What is an In vitro Diagnostic Device?

by Harry Mingay and Dr. Rita Hendricusdottir on 15 Apr 2021

Reading time: 2 minutes

The first step in the regulatory pathway for any organisation is to identify the relevant regulation. Within the medical device industry, the most important distinction is whether a device is governed by the Medical Device Regulation (MDR), or the in vitro Diagnostic Regulation (IVDR) – or in some (rare) cases, both.

Once the device is deemed to be a medical device, according to the definition in Article 2 (1) of the MDR, the distinction between the MDR and IVDR is made by the definition of an in vitro diagnostic (IVD) device - something that RegMetrics has seen some users struggle with.

The definition of an in vitro diagnostic medical device, as stated in Article 2 (2) of the IVDR, is as follows:

'in vitro diagnostic medical device' means any medical device which is a reagent, reagent product, calibrator, control material, kit, instrument, apparatus, piece of equipment, software or system, whether used alone or in combination, intended by the manufacturer to be used in vitro for the examination of specimens, including blood and tissue donations, derived from the human body, solely or principally for the purpose of providing information on one or more of the following: (a) concerning a physiological or pathological process or state; (b) concerning congenital physical or mental impairments; (c) concerning the predisposition to a medical condition or a disease; (d) to determine the safety and compatibility with potential recipients; (e) to predict treatment response or reactions; (f) to define or monitoring therapeutic measures. Specimen receptacles shall also be deemed to be in vitro diagnostic medical devices.'

The definition for an IVD device hinges on the statement 'intended by the manufacturer to be used in vitro for the examination of specimens'. In order to fully understand this definition, the Medical Device Coordination Group (MDCG) has provided a definition of the term 'specimens' in their recent guidance document: 'Guidance on Classification Rules for in vitro Diagnostic Medical Devices'.

'specimen' is a discrete portion of a body fluid or tissue taken from an individual for examination, study or analysis of one or more quantities or characteristics to determine the character of the whole. This also includes other materials, for example, hair, nails excretions, secretions, or a sample from the skin surface.

This definition emphasises that a specimen is a discrete sample taken from the individual for subsequent analysis. While it is not explicitly mentioned, almost all specimens taken for IVD analysis are not re-administered into the body after the analysis has been concluded. For image analysis devices, the specimen being analysed is critical to determining whether this medical device is an IVD device. Software that analyses and interprets the optical density delivered by an enzyme-linked immunosorbent assay (ELISA) reader for diagnostic purpose would qualify as an IVD device, as the ELISA assay provides analysis on a specimen which is bound to the coated plates. However, melanoma image analysis software using images taken of the patient would be classified as a medical device due to the fact that the analysis is not examining a specimen (MDCG 2019-11).

The important distinction between IVD devices and medical devices is that IVD devices cannot cause direct physical harm to a patient in the same way that a medical device can. This suggests why they are governed under different regulations using different classification systems. The harm caused by IVD devices is in the form of false positive or false negative results. In the case of a false negative, this risk is not only for the patient, but for the wider population if the disease or condition in question is contagious – and especially so if it is also life-threatening.