  In its broadest definition, systems biology is the application of a `systems'
way of thinking about and doing cell biology. By implication, this also invites
us to consider a systems approach in the context of medicine and the treatment
of disease. In particular, the idea that systems biology can form the basis of
a personalised, predictive medicine will require that much closer attention is
paid to the analytic properties of the feedback loops which will be set up by a
personalised approach to healthcare. To emphasize the role that feedback theory
will play in understanding personalised medicine, we use the term feedback
medicine to describe the issues outlined.In these notes we consider feedback
and control systems concepts applied to two important themes in medical systems
biology - personalised medicine and combinatorial intervention. In particular,
we formulate a feedback control interpretation for the administration of
medicine, and relate them to various forms of medical treatment.
