A continuous noninvasive method of systolic blood pressure estimation is described. Systolic blood pressure is estimated by combining two separately obtained components: a higher frequency component obtained by extracting a specific frequency band of pulse arrival time and a lower frequency component obtained from the intermittently acquired systolic blood pressure measurements with an auscultatory or oscillometric system. The pulse arrival time was determined by the time interval from QRS apex in electrocardiogram to the onset of photoplethysmogram in a fingertip beat-by-beat via an oximetric sensor. The method was examined in 20 patients during cardiovascular surgery. The estimated values of systolic blood pressure were compared with those measured invasively using a radial arterial catheter. The results showed that the correlation coefficients between estimated values and invasively obtained systolic blood pressure reached 0.97 +/- 0.02 (mean +/- SD), and the error remained within +/- 10% in 97.8% of the monitoring period. By using a system with automatic cuff inflation and deflation to acquire intermittent systolic blood pressure values, this method can be applicable for the continuous noninvasive monitoring of systolic blood pressure.

We report what is to our knowledge the first dual operation comprising laser action and Q switching of Cr(4+):YAG pumped intracavity by a Nd:YAG laser. This technique produced dual 1.06- and 1.44-microm pulses with 35- and 200-ns pulse widths, respectively. The Nd:YAG rod was pumped by a 1-ms flash-lamp pulse, resulting in a train of 1.06- and 1.44-microm pulse pairs at approximately a 30-kHz rate.

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A short pulsed current–voltage (I-V) measurement method is proposed for phase-change random access memory (PCRAM) to investigate the self-heating behavior. The pulse widths and periods are indispensable parameters to describe pulsed I-V characteristics of PCRAM cells. By comparing the difference between direct current I-V curves and pulsed I-V curves, the threshold voltages of pulsed I-V are much higher. It implies the existence of self-heating and energy accumulation. Assume that the heating of the active region causes the change of the electronic barrier and the electronic activity, the physical model dominated by the self-heating in PCRAM cells is proposed.