Abstract: Systems for controlling or aiding patient therapy are provided. The systems may include a tissue oxygenation measurement device and a therapy delivery apparatus that is controllable to assist in attaining a target tissue oxygenation level or range, whereby patient health is improved by optimizing delivery of therapy based on measured tissue oxygenation. The therapy delivery apparatus may include, for example, a drug delivery apparatus, a ventilating apparatus, a fluid delivery apparatus and/or a chest compression delivery apparatus. The tissue oxygenation measurement device may include a probe for determining the oxygenation of tissue, for example, muscle tissue, by optically interrogating the tissue. Related methods for guiding patient therapy and exercise training are also provided.