2020 ◽  
Vol 12 (2) ◽  
pp. 37
Author(s):  
Przemysław Struk

This paper presents sensor structure dedicated for determination the key properties of blood – concentration level and oxidation level. The sensor structure is based integrated optics circuit with diamond-based planar waveguide including prism and grating coupler. The paper is focused on numerical analysis of selected properties of sensor structure for optimization sensing parameters. Full Text: PDF ReferencesD.A. Gell, Blood Cells, "Structure and function of haemoglobins", Molecules and Diseases 70 (2018). CrossRef I. Singh, A. Weston, A. Kundur, G. Dobie, Haematology Case Studies with Blood Cell Morphology and Pathophysiology (Elsevier: Amsterdam, The Netherlands, 2017) DirectLink P. D. Sturkie, P. Griminger, Blood: Physical Characteristics, Formed Elements, Hemoglobin, and Coagulation Avian Physiology (Springer-Verlag New York Inc. 1976). CrossRef A. Dutta, B. Deka, P.P. Partha, Planar Waveguide Optical Sensors: From Theory to Applications (Springer: Berlin, Germany, 2016). CrossRef S. Kang, K. Sasaki, H. Minamitani, "Determining the absorption coefficient of hemoglobin derivatives with integrated optic waveguide sensor", IEEE Engineering in Medicine and Biology Society (1992). CrossRef P. Struk, "Design of an Integrated Optics Sensor Structure Based on Diamond Waveguide for Hemoglobin Property Detection", Materials 12(1) 175 (2019). CrossRef W. Lukosz, K. Tiefenthaler, "Sensitivity of integrated optical grating and prism couplers as (bio)chemical sensors", Sensors and Actuators 15 (1988). CrossRef P.V. Lambeck, "Integrated optical sensors for the chemical domain", Measurement Science and Technology - IOPscience 17 (2006), CrossRef W. Lukosz, "Integrated optical chemical and direct biochemical sensors", Sensors and Actuators B: Chemical 29 (1995). CrossRef P. Struk, T. Pustelny, K. Gołaszewska, E. Kamińska, M. Borysiewicz, M. Ekielski, And A. Piotrowska, "Photonic structures with grating couplers based on ZnO", Opto−Electronics Review 19(4) (2011). CrossRef J. Haas, E. V. Catalán, P. Piron, F. Nikolajeff, L. Österlund, M. Karlsson, B. Mizaikoff, "Polycrystalline Diamond Thin-Film Waveguides for Mid-Infrared Evanescent Field Sensors", ACS Omega 3 (2018). CrossRef P. Struk, "Design of an integrated optics sensor structure for hemoglobin property detection", Proceedings of SPIE 11204 (2019). CrossRef P. Struk, T. Pustelny, K. Gołaszewska, E. Kamińska, M. Borysiewicz, M. Ekielski, A. Piotrowska, "Hybrid photonics structures with grating and prism couplers based on ZnO waveguides", Opto-Electronics Review 21 (2013). CrossRef V. Prajzler, M. Varga, P. Nekvindova, Z.; Remes, A. Kromka, "Design and investigation of properties of nanocrystalline diamond optical planar waveguides", Optics Express 21 (2013), CrossRef E.N. Lazareva, V.V. Tuchin, "Measurement of refractive index of hemoglobin in the visible/NIR spectral range", Journal of Biomedical Optics 23 (2018). CrossRef Optiwave Systems Inc. "OptiFDTD Technical Background and Tutorials - Finite" (2013). DirectLink K. Yee, Antennas and Propagation, "Numerical solution of initial boundary value problems involving maxwell's equations in isotropic media", IEEE Transactions 14,3 (1966). CrossRef


1985 ◽  
Vol 107 (4) ◽  
pp. 851-855
Author(s):  
R. J. Baumbick

The term “fiber optics” means the use of dielectric waveguides to transfer information. In aircraft systems with digital controls, fiber optics has advantages over wire systems because of its inherent immunity to electromagnetic noise (EMI) and electromagnetic pulses (EMP). It also offers a weight benefit when metallic conductors are replaced by optical fibers. To take full advantage of the benefits of optical waveguides, passive optical sensors are also being developed to eliminate the need for electrical power to the sensor. Fiber optics may also be used for controlling actuators on engine and airframe. In this application, the optical fibers, connectors, etc., will be subjected to high temperatures and vibrations. This paper discusses the use of fiber optics in aircraft propulsion systems, together with the optical sensors and optically controlled actuators being developed to take full advantage of the benefits which fiber optics offers. The requirements for sensors and actuators in advanced propulsion systems are identified. The benefits of using fiber optics in place of conventional wire systems are discussed as well as the environmental conditions under which the optical components must operate. Work being done under contract to NASA Lewis on optical and optically activated actuators sensors for propulsion control systems is presented.


2021 ◽  
Vol 12 ◽  
Author(s):  
M. Caroline Müllenbroich ◽  
Allen Kelly ◽  
Corey Acker ◽  
Gil Bub ◽  
Tobias Bruegmann ◽  
...  

Optical techniques for recording and manipulating cellular electrophysiology have advanced rapidly in just a few decades. These developments allow for the analysis of cardiac cellular dynamics at multiple scales while largely overcoming the drawbacks associated with the use of electrodes. The recent advent of optogenetics opens up new possibilities for regional and tissue-level electrophysiological control and hold promise for future novel clinical applications. This article, which emerged from the international NOTICE workshop in 20181, reviews the state-of-the-art optical techniques used for cardiac electrophysiological research and the underlying biophysics. The design and performance of optical reporters and optogenetic actuators are reviewed along with limitations of current probes. The physics of light interaction with cardiac tissue is detailed and associated challenges with the use of optical sensors and actuators are presented. Case studies include the use of fluorescence recovery after photobleaching and super-resolution microscopy to explore the micro-structure of cardiac cells and a review of two photon and light sheet technologies applied to cardiac tissue. The emergence of cardiac optogenetics is reviewed and the current work exploring the potential clinical use of optogenetics is also described. Approaches which combine optogenetic manipulation and optical voltage measurement are discussed, in terms of platforms that allow real-time manipulation of whole heart electrophysiology in open and closed-loop systems to study optimal ways to terminate spiral arrhythmias. The design and operation of optics-based approaches that allow high-throughput cardiac electrophysiological assays is presented. Finally, emerging techniques of photo-acoustic imaging and stress sensors are described along with strategies for future development and establishment of these techniques in mainstream electrophysiological research.


Author(s):  
V. Saikumar ◽  
H. M. Chan ◽  
M. P. Harmer

In recent years, there has been a growing interest in the application of ferroelectric thin films for nonvolatile memory applications and as a gate insulator in DRAM structures. In addition, bulk ferroelectric materials are also widely used as components in electronic circuits and find numerous applications in sensors and actuators. To a large extent, the performance of ferroelectric materials are governed by the ferroelectric domains (with dimensions in the micron to sub-micron range) and the switching of domains in the presence of an applied field. Conventional TEM studies of ferroelectric domains structures, in conjunction with in-situ studies of the domain interactions can aid in explaining the behavior of ferroelectric materials, while providing some answers to the mechanisms and processes that influence the performance of ferroelectric materials. A few examples from bulk and thin film ferroelectric materials studied using the TEM are discussed below.Figure 1 shows micrographs of ferroelectric domains obtained from undoped and Fe-doped BaTiO3 single crystals. The domain boundaries have been identified as 90° domains with the boundaries parallel to <011>.


VASA ◽  
2015 ◽  
Vol 44 (5) ◽  
pp. 355-362 ◽  
Author(s):  
Marie Urban ◽  
Alban Fouasson-Chailloux ◽  
Isabelle Signolet ◽  
Christophe Colas Ribas ◽  
Mathieu Feuilloy ◽  
...  

Abstract. Summary: Background: We aimed at estimating the agreement between the Medicap® (photo-optical) and Radiometer® (electro-chemical) sensors during exercise transcutaneous oxygen pressure (tcpO2) tests. Our hypothesis was that although absolute starting values (tcpO2rest: mean over 2 minutes) might be different, tcpO2-changes over time and the minimal value of the decrease from rest of oxygen pressure (DROPmin) results at exercise shall be concordant between the two systems. Patients and methods: Forty seven patients with arterial claudication (65 + / - 7 years) performed a treadmill test with 5 probes each of the electro-chemical and photo-optical devices simultaneously, one of each system on the chest, on each buttock and on each calf. Results: Seventeen Medicap® probes disconnected during the tests. tcpO2rest and DROPmin values were higher with Medicap® than with Radiometer®, by 13.7 + / - 17.1 mm Hg and 3.4 + / - 11.7 mm Hg, respectively. Despite the differences in absolute starting values, changes over time were similar between the two systems. The concordance between the two systems was approximately 70 % for classification of test results from DROPmin. Conclusions: Photo-optical sensors are promising alternatives to electro-chemical sensors for exercise oximetry, provided that miniaturisation and weight reduction of the new sensors are possible.


2020 ◽  
pp. 38-44
Author(s):  
A. V. Polyakov ◽  
M. A. Ksenofontov

Optical technologies for measuring electrical quantities attract great attention due to their unique properties and significant advantages over other technologies used in high-voltage electric power industry: the use of optical fibers ensures high stability of measuring equipment to electromagnetic interference and galvanic isolation of high-voltage sensors; external electromagnetic fields do not influence the data transmitted from optical sensors via fiber-optic communication lines; problems associated with ground loops are eliminated, there are no side electromagnetic radiation and crosstalk between the channels. The structure and operation principle of a quasi-distributed fiber-optic high-voltage monitoring system is presented. The sensitive element is a combination of a piezo-ceramic tube with an optical fiber wound around it. The device uses reverse transverse piezoelectric effect. The measurement principle is based on recording the change in the recirculation frequency under the applied voltage influence. When the measuring sections are arranged in ascending order of the measured effective voltages relative to the receiving-transmitting unit, a relative resolution of 0,3–0,45 % is achieved for the PZT-5H and 0,8–1,2 % for the PZT-4 in the voltage range 20–150 kV.


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