The disclosed invention relates to a system for restricting radio frequency transmissions within a restricted area and more particularly to a mechanism for overriding the restriction of radio frequency transmissions within a restricted area using an override mechanism. A tube arrangement has exactly four curved or bent measuring tubes connected to the flow dividers for guiding flowing medium along flow paths connected in parallel. Each programmable crosspoint device includes a data element with a first programming threshold and a control element with a second programming threshold, in which the second programming threshold is greater than the first programming threshold. In the step of laser crystallization of an amorphous silicon film into a polysilicon film, the heat relaxation layer prevents local temperature gradation in the film owing to the heat-absorbing effect of the underlying gate electrode. The charging time of the inductor is controlled by a comparator that selectively disables the transistor in response to the ramp voltage. The arterial perfusion catheters andor cannulas are constructed with an upstream flow control member located in the patient’s ascending aorta and a downstream flow control member located in the patient’s descending aorta.