14 research outputs found

    BÄ°yopotansiyel iƟaretlerin ikinci nesil akım taĆŸÄ±yıcılar ile iƟlenmesi ve yeni bir EKG devresi tasarımı

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    06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “YĂŒksekĂ¶ÄŸretim Kanunu Ä°le Bazı Kanun Ve Kanun HĂŒkmĂŒnde Kararnamelerde DeğiƟiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “LisansĂŒstĂŒ Tezlerin Elektronik Ortamda Toplanması, DĂŒzenlenmesi ve EriƟime Açılmasına Ä°liƟkin Yönerge” gereğince tam metin eriƟime açılmÄ±ĆŸtır.Anahtar kelimeler: CCII, ikinci nesil akım taĆŸÄ±yıcılar, filtre, EKG Bu çalÄ±ĆŸmada bir EKG cihazı tasarlanmÄ±ĆŸ ve bu cihaz ikinci nesil akım taĆŸÄ±yıcılar ile gerçekleƟtirilmiƟtir. Bu EKG devresinde ikinci nesil akım taĆŸÄ±yıcılar filtre olarak kullanılmÄ±ĆŸtır. Bu cihazın doğruluğunu kontrol edebilmek ve karĆŸÄ±laƟtırmasını yapabilmek için Sakarya Üniversitesi Elektrik-Elektronik MĂŒhendisliği'ne ait olan BIOPAC Systems Inc. Ɵirketinin imal ettiği MP36 EKG cihazı ile ölĂ§ĂŒmler eƟ zamanlı olarak yapılmÄ±ĆŸtır. Ayrıca OPAMP'larla tasarlanan bir EKG devresi de gerçekleƟtirilmiƟ ve sonuçları değerlendirilmiƟtir. OPAMP'larla gerçekleƟtirilen bu devre ikinci nesil akım taĆŸÄ±yıcılarla yeniden dizayn edilmiƟ ve gerçekleƟtirilerek sonuçları değerlendirilmiƟtir. Böylece OPAMP'larla gerçekleƟtirilmiƟ bir EKG devresi, ikinci nesil akım taĆŸÄ±yıcılarla yeniden dizayn edilmiƟ bir EKG devresi, bu çalÄ±ĆŸmada tasarlanmÄ±ĆŸ ve ikinci nesil akım taĆŸÄ±yıcılarla tasarlanmÄ±ĆŸ bir EKG devresi, MP36 devresi ve daha önce literatĂŒrde gerçekleƟtirilmiƟ EKG devrelerinin kıyaslaması yapılmÄ±ĆŸtır. Ayrıca biyomedikal cihazlarda sıklıkla kullanılan filtreler, yĂŒkselteçler ve bazı devreler simule edilmiƟtir. CCII tabanlı olan devrede gĂŒrĂŒltĂŒler minimuma inmiƟ ve çok net EKG ölĂ§ĂŒmĂŒ yapılabilmiƟtir. EKG devresi 9,5*9,5 cm2 boyutlarına kadar indirgenebilmiƟtir. Entegrelerin ve diğer elemanların SMD tĂŒrlerinin kullanılması ile daha da kĂŒĂ§ĂŒltĂŒlebilmesi mĂŒmkĂŒndĂŒr. Gerçeklenen devre maliyet açısından da avantajlıdır. 4 adet kalem pille çalÄ±ĆŸabilir olması da bir diğer avantajıdır. CMRR oranı, frekans aralığı, yĂŒkseltme oranı ve uygulanabilme kolaylığı açısından CCII tabanlı olan EKG devrelerinin daha avantajlı olduğu sonucu ortaya çıkmaktadır. Ayrıca bu çalÄ±ĆŸmada rezonans frekansını ayarlamak ve daha iyi sonuç elde edebilmek için CCII yapısına ayarlı dirençler eklenmesi sebebiyle 5 Hz ile 100 MHz arasında bir kesim frekansına sahip bir filtre yapısı öne sĂŒrĂŒldĂŒ ve bu devrede kullanılabilir olduğu gözlemlendi.Keywords: CCII, second generation current conveyors, filter, ECG In this study, an ECG device was designed and this device was carried out with second generation current carriers. Second generation current carriers were used as filters in this ECG circuit. Measurements were simultaneously performed with MP36 ECG device produced by BIOPAC Systems Inc. that is belong to Sakarya University Electrical and Electronics Engineering Department in order to be able to check and compare accuracy of this device. An ECG circuit designed with OPAMPs was also carried out and results were evaluated. This circuit, which was realized with OPAMPs, was redesigned with second generation current carriers and results were evaluated by performing. Thus, an ECG circuit realized with OPAMPs, a redesigned ECG circuit with second generation current carriers were designed in this study, and an ECG circuit with second generation current carriers, MP36 circuit and previous circuits in literature were compared. In addition, filters, amplifiers and some circuits, which are frequently used in biomedical devices are simulated. Noises were reduced to minimum in CCII-based circuit and very clear ECG measurements was done. ECG circuit can be reduced to size of 9.5 * 9.5 cm2. It is possible to further reduce integrals and other elements by use of SMD types. Performed circuit is also advantageous in terms of cost. Another advantage is that it can work with 4 batteries. It was concluded that CCII based ECG circuits are more advantageous in terms of CMRR ratio, frequency range, amplification rate and ease of application. Also, in this study, a filter structure having a cut-off frequency between 5 Hz to 100 MHz was proposed because of adding adjusted resistors to CCII structure to adjust resonance frequency and achieve better results, and it was observed to be usable in this circuit

    Low Voltage Low Power Analogue Circuits Design

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    DisertačnĂ­ prĂĄce je zaměƙena na vĂœzkum nejbÄ›ĆŸnějĆĄĂ­ch metod, kterĂ© se vyuĆŸĂ­vajĂ­ pƙi nĂĄvrhu analogovĂœch obvodĆŻ s vyuĆŸitĂ­ nĂ­zkonapěƄovĂœch (LV) a nĂ­zkopƙíkonovĂœch (LP) struktur. Tyto LV LP obvody mohou bĂœt vytvoƙeny dĂ­ky vyspělĂœm technologiĂ­m nebo takĂ© vyuĆŸitĂ­m pokročilĂœch technik nĂĄvrhu. DisertačnĂ­ prĂĄce se zabĂœvĂĄ prĂĄvě pokročilĂœmi technikami nĂĄvrhu, pƙedevĆĄĂ­m pak nekonvenčnĂ­mi. Mezi tyto techniky patƙí vyuĆŸitĂ­ prvkĆŻ s ƙízenĂœm substrĂĄtem (bulk-driven - BD), s plovoucĂ­m hradlem (floating-gate - FG), s kvazi plovoucĂ­m hradlem (quasi-floating-gate - QFG), s ƙízenĂœm substrĂĄtem s plovoucĂ­m hradlem (bulk-driven floating-gate - BD-FG) a s ƙízenĂœm substrĂĄtem s kvazi plovoucĂ­m hradlem (quasi-floating-gate - BD-QFG). PrĂĄce je takĂ© orientovĂĄna na moĆŸnĂ© zpĆŻsoby implementace znĂĄmĂœch a modernĂ­ch aktivnĂ­ch prvkĆŻ pracujĂ­cĂ­ch v napěƄovĂ©m, proudovĂ©m nebo mix-mĂłdu. Mezi tyto prvky lze začlenit zesilovače typu OTA (operational transconductance amplifier), CCII (second generation current conveyor), FB-CCII (fully-differential second generation current conveyor), FB-DDA (fully-balanced differential difference amplifier), VDTA (voltage differencing transconductance amplifier), CC-CDBA (current-controlled current differencing buffered amplifier) a CFOA (current feedback operational amplifier). Za Ășčelem potvrzenĂ­ funkčnosti a chovĂĄnĂ­ vĂœĆĄe zmĂ­něnĂœch struktur a prvkĆŻ byly vytvoƙeny pƙíklady aplikacĂ­, kterĂ© simulujĂ­ usměrƈovacĂ­ a induktančnĂ­ vlastnosti diody, dĂĄle pak filtry dolnĂ­ propusti, pĂĄsmovĂ© propusti a takĂ© univerzĂĄlnĂ­ filtry. VĆĄechny aktivnĂ­ prvky a pƙíklady aplikacĂ­ byly ověƙeny pomocĂ­ PSpice simulacĂ­ s vyuĆŸitĂ­m parametrĆŻ technologie 0,18 m TSMC CMOS. Pro ilustraci pƙesnĂ©ho a ĂșčinnĂ©ho chovĂĄnĂ­ struktur je v disertačnĂ­ prĂĄci zahrnuto velkĂ© mnoĆŸstvĂ­ simulačnĂ­ch vĂœsledkĆŻ.The dissertation thesis is aiming at examining the most common methods adopted by analog circuits' designers in order to achieve low voltage (LV) low power (LP) configurations. The capability of LV LP operation could be achieved either by developed technologies or by design techniques. The thesis is concentrating upon design techniques, especially the non–conventional ones which are bulk–driven (BD), floating–gate (FG), quasi–floating–gate (QFG), bulk–driven floating–gate (BD–FG) and bulk–driven quasi–floating–gate (BD–QFG) techniques. The thesis also looks at ways of implementing structures of well–known and modern active elements operating in voltage–, current–, and mixed–mode such as operational transconductance amplifier (OTA), second generation current conveyor (CCII), fully–differential second generation current conveyor (FB–CCII), fully–balanced differential difference amplifier (FB–DDA), voltage differencing transconductance amplifier (VDTA), current–controlled current differencing buffered amplifier (CC–CDBA) and current feedback operational amplifier (CFOA). In order to confirm the functionality and behavior of these configurations and elements, they have been utilized in application examples such as diode–less rectifier and inductance simulations, as well as low–pass, band–pass and universal filters. All active elements and application examples have been verified by PSpice simulator using the 0.18 m TSMC CMOS parameters. Sufficient numbers of simulated plots are included in this thesis to illustrate the precise and strong behavior of structures.

    Utilizing Unconventional CMOS Techniques for Low Voltage Low Power Analog Circuits Design for Biomedical Applications

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    Tato disertačnĂ­ prĂĄce se zabĂœvĂĄ navrĆŸenĂ­m nĂ­zkonapěƄovĂœch, nĂ­zkopƙíkonovĂœch analogovĂœch obvodĆŻ, kterĂ© pouĆŸĂ­vajĂ­ nekonvenčnĂ­ techniky CMOS. LĂ©kaƙskĂĄ zaƙízenĂ­ na bateriovĂ© napĂĄjenĂ­, jako systĂ©my pro dlouhodobĂœ fyziologickĂœ monitoring, pƙenosnĂ© systĂ©my, implantovatelnĂ© systĂ©my a systĂ©my vhodnĂ© na noĆĄenĂ­, musĂ­ bĂœt male a lehkĂ©. Kromě toho je nutnĂ©, aby byly tyto systĂ©my vybaveny bateriĂ­ s dlouhou ĆŸivotnostĂ­. Z tohoto dĆŻvodu pƙevlĂĄdajĂ­ v biomedicĂ­nskĂœch aplikacĂ­ch tohoto typu nĂ­zkopƙíkonovĂ© integrovanĂ© obvody. NekonvenčnĂ­ techniky jako napƙ. vyuĆŸitĂ­ transistorĆŻ s ƙízenĂœm substrĂĄtem (Bulk-Driven “BD”), s plovoucĂ­m hradlem (Floating-Gate “FG”), s kvazi plovoucĂ­m hradlem (Quasi-Floating-Gate “QFG”), s ƙízenĂœm substrĂĄtem s plovoucĂ­m hradlem (Bulk-Driven Floating-Gate “BD-FG”) a s ƙízenĂœm substrĂĄtem s kvazi plovoucĂ­m hradlem (Bulk-Driven Quasi-Floating-Gate “BD-QFG”), se v nedĂĄvnĂ© době ukĂĄzaly jako efektivnĂ­ prostƙedek ke zjednoduĆĄenĂ­ obvodovĂ©ho zapojenĂ­ a ke snĂ­ĆŸenĂ­ velikosti napĂĄjecĂ­ho napětĂ­ směrem k prahovĂ©mu napětĂ­ u tranzistorĆŻ MOS (MOST). V prĂĄci jsou podrobně pƙedstaveny nejdĆŻleĆŸitějĆĄĂ­ charakteristiky nekonvenčnĂ­ch technik CMOS. Tyto techniky byly pouĆŸity pro vytvoƙenĂ­ nĂ­zko napěƄovĂœch a nĂ­zko vĂœkonovĂœch CMOS struktur u některĂœch aktivnĂ­ch prvkĆŻ, napƙ. Operational Transconductance Amplifier (OTA) zaloĆŸenĂ© na BD, FG, QFG, a BD-QFG techniky; Tunable Transconductor zaloĆŸenĂœ na BD MOST; Current Conveyor Transconductance Amplifier (CCTA) zaloĆŸenĂœ na BD-QFG MOST; Z Copy-Current Controlled-Current Differencing Buffered Amplifier (ZC-CC-CDBA) zaloĆŸenĂœ na BD MOST; Winner Take All (WTA) and Loser Take All (LTA) zaloĆŸenĂœ na BD MOST; Fully Balanced Four-Terminal Floating Nullor (FBFTFN) zaloĆŸenĂœ na BD-QFG technice. Za Ășčelem ověƙenĂ­ funkčnosti vĂœĆĄe zmĂ­něnĂœch struktur, byly tyto struktury pouĆŸity v několika aplikacĂ­ch. VĂœkon navrĆŸenĂœch aktivnĂ­ch prvkĆŻ a pƙíkladech aplikacĂ­ je ověƙovĂĄn prostƙednictvĂ­m simulačnĂ­ch programĆŻ PSpice či Cadence za pouĆŸitĂ­ technologie 0.18 m CMOS.This doctoral thesis deals with designing ultra-low-voltage (LV) low-power (LP) analog circuits utilizing the unconventional CMOS techniques. Battery powered medical devices such as; long term physiological monitoring, portable, implantable, and wearable systems need to be small and lightweight. Besides, long life battery is essential need for these devices. Thus, low-power integrated circuits are always paramount in such biomedical applications. Recently, unconventional CMOS techniques i.e. Bulk-Driven (BD), Floating-Gate (FG), Quasi-Floating-Gate (QFG), Bulk-Driven Floating-Gate (BD-FG) and Bulk-Driven Quasi-Floating-Gate (BD-QFG) MOS transistors (MOSTs) have revealed as effective devices to reduce the circuit complexity and push the voltage supply of the circuit towards threshold voltage of the MOST. In this work, the most important features of the unconventional CMOS techniques are discussed in details. These techniques have been utilized to perform ultra-LV LP CMOS structures of several active elements i.e. Operational Transconductance Amplifier (OTA) based on BD, FG, QFG, and BD-QFG techniques; Tunable Transconductor based on BD MOST; Current Conveyor Transconductance Amplifier (CCTA) based on BD-QFG MOST; Z Copy-Current Controlled-Current Differencing Buffered Amplifier (ZC-CC-CDBA) based on BD MOST; Winner Take All (WTA) and Loser Take All (LTA) based on BD MOST; Fully Balanced Four-Terminal Floating Nullor (FBFTFN) based on BD-QFG technique. Moreover, to verify the workability of the proposed structures, they were employed in several applications. The performance of the proposed active elements and their applications were investigated through PSpice or Cadence simulation program using 0.18 m CMOS technology.

    Low-power Wearable Healthcare Sensors

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    Advances in technology have produced a range of on-body sensors and smartwatches that can be used to monitor a wearer’s health with the objective to keep the user healthy. However, the real potential of such devices not only lies in monitoring but also in interactive communication with expert-system-based cloud services to offer personalized and real-time healthcare advice that will enable the user to manage their health and, over time, to reduce expensive hospital admissions. To meet this goal, the research challenges for the next generation of wearable healthcare devices include the need to offer a wide range of sensing, computing, communication, and human–computer interaction methods, all within a tiny device with limited resources and electrical power. This Special Issue presents a collection of six papers on a wide range of research developments that highlight the specific challenges in creating the next generation of low-power wearable healthcare sensors

    CMOS Design of Reconfigurable SoC Systems for Impedance Sensor Devices

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    La rĂĄpida evoluciĂłn en el campo de los sensores inteligentes, junto con los avances en las tecnologĂ­as de la computaciĂłn y la comunicaciĂłn, estĂĄ revolucionando la forma en que recopilamos y analizamos datos del mundo fĂ­sico para tomar decisiones, facilitando nuevas soluciones que desempeñan tareas que antes eran inconcebibles de lograr.La inclusiĂłn en un mismo dado de silicio de todos los elementos necesarios para un proceso de monitorizaciĂłn y actuaciĂłn ha sido posible gracias a los avances en micro (y nano) electrĂłnica. Al mismo tiempo, la evoluciĂłn de las tecnologĂ­as de procesamiento y micromecanizado de superficies de silicio y otros materiales complementarios ha dado lugar al desarrollo de sensores integrados compatibles con CMOS, lo que permite la implementaciĂłn de matrices de sensores de alta densidad. AsĂ­, la combinaciĂłn de un sistema de adquisiciĂłn basado en sensores on-Chip, junto con un microprocesador como nĂșcleo digital donde se puede ejecutar la digitalizaciĂłn de señales, el procesamiento y la comunicaciĂłn de datos proporciona caracterĂ­sticas adicionales como reducciĂłn del coste, compacidad, portabilidad, alimentaciĂłn por baterĂ­a, facilidad de uso e intercambio inteligente de datos, aumentando su potencial nĂșmero de aplicaciones.Esta tesis pretende profundizar en el diseño de un sistema portĂĄtil de mediciĂłn de espectroscopĂ­a de impedancia de baja potencia operado por baterĂ­a, basado en tecnologĂ­as microelectrĂłnicas CMOS, que pueda integrarse con el sensor, proporcionando una implementaciĂłn paralelizable sin incrementar significativamente el tamaño o el consumo, pero manteniendo las principales caracterĂ­sticas de fiabilidad y sensibilidad de un instrumento de laboratorio. Esto requiere el diseño tanto de la etapa de gestiĂłn de la energĂ­a como de las diferentes celdas que conforman la interfaz, que habrĂĄn de satisfacer los requisitos de un alto rendimiento a la par que las exigentes restricciones de tamaño mĂ­nimo y bajo consumo requeridas en la monitorizaciĂłn portĂĄtil, caracterĂ­sticas que son aĂșn mĂĄs crĂ­ticas al considerar la tendencia actual hacia matrices de sensores.A nivel de celdas, se proponen diferentes circuitos en un proceso CMOS de 180 nm: un regulador de baja caĂ­da de voltaje como unidad de gestiĂłn de energĂ­a, que proporciona una alimentaciĂłn de 1.8 V estable, de bajo ruido, precisa e independiente de la carga para todo el sistema; amplificadores de instrumentaciĂłn con una aproximaciĂłn completamente diferencial, que incluyen una etapa de entrada de voltaje/corriente configurable, ganancia programable y ancho de banda ajustable, tanto en la frecuencia de corte baja como alta; un multiplicador para conformar la demodulaciĂłn dual, que estĂĄ embebido en el amplificador para optimizar consumo y ĂĄrea; y filtros pasa baja totalmente integrados, que actĂșan como extractores de magnitud de DC, con frecuencias de corte ajustables desde sub-Hz hasta cientos de Hz.<br /

    Design and implementation of a multi-modal sensor with on-chip security

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    With the advancement of technology, wearable devices for fitness tracking, patient monitoring, diagnosis, and disease prevention are finding ways to be woven into modern world reality. CMOS sensors are known to be compact, with low power consumption, making them an inseparable part of wireless medical applications and Internet of Things (IoT). Digital/semi-digital output, by the translation of transmitting data into the frequency domain, takes advantages of both the analog and digital world. However, one of the most critical measures of communication, security, is ignored and not considered for fabrication of an integrated chip. With the advancement of Moore\u27s law and the possibility of having a higher number of transistors and more complex circuits, the feasibility of having on-chip security measures is drawing more attention. One of the fundamental means of secure communication is real-time encryption. Encryption/ciphering occurs when we encode a signal or data, and prevents unauthorized parties from reading or understanding this information. Encryption is the process of transmitting sensitive data securely and with privacy. This measure of security is essential since in biomedical devices, the attacker/hacker can endanger users of IoT or wearable sensors (e.g. attacks at implanted biosensors can cause fatal harm to the user). This work develops 1) A low power and compact multi-modal sensor that can measure temperature and impedance with a quasi-digital output and 2) a low power on-chip signal cipher for real-time data transfer

    Interface Circuits for Microsensor Integrated Systems

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    ca. 200 words; this text will present the book in all promotional forms (e.g. flyers). Please describe the book in straightforward and consumer-friendly terms. [Recent advances in sensing technologies, especially those for Microsensor Integrated Systems, have led to several new commercial applications. Among these, low voltage and low power circuit architectures have gained growing attention, being suitable for portable long battery life devices. The aim is to improve the performances of actual interface circuits and systems, both in terms of voltage mode and current mode, in order to overcome the potential problems due to technology scaling and different technology integrations. Related problems, especially those concerning parasitics, lead to a severe interface design attention, especially concerning the analog front-end and novel and smart architecture must be explored and tested, both at simulation and prototype level. Moreover, the growing demand for autonomous systems gets even harder the interface design due to the need of energy-aware cost-effective circuit interfaces integrating, where possible, energy harvesting solutions. The objective of this Special Issue is to explore the potential solutions to overcome actual limitations in sensor interface circuits and systems, especially those for low voltage and low power Microsensor Integrated Systems. The present Special Issue aims to present and highlight the advances and the latest novel and emergent results on this topic, showing best practices, implementations and applications. The Guest Editors invite to submit original research contributions dealing with sensor interfacing related to this specific topic. Additionally, application oriented and review papers are encouraged.

    Electronics for Sensors

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    The aim of this Special Issue is to explore new advanced solutions in electronic systems and interfaces to be employed in sensors, describing best practices, implementations, and applications. The selected papers in particular concern photomultiplier tubes (PMTs) and silicon photomultipliers (SiPMs) interfaces and applications, techniques for monitoring radiation levels, electronics for biomedical applications, design and applications of time-to-digital converters, interfaces for image sensors, and general-purpose theory and topologies for electronic interfaces
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