What are diagnostic medical devices?

Diagnostic medical devices generate information used to identify disease, evaluate physiological function, determine health risks, or monitor an existing condition. They range from simple thermometers and blood-pressure monitors to laboratory analyzers, medical imaging systems, and molecular diagnostic platforms.

Two broad groups are commonly recognized.
1. In vivo diagnostic devices examine or measure the patient directly; examples include electrocardiographs, ultrasound machines, X-ray systems, pulse oximeters, spirometers, and blood-pressure monitors.
2. In vitro diagnostic devices, or IVDs, examine specimens collected from the body, such as blood, urine, saliva, or tissue. IVD examples include pregnancy tests, glucose meters and test strips, hematology analyzers, infectious-disease test kits, and pathology reagents.

The FDA includes reagents, test kits, and blood glucose meters within its medical-device framework, while European legislation regulates IVDs separately under Regulation (EU) 2017/746. Device classification and premarket requirements depend on intended use, patient risk, testing environment, and the consequences of an incorrect result.

A diagnostic result does not always establish a final diagnosis. Screening devices may identify individuals requiring further evaluation, while confirmatory tests provide more specific evidence. Manufacturers must clearly define intended users, specimen types, performance characteristics, limitations, calibration requirements, and result-interpretation procedures. Procurement teams should assess regulatory authorization, analytical and clinical performance, quality controls, maintenance requirements, connectivity, consumable availability, and operator training.