Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Medical Devices: Definition, Classification, and Regulatory Implications

  • 156 Accesses


We propose the following definition of a medical device: “A contrivance designed and manufactured for use in healthcare, and not solely medicinal or nutritional.” Current regulatory classifications of medical devices are complex and designed primarily for regulators. We propose a simpler classification, based on (1) the site of application of the device, (2) the time scale of its use, and (3) whether it has an external power source. The regulation of medical devices is less well developed than the regulation of medicinal products, which it could follow more closely. In particular, devices that incorporate medicines should be required to meet the same regulatory standards as medicinal products. This would remove the anomaly that some delivery systems that incorporate medicines are classified as devices while other similar systems that deliver the same medicines are classified as medicinal products. Some improvements might also result from more widespread use of registries, such as those used for prosthetic joint replacements. Registries would allow both a prospective examination of the performance of high-risk devices and a retrospective analysis when signals from other sources of information suggest problems. Those who apply for a marketing authorization for a new device should have to assure regulators of its quality of manufacture, safety, and efficacy before licensing. Even the most straightforward device should be shown to be useable in practice. Trials on patients, or at least simulations of use in the real world, should be practicable for most devices.

This is a preview of subscription content, log in to check access.

Fig. 1
Fig. 2


  1. 1.

    World Health Organization. 2019. Medical devices. https://www.who.int/medical_devices/full_deffinition/en. Accessed 21 Oct 2019.

  2. 2.

    Aronson JK, Ferner RE. Clarification of terminology in drug safety. Drug Saf. 2005;28(10):851–70.

  3. 3.

    Aronson JK. Defining “nutraceuticals”: neither nutritious nor pharmaceutical. Br J Clin Pharmacol. 2017;83(1):8–19.

  4. 4.

    US Food and Drug Administration. 2019. Product classification: coronary drug-eluting stents. https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfPCD/classification.cfm?ID=1030. Accessed 21 Oct 2019.

  5. 5.

    Regulatory Information Task Force. Japan Pharmaceutical Manufacturers Association. Pharmaceutical administration and regulations in Japan. 2015. http://www.jpma.or.jp/about/issue/gratis/index2.html (Japanese). http://www.jpma.or.jp/english/parj/whole.html (English). Accessed 21 Oct 2019.

  6. 6.

    International Medical Device Regulators Forum. About IMDRF. 2019. http://www.imdrf.org/about/about.asp. Accessed 21 Oct 2019.

  7. 7.

    Statutory Instruments 2002 No. 618. Consumer protection. The Medical Devices Regulations 2002, amended by The Medical Devices (Amendments) Regulations 2008 No. 2936. http://www.legislation.gov.uk/uksi/2002/618/contents/made.

  8. 8.

    Council Directive 93/42/EEC of 14 June 1993 concerning medical devices. https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CONSLEG:1993L0042:20071011:en:PDF.

  9. 9.

    The Medical Devices (Amendments) Regulations 2008 No. 2936. http://www.legislation.gov.uk/uksi/2008/2936/contents/made.

  10. 10.

    European Medicines Agency. Medical devices. 2019. https://www.ema.europa.eu/en/human-regulatory/overview/medical-devices. Accessed 21 Oct 2019.

  11. 11.

    US Food and Drug Administration. Medical device overview. 2019. https://www.fda.gov/ForIndustry/ImportProgram/ImportBasics/RegulatedProducts/ucm510630.htm. Accessed 21 Oct 2019.

  12. 12.

    US Food and Drug Administration. Combination products guidance documents. 2019. https://www.fda.gov/combination-products/guidance-regulatory-information/combination-products-guidance-documents. Accessed 21 Oct 2019.

  13. 13.

    “device, n.” OED Online, Oxford University Press, December 2018. 2019. https://www.oed.com/view/Entry/51464. Accessed 21 Oct 2019.

  14. 14.

    Frumento C. Classification of medical devices. Write Stuff. 2011;20(2):84–7.

  15. 15.

    US Food and Drug Administration. Global Unique Device Identification Database (GUDID). 2019. https://www.fda.gov/medical-devices/unique-device-identification-system-udi-system/global-unique-device-identification-database-gudid. Accessed 21 Oct 2019.

  16. 16.

    US Food and Drug Administration. Device classification panels. 2019. https://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/Overview/ClassifyYourDevice/ucm051530.htm. Accessed 21 Oct 2019.

  17. 17.

    US Food and Drug Administration. Product code classification file. 2019. https://www.fda.gov/medicaldevices/deviceregulationandguidance/overview/classifyyourdevice/ucm051668.htm#file. Accessed 21 Oct 2019.

  18. 18.

    Regulation (EU) 2017/745 of the European Parliament and of the Council of 5 April 2017 on medical devices, amending Directive 2001/83/EC, Regulation (EC) No 178/2002 and Regulation (EC) No 1223/2009 and repealing Council Directives 90/385/EEC and 93/42/EEC. 2019. https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32017R0745&from=EN. Accessed 21 Oct 2019.

  19. 19.

    European Commission. MDCG 2018-2 future EU medical device nomenclature: description of requirements. 2019. https://ec.europa.eu/docsroom/documents/28668. Accessed 21 Oct 2019.

  20. 20.

    Medicines and Healthcare products Regulatory Agency (MHRA). Further guidance note on the regulation of medicines, medical devices and clinical trials if there’s no Brexit deal. 2019. https://www.gov.uk/government/publications/further-guidance-note-on-the-regulation-of-medicines-medical-devices-and-clinical-trials-if-theres-no-brexit-deal. Accessed 21 Oct 2019.

  21. 21.

    Regulation (EC) No 1394/2007 of the European Parliament and of the Council of 13 November 2007 on advanced therapy medicinal products and amending Directive 2001/83/EC and Regulation (EC) No 726/2004. 2019. https://ec.europa.eu/health//sites/health/files/files/eudralex/vol-1/reg_2007_1394/reg_2007_1394_en.pdf. Accessed 21 Oct 2019.

  22. 22.

    CEN/CLC/JTC 3. Quality management and corresponding general aspects for medical devices. 2019. https://standards.cen.eu/dyn/www/f?p=204:32:0::::FSP_ORG_ID,FSP_LANG_ID:581003,25&cs=15E56AA1B5E36714FDA7D18423912D106. Accessed 21 Oct 2019.

  23. 23.

    Public Law 94-295 94th Congress. An Act to amend the Federal Food, Drug, and Cosmetic Act to provide for the safety and effectiveness of medical devices intended for human use, and for other purposes. May 28, 1976 [S.510]. https://uscode.house.gov/statutes/pl/94/295.pdf.

  24. 24.

    Wang C, Hefflin B, Cope JU, Gross TP, Ritchie MB, Qi Y, et al. Emergency department visits for medical device-associated adverse events among children. Pediatrics. 2010;126(2):247–59.

  25. 25.

    Maisel WH. Medical device regulation: an introduction for the practicing physician. Ann Intern Med. 2004;140:296–302.

  26. 26.

    Heneghan CJ, Goldacre B, Onakpoya I, Aronson JK, Jefferson T, Plüddemann A, et al. Trials of transvaginal mesh devices for pelvic organ prolapse: a systematic database review of the US FDA approval process. BMJ Open. 2017;7(12):e017125.

  27. 27.

    Breckenridge A. The changing scene of the regulation of medicines in the UK. Paper from The Use of Medicines: Regulation and Clinical Pharmacology in the 21st Century Symposium: December 2003. Br J Clin Pharmacol. 2004;58(6):571–4.

  28. 28.

    Aronson JK, Ferner RE. Unlicensed and off-label uses of medicines: definitions and clarification of terminology. Br J Clin Pharmacol. 2017;83(12):2615–25.

  29. 29.

    Lübbeke A, Silman AJ, Barea C, Prieto-Alhambra D, Carr AJ. Mapping existing hip and knee replacement registries in Europe. Health Policy. 2018;122(5):548–57.

  30. 30.

    Practical aspects of signal detection in pharmacovigilance: report of CIOMS Working Group VIII. 2010. https://cioms.ch/shop/product/practical-aspects-of-signal-detection-in-pharmacovigilance-report-of-cioms-working-group-viii. Accessed 21 Oct 2019.

  31. 31.

    EUDAMED: European Database on Medical Devices. 2019. http://ec.europa.eu/idabc/en/document/2256/5637.html. Accessed 21 Oct 2019.

  32. 32.

    Wilkinson J, Crosbie A. A UK medical devices regulator’s perspective on registries. Biomed Tech (Berl). 2016;61(2):233–7.

  33. 33.

    Privitera MB, Evans M, Southee D. Human factors in the design of medical devices: approaches to meeting international standards in the European Union and USA. Appl Ergon. 2017;59(Pt A):251–63.

  34. 34.

    Alexander K, Clarkson PJ. Good design practice for medical devices and equipment, Part I: a review of current literature. J Med Eng Technol. 2000;24(1):5–13.

  35. 35.

    Luk A, Junnarkar G. Critical challenges to the design of drug-eluting medical devices. Ther Deliv. 2013;4(4):471–7.

  36. 36.

    Morrison RJ, Kashlan KN, Flanangan CL, Wright JK, Green GE, Hollister SJ, et al. Regulatory considerations in the design and manufacturing of implantable 3D-printed medical devices. Clin Transl Sci. 2015;8(5):594–600.

  37. 37.

    Altomare L, Bonetti L, Campiglio CE, De Nardo L, Draghi L, Tana F, Farè S. Biopolymer-based strategies in the design of smart medical devices and artificial organs. Int J Artif Organs. 2018;41(6):337–59.

  38. 38.

    US Food and Drug Administration. Code of Federal Regulations. Title 21, Volume 8. Revised as of April 1, 2018. Cite: 21CFR860.3. Title 21: Food and Drugs. Chapter I: Food and Drug Administration. Department of Health and Human Services. Subchapter H: Medical Devices. Part 860: Medical Device Classification Procedures. 2019. https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=860.3&SearchTerm=%22general%20controls%22. Accessed 21 Oct 2019.

Download references


We are grateful to the International Society of Pharmacovigilance for allowing us to organize a symposium on medical devices, held at the International Society of Pharmacovigilance 2018 meeting in Geneva, on which this and a companion paper are based.

Author information

Correspondence to Jeffrey K. Aronson.

Ethics declarations


No sources of funding were used to assist in the preparation of this article.

Conflict of interest

Jeffrey K. Aronson has received royalties for material published in Meyler’sSide Effects of Drugs: the International Encyclopedia of Adverse Drug Reactions and Interactions and the Side Effects of Drugs Annuals, which include material on medical devices. Carl Heneghan receives funding from the National Institute for Health Research (NIHR) Oxford Biomedical Research Centre and the NIHR School of Primary Care Research Evidence Synthesis Working Group [Project 390]. He receives expenses for teaching evidence-based medicine and is paid for his general practitioner work in the National Health Service out of hours. He is the Editor-in-Chief of BMJ Evidence-Based Medicine and an NIHR Senior Investigator. Robin E. Ferner has no conflicts of interest that are directly relevant to the content of this article.

Ethical approval

Patients were not involved in this study and ethics approval was not required.

Data sharing

The data on which this work is based are freely available on request.


Appendix 1: European Union regulation of medical devices

The European Union legislation distinguishes four classes (I, IIa, IIb, III) [6]. The class of a device is decided according to rules that consider:

  1. 1.

    Duration of use of the device

    • Transient

    • Short-term

    • Long-term

  2. 2.

    Invasiveness of the device

    • Non-invasive

    • Invasive

      • Body Orifice

      • Surgically invasive

      • Implantable

The rules also examine whether the device comes into one or more of the following categories:

  1. 3.

    Reusable surgical instrument

    “Instrument intended for surgical use by cutting, drilling, sawing, scratching, scraping, clamping, retracting, clipping or similar procedures, without connection to any active medical device and which can be reused after appropriate procedures have been carried out.”

  2. 4.

    Active medical device

    “Any medical device operation of which depends on a source of electrical energy or any source of power other than that directly generated by the human body or gravity and which acts by converting this energy.”

  3. 5.

    Active therapeutical [sic] device

    “Any active medical device, whether used alone or in combination with other medical devices, to support, modify, replace or restore biological functions or structures with a view to treatment or alleviation of an illness, injury or handicap.”

  4. 6.

    Active device for diagnosis

  5. 7.

    Central circulatory system

    • Including the pulmonary circulation

  6. 8.

    Central nervous system

All medical devices in the European Union must fulfil the essential requirements, which are that “The devices must be designed and manufactured in such a way that, when used under the conditions and for the purposes intended, they will not compromise the clinical condition or the safety of patients, or the safety and health of users or, where applicable, other persons, provided that any risks which may be associated with their use constitute acceptable risks when weighed against the benefits to the patient and are compatible with a high level of protection of health and safety.” Those devices deemed to be in Classes IIa, IIb, and III must fulfil additional requirements. The classification rules are detailed. For example, “Rule 17: All devices manufactured utilizing animal tissues or derivatives rendered non-viable are Class III except where such devices are intended to come into contact with intact skin only.”

There are specific regulations for advanced therapy products that combine a medicine and a device [16].

European standards organizations set out the criteria for a large range of devices, including, for example, the symbols to be used on labels; the form of connectors for liquids and gases; and risk management [17].

Appendix 2: US regulation of medical devices

The US legislation divides medical devices into three classes, intended to reflect the risks that the device poses (Table 3) [18].

Table 3 The US Food and Drug Administration’s classification of medical devices; the full definitions are given in the text

Assignment to one of the three classes is determined by a series of decisions based on the perceived risks of the device when used for its intended purpose [19]. In principle, the least stringent requirements are that the device is perceived to be of low risk, and that the manufacturer has complied with the standards of good manufacturing practices (GMP). A device can be approved through a so-called 510(k) application if it is thought to be “substantially equivalent” to a previously approved device. Any device that is perceived to pose a significant risk and is not similar to a previously approved device may be required to undergo investigation.

The following are the full definitions of the three classes shown in Table 3 [38].

  1. 1.

    Class I means the class of devices that are subject to only the general controls authorized by or under sections 501 (adulteration), 502 (misbranding), 510 (registration), 516 (banned devices), 518 (notification and other remedies), 519 (records and reports), and 520 (general provisions) of the act. A device is in class I if (1) general controls are sufficient to provide reasonable assurance of the safety and effectiveness of the device, or (2) there is insufficient information from which to determine that general controls are sufficient to provide reasonable assurance of the safety and effectiveness of the device or to establish special controls to provide such assurance, but the device is not life-supporting or life-sustaining or for a use which is of substantial importance in preventing impairment of human health, and which does not present a potential unreasonable risk of illness of injury.

  2. 2.

    Class II means the class of devices that is or eventually will be subject to special controls. A device is in class II if general controls alone are insufficient to provide reasonable assurance of its safety and effectiveness and there is sufficient information to establish special controls, including the promulgation of performance standards, postmarket surveillance, patient registries, development and dissemination of guidance documents (including guidance on the submission of clinical data in premarket notification submissions in accordance with section 510(k) of the act), recommendations, and other appropriate actions as the Commissioner deems necessary to provide such assurance. For a device that is purported or represented to be for use in supporting or sustaining human life, the Commissioner shall examine and identify the special controls, if any, that are necessary to provide adequate assurance of safety and effectiveness and describe how such controls provide such assurance.

  3. 3.

    Class III means the class of devices for which premarket approval is or will be required in accordance with section 515 of the act. A device is in class III if insufficient information exists to determine that general controls are sufficient to provide reasonable assurance of its safety and effectiveness or that application of special controls described in paragraph (c)(2) of this section would provide such assurance and if, in addition, the device is life-supporting or life-sustaining, or for a use which is of substantial importance in preventing impairment of human health, or if the device presents a potential unreasonable risk of illness or injury.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Aronson, J.K., Heneghan, C. & Ferner, R.E. Medical Devices: Definition, Classification, and Regulatory Implications. Drug Saf 43, 83–93 (2020). https://doi.org/10.1007/s40264-019-00878-3

Download citation