Abstract: A method includes: obtaining, by an apparatus, instantaneous images from an optical heart activity sensor, wherein the instantaneous images characterize a heart activity data of a user; obtaining information about spatial shifts of a measuring area of the optical heart activity sensor in relation to a body tissue of the user; determining effect of the spatial shifts in the instantaneous images based on the information about the spatial shifts; enhancing the instantaneous images by decreasing the effect of the spatial shifts in the instantaneous images; and processing the enhanced instantaneous images into the heart activity data of the user.

Abstract: A method includes: obtaining, by an apparatus, instantaneous images from an optical heart activity sensor, wherein the instantaneous images characterize a heart activity data of a user; obtaining information about spatial shifts of a measuring area of the optical heart activity sensor in relation to a body tissue of the user; determining effect of the spatial shifts in the instantaneous images based on the information about the spatial shifts; enhancing the instantaneous images by decreasing the effect of the spatial shifts in the instantaneous images; and processing the enhanced instantaneous images into the heart activity data of the user.

Abstract: A micro-optical grid structure is produced on a surface layer of a substrate by an embossing device and method. The embossing device includes an embossing member and a backing member, a temperature adjuster for adjusting the embossing temperature and a pressure adjuster for adjusting the pressure exerted by the embossing member and the backing member to the surface layer of the substrate. An optical measuring device is arranged to produce a diffraction signal dependent on the intensity of light diffracted from the surface of the substrate. The embossing pressure and/or temperature is/are adjusted on the basis of the diffraction signal to produce an optimal and even pattern depth of the grid structure. With the adjustment based on the diffraction signal, it is possible to avoid the sticking of the surface of the substrate to the embossing member due to too high an embossing temperature. When the pattern depth is optimal, collapse of the substrate caused by the too high embossing pressure is avoided.

Abstract: The invention relates to an optical measuring head for measuring a Raman spectrum and to a method of manufacturing an optical measuring head. The measuring head comprises a first optical fiber means for guiding radiation causing a Raman excitation to an object being measured, a second optical fiber means for guiding the optical radiation from the object being measured for measuring, and a high-pass filter that is made of a semi-conducting material for filtering the optical radiation causing a Raman excitation from the radiation received from the object being measured before the radiation propagates to the second optical fiber means. A desired cut-on wavelength is adjusted for the high-pass filter by changing the thickness or impurity content of the high-pass filter.