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 (S1) residing in the first cell , the first sensor system element (S1) being one of an emitter and a detector ; two or more second sensor system elements (S2) residing in at least some of the plurality of second cells , each second sensor system element (S2) 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 (S1) is an emitter ; the second sensor system elements (S2) 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 (S1) residing in the first cell , the first sensor system element (S1) being one of an emitter and a detector ; two or more second sensor system elements (S2) residing in at least some of the plurality of second cells , each second sensor system element (S2) 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 (S1) is an emitter ; the second sensor system elements (S2) 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 (S1) is an emitter ; the second sensor system elements (S2) 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 . <EOS>