A physiological parameter sensor system comprising: a housing having a patient facing side having a baseline configuration, an opposite side longitudinally spaced from the patient facing side, and a set of longitudinally extending sidewalls which cooperate with the patient facing side and the opposite side to define a first cell and a plurality of second cells which circumscribe the first cell; a first sensor system element residing in the first cell, the first sensor system element being one of an emitter and a detector; two or more second sensor system elements residing in at least some of the plurality of second cells, each second sensor system element being the other of an emitter and a detector; the patient facing side of the housing being conformable to a non-baseline configuration, characterised in that: the first sensor system element is an emitter; the second sensor system elements are detectors; and the system includes a processor adapted to: A) cause the emitter to emit a test signal, B) sample each detector for a return signal associated with the emitted signal, C) select one of the detectors to be a companion to the emitter based on quality of the return signal, and D) deselect, at least temporarily, all detectors other than the companion detector. a housing having a patient facing side having a baseline configuration, an opposite side longitudinally spaced from the patient facing side, and a set of longitudinally extending sidewalls which cooperate with the patient facing side and the opposite side to define a first cell and a plurality of second cells which circumscribe the first cell; a first sensor system element residing in the first cell, the first sensor system element being one of an emitter and a detector; two or more second sensor system elements residing in at least some of the plurality of second cells, each second sensor system element being the other of an emitter and a detector; the patient facing side of the housing being conformable to a non-baseline configuration, characterised in that: the first sensor system element is an emitter; the second sensor system elements are detectors; and the system includes a processor adapted to: A) cause the emitter to emit a test signal, B) sample each detector for a return signal associated with the emitted signal, C) select one of the detectors to be a companion to the emitter based on quality of the return signal, and D) deselect, at least temporarily, all detectors other than the companion detector. the first sensor system element is an emitter; the second sensor system elements are detectors; and the system includes a processor adapted to: A) cause the emitter to emit a test signal, B) sample each detector for a return signal associated with the emitted signal, C) select one of the detectors to be a companion to the emitter based on quality of the return signal, and D) deselect, at least temporarily, all detectors other than the companion detector. A) cause the emitter to emit a test signal, B) sample each detector for a return signal associated with the emitted signal, C) select one of the detectors to be a companion to the emitter based on quality of the return signal, and D) deselect, at least temporarily, all detectors other than the companion detector.