Previous: Medical Device Software (MDSW) I – Definition


Once you know that the software with a medical purpose is considered a MDSW and it is covered by the Medical Device Regulations, you need to classify it according to the classification rules from the regulation.


The new Medical Device Regulation (EU) 2017/745 – MDR includes Rule 11 that is specific for software:


  • Software intended to provide information which is used to take decisions with diagnosis or therapeutic purposes is classified as class IIa, except if such decisions have an impact that may cause:

— death or an irreversible deterioration of a person’s state of health, in which case it is in class III; or

— a serious deterioration of a person’s state of health or a surgical intervention, in which case it is classified as class IIb.

  • Software intended to monitor physiological processes is classified as class IIa, except if it is intended for monitoring of vital physiological parameters, where the nature of variations of those parameters is such that it could result in immediate danger to the patient, in which case it is classified as class IIb.
  • All other software is classified as class I.


Moreover, there are some other statements that need to be considered:

  • If several rules, or if, within the same rule, several sub-rules, apply to the same device based on the device’s intended purpose, the strictest rule and sub-rule resulting in higher classification will apply
  • Software, which drives or influences the use of a device, shall fall within the same class as the device
  • If software is independent of any other device, it shall be classified in its own right


The classification of the software is an important step because most of the MDSW that were classified as class I under the old directive (93/42/CEE) are now upclassified to class IIa (or higher) according to MDR. That means that a Notified Body will review all the Technical Documentation and the Quality Management System to certify the MDSW. The Technical Documentation is the same for any Medical Device. The Design and Development of the MDSW (among other quality processes), may be performed according to the stages described at ISO 13485:2016 – Medical devices – Quality management systems.

However, we would like to outline some important considerations related to the product verification and validation.

The IEC 62304 is the standard that defines the life cycle requirements for MDSW. The set of processes, activities and tasks described in this standard establish a common framework for MDSW life cycle processes. According to the IEC 62304, the manufacturer shall assign to each MDSW the appropriate software safety class according to the possible effect on the patient or user resulting from a hazard to which the software system can contribute:

  • Class A: No injury or damage to health is possible
  • Class B: Non-serious injury is possible
  • Class C: Death or serious injury is possible


That is a different classification from the MD class according to the classification rules from the MDR. The A, B, C classification allows the manufacturer to establish a software development plan for conducting the activities of the software development process. Obviously, the higher MDSW classification according to MDR would also drive to a higher classification of the software (A, B, C) due tthat both classifications are based on risks for the patient.


Which class is your MDSW under the MDR? Is it up-classified comparing to the old Directive (93/42/CEE)? How should you classify the MDSW? Which is the best strategy to get the CE Mark? TDV can assess your MDSW project from classification to certification.


Next: Medical Device Software (MDSW) III – Validation


For more information on MDSW please contact us.