Abstract: Methods and arrangements for detecting osteoarthritis (OA) relate to image processing for enhancing, visualizing and quantifying the fibrillation structure of cartilage using endoscopes. A structure enhancement method comprises obtaining input data, conversion to intensity data, preprocess filtering, intensity fluctuation filtering and contrast enhancement. The degeneration is quantified by a degeneration index (DI) algorithm, applied to the structure enhanced image. Results are then compiled in an output frame presentation.

Abstract: A pulse-frequency analyzing monitor which is provided with an optical sensor and which is intended for measuring photoplethysmographically the blood circulation of a subject, such as a body part of a human being or an animal, includes a light source, preferably a light-emitting diode for infrared light, fibre optics, a detector unit for detecting the alternating voltage, or AC-component of a generated PPG-signal for the purpose of determining the heart frequency of the subject, an electronic amplifying unit and a presentation unit, for instance an oscilloscope of a display unit. The apparatus also includes means for separating from the detected PPG-signal a signal component which indicates the respiration frequency of the subject. The PPG-signal is coupled to a filter, preferably a digital filter, which enables limit frequencies and the degree of amplification to be set.