The present invention relates to a structurally rigid, X-ray translucent backboard for transporting an injured person from the scene of an injury to a treatment center. The system includes an acquisition subsystem with a computed tomography machine and an alternate modality subsystem. The platelet rich plasma may be collected in a plurality of cycles. In one embodiment, the processing device is connected to the input device to receive the signals, determine the position of a moving indicator relative to the document, and correlate the determined position with the electronic representation of the hardcopy document. In a multiple-quantum well layer of the semiconductor electroluminescent device, a magnitude of interface strain at an interface between the well layer and the barrier layer is smaller than a magnitude of critical interface strain determined by a layer thickness value which is larger one of a thickness of the well layer and a thickness of the barrier layer.