{"title":"A experimental method to the study of wireless passive LC sensors","authors":"R. J. Rodrigues, Renan Melo De Freitas","doi":"10.15406/IJBSBE.2018.04.00121","DOIUrl":null,"url":null,"abstract":"The wireless passive resonant LC sensors studies and developments have had a significant growing in the last two decades because these sensors do not need for power supply, wiring connections and electronics circuits.1,2 These sensors represent great possibilities for monitoring of physiological parameters inside the human body.3 An implantable device has to operate under harsh environment as a blood vessel.2,3 Both development of an implantable intraocular pressure sensor for detection of glaucoma,1 and blood pressure sensor for monitoring blood vessel pressure are application examples.3‒6 The measuring, i.e. pressure in most cases, changes the capacitance of the LC circuit placed within the environment being monitored (Figure 1). Thus the LC resonant frequency is changed as a pressure function. This resonant frequency is detected by a coil, magnetically coupled and outside the sensor environment. A readout circuit is connected to this external coil.6 The coil L1 receives an AC signal from Signal Generator, which induces an electrical current in the coil L2 (Lei de Faraday-Lenz). The energy changes between L2 and the capacitor C induces an electrical current in the coil L1, which will be detected as coupled impedance, measured between (a) and (b) points marked in the Figure 1. The total impedance measured between (a) and (b) points is given by Equation 1.2,7","PeriodicalId":15247,"journal":{"name":"Journal of Biosensors and Bioelectronics","volume":"14 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2018-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Biosensors and Bioelectronics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.15406/IJBSBE.2018.04.00121","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 2
Abstract
The wireless passive resonant LC sensors studies and developments have had a significant growing in the last two decades because these sensors do not need for power supply, wiring connections and electronics circuits.1,2 These sensors represent great possibilities for monitoring of physiological parameters inside the human body.3 An implantable device has to operate under harsh environment as a blood vessel.2,3 Both development of an implantable intraocular pressure sensor for detection of glaucoma,1 and blood pressure sensor for monitoring blood vessel pressure are application examples.3‒6 The measuring, i.e. pressure in most cases, changes the capacitance of the LC circuit placed within the environment being monitored (Figure 1). Thus the LC resonant frequency is changed as a pressure function. This resonant frequency is detected by a coil, magnetically coupled and outside the sensor environment. A readout circuit is connected to this external coil.6 The coil L1 receives an AC signal from Signal Generator, which induces an electrical current in the coil L2 (Lei de Faraday-Lenz). The energy changes between L2 and the capacitor C induces an electrical current in the coil L1, which will be detected as coupled impedance, measured between (a) and (b) points marked in the Figure 1. The total impedance measured between (a) and (b) points is given by Equation 1.2,7