If sample sizes need to be determined there are many statistical methods and assumptions related to this so decisions should be carefully considered. Two of the most commonly used sample tables are ISO 2859 for attibutes and ISO 3951 for variables.
IEC 62304 and Emerging Standards Impacting Medical Device and HealthIT Software
ISO 14971 Risk Management (typically with heavy emphasis on software aspect)
IEC 81001-5-1 Cybersecurity Lifecycle
ISO 13485 QMS Requirements & optionally ISO 19011 for leading audits
Being Agile Yet Compliant (AAMI TIR 45)
IEC 29119-1 Software and System Testing
US Classification for Software Devices
IEC 62366 Usability Process and Documentation
Or just email training@softwarecpr.com for more info.