From MDD to MDR, instruments are still divided into four categories: 

Class I, Class IIa, Class IIb, and Class III.

The classification related MDD is Annex IX in 93/42/EEC and the corresponding guidelines MEDDEV 2 4/1 Rev. 9; 

Article 51 and Annex VIII in the new MDR provide detailed product classification information. The main change is from "18 items" in MDD to "22 items" in MDR.

Rule1-Rule 4: Non Invasive Devices

Rule3: Added Class III instruments for directly removing human cells, tissues, and trachea from the human body or embryo for external use, and then implanting or injecting them into the body.

Rule 5-Rule 8: Invasive Devices

Rule 8: On the basis of the original, active implant instruments or their related accessories, breast implants or heart repair mesh fabrics, complete or partial joint replacements, and intervertebral disc 

replacement implants directly in contact with the spine have been added as Class III.

Rule 9-Rule 13: Active Devices

Rule9: On the basis of the original, "active devices for releasing ionizing radiation for mitigation purposes" and "active implantable devices for controlling, monitoring, or directly affecting" have been added,

 both of which are Class IIb devices.

Rule11: Newly added, proposing software for providing diagnostic or mitigation purpose decision information and monitoring physiological processes, all of which are Class IIa; Other software classes are 

classified as Class I.

Rule 14 Rule 22: Special RULES

Rule14: Further improved the classification requirements for medical products derived from human blood or plasma.

Rule 18: Further improve the classification requirements for devices made from inactive or processed human or animal derived tissues, cells, or other derivatives.

Rule19: Add classification requirements for nanomaterial instruments.

Rule20: Added classification of invasive instruments related to body orifices through inhalation.

Rule 21: Added instruments that introduce absorbable substances into the human body.

Rule22: Added classification of active relief devices with integrated or merged diagnostic functions.

In addition, the separate classification of blood bags in MDD has been removed.