Stanisław Galla

Use of optical skin phantoms for preclinical evaluation of laser efficiency for skin lesion therapy

Abstract. Skin lesions are commonly treated using laser heating. However, the introduction of new devices into clinical practice requires evaluation of their performance. This study presents the application of optical phantoms for assessment of a newly developed 975-nm pulsed diode laser system for dermatological purposes. Such phantoms closely mimic the absorption and scattering of real human skin (although not precisely in relation to thermal conductivity and capacitance); thus, they can be used as substitutes for human skin for approximate evaluation of laser heating efficiency in an almost real environment. Thermographic imaging was applied to measure the spatial and temporal temperature distributions on the surface of laser-irradiated phantoms. The study yielded results of heating with regard to phantom thickness and absorption, as well as laser settings. The methodology developed can be used in practice for preclinical evaluations of laser treatment for dermatology.

Investigation of photothermolysis therapy of human skin diseases using optical phantoms

Dermatological diseases, such as neurofibroma (Recklinghausen disease) or hemangiomas can be efficiently treated using photothermolysis from laser irradiation. We have utilized a developed 975 nm fiber diode laser as a low-cost alternative over common Nd:YAG lasers. This paper describes the investigations of interaction of 975 nm diode laser radiation-pulses with optical skin phantoms which were designed and manufactured in our laboratory. Such phantoms match the scattering and absorption coefficients of real human skin. Spatial and temporal temperature evolutions during laser irradiation with various laser settings (pulsed and CW mode), were recorded by an IR camera. Subsequent analysis yielded optimum choice of parameters for laser therapy of coetaneous lesions.

Noise of optoelectronic coupled devices

The three systems for low frequency noise measurements of an optoelectronic coupled device (an infrared emitting diode and a phototransistor) were described. In the system I a low frequency noise of an infrared diode was measured, in the system II a low frequency noise of a phototransistor was measured, in the system III a low frequency noise of an optoelectronic coupled device was measured. The investigations were carried out for optoelectronic coupled devices of CNY type. The results of noise measurements in three systems are compared and a main source of noise in optoelectronic coupled devices was evaluated.

Analiza impedancji sieci prądu stałego w instalacjach fotowoltaicznych

Dokonano analizy impedancji sieci prądu stalego w instalacji fotowoltaicznej. Analize te przeprowadzono pod wzgledem predykcji charakterystyki zaburzen elektromagnetycznych generowanych przez instalacje PV. Badania przeprowadzono zarowno dla zaburzen roznicowych, jak i wspolnych. Zastosowano podejście analityczne - wykorzystując teorie linii dlugiej oraz pomiary wykonane na stanowisku laboratoryjnym.

The measurement of input power of power supply in network disturbed by low frequency distortions

In the paper authors present results of observation of input power changes versus harmonics amplitude in supply voltage of low-power power supply device. In the study, the electrical measurements supported with thermal imaging were used. The input circuit elements of studied device responsible for input power increase are pointed