Abstract: An apparatus for depth-resolved measurements of properties of tissue includes an illuminator that illuminates the tissue with light, a collector for collecting light which has not been absorbed by the tissue, and a determination device configured to determine properties of the tissue in different depths from the collected light. A casing for advancing into a hollow object includes at least a part of the illuminator and collector. The illuminator and collector are configured to collect light depth-resolved, and the determination device is configured to determine depth-resolved properties of the tissue from the light which has been collected depth-resolved.

Abstract: The invention relates to a multivariate calibration which can be used when the optical system used for that method does not comprise a multi-channel detector such as a CCD sensor or a line array of photodiodes. An optical system without a multi-channel detector doesn't allow to carry out preprocessing steps. Thus there is the need to carry out these preprocessing steps in another way. It is suggested to partially replace the preprocessing step by a measurement of the optical signal, whereby the measurement comprises transmitting or reflecting the optical signal by an optical element, thereby weighing the optical signal by a spectral weighing function. The advantage of the invention is to teach how such an optical system without a bulky and expensive CCD sensor can be used to carry out a multivariate calibration and preprocessing steps.

Abstract: There is provided a device for imaging a skin object (7) near a skin surface of a body part, comprising a light source (1) and a detector (8) for detecting radiation returning from said object (7), wherein the device further comprises an elliptical, preferably circular, polarizer (4, 19) between the source (1) and said skin (6) surface, the device comprising a 5 ratio increaser means (3, 4, 19) for increasing the ratio of radiation from said object (7) to radiation from said skin (6) surface. The ratio increaser may be an additional or the same elliptical polarizer. Using elliptically or even circularly polarized light makes hair detection independent of the orientation of hair (7) with respect to light or polarization, which renders 10 the detection more reliable. The invention also provides an imaging method and a hair-shortening device and method.

Abstract: The invention relates to a multivariate calibration which can be used when the optical system used for that method does not comprise a multi-channel detector such as a CCD sensor or a line array of photodiodes. An optical system without a multi-channel detector doesn't allow to carry out preprocessing steps. Thus there is the need to carry out these preprocessing steps in another way. It is suggested to partially replace the preprocessing step by a measurement of the optical signal, whereby the measurement comprises transmitting or reflecting the optical signal by an optical element, thereby weighing the optical signal by a spectral weighing function. The advantage of the invention is to teach how such an optical system without a bulky and expensive CCD sensor can be used to carry out a multivariate calibration and preprocessing steps.

Abstract: The invention relates to an apparatus (20) for depth-resolved measurements of properties of tissue (114). The apparatus comprises illumination means (112) adapted to illuminate the tissue (114) with light, collector means (115) for collecting light which has not been absorbed by the tissue (114), determination means (108) for determining properties of the tissue (114) in different depths from the collected light, and a casing (121), in which at least a part of the illumination means and the collector means are located, for advancing into a hollow object. The illumination means (112) and the collector means (115) are adapted to collect light depth-resolved, and the determination means (108) is adapted to determine depth-resolved properties of the tissue (114) from the light, which has been collected depth-resolved.