A glucose sensor assembly useful in patient systems includes an oxygen sensor from which glucose levels in the vicinity of the peritoneal cavity may be inferred. The sensor assembly may be associated with electronics, such as any or all of a DC power supply, an LED source of blue light, a photoreceptor for red light, a CPU, and transceiver, by a direct percutaneous connection. Alternatively they may be associated transdermally with the sensor and some of the electronics being located subdurally. Insulin infusion means are contemplated to respond manually or mechanically to information from the sensors through the CPU. Mechanical response may be automatic. Infusion means may be located subdurally. It is contemplated that the present invention enable revitalization or replacement of fluorescing compounds and glucose oxidase within the sensor assembly.