Žurnālu raksti (ASI) / Journal articles
https://dspace.lu.lv/dspace/handle/7/129
2024-03-29T10:00:16ZSkimager for the objective erythema estimation in atopic dogs
https://dspace.lu.lv/dspace/handle/7/50049
Skimager for the objective erythema estimation in atopic dogs
Cugmas, Blaž; Olivry, Thierry; Olivrī, Alla; Spīgulis, Jānis
In this study, the severity of canine skin erythema was assessed objectively for the first time. Atopic dermatitis (AD) is a common canine inflammatory and pruritic skin disease associated with an allergic reaction to exogenous allergens. The monitoring of skin erythema over time with lesion severity scales like the CADESI-4 is an essential diagnostic and research tool, especially for clinical trials. Currently, the erythema assessment is subjective due to visual estimation. In our study, we calculated the erythema index (EI) in 14 atopic dogs based on the analysis of multispectral skin images taken with the Skimager device. The relationship between the EI and a visual erythema estimation was modeled by linear regression with the first-order polynomial. The coefficient of determination (r squared) reached 0.81. Based on such high correlation, we conclude that optical measurements could replace the visual estimation of erythema in atopic dogs and, thus, improve the validity of skin lesion severity scales in dogs.
2020-02-19T00:00:00ZPhotoplethysmography in dogs and cats: a selection of alternative measurement sites for a pet monitor
https://dspace.lu.lv/dspace/handle/7/46616
Photoplethysmography in dogs and cats: a selection of alternative measurement sites for a pet monitor
Cugmas, Blaž; Štruc, Eva; Spīgulis, Jānis
Objective: Photoplethysmography (PPG) is an increasingly popular health and well-being tool for monitoring heart rate and oxygen saturation. Due to the pigmentation and hairiness of dogs and cats, a pulse oximeter is routinely placed solely on the tongue. As this approach is feasible only for pet monitor use during surgical procedures, we investigate PPG signal quality on several other measurement sites that would be better tolerated by conscious animals. Approach: Acquired PPG signals are analyzed by four signal quality indices: mean baseline, signal power, kurtosis, and tolerance score. Main results: In dogs, the metacarpus and tail can be substituted for oral pulse oximeter placement since both measurement sites exhibited high PPG signal kurtosis and were considered well-tolerated. In cats, the digit could be used with some limitations. Significance:
Pet monitors with pulse oximeter probes adjusted to promising measurement sites could enable veterinarians and owners to monitor animals when fully awake.
2019-01-22T00:00:00ZPoor optical stability of molecular dyes when used as absorbers in water-based tissue-simulating phantoms
https://dspace.lu.lv/dspace/handle/7/46615
Poor optical stability of molecular dyes when used as absorbers in water-based tissue-simulating phantoms
Cugmas, Blaž; Naglič, Peter; Menachery, Sunil Paul Matthew; Pernuš, Franjo; Likar, Boštjan
Biomedical optical systems and models can be easily validated by the use of tissue-simulating phantoms. They can
consist of water-based turbid media which often include inks (India ink and molecular dyes) as absorbers. Optical
stability of commonly exploited inks under the influence of light, pH changes and the addition of TiO2 and surfactant,
was studied. We found that the exposure to ultraviolet and visible light can crucially affect the absorption properties of
molecular dyes. On average, absorption peaks decreased by 47.3% in 150 exposure hours. Furthermore, dilution can
affect ink’s pH and by that, its decay rate under light exposure. When TiO2 was added to the phantoms, all molecular
dyes decayed rapidly. Photocatalytic nature of TiO2 can be partially avoided by selecting TiO2 with surface and crystal
structure modification. Surfactant, normally present in the phantoms with polystyrene spheres, can cause absorption peak
shifts up to 20 nm and amplitude changes of 29.6%. Therefore, it is crucial to test the optical stability of inks in the
presented manner before their exploitation in water-based phantoms.
2019-02-27T00:00:00ZBiophotonics in veterinary medicine: the first steps toward clinical translation
https://dspace.lu.lv/dspace/handle/7/46614
Biophotonics in veterinary medicine: the first steps toward clinical translation
Cugmas, Blaž; Spīgulis, Jānis
In this paper, we analyzed the current situation and the potential of biophotonics and biomedical optics in veterinary
medicine. Promising optical techniques such as optical coherence tomography, pulse oximeter, and hyperspectral
imaging have been clinically translated into human medicine. But even though human and small animal medicine share
personalized and state-of-the-art approach, biophotonics remains rarely exploited in the canine and feline medicine.
However, there are some biophotonics studies in veterinary oncology which addressed tumor diagnosis (skin and
subcutaneous tumors), prognosis (lymphoma), and therapy (clear surgical margins). Visible and near-infrared
spectroscopy served for measuring various physiological parameters related to circulation, and photobiomodulation
therapy was often used for the management of wounds, skin conditions, and orthopedic problems. In the research, the
most popular clinically translated technique is thermography which was applied for the diagnosis of orthopedic problems
and diseases as infections and hyperthyroidism. The future optical devices for small animals such as dogs and cats
should be robust and resilient to damage (e.g., due to biting, chewing), offering user-friendly and short measurements. In
veterinary oncology, biophotonics could replace invasive fine-needle aspiration procedure. The potential of a pulse
oximeter for pet monitoring has yet to be explored. What is more, photobiomodulation efficiency should be tested in an
extensive clinical (in vivo) study. The technique would be very beneficial in dentistry which currently requires expensive
and risky anesthesia.
2019-02-20T00:00:00Z