The invention features a monitoring device that measures a patient’s vital signs. The plates are provided with facing apertures and facing pole pieces so that particles entering the recesses are both repelled from the apertures and attracted towards and retained in collecting regions between exposed facing plate portions. Especially, in the anticorrosion paint, the top coat paint for improving the protection of the primer coat paint and the anticorrosion effect. A separation process is performed to separate the male mold and the other portion of the photocuring resin, the LED and the substrate. The invention further relates to methods for splicing such an optical fiber to an optical component and to methods for using such an optical fiber.