To provide assistance functions, e.g. in context of surgical interventions, the use of a phase detection plays an important role. For instance, by assessing the progress of an on-going surgery, a tailored (i.e. context sensitive) decision support for medical practitioners can be carried out. The optimization of a workflow, e.g. by comparing recorded data with a predefined target model, is another application example. Subsequently, a phase detection provides opportunities to prevent errors, injuries, negligence or malpractices in the medical context. In this work, an overview of notable model approaches for a phase detection in medical context is presented. Based on this, further suggestions for future models are proposed.