Abstract: In a device, system and method for determining the concentration of a substance, such as the oxygen saturation in the blood of a subject, the influence of specular reflection is reduced or removed. An input unit is configured to receive detection signals reflected back from a skin area of the subject in response to irradiation of the skin area by a radiation signal. A signal extraction unit is configured to extract at least two photo-plethysmography, PPG, signals at two different wavelengths from the detection signals. A processing unit is configured to compute the concentration of a selected substance in the blood of the subject based on the PPG signals taking into account a skin tone of the subject.

Abstract: A device for determining the concentration of a substance in the blood of a subject, such as the oxygen saturation, which device reduces or removes the influence of specular reflection and/or subject motion, comprises an input unit for receiving detection signals reflected back or transmitted through a skin area of the subject in response to irradiation of the skin area by a radiation signal, a signal extraction unit for extracting at least three photo-plethysmography, PPG, signals at different wavelengths from said detection signals, a processing unit for normalizing said at least three PPG signals and forming a first difference signal between a first normalized PPG signal and a second normalized PPG signal and a second difference signal between a third normalized PPG signal and one other of the at least three normalized PPG signals and for forming a ratio between said first difference signal and said second difference signal, and an concentration detection unit for calculating the concentration of a substan

Abstract: The present invention relates to system for extracting physiological information indicative of at least one vital sign of a subject from detected light transmitted through a part of the subject (1). To overcome the limitations of the contactless camera-based reflective PPG technique and classical contact sensors the proposed system comprises a medical instrument (12, 24) for at least partly introduction into a subject's body, one or more light sources (14, 15) for emitting light, said one or more light sources being mounted to the part of the medical instrument that is introduced into the subject's body during use, a light detection unit (16) for detecting light emitted by said one or more light sources and transmitted through a part of the subject, and a processing unit (18) for deriving physiological information indicative of at least one vital sign from the detected light using remote photo-plethysmography.

Abstract: A device, system and method for determining the concentration of a substance, such as the oxygen saturation, in the blood of a subject are provided, which reduce or remove the influence of specular reflection. The proposed device comprises an input unit configured to receive detection signals reflected back from a skin area of the subject in response to irradiation of the skin area by a radiation signal, a signal extraction unit configured to extract at least two photo-plethysmography, PPG, signals at two different wavelengths from said detection signals, and a processing unit configured to compute the concentration of a desired substance in the blood of the subject based on said PPG signals, wherein said computation is adapted to the skin tone of the subject.

Abstract: A device for determining the concentration of a substance in the blood of a subject, such as the oxygen saturation, which device reduces or removes the influence of specular reflection and/or subject motion, comprises an input unit for receiving detection signals reflected back or transmitted through a skin area of the subject in response to irradiation of the skin area by a radiation signal, a signal extraction unit for extracting at least three photo-plethysmography, PPG, signals at different wavelengths from said detection signals, a processing unit for normalizing said at least three PPG signals and forming a first difference signal between a first normalized PPG signal and a second normalized PPG signal and a second difference signal between a third normalized PPG signal and one other of the at least three normalized PPG signals and for forming a ratio between said first difference signal and said second difference signal, and an concentration detection unit for calculating the concentration of a substan