Systems and methods for non-vascular sensor implantation and for measuring physiological parameters in areas of a body where the physiological parameters are heterogeneous. An implant unit is implanted in an area of a body and a foreign body capsule is allowed to form around the implant unit area. A sensor may be directed into a body cavity such as, for example, the peritoneal space, subcutaneous tissues, the foreign body capsule, or other area. A subcutaneous area of the body may be tunneled for sensor placement. Spatially separated sensing elements may be used for detecting individual amounts of the physiological parameter. An overall amount of the physiological parameter may be determined by calculating a statistical measurement of the individual sensed amounts in the area. Another embodiment of the invention, a multi-analyte measuring device, may include a substrate having an electrode array on one side and an integrated circuit on another side.