Development of an integrated hardware and software platform for the rapid detection of cerebral aneurysm rupture

A cerebral aneurysm is defined as a weakened portion of an artery in the brain. Rupture of a cerebral aneurysm leads to subarachnoid hemorrhage (SAH). A significant number of patients with SAH are initially misdiagnosed and subjected to the risks associated with aneurysm re-rupture. Traditional detection methods recommended by physicians include computed tomography (CT) scan, lumbar puncture and angiography. Unfortunately, the CT scan is ineffective after 12 h, and angiography is best suited for those cases of finding the aneurysm before surgery. Physicians may therefore rely on lumbar puncture to develop a quick and objective evaluation by assessing xanthochromia. Bilirubin in the cerebrospinal fluid, resulting from the chemical decomposition of whole blood, is an indicator of hemorrhage. This metabolite can be detected after lumbar puncture, by differentiating its optical signature in the spinal fluid. In cases of traumatic spinal tap, bilirubin needs to be distinguished from whole blood. We introduce a diagnostic system based on visible spectroscopy to quickly and objectively assess low blood-volume SAH. The system integrates innovative hardware and a powerful software interface. We explore an algorithm that accounts for the noise and distortion from blood in the cerebrospinal fluid. We introduce a portable, user-friendly hardware platform composed of specific components designed for their sensitivity and specificity.     

用于应变硅技术的高应力SiN薄膜的开发

在高级CMOS器件中,高应力氮化硅(SiN)薄膜是增强应变的主要方法。如果要改善PMOS或NMOS器件性能,则分别需要采用具有压应力和张应力的氮化硅薄膜。我们对相关机理进行了回顾,根据不同的淀积和工艺处理条件的组合,从而得到了张应力大于1．6 GPa和压应力大于2．9GPa的氮化硅薄膜覆盖。     

Miniaturized redox potential probe for in situ environmental monitoring

The need for accurate, robust in situ microscale monitoring of oxidation-reduction potentials (ORP) is required for continuous soil pore water quality monitoring. We are developing a suite of self-contained microelectrodes that can be used in the environment, such as at Superfund sites, to monitor ORP in contaminated soils and sediments. This paper presents details on our development of microelectrode sensor arrays for ORP measurements. The electrochemical performance of these ORP electrodes was fully characterized by measuring redox potentials in standard solutions. It found that the newly developed integrated ORP microelectrodes produced a very stable voltage response (the corresponding rate of the integrated microelectrode potential change was in the range of 0.6-1.1 mV/min), even when the measurement was carried out outside of a Faraday cage where signals from most conventional microelectrodes are usually inhibited by external electrical nose. These new microelectrodes were easier to fabricate and were more robust than conventional microelectrodes. The tip size of the integrated ORP microelectrode was approximately 200 nm square, with a taper angle of approximately 20 degrees and a length of 57 microm. The integrated ORP microelectrode exhibited better signal stability and substantially shorter response times (from less than a few milliseconds to 30 s, depending on the standard solution used) than the commercial millielectrode (a few minutes). Compared with the slope of the commercial millelectrode, the slope of the integrated microelectrode (61.5 mV/pH) was closerto the ideal slope against quinhydrone calibration solutions. Therefore, it is to be expected that the newly developed ORP microelectrode may have wider applications in contaminated soils, biofilms, and sediments.