Ilkka Pölönen

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Imaging using lightweight, unmanned airborne vehicles (UAVs) is one of the most rapidly developing fields in remote sensing technology. The new, tunable, Fabry-Perot interferometer-based (FPI) spectral camera, which weighs less than 700 g, makes it possible to collect spectrometric image blocks with stereoscopic overlaps using light-weight UAV platforms.(More)
BACKGROUND Field cancerization denotes subclinical abnormalities in a tissue chronically exposed to UV radiation. These abnormalities can be found surrounding the clinically visible actinic keratoses. OBJECTIVES The aim of this study was to test the feasibility of a hyperspectral imaging system in the detection of multiple clinical and subclinical AKs for(More)
A new non-invasive method for delineation of lentigo maligna and lentigo maligna melanoma is demonstrated. The method is based on the analysis of the hyperspectral images taken in vivo before surgical excision of the lesions. For this, the characteristic features of the spectral signatures of diseased pixels and healthy pixels are extracted, which combine(More)
Photodynamic therapy (PDT) is a highly effective treatment for superficial skin cancers and skin cancer precursors (1, 2). In PDT, the administration of a photosensitizing drug, followed by its activation by a specific wavelength of light matching the absorbance of the sensitizer, leads to a phototoxic reaction destroying the tumour cells (3). Adverse(More)
To assess the botulism hazard in fur animal feed production, 236 fur animal feed components and feed samples were analysed for Clostridium botulinum by detecting BoNT-encoding genes (botA, botB, botC, botE or botF) by PCR and for sulphite-reducing clostridia (SRC) by iron sulphite agar. The quality of the hazard analysis of critical control points (HACCP)(More)
Miniaturized hyperspectral imaging sensors are becoming available to small unmanned airborne vehicle (UAV) platforms. Imaging concepts based on frame format offer an attractive alternative to conventional hyperspectral pushbroom scanners because they enable enhanced processing and interpretation potential by allowing for acquisition of the 3-D geometry of(More)
Small unmanned aerial vehicle (UAV) based remote sensing is a rapidly evolving technology. Novel sensors and methods are entering the market, offering completely new possibilities to carry out remote sensing tasks. Three-dimensional (3D) hyperspectral remote sensing is a novel and powerful technology that has recently become available to small UAVs. This(More)
We apply the knowledge discovery process to the mapping of current topics in a particular field of science. We are interested in how articles form clusters and what are the contents of the found clusters. A framework involving web scraping, keyword extraction, dimensionality reduction and clustering using the diffusion map algorithm is presented. We use(More)
Methods: We applied for the first time the two in vivo confocal microscopes commonly used in dermatology (VivaScope ® 1500 and 3000, CALIBER, distributed in Europe by Mavig GmbH, Munich, Germany) to observe the cornea, the bulbar and tarsal conjunctiva, the eyelid margin, the lacrimal punctum and the palpebral skin of healthy volunteers. Tumoral,(More)
Lentigo maligna (LM) is an in situ form of melanoma which can progress into invasive lentigo maligna melanoma (LMM). Variations in the pigmentation and thus visibility of the tumour make assessment of lesion borders challenging. We tested hyperspectral imaging system (HIS) in in vivo preoperative delineation of LM and LMM margins. We compared lesion margins(More)