Multispectral diffuse reflectance imaging and autofluorescence photo-bleaching imaging are methods that have been investigated for use in skin disorder diagnostics. In response to the ever-increasing incidence of skin cancer in light skinned populations a new device has been designed incorporating both of these methods. The aim of the study was to create a device that is most efficient in terms of hardware and software parameters for the screening of malignant and benign skin lesions. A set of 525 nm, 630 nm and 980 nm LEDs were used to illuminate the skin area at three wavelengths  and a set of 405 nm LEDs were used to induce the skin autofluorescence . For a more homogenous illumination of investigated skin area the optimal placement for LEDs in a cylindrical case was found. The requisite spacing from the camera lens was taken into account to produce a focused RGB image. The geometrical shape of the device allows to capture images of skin that are illuminated solely by the diodes without interference from sunlight or other nearby light sources. Polarizing filters were used to decrease glare effects, therefore preventing image overexposure of very reflective skin areas. 515 nm long pass filter was used to enable the 405 nm excitation while capturing autofluorescence images of the skin. Further improvements to the quality of the diagnostic data can be achieved using reference images to track homogeneity of the intensity and then applying a compensating algorithm on the subsequent screening images. These and other design considerations serve to realize the full potential of the diagnostic method.
Results of clinical approbation to assess the efficacy of the new device to diagnose malignant skin lesions will be demonstrated.
As the incidence of skin cancer is still increasing worldwide, there is a high demand for early, non-invasive and inexpensive skin lesion diagnostics. In this article we describe and combine two skin imaging methods: skin autofluorescence (AF) and multispectral criterion p’. To develop this method, we used custom made prototype with 405 nm, 526 nm, 663 nm and 964 nm LED illuminations, perpendicular positioned linear polarizers, 515 nm filter and IDS camera. Our aim is to develop a skin lesion diagnostic device for primary care physicians who do not have experience in dermatology or skin oncology. In this study we included such common benign lesion groups as seborrheic keratosis, hyperkeratosis, melanocytic nevi and hemangiomas, as well two types of skin cancers: basal cell carcinoma and melanoma. By combining skin AF and multispectral p’ imaging methods, we achieved 100% sensitivity and 100% specificity for distinguishing melanoma (3 histologically confirmed cases) from seborrheic keratosis (13 dermatologically confirmed cases), hyperkeratosis (8 histologically and 1 dermatologically confirmed case), melanocytic nevi (23 dermatologically confirmed cases ), basal cell carcinomas (2 histologically and 16 dermatologically confirmed cases) and hemangiomas (8 dermatologically confirmed cases). Unfortunately, currently this method cannot distinguish the basal cell carcinoma group from benign lesion groups.
Determining the level of regional anesthesia (RA) is vitally important to both an anesthesiologist and surgeon, also knowing the RA level can protect the patient and reduce the time of surgery. Normally to detect the level of RA, usually a simple subjective (sensitivity test) and complicated quantitative methods (thermography, neuromyography, etc.) are used, but there is not yet a standardized method for objective RA detection and evaluation. In this study, the advanced remote photoplethysmography imaging (rPPG) system for unsupervised monitoring of human palm RA is demonstrated. The rPPG system comprises compact video camera with green optical filter, surgical lamp as a light source and a computer with custom-developed software. The algorithm implemented in Matlab software recognizes the palm and two dermatomes (Medial and Ulnar innervation), calculates the perfusion map and perfusion changes in real-time to detect effect of RA. Seven patients (aged 18-80 years) undergoing hand surgery received peripheral nerve brachial plexus blocks during the measurements. Clinical experiments showed that our rPPG system is able to perform unsupervised monitoring of RA.
A clinical trial on autofluorescence imaging of malignant and non-malignant skin pathologies comprising 32 basal cell carcinomas (BCC), 4 malignant melanomas (MM), 1 squamous cell carcinoma (SCC), 89 nevi, 14 dysplastic nevi, 20 hemangiomas, 23 seborrheic keratoses, 4 hyperkeratoses, 3 actinic keratoses, 3 psoriasis, 1 dematitis, 2 dermatofibromas, 5 papillofibromas, 12 lupus erythematosus, 7 purpura, 6 bruises, 5 freckles, 3 fungal infections, 1 burn, 1 tattoo, 1 age spot, 1 vitiligo, 32 postoperative scars, 8 post cream therapy BCCs, 4 post radiation therapy scars, 2 post laser therapy scars, 1 post freezing scar as well as 114 reference images of healthy skin was performed. The sequence of autofluorescence images of skin pathologies were recorded by smartphone RGB camera under continuous 405 nm LED excitation during 20 seconds with 0.5 fps. Obtained image sequences further were processed with subsequent extraction of autofluorescence intensity and photobleaching parameters.
The feasibility of smartphones for in vivo skin autofluorescence imaging has been investigated. Filtered autofluorescence images from the same tissue area were periodically captured by a smartphone RGB camera with subsequent detection of fluorescence intensity decreasing at each image pixel for further imaging the planar distribution of those values. The proposed methodology was tested clinically with 13 basal cell carcinoma and 1 atypical nevus. Several clinical cases and potential future applications of the smartphone-based technique are discussed.
Atherosclerosis is among the most widespread cardiovascular diseases and one of the leading cause of death in the Western World. Characterization of arterial tissue in atherosclerotic condition is extremely interesting from the diagnostic point of view, especially for what is concerning collagen content and organization because collagen plays a crucial role in plaque vulnerability. Routinely used diagnostic methods, such as histopathological examination, are limited to morphological analysis of the examined tissues, whereas an exhaustive characterization requires immunehistochemical examination and a morpho-functional approach. Non-linear microscopy techniques offer the potential for providing morpho-functional information on the examined tissues in a label-free way. In this study, we employed combined SHG and FLIM microscopy for characterizing collagen organization in both normal arterial wall and within atherosclerotic plaques. Image pattern analysis of SHG images allowed characterizing collagen organization in different tissue regions. In addition, the analysis of collagen fluorescence decay contributed to the characterization of the samples based on collagen fluorescence lifetime. Different values of collagen fiber mean size, collagen distribution, and collagen anisotropy and collagen fluorescence lifetime were found in normal arterial wall and within plaque depositions, prospectively allowing for automated classification of atherosclerotic lesions and plaque vulnerability. The presented method represents a promising diagnostic tool for evaluating atherosclerotic tissue and has the potential to find a stable place in clinical setting as well as to be applied in vivo in the near future.
Heart and cardiovascular diseases are one of the most common in the world, in particular – arthrosclerosis. The aim of
the research is to distinguish pathological and healthy tissue regions in biological samples, in this case – to distinguish
collagen and lipid rich regions within the arterial wall.
In the work a specific combination of such methods are used: FLIM and SHG in order to evaluate the biological tissue
morphology and functionality, so that this research could give a contribution for creating a new biological tissue imaging
standard in the closest future.
During the study the most appropriate parameter for fluorescence lifetime decay was chosen in order to evaluate lifetime
decay parameters and the isotropy of the arterial wall and deposition, using statistical methods FFT and GLCM.
The research gives a contribution or the future investigations for evaluating lipid properties when it can de-attach from
the arterial wall and cause clotting in the blood vessel or even a stroke.
Possibilities to determine chromophore distribution in skin by spectral imaging were explored. Simple RGB sensor devices were used for image acquisition. Totally 200 images of 40 different bruises of 20 people were obtained in order to map chromophores bilirubin and haemoglobin. Possibilities to detect water in vitro and in vivo were estimated by using silicon photodetectors and narrow band LEDs. The results show that it is possible to obtain bilirubin and haemoglobin distribution maps and observe changes of chromophore parameter values over time by using a simple RGB imaging device. Water in vitro was detected by using differences in absorption at 450 nm and 950 nm, and 650 nm and 950 nm.