An ExAblateâ„¢ 4000 HIFU headsystem (InSightec, Inc., Israel) was used. The goal was to test the effects of various combinations of pulse widths (PW) and duty cycles (DC) on high-intensity focused ultrasound (HIFU)-induced sonothrombolysis efficacy using an in vitro flow model. Longer duty cycles in combination with longer pulse widths seem to have the highest potential to optimize clot lysis efficacy.Įffects of varying duty cycle and pulse width on high-intensity focused ultrasound (HIFU)-induced transcranial thrombolysis Using transcranial HIFU, significant thrombolysis can be achieved within seconds and without the use of lytic drugs in vitro. For all study groups, an increase in thrombolysis efficacy could be seen in association with increasing DC and/or PW (p < 0.0001). Four different duty cycles were tested against four different pulse widths. Artificial blood clots were placed into test tubes inside a human calvarium and exposed to pulsatile flow. Hölscher, Thilo Raman, Rema Fisher, David J Ahadi, Golnaz Zadicario, Eyal Voie, Arne
The C4F8-co-AA plasma polymer coatings on the nanotextured surfaces are tuned from repulsive superhydrophobicity to adhesive superhydrophobicity, and further to superhydrophilicity by adjusting the duty cycles with the monomer feed rates.Įffects of varying duty cycle and pulse width on high-intensity focused ultrasound (HIFU)-induced transcranial thrombolysis. The gradual emergence of hydrophilic contents leads to surface heterogeneity by lowering duty cycle causing an increased surface adhesion in hydrophobic coatings. The combined effect of surface chemistry and surface morphology of the RF pulsed plasma copolymer coatings causes tunable surface wettability and surface adhesion. The concentration of the carboxylic acid (hydrophilic) groups increase, and that of fluorocarbon (hydrophobic) groups decrease by lowering the duty cycle. The influence of duty cycle in pulsed process with the monomer feed rate on the surface chemistry and wettability of C4F8-co-AA plasma polymer coatings is studied.
Octafluorocyclobutane and acrylic acid (C4F8-co-AA) plasma copolymer coatings are deposited using a pulsed wave (PW) radio frequency (RF) plasma on low density polyethylene (LDPE). Since the DCC circuit adjusts the falling edge of the clock cycle to achieve a desired duty cycle, the DCC may be incorporated into existing PLL control loops that adjust the rising edge of a clock signal without interfering with the operation of such PLL control loops.ĭuty cycle dependent chemical structure and wettability of RF pulsed plasma copolymers of acrylic acid and octafluorocyclobutane In some examples, the DCC circuit may generate a pulse in response to a falling edge of an input clock signal, delay the pulse based on a control voltage, adjust the falling edge of the input clock signal based on the delayed pulse to produce an output clock signal, and adjust the control voltage based on the difference between a duty cycle of the output clock signal and a desired duty cycle. In general, this disclosure is directed to a duty cycle correction (DCC) circuit that adjusts a falling edge of a clock signal to achieve a desired duty cycle. Feng, Xiaoxin (Inventor) Roper, Weston (Inventor) Seefeldt, James D.
0 kommentar(er)
