THE INTERACTION BETWEEN ELECTRORHEOLOGICAL PARTICLES IN AC ELECTRIC FIELD STUDIED USING OPTICAL TWEEZERS

2002 ◽  
Vol 16 (17n18) ◽  
pp. 2300-2306
Author(s):  
J. XU ◽  
X. DONG ◽  
Z. Y. CHEN ◽  
Y. G. JIANG ◽  
L. W. ZHOU

The dipole interaction between a pair of electrorheological (ER) particles under an external AC electric field was confirmed in a dynamic case using optical tweezers positioning and a system of high speed imaging and image processing. By measuring the interactions between two micron-sized ER particles with both central distance and structure forming time, the structure response time and the interaction strength were obtained for the particles under an AC electric field. The spacial resolution of the optical tweezers-high speed imaging-image processing system is 0.26μm. The sampling rate of the high-speed video recorder is up to 8000 frame/s with the corresponding time resolution being 0.125 ms.

2020 ◽  
Author(s):  
Jun Ki Kim ◽  
Youngkyu Kim ◽  
Jungmin Oh ◽  
Seung-Ho Choi ◽  
Ahra Jung ◽  
...  

BACKGROUND Recently, high-speed digital imaging (HSDI), especially HSD endoscopic imaging is being routinely used for the diagnosis of vocal fold disorders. However, high-speed digital endoscopic imaging devices are usually large and costly, which limits access by patients in underdeveloped countries and in regions with inadequate medical infrastructure. Modern smartphones have sufficient functionality to process the complex calculations that are required for processing high-resolution images and videos with a high frame rate. Recently, several attempts have been made to integrate medical endoscopes with smartphones to make them more accessible to underdeveloped countries. OBJECTIVE To develop a smartphone adaptor for endoscopes to reduce the cost of devices, and to demonstrate the possibility of high-speed vocal cord imaging using the high-speed imaging functions of a high-performance smartphone camera. METHODS A customized smartphone adaptor was designed for clinical endoscopy using selective laser melting (SLM)-based 3D printing. Existing laryngoscope was attached to the smartphone adaptor to acquire high-speed vocal cord endoscopic images. Only existing basic functions of the smartphone camera were used for HSDI of the vocal folds. For image processing, segmented glottal areas were calculated from whole HSDI frames, and characteristics such as volume, shape and longitudinal edge length were analyzed. RESULTS High-speed digital smartphone imaging with the smartphone-endoscope adaptor could achieve 940 frames per second, and was used to image the vocal folds of five volunteers. The image processing and analytics demonstrated successful calculation of relevant diagnostic variables from the acquired images. CONCLUSIONS A smartphone-based HSDI endoscope system can function as a point-of-care clinical diagnostic device. Furthermore, this system is suitable for use as an accessible diagnostic method in underdeveloped areas with inadequate medical service infrastructure.


Lab on a Chip ◽  
2017 ◽  
Vol 17 (17) ◽  
pp. 2969-2981 ◽  
Author(s):  
Y. Huang ◽  
Y. L. Wang ◽  
T. N. Wong

We investigate the AC electric field controlled filament thinning and droplet formation dynamics of one non-Newtonian fluid. Furthermore, for the first time, we quantitatively measure the flow field of the non-Newtonian droplet formation under the influence of AC electric field, via a high-speed micro particle imaging velocimetry (μPIV) system. We discover the viscoelasticity contributes to the discrepancies majorly.


2014 ◽  
Vol 971-973 ◽  
pp. 1454-1458
Author(s):  
Lei Qu ◽  
Yan Tian ◽  
Jun Liu

For real time target detection, identification and tracking in high frame rates, large field of view images, a real-time image processing system is designed. A TMS320C6678 DSP runs as the chief arithmetic processor of this system and FPGA as the secondary controller. C6678 is compared with the same series C6414 in image compression algorithm test. Experimental results show that the new system has a more effective construct, and higher reliability, and can provide a platform for the new high-speed image processing.


2015 ◽  
Vol 656-657 ◽  
pp. 549-553
Author(s):  
Kyohei Nishimoto ◽  
Kozo Taguchi

Dielectrophoresis (DEP) force will arise when an inhomogeneous AC electric field with sinusoidal wave is applied to microelectrodes. By using DEP, we could distinguish between viable and non-viable cells by their movement through a non-uniform electric field. In this paper, we propose a yeast cell separation system, which utilizes an Au DEP chip and an optical tweezers. The Au DEP chip is planar quadrupole microelectrodes, which were fabricated by Au thin-film and a box cutter. This fabrication method is low cost and simpler than previous existing methods. The tip of the optical tweezers was fabricated by dynamic chemical etching in a mixture of hydrogen fluoride and toluene. The optical tweezers has the feature of high manipulation performance. That does not require objective lens for focusing light because the tip of optical tweezers has conical shape. By using both the Au DEP chip and optical tweezers, we could obtain three-dimensional manipulation of specific cells after viability separation.


2001 ◽  
Author(s):  
Haiju Lei ◽  
Dehua Li ◽  
Hanping Hu ◽  
Zhaonan Guo

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