Photoplethysmograph prototype for clinical use Further improvement of developed photoplethysmograph (PPG) prototype, consisting of silicon photodiode and LED, is reported. Based on modifications of built-in photodiode fabrication process and PPG prototype assembling optimization, photodiode dark current and its series resistance were refined. Readout electronics was designed and built in order to create portable measuring setup necessary for clinical use. Finally, entire setup was tested in atypical conditions at daylight, without using integrated LED as light source. PPG waveform measured at daylight intensity of 400 lux was easily detected on fingertip of right hand index finger.
COBISS.SI-ID: 10146132
A strip-type microthrottle pump This article reports a novel strip-type micro-throttle pump with a rectangular actuator geometry, with more efficient chip surface consumption compared to existing micro-pumps with circular actuators. Due to the complex structure and operation of the proposed device, determination of detailed structural parameters is essential. Therefore, we developed an advanced, fully coupled 3D electro-fluid-solid mechanics simulation model in COMSOL that includes fluid inertial effects and a hyper-elastic model for PDMS and no-slip boundary condition in fluid-wall interface. Numerical simulations resulted in accurate virtual prototyping of the proposed device, detailed operation analysis and optimization of crucial geometrical parameters.
COBISS.SI-ID: 9729620
Triton X-100 as an effective surfactant for micropump bubble tolerance enhancement Improvement of bubble tolerance and priming in micropumps based on Triton X-100 surfactant is investigated. Transparent membrane piezoelectric micropumps were fabricated. Precise air volumes were introduced into the micropump chamber to emulate micropump bubble disturbance. Micropump recovery time decreased with increased addition of Triton X-100 surfactant between 50-100 ppm. Effective recovery is mainly a consequence of the air bubble dispersion into a foam of small bubbles. Small bubbles are then readily removed by liquid flow, leading to significant enhancement of micropump bubble tolerance. Bubbles behavior was monitored with reflective optical method.
COBISS.SI-ID: 9933140