scholarly journals An Active Self-Driven Piezoelectric Sensor Enabling Real-Time Respiration Monitoring

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3241 ◽  
Author(s):  
Ahmed Rasheed ◽  
Emad Iranmanesh ◽  
Weiwei Li ◽  
Yangbing Xu ◽  
Qi Zhou ◽  
...  
Keyword(s):  
Real Time ◽  
Piezoelectric Transducer ◽  
Thin Film Transistor ◽  
High Sensitivity ◽  
Piezoelectric Sensor ◽  
Great Promise ◽  
Dynamic Force ◽  
Respiration Monitoring ◽  
Respiration Rhythm ◽  
Transducer Signal

In this work, we report an active respiration monitoring sensor based on a piezoelectric-transducer-gated thin-film transistor (PTGTFT) aiming to measure respiration-induced dynamic force in real time with high sensitivity and robustness. It differs from passive piezoelectric sensors in that the piezoelectric transducer signal is rectified and amplified by the PTGTFT. Thus, a detailed and easy-to-analyze respiration rhythm waveform can be collected with a sufficient time resolution. The respiration rate, three phases of respiration cycle, as well as phase patterns can be further extracted for prognosis and caution of potential apnea and other respiratory abnormalities, making the PTGTFT a great promise for application in long-term real-time respiration monitoring.

scholarly journals Research Papers. An Approach to Design Broadband Air Backed Piezoelectric Sensor

2015 ◽  
Vol 40 (1) ◽  
pp. 3-10
Author(s):  
Mohamed G.S. Ali ◽  
Nour Z. Elsayed ◽  
Ebtsam A. Eid
Keyword(s):  
Impulse Response ◽  
Piezoelectric Transducer ◽  
High Sensitivity ◽  
Piezoelectric Sensor ◽  
Time Signal ◽  
Research Papers ◽  
Time Model ◽  
Water Load ◽  
Quarter Wavelength ◽  
Thickness Mode

Abstract In this work, an approach to the design of broadband thickness-mode piezoelectric transducer is pre- sented. In this approach, simulation of discrete time model of the impulse response of matched and backed piezoelectric transducer is used to design high sensitivity, broad bandwidth, and short-duration impulse response transducers. The effect of matching the performance of transmitting and receiving air backed PZT-5A transducer working into water load is studied. The optimum acoustical characteristics of the quarter wavelength matching layers are determined by a compromise between sensitivity and pulse duration. The thickness of bonding layers is smaller than that of the quarter wavelength matching layers so that they do not change the resonance peak significantly. Our calculations show that the −3 dB air backed transducer bandwidth can be improved considerably by using quarter wavelength matching layers. The computer model developed in this work to predict the behavior of multilayer structures driven by a transient waveform agrees well with measured results. Furthermore, the advantage of this this model over other approaches is that the time signal for optimum set of matching layers can be predicted rapidly

Analysis of AC-DC Converter Circuit Performance with Difference Piezoelectric Transducer Array Connection

2020 ◽  
Vol 12 (7) ◽  
Author(s):  
Nik Ahmad Zainal Abidin ◽  
◽  
Norkharziana Mohd Nayan ◽  
Azuwa Ali ◽  
N. A. Azli ◽  
...  
Keyword(s):  
Piezoelectric Transducer ◽  
Simulation Analysis ◽  
Piezoelectric Sensor ◽  
Transducer Array ◽  
Circuit Performance ◽  
Array Configuration ◽  
Full Wave ◽  
Bridge Rectifier ◽  
In Series ◽  
Parallel Voltage

This research presents a simulation analysis for the AC-DC converter circuit with a different configurations of the array connection of the piezoelectric sensor. The selection of AC-DC converter circuits is full wave bridge rectifier (FWBR), parallel SSHI (P-SSHI) and parallel voltage multiplier (PVM) with array configuration variation in series (S), parallel (P), series-parallel (SP) and parallel-series (PS). The system optimizes with different load configurations ranging from 10 kΩ to 1 MΩ. The best configuration of AC-DC converter with an appropriate array piezoelectric connection producing the optimum output of harvested power is presented. According to the simulation results, the harvested power produced by using P-SSHI converter connected with 3 parallel piezoelectric transducer array was 85.9% higher than for PVM and 15.88% higher than FWBR.

scholarly journals A novel method for visualizing and tracking endogenous mRNA in a specific cell population in pathological neovascularization

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Md Imam Uddin ◽  
Tyler C. Kilburn ◽  
Sara Z. Jamal ◽  
Craig L. Duvall ◽  
John S. Penn
Keyword(s):  
Real Time ◽  
Disease Burden ◽  
Ex Vivo ◽  
Expression Patterns ◽  
Fluorescence Emission ◽  
High Sensitivity ◽  
Living Systems ◽  
Specific Cell ◽  
Potential Marker

AbstractDiabetic retinopathy, retinopathy of prematurity and retinal vein occlusion are potentially blinding conditions largely due to their respective neovascular components. The development of real-time in vivo molecular imaging methods, to assess levels of retinal neovascularization (NV), would greatly benefit patients afflicted with these conditions. mRNA hybridization techniques offer a potential method to image retinal NV. The success of these techniques hinges on the selection of a target mRNA whose tissue levels and spatial expression patterns correlate closely with disease burden. Using a model of oxygen-induced retinopathy (OIR), we previously observed dramatic increases in retinal endoglin that localized to neovascular structures (NV), directly correlating with levels of neovascular pathology. Based on these findings, we have investigated Endoglin mRNA as a potential marker for imaging retinal NV in OIR mice. Also of critical importance, is the application of innovative technologies capable of detecting mRNAs in living systems with high sensitivity and specificity. To detect and visualize endoglin mRNA in OIR mice, we have designed and synthesized a novel imaging probe composed of short-hairpin anti-sense (AS) endoglin RNA coupled to a fluorophore and black hole quencher (AS-Eng shRNA). This assembly allows highly sensitive fluorescence emission upon hybridization of the AS-Eng shRNA to cellular endoglin mRNA. The AS-Eng shRNA is further conjugated to a diacyl-lipid (AS-Eng shRNA–lipid referred to as probe). The lipid moiety binds to serum albumin facilitating enhanced systemic circulation of the probe. OIR mice received intraperitoneal injections of AS-Eng shRNA–lipid. Ex vivo imaging of their retinas revealed specific endoglin mRNA dependent fluorescence superimposed on neovascular structures. Room air mice receiving AS-Eng shRNA–lipid and OIR mice receiving a non-sense control probe showed little fluorescence activity. In addition, we found that cells in neovascular lesions labelled with endoglin mRNA dependent fluorescence, co-labelled with the macrophage/microglia-associated marker IBA1. Others have shown that cells expressing macrophage/microglia markers associate with retinal neovascular structures in proportion to disease burden. Hence we propose that our probe may be used to image and to estimate the levels of retinal neovascular disease in real-time in living systems.

scholarly journals Ultrasound Doppler-guided real-time navigation of a magnetic microswarm for active endovascular delivery

2021 ◽  
Vol 7 (9) ◽  
pp. eabe5914 ◽  
Author(s):  
Qianqian Wang ◽  
Kai Fung Chan ◽  
Kathrin Schweizer ◽  
Xingzhou Du ◽  
Dongdong Jin ◽  
...  
Keyword(s):  
Blood Flow ◽  
Real Time ◽  
Targeted Delivery ◽  
Ex Vivo ◽  
Dynamic Environments ◽  
Doppler Imaging ◽  
Great Promise ◽  
Mean Velocity ◽  
Ultrasound Doppler ◽  
Flowing Blood

Swarming micro/nanorobots offer great promise in performing targeted delivery inside diverse hard-to-reach environments. However, swarm navigation in dynamic environments challenges delivery capability and real-time swarm localization. Here, we report a strategy to navigate a nanoparticle microswarm in real time under ultrasound Doppler imaging guidance for active endovascular delivery. A magnetic microswarm was formed and navigated near the boundary of vessels, where the reduced drag of blood flow and strong interactions between nanoparticles enable upstream and downstream navigation in flowing blood (mean velocity up to 40.8 mm/s). The microswarm-induced three-dimensional blood flow enables Doppler imaging from multiple viewing configurations and real-time tracking in different environments (i.e., stagnant, flowing blood, and pulsatile flow). We also demonstrate the ultrasound Doppler–guided swarm formation and navigation in the porcine coronary artery ex vivo. Our strategy presents a promising connection between swarm control and real-time imaging of microrobotic swarms for localized delivery in dynamic environments.

scholarly journals Metal Oxide Nanorods-Based Sensor Array for Selective Detection of Biomarker Gases

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1922
Author(s):  
Gwang Su Kim ◽  
Yumin Park ◽  
Joonchul Shin ◽  
Young Geun Song ◽  
Chong-Yun Kang
Keyword(s):  
Real Time ◽  
Sensor Array ◽  
High Sensitivity ◽  
Gas Analysis ◽  
Diagnostic Methods ◽  
Real Time Monitoring ◽  
Non Invasive ◽  
Sensitivity And Selectivity ◽  
Breath Gas Analysis ◽  
Angle Method

The breath gas analysis through gas phase chemical analysis draws attention in terms of non-invasive and real time monitoring. The array-type sensors are one of the diagnostic methods with high sensitivity and selectivity towards the target gases. Herein, we presented a 2 × 4 sensor array with a micro-heater and ceramic chip. The device is designed in a small size for portability, including the internal eight-channel sensor array. In2O3 NRs and WO3 NRs manufactured through the E-beam evaporator’s glancing angle method were used as sensing materials. Pt, Pd, and Au metal catalysts were decorated for each channel to enhance functionality. The sensor array was measured for the exhaled gas biomarkers CH3COCH3, NO2, and H2S to confirm the respiratory diagnostic performance. Through this operation, the theoretical detection limit was calculated as 1.48 ppb for CH3COCH3, 1.9 ppt for NO2, and 2.47 ppb for H2S. This excellent detection performance indicates that our sensor array detected the CH3COCH3, NO2, and H2S as biomarkers, applying to the breath gas analysis. Our results showed the high potential of the gas sensor array as a non-invasive diagnostic tool that enables real-time monitoring.

scholarly journals Single-copy detection of somatic variants from solid and liquid biopsy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ana-Luisa Silva ◽  
Paulina Klaudyna Powalowska ◽  
Magdalena Stolarek ◽  
Eleanor Ruth Gray ◽  
Rebecca Natalie Palmer ◽  
...  
Keyword(s):  
Real Time ◽  
Single Molecule ◽  
Real Time Pcr ◽  
Clinical Decision Making ◽  
High Sensitivity ◽  
Clinical Decision ◽  
Single Copy ◽  
Turnaround Time ◽  
Copy Detection ◽  
Allele Specific

AbstractAccurate detection of somatic variants, against a background of wild-type molecules, is essential for clinical decision making in oncology. Existing approaches, such as allele-specific real-time PCR, are typically limited to a single target gene and lack sensitivity. Alternatively, next-generation sequencing methods suffer from slow turnaround time, high costs, and are complex to implement, typically limiting them to single-site use. Here, we report a method, which we term Allele-Specific PYrophosphorolysis Reaction (ASPYRE), for high sensitivity detection of panels of somatic variants. ASPYRE has a simple workflow and is compatible with standard molecular biology reagents and real-time PCR instruments. We show that ASPYRE has single molecule sensitivity and is tolerant of DNA extracted from plasma and formalin fixed paraffin embedded (FFPE) samples. We also demonstrate two multiplex panels, including one for detection of 47 EGFR variants. ASPYRE presents an effective and accessible method that simplifies highly sensitive and multiplexed detection of somatic variants.

High sensitivity and high Q-factor nanoslotted parallel quadrabeam photonic crystal cavity for real-time and label-free sensing

2014 ◽  
Vol 105 (6) ◽  
pp. 063118 ◽  
Author(s):  
Daquan Yang ◽  
Shota Kita ◽  
Feng Liang ◽  
Cheng Wang ◽  
Huiping Tian ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Real Time ◽  
High Sensitivity ◽  
Q Factor ◽  
Label Free ◽  
Photonic Crystal Cavity ◽  
High Q

Genetically Engineered Pores as Metal Ion Biosensors

1993 ◽  
Vol 330 ◽  
Author(s):  
John Kasianowicz ◽  
Barbara Walker ◽  
Musti Krishnasastry ◽  
Hagan Bayley
Keyword(s):  
Response Time ◽  
Lipid Bilayers ◽  
Metal Ion ◽  
Dynamic Range ◽  
Divalent Cations ◽  
High Sensitivity ◽  
Genetically Engineered ◽  
Great Promise ◽  
Lipid Bilayer Membranes ◽  
Time Dynamic

ABSTRACTWe are adapting proteins that form pores in lipid bilayers for use as components of biosensors. Specifically, we have produced genetically engineered variants of the α hemolysin (αHL) fromStaphylococcusaureus with properties that are sensitive to low concentrations of divalent cations. For example, the pore-forming activity of one mutant (αHL-H5: residues 130–134 inclusive replaced with histidine) is inhibited by Zn2+at concentrations as low as 1 μM, as judged by the reduction in its ability to lyse rabbit red blood cells and to increase the conductance of planar lipid bilayer membranes. When αHL-H5 is added to the aqueous phase bathing one side of a planar membrane, the subsequent addition of 100 μM Zn2+to either side blocks the pores that form. This result suggests that at least part of the mutated region lines the channel lumen. Ca2+and Mg2+do not block the channel and therefore the H5 mutation confers a degree of analyte specificity to the αHL pore. The results suggest that genetically engineered pores have great promise for the rapid and sensitive detection of metal cations and we discuss the merits and potential limitations for their use in this application. Specifically, we examine the issues of selectivity, sensitivity, response time, dynamic range and longevity. Some of these properties are interdependent. For example, the goals of high sensitivity and rapid response time can be in conflict.

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