A chemically amplified positive resist includes at least both a polyhydroxystyrene resin having a protective base which varies in polarity by an acid catalyst and a photoacid generator, wherein the chemically amplified positive resist is admixed with at least a styrene derivative. The pyramid-like structure is disposed on one surface of the substrate and has a base, a first face, a second face and a third face. The detected sleep stage information may then be used to indicate sleep quality, identify or monitor a medical condition, or guide treatment thereof.