ISO 5840-1:2015 is applicable to heart valve substitutes intended for human implantation and provides general requirements. Subsequent parts of the ISO 5840?series provide specific requirements. ISO 5840-1:2015 is applicable to both newly developed and modified heart valve substitutes and to the accessories, packaging, and labelling required for their implantation and for determining the appropriate size of the heart valve substitute to be implanted. ISO 5840-1:2015 outlines an approach for qualifying the design and manufacture of a heart valve substitute through risk management. The selection of appropriate qualification tests and methods are derived from the risk assessment. The tests may include those to assess the physical, chemical, biological, and mechanical properties of heart valve substitutes and of their materials and components. The tests may also include those for preclinical in vivo evaluation and clinical evaluation of the finished heart valve substitute. ISO 5840-1:2015 defines operational conditions for heart valve substitutes. ISO 5840-1:2015 excludes homografts. NOTE A rationale for the provisions of this part of ISO 5840 is given in Annex A.