introduction blood pressure (bp) is one of the important vital signs that need to be monitored for personal healthcare. arterial blood pressure is estimated from pulse transit time (ptt). this study uses two pulse sensors to get ptt. the aim of this study was to construct an optical system and to monitor blood pressure continuously and without cuff in people with different ages. materials and m...

We demonstrate an approach to achieve patterned optical trapping with two-dimensional photonic crystals (2D PC). A Gaussian beam infrared laser is guided and loosely focused by a simple optical system onto the surface of the 2D PC, which generates an enhanced diffraction field for optical trapping of microbeads with high efficiency. The diffraction patterns are determined by the structures of t...

In this paper, a phase-sensitive optical time domain reflectometry ( ?-OTDR) based on Rayleigh enhanced fiber is proposed to improve the system signal-to-noise ratio (SNR). experiment, vibration performance of analyzed and compared with standard single-mode telecom fiber. The results demonstrate that measured SNRs peaks in frequency spectra have been improved by 14 dB (at 1 kHz frequency) at en...