machine learning and meets the definition of a medical device, for example by detecting disease or guiding treatment. It is a type of SaMD and is regulated according to its intended purpose and risk.

The substance or chemical constituent being identified and measured in an analytical procedure or diagnostic test.

The number and type of viable microorganisms present on or in a product, component or raw material before sterilisation. Bioburden testing supports sterilisation validation and routine monitoring of manufacturing hygiene.

The ability of a material or device to perform with an appropriate host response when applied as intended, without causing adverse effects.

Contract Development and Manufacturing Organisation. A company that provides development and manufacturing services to the pharmaceutical, biotechnology and diagnostics industries on a contract basis.

A certification mark indicating conformity with health, safety and environmental protection standards for products sold within the European Economic Area.

The ongoing process of collecting and assessing clinical data to confirm that a medical device is safe, performs as intended and delivers its claimed clinical benefits. Under the EU MDR, the findings are documented in a clinical evaluation report (CER).

The ability of a diagnostic device to yield results correlating with particular clinical conditions or physiological states in the target population.

Clinical and Laboratory Standards Institute. A not-for-profit organisation that publishes consensus guidelines on laboratory testing, including the EP series used to design analytical performance studies such as precision, interference and limit of detection.

Gold nanoparticles used as detection labels in lateral flow immunoassays, producing the characteristic red or pink test line visible to the naked eye.

An in vitro diagnostic device that provides information essential for the safe and effective use of a corresponding therapeutic product.

The part of a lateral flow test strip that holds dried detection reagents, typically antibodies attached to coloured particles such as colloidal gold. When the sample reaches it, the reagents are released and travel along the strip.

Contract Research Organisation. A company providing research services, including clinical trial management and performance evaluation, on behalf of pharmaceutical and diagnostics companies.

When a test responds to a substance other than its intended target, such as a closely related organism or molecule. Cross-reactivity studies check that these substances do not cause false positive results.

The measures that protect connected devices and medical software from unauthorised access, data loss or tampering. Regulators expect cybersecurity to be addressed through design, risk management, testing and ongoing monitoring once a device is on the market.

An FDA marketing pathway for novel devices of low to moderate risk that have no suitable predicate device for a 510(k). A successful De Novo request creates a new device classification that later products can use as a predicate.

A systematic approach to the design and development of medical devices, required under FDA 21 CFR 820 and ISO 13485.

A set of documents describing the design, development and testing of a device, often prepared for review by a Notified Body or regulator. Under current EU regulations this information forms part of the technical documentation.

A person or company based in the EU, appointed by a manufacturer outside the EU to act on its behalf under the EU MDR or IVDR. The representative keeps documentation available and liaises with the relevant authorities.

European Union Medical Devices Regulation (EU) 2017/745, governing the safety and performance requirements for medical devices placed on the EU market.

The European database on medical devices, used to register manufacturers, devices and certificates and to record information on vigilance, clinical investigations and performance studies. It is intended to improve transparency across the EU market.

Chemical compounds that can be extracted from or leach out of materials, packaging or devices under specified conditions, relevant to safety assessment.

The United States Food and Drug Administration, responsible for regulating food, drugs, medical devices and diagnostics.

Good Manufacturing Practice. A system ensuring products are consistently produced and controlled according to quality standards.

A problem in some immunoassays where a very high concentration of analyte causes a falsely low or negative result. Measuring range studies test high concentrations to check whether a hook effect occurs.

The international standard for medical device software life cycle processes. It sets out requirements for software development, maintenance, risk management and problem resolution, scaled to the software’s safety class.

The international standard for applying usability engineering to medical devices. It describes how manufacturers should identify user tasks and use errors, and evaluate the user interface to reduce risks linked to use.

A biochemical test that measures the presence or concentration of a substance using an antibody-antigen reaction.

The effect of another substance in a sample, such as a medicine, lipids or blood components, that changes a test result. Interference studies show which substances, and at what levels, can affect performance.

A series of international standards for the biological evaluation of medical devices. It sets out how to assess risks such as cytotoxicity, irritation and sensitisation, within a risk management process aligned with ISO 14971.

An international standard series covering microbiological methods for the sterilisation of medical devices. Part 1 covers determining bioburden on products and Part 2 covers tests of sterility used to validate sterilisation processes.

An international standard specifying requirements for a quality management system where an organisation needs to demonstrate its ability to provide medical devices and related services.

The international standard for the application of risk management to medical devices, covering hazard identification, risk estimation, evaluation and control.

The international standard for testing and calibration laboratories. Accreditation to ISO/IEC 17025 demonstrates technical competence, validated methods and robust quality management systems, providing confidence in the accuracy and reliability of laboratory data.

In vitro diagnostic. A test performed on samples such as blood, urine or tissue taken from the human body, used for diagnosis, monitoring or screening.

In Vitro Diagnostic Regulation (EU) 2017/746, the European regulation governing in vitro diagnostic medical devices.

The four risk classes for in vitro diagnostic devices under the EU IVDR, from Class A (lowest risk) to Class D (highest risk). The class determines the conformity assessment route, and most devices above Class A need Notified Body involvement.

A paper-based diagnostic device designed to detect the presence of a target substance in a sample, using capillary flow along a membrane strip.

An electronic device or smartphone application that reads the lines on a lateral flow test and records the result. Readers can make interpretation more objective and may allow semi-quantitative or quantitative results.

The lowest amount of analyte that a test can reliably detect. It is a key measure of analytical sensitivity and is usually established using statistical methods described in recognised guidelines.

The ability of a quantitative test to give results that are directly proportional to the amount of analyte in a sample across a stated range. Linearity studies help define the reportable measuring range.

The rules in Annex VIII of the EU MDR that assign medical devices to Class I, IIa, IIb or III based on factors such as duration of use, invasiveness and the body part affected. Higher classes need greater scrutiny.

Medical Device Single Audit Program. A scheme that allows one audit of a manufacturer’s quality management system to meet the requirements of several participating regulators, including those of Australia, Brazil, Canada, Japan and the United States.

The documented process of proving that a laboratory method is suitable for its intended use. It typically assesses characteristics such as accuracy, precision, specificity, detection limits and robustness.

Medicines and Healthcare products Regulatory Agency. The UK government agency responsible for regulating medicines, medical devices and blood components for transfusion.

Technology dealing with the precise control and manipulation of fluids at the sub-millimetre scale, used in advanced diagnostic devices.

A diagnostic test capable of simultaneously detecting and measuring multiple analytes or biomarkers from a single sample.

A porous membrane material used as the detection surface in lateral flow tests, providing protein-binding properties for capturing target molecules.

An organisation designated by an EU member state to assess the conformity of certain products, including medical devices and IVDs, before they are placed on the market.

The systematic assessment of an IVD device’s analytical and clinical performance to demonstrate it meets its intended purpose.

A named individual with defined qualifications who is responsible for regulatory compliance within a manufacturer or EU Authorised Representative. The role is required under the EU MDR and IVDR.

Premarket Approval. The FDA regulatory pathway for Class III medical devices, requiring clinical evidence of safety and effectiveness.

Diagnostic testing performed near or at the site of patient care, rather than in a centralised laboratory.

PPV is the likelihood that a person with a positive result truly has the condition, and NPV is the likelihood that a person with a negative result truly does not. Both depend on how common the condition is.

Activities under the EU MDR in which a manufacturer gathers and assesses clinical data from a device already on the market. PMCF confirms safety and performance over the device’s lifetime and feeds into the clinical evaluation.

The IVDR equivalent of PMCF. A manufacturer collects and evaluates performance data from an in vitro diagnostic device on the market to confirm its scientific validity, analytical performance and clinical performance over time.

The systematic monitoring of the safety and performance of medical devices and IVDs after they have been placed on the market.

How closely repeated measurements of the same sample agree with each other. Precision studies look at repeatability under the same conditions and reproducibility across different runs, days, operators, reagent lots and sites.

Quality Management System. A formalised system documenting processes, procedures and responsibilities for achieving quality policies and objectives.

Quality Management System Regulation. The FDA’s quality system requirements for medical device manufacturers, set out in 21 CFR Part 820. It replaced the earlier Quality System Regulation (QSR) and incorporates ISO 13485 by reference.

Clinical evidence about the use, benefits and risks of a medical product, drawn from data collected outside controlled studies, such as health records, registries and device data. Regulators may accept it to support certain decisions.

The collection of records produced by a manufacturer’s risk management process under ISO 14971. It includes the risk management plan, hazard analysis, risk controls, evaluation of residual risk and the risk management report.

Receiver operating characteristic curve. A graph showing the trade-off between sensitivity and specificity at different cut-off values. It helps developers choose the cut-off that gives the most suitable balance for a test’s intended use.

The part of a lateral flow test where the sample is applied. It filters the sample and can contain buffers or other treatments that prepare it to flow evenly along the strip.

The ability of a diagnostic test to correctly identify individuals with the condition (true positive rate).

Software intended for one or more medical purposes that performs those purposes without being part of a hardware medical device, such as an app that analyses images to support diagnosis. Its classification depends on the risk of its intended use.

The ability of a diagnostic test to correctly identify individuals without the condition (true negative rate).

Studies that show how long a product or reagent continues to perform as intended under defined storage and use conditions. They support shelf-life claims, in-use stability and shipping conditions, using real-time or accelerated testing.

The body of evidence, often called the technical file, showing that a device meets the applicable regulatory requirements. It covers the device description, design and manufacture, risk management, verification and validation results, and labelling.

The two lines on a typical lateral flow test. The test line shows whether the target analyte is present, while the control line confirms that the sample has flowed correctly and the test has worked.

A UK-based person or company appointed by a manufacturer located outside the UK to place medical devices on the market in Great Britain. The UKRP registers devices with the MHRA and acts as a point of contact.

United Kingdom Accreditation Service. The national accreditation body for the UK, which assesses organisations such as testing laboratories against international standards including ISO/IEC 17025 and ISO 15189.

The UK Conformity Assessed mark, showing that a product meets the requirements for sale in Great Britain. For medical devices, CE marking continues to be accepted in Great Britain under transitional arrangements.

A system of unique codes placed on device labels and packaging to identify a specific device and its production details, such as lot or serial number. UDI improves traceability, recalls and post-market surveillance.

A person or company in the United States that a foreign medical device establishment must appoint when registering with the FDA. The US Agent acts as the main contact for communications between the FDA and the manufacturer.

Two related steps in device development. Verification confirms that the design outputs meet the specified requirements, while validation confirms that the finished device meets user needs and its intended use in real conditions.