A protective helmet, particularly for sports and work use, including a rigid outer shell which itself comprises a front cap having a concavity able to cover at least the upper part of the cranium, and a rear cap having a concavity able to cover the rear part of the cranium. The microchip comprises an injection channel and a separation channel configured to receive a sample through a sample well disposed on a first end of the separation channel; wherein the injection channel and the separation channel intersect to form a \u2018T\u2019 junction. 5 mm or more, a discharge gap being formed between the discharge portion and the tip end portion of said center electrode, the method including: forming the tapered faces before the discharge portion is laser-welded to the inner side face. Additionally, the drain may be electrically connected to the gate of the transistor. In another embodiment, the method is used to diagnose or genotype cancer cells in a blood or tissue biopsy sample. Between the two flanges is attached a flexible air hose that passes the air flowing from the toilet bowl into the sewer.