The development of low-cost point-of-care sensor systems is essential for the screening and diagnostics of different diseases. However, this type of application requires effective integration of different sensor hardw...
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The development of low-cost point-of-care sensor systems is essential for the screening and diagnostics of different diseases. However, this type of application requires effective integration of different sensor hardware and electronics in a portable, wireless, and reliable platform. We report herein the development of such a platform by integrating a nanostructured chemiresistive sensing array (CSA) with a low-current multichannel electronics board (MEB) and a Raspberry Pi board (RPB). The system allows the collection of data from the sensorarray responses to volatile organic compounds (VOCs) and human breaths (HBs), then transfers the data through a serial connection from MEB to RPB. After processing and restructuring the data, RPB will wirelessly upload it to MongoDB Atlas (MDBA) cloud database. A workstation periodically retrieves the data from the MDBA cloud database and trains them with customized machine learning models. The best result feeds back to the MDBA cloud server, providing a pretrained model for a future prediction or disease identification. At the same time, the real-time sensor response data are displayed on the Thing speak portal. Once programed, the system runs in an independent mode without a PC connection with various functions, including remote monitoring services and ad hoc applications that are typically not accessible from traditional stationary monitoring systems housed in hospitals and laboratories. Some of these functions are demonstrated by testing the performance in sensing HB samples with and without simulated lung cancer-specific VOCs, showing promises for potential applications in remote breath monitoring and screening of lung cancer.
Acoustic cavitation continues to be widely used in advanced 193i and EUV megasonic photomask cleaning [1]. However, process challenges remain complex as patterns become smaller [2], denser, and more irregular in shape...
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ISBN:
(纸本)9781510656420
Acoustic cavitation continues to be widely used in advanced 193i and EUV megasonic photomask cleaning [1]. However, process challenges remain complex as patterns become smaller [2], denser, and more irregular in shape. For instance, the wide adoption of curvilinear ILT patterns is imminent to defend against shrinking process windows. Operating within a narrow process window that ensures both full particle removal and pattern damage control is a balancing act that requires many parameters to be optimized and controlled. These include the transducer type, drive frequency, power setting, flow rate, gas concentration, temperature, chemistry, and transducer position [3, 4, 5, 6, 7]. While batch processing may be more economical for less critical cleaning steps, advanced lithography processes rely on single photomask cleaning technologies because of the increased need for within mask control. Improved cleaning uniformity is achieved through the continuous movement of the photomask and transducer. correlate acoustic parameters with cleaning performance, an in-situ measurement of the acoustic field is required. Previous work introduced a photomask-shaped cavitation sensorarray wired to a cavitation meter which characterized how acoustic cavitation varied with parameters such as drive frequency, generator power, transducer distance, and sensor position were correlated with cavitation pressure under a static condition [7]. In this study, the technology was extended by developing a wireless sensor array to incorporate the dynamic effects of the photomask rotation and the transducer arm translation. The acoustic pressure uniformity across the photomask was evaluated for varying parameters, including mask rotational speed, transducer arm speed, and exposure time. Pressure measurements of the direct field, stable cavitation, and transient cavitation exhibited distinct signatures that may be indicative of cleaning performance, specifically particle removal or pattern damage. The
Simultaneous monitoring of critical parameters (e.g., pressure, shear, and temperature) at bony prominences is essential for the prevention of pressure injuries in a systematic manner. However, the development of wire...
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Simultaneous monitoring of critical parameters (e.g., pressure, shear, and temperature) at bony prominences is essential for the prevention of pressure injuries in a systematic manner. However, the development of wireless sensor array for accurate mapping of risk factors has been limited due to the challenges in the convergence of wireless technologies and wearable sensorarrays with a thin and small form factor. Herein, a battery-free, wireless, miniaturized multi-modal sensorarray is introduced for continuous mapping of pressure, shear, and temperature at skin interfaces. The sensorarray includes an integrated pressure and shear sensor consisting of 3D strain gauges and micromachined components. The mechanically decoupled design of the integrated sensor enables reliable data acquisition of pressure and shear at skin interfaces without the need for additional data processing. The sensor platform enables the analysis of interplay among localized pressure, shear, and temperature in response to changes in the patient's movement, posture, and bed inclination. The validation trials using a novel combination of wireless sensor arrays and customized pneumatic actuator demonstrate the efficacy of the platform in continuous monitoring and efficient redistribution of pressure and shear without repositioning, thereby improving the patient's quality of life.
The COVID-19 pandemic has emphasized the need for infection risk analysis and assessment of ventilation systems in indoor environments based on air quality criteria. In this context, simulations and direct measurement...
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The COVID-19 pandemic has emphasized the need for infection risk analysis and assessment of ventilation systems in indoor environments based on air quality criteria. In this context, simulations and direct measurements of CO2 concentrations as a proxy for exhaled air can help to shed light on potential aerosol pathways. While the former typically lack accurate boundary conditions as well as spatially and temporally resolved validation data, currently existing measurement systems often probe rooms in non-ideal, single locations. Addressing both of these issues, a large and flexible wirelessarray of 50 embedded sensor units is presented that provides indoor climate metrics with configurable spatial and temporal resolutions at a sensor response time of 20 s. Augmented by an anchorless self-localization capability, three-dimensional air quality maps are reconstructed up to a mean 3D Euclidean error of 0.21 m. Driven by resolution, ease of use, and fault tolerance requirements, the system has proven itself in day-to-day use at ETH Zurich, where topologically differing auditoria (at-grade, sloped) were investigated under real occupancy conditions. The corresponding results indicate significant spatial and temporal variations in the indoor climate rendering large sensorarrays essential for accurate room assessments. Even in well-ventilated auditoria, cleanout time constants exceeded 30 min.
The proposed circuit utilizes a method to lower the output noise (V-ONOISE) of an amplifier by band-pass filtering it, while the amplifier's speed is increased by dynamically boosting its operating current when th...
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ISBN:
(纸本)9781538623114
The proposed circuit utilizes a method to lower the output noise (V-ONOISE) of an amplifier by band-pass filtering it, while the amplifier's speed is increased by dynamically boosting its operating current when the amplifier's inputs (V-IN) receive a large transient signal. This amplifier uses a winner-take-all (WTA) circuit that detects un-equilibrium at V-IN, upon which the amplifier's bias current and its dynamic response are boosted. The WTA has a symmetric structure and operates in current mode that enhances the amplifier's dynamic response during boost on and off conditions, and facilitates operations at low power supply voltage (V-DD). The boost signals that WTA initiates, feed a summing and floating current source (FCS) that also have a complementary and symmetric structure, which accommodates rail-to-rail (RR) dynamic biasing and improves V-DD transient and noise rejection. Monte Carlo (MC) and worst case (WC) simulations are performed, indicating the following specifications as attainable: large-signal settling time (ts) similar to 1 mu s, current consumption (I-DD) similar to 85nA, V-DD under 1 volt (V), V-ONOISE at 1KHz similar to 75 mu V/root Hz, gain (Av) similar to 98dB, unity gain frequency (fu) similar to 70kHz, phase margin (PM) similar to 80 degrees, PSRR similar to 115dB, CMRR similar to 145dB. Amplifier rough area similar to 45 mu m/side in 0.18 mu m CMOS.
A data acquisition system based on wireless sensor array is used to collect underground three-dimension data in this paper. sensors are installed in a mode of plane array, using 2D excitation source explode signal, th...
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ISBN:
(纸本)1424405289
A data acquisition system based on wireless sensor array is used to collect underground three-dimension data in this paper. sensors are installed in a mode of plane array, using 2D excitation source explode signal, the acquisition system can repeat receiving the data of different excitation source, and the collective data can form 3D data cube by corresponding process. The data structure of 3D data cube is analyzed and the 3D emulation model of underground oil reservoir is established. The methods of displaying slice about the 3D emulation model are studied using the technology of computer graphic and image processing. We accomplish the vertical slices of underground oil reservoir from multidirection and multiangle in this paper, in order to display clearly the structural feature of underground oil reservoir and to make the oil engineer have a clear apprehend about the underground oil reservoir overall structure. Programming the corresponding algorithm and graphic display programmes using C++. Some typical emulation images are given taking example for a underground oil reservoir of one oilfield.
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