A high performance piezoelectric PDMS peristaltic micropump with a single actuator is presented that enables driving with less expensive and simpler single-phase controllers while maintaining all the superior properties of conventional peristaltic micropumps, such as robustness, simplicity and purity due to the absence of valves. Fabricated prototypes featured high water / air flowrate performance (up to 0.24 ml min−1/up to 0.84 ml min−1), back-pressure performance (up to 360 mbar/up to 80 mbar) and suction pressure performance (down to −165 mbar/down to −140 mbar). Furthermore, bubble tolerance and self-priming capability have been proved, together with valve regime of operation that enables sealing of the fluidic path when appropriate dc voltage is applied.
COBISS.SI-ID: 10790484
Impact of the shapes of driving signals on micropump operation is investigated by numerical simulations and by experimental verification on a strip-type microthrottle pump. Numerical simulation is based on an advanced, fully-coupled electro, fluid and solid-mechanics model, enabling detailed analysis of device operation. Flowrate performance and cavitation risk were evaluated by analyzing pressure response in critical points near and under the membrane and by analyzing simulated flowrate response on various excitation waveforms. Sinusoidal excitation provides lower flowrate compared to square-wave excitation (typically 33 % lower) but with significantly smaller risk of cavitation. Sawtooth excitation was found the most inappropriate waveform, providing lowest flowrate performance at high cavitation probability.
COBISS.SI-ID: 10803796
Contact pressure-induced by manually operated fiber optic probes can significantly affect the optical properties of the studied tissue. If the contact pressure and the changes in optical properties are measured properly, the complimentary information about the investigated tissue can be obtained. However, as reliable assessment of the contact pressure in the existing diffuse reflectance setups is difficult, the impact of contact pressure is usually neglected or considered as a source of errors. In this letter we introduce a novel measurement system for controlled application of contact pressure and for the acquisition of diffuse reflectance spectra, which is suitable for in vivo studies and for overcoming the limitations of the existing measurement setups. A spectral-contact-pressure plane is proposed to present the combined information, highlighting the unique tissue response to the applied pressure.
COBISS.SI-ID: 10432084
Lyme borreliosis is the most common human tick-borne infectious disease in the northern hemisphere, occurring predominantly in temperate regions of North America, Europe and Asia. The diseases most frequent manifestation is erythema migrans, a skin lesion that appears within days to weeks of a tick bite. Early recognition of the lesion is important since it enables proper management and thus prevention of later consequences of the disease which can hamper normal life. In this article, a novel visual system for recognition of erythema migrans is presented based on new multimedia interactive terminal technology available also on smartphones. For potential erythema migrans skin lesion edge detection, we compared three different methods: GrowCut, maximal similarity based region merging and random walker segmentation method. The results obtained with GrowCut method are better than those obtained with random walker method. The GrowCut method, improved with our new finger draw (FD1) marker yields comparable results to those obtained with maximal similarity based region merging method. Several classification algorithms including naive Bayes, support vector machine, AdaBoost, random forest, and neural network were compared and used for classification of skin lesions into ellipse, the most common shape of erythema migrans and erythema migrans class.
COBISS.SI-ID: 13354011
Design and implementation of silicon dry etching system with xenon difluoride is presented. The goal was to build a portable, self-sufficient and flexible dry etching system using xenon difluoride as the etchant gas. The system comprises control electronics and a vacuum system. A detailed testing and verification of the realized vacuum system and electronics with associated software was performed. Finally, etching of silicon samples was done to determine the typical etching parameters such as silicon etch rate as a function of exposed silicon area and etch time, etching selectivity to silicon dioxide mask and degree of process isotropy.
COBISS.SI-ID: 10907988