Design and simulation of a multi-function MEMS sensor for health and usage monitoring.

Health and usage monitoring as a technique for online test, diagnosis or prognosis of structures and systems has evolved as a key technology for future critical systems. The technology, often referred to as HUMS is usually based around sensors that must be more reliable than the system or structure they are monitoring. This paper proposes a fault tolerant sensor architecture and demonstrates the feasibility of realising this architecture through the design of a dual mode humidity/pressure MEMS sensor with an integrated temperature function. The sensor has a simple structure, good linearity and sensitivity, and the potential for implementation of built-in-self-test features. We also propose a re-configurable sensor network based on the multi-functional sensor concept that supports both normal operational and fail safe modes. The architecture has the potential to significantly increase system reliability and supports a reduction in the number of sensors required in future HUMS devices. The technique has potential in a wide range of applications, especially within wireless sensor networks

NUTMEG: A randomized phase II study of nivolumab and temozolomide versus temozolomide alone in newly diagnosed older patients with glioblastoma.

BACKGROUND: There is an immunologic rationale to evaluate immunotherapy in the older glioblastoma population, who have been underrepresented in prior trials. The NUTMEG study evaluated the combination of nivolumab and temozolomide in patients with glioblastoma aged 65 years and older. METHODS: NUTMEG was a multicenter 2:1 randomized phase II trial for patients with newly diagnosed glioblastoma aged 65 years and older. The experimental arm consisted of hypofractionated chemoradiation with temozolomide, then adjuvant nivolumab and temozolomide. The standard arm consisted of hypofractionated chemoradiation with temozolomide, then adjuvant temozolomide. The primary objective was to improve overall survival (OS) in the experimental arm. RESULTS: A total of 103 participants were randomized, with 69 in the experimental arm and 34 in the standard arm. The median (range) age was 73 (65-88) years. After 37 months of follow-up, the median OS was 11.6 months (95% CI, 9.7-13.4) in the experimental arm and 11.8 months (95% CI, 8.3-14.8) in the standard arm. For the experimental arm relative to the standard arm, the OS hazard ratio was 0.85 (95% CI, 0.54-1.33). In the experimental arm, there were three grade 3 immune-related adverse events which resolved, with no unexpected serious adverse events. CONCLUSIONS: Due to insufficient evidence of benefit with nivolumab, the decision was made not to transition to a phase III trial. No new safety signals were identified with nivolumab. This complements the existing series of immunotherapy trials. Research is needed to identify biomarkers and new strategies including combinations

Design and simulation of modified 1-D electrostatic torsional micromirrors with z-axis displacement

Micromirrors based on Micromechanical. systems (MEMS) have been essential components in many applications, such as micro confocal microscopy, optical data storage and biomedical imaging [1-3]. A variety of microfabrication and actuation technologies have been used to realize micromirrors, including electrothermal [3], electrostatic [1], etc., of which electrostatic torsional drive ha s been thought to be the most popular driving mechanism. K. E. Peterson [4] has developed the world first 1-D electrostatic driven torsional micromirror. The Lucent [5] Lambdroutor is one of famous and successful examples of 2-D electrostatic torsional micromirrors. For design improvement of this type of 2-D micromirror, Toshiyoshi et al. [6] have proposed a linearization method based on applying a small control voltage over a large bias voltage. Chiou et al. [7] have presented improved design to demonstrate linear stepping angles of 1-D micromirrors based on multiple electrodes. These developments are focus on realizing linear steps in angle. As mentioned by above articles, there are also displacements in z-axis as the micromirror is actuated, which have been ignored. The z-axis displacements have become a significant problem when the micromirrors are used on high resolution spatial scanning. Krishnamoorthy et al. [8] presents a dual-mode 1-D micromirror utilizing stacked multilayer vertical comb drive actuators, which can provide both piston and tilt motion. We have developed a z-axis displacement compensation concept for 2-D electrostatic torsional micromirrors previously [9]

Move from Online Test to Fault-tolerant: Design and Simulation of a Multi-Functional MEMS Sensor

Fault-tolerance is an important design requirement in critical sensor applications. It is conventionally achieved by using redundant components, which increases system’s size, cost and complexity, that are often sacrificed or comprised due to associated limitations. This paper proposes a novel solution to achieve sensor fault-tolerance at the system level instead of the usual approach that targets the component level. The architecture consists of multi-functional sensors which are used to replace conventional single mode sensors, and a data fusion algorithm which provides online test and fault-tolerance. This method has the potential to significantly increase system reliability and supports a reduction in the overheads inherent with the use of redundancy in fault-tolerant systems. A MEMS humidity/pressure sensor has been designed as an example to support the method. The sensor has simple structure, good linearity and sensitivity, and the potential of further integrating a temperature function

Design of an integrated monolithic 3-axis piezoresistive accelerometer on SOI

This paper discusses the design of an integrated monolithic 3-axis piezoresistive accelerometer on SOI