Biophotonics Laboratory

Main directions of scientific work: Development of optical methods and devices for medical and technological applications. early non-invasive skin cancer diagnostics and classification of skin lesions using multispectral diffuse reflectance and autofluorescence imaging techniques combined with artificial neural network analysis; early detection of sepsis on the knees using multispectral imaging techniques; contactless photoplethysmography imaging to monitor the time of exposure to anesthesia; assessment and presentation of oxygen saturation in the skin; laser beam contrast imaging for microbial growth analysis; time-resolved diffuse reflectance and in vivo skin autofluorescence using time-d…

<title>Photonic vascular diagnostics by four-channel photoplethysmography</title>

2005

A four-channel photoplethysmography device was designed and built at University of Latvia to detect signals from different body parts and to analyze the signal shapes. The device consists of optical contact probes, interface, and a standard PC. Clinical tests were performed with occlusion patients having vascular problems at arm or leg arteries. Results showed significant difference in the pulse wave transit time in occluded and nonoccluded part of the body.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Biophotonics in veterinary medicine: the first steps toward clinical translation

2019

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…

Skimager for the objective erythema estimation in atopic dogs

2020

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 w…

<title>Optical non-invasive monitoring of skin blood pulsations</title>

2005

Time resolved detection and analysis of the skin backscattered optical signals (remission photoplethysmography or PPG) provide rich information on skin blood volume pulsations and can serve for reliable cardiovascular assessment. The single- and multi-channel PPG concepts are discussed in this work. Simultaneous data flow from several body locations allows one to study the heartbeat pulse wave propagation in real time and evaluate the vascular resistance. Portable single-, dual- and four-channel PPG monitoring devices with special software have been designed for real-time data acquisition and processing. The clinical studies confirmed their potential in the monitoring of heart arrhythmias, …

Photoplethysmography imaging algorithm for continuous monitoring of regional anesthesia

2016

An efficient photoplethy smography imaging system and advanced algorithm for continuous monitoring of skin microcirculation was developed. The system comprises compact device and computer with software for visualizing of skin blood volume changes. The software is able to process high-resolution microcirculation amplitude maps in real-time. It was tested in clinical environment during the regional anesthesia procedures. The Eulerian-based method showed improved sensitivity and higher resolution of microcirculation maps.

Selection of erythema index and image sampling method for the objective erythema estimation in dogs with atopic dermatitis

2020

Canine atopic dermatitis (CAD) is a common inflammatory and pruritic skin disease associated with allergy to exogenous allergens. The regular monitoring of skin lesions is essential to execute the anti-allergic therapy successfully. Erythema is one of the most important CAD-related lesions since it represents acute skin inflammation. Previously, we studied two optical systems (i.e., multispectral and dermatoscopic devices), which could objectively estimate erythema severity. However, we did not investigate, which image sampling method for selecting erythema-representing pixels and erythema index (EI) are correlated with the visual erythema assessment the most. In this paper, we tested three…

Photoplethysmography for bovine heat detection: the preliminary results

2020

In this study, we applied photoplethysmography (PPG) as an alternative, convenient, and affordable method for bovine heat detection. Heat detection is an essential part of effective herd reproduction management. Currently, there are many different heat detection techniques, but they can be ineffective or impractical to use. Since heat affects local vulvar blood circulation (resulting in swelling and erythema), photoplethysmography could represent an affordable alternative to detect this bovine phenomenon. In this study, we enrolled 20 animals in heat and other stages of the bovine reproduction cycle. We analyzed the PPG signal in terms of baseline (DC component), power, kurtosis, and erythe…

Photoplethysmography In Dogs And Cats: Selection Of Measurement Sites For Pet Monitor

2018

The PPG measurements of the study Cugmas et al, 2018. Notes.txt include all information about the dataset.