3,092 research outputs found

    Biomedical integrated circuit design for an electro-therapy device : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Electronics and Computer Engineering (Bioelectronics) at School of Engineering and Advanced Technology, Massey University, Albany Campus, New Zealand

    Get PDF
    Journal articles in Appendix A removed for copyright reasons. Chapters 3, 4 and 5 published respectively as: Abbas Al-Darkazly, Ibtisam A., & Hasan, S. M. Rezaul. (2016). A waveform generator circuit for extra low‐frequency CMOS micro‐power applications, International Journal of Circuit Theory and Applications, 44, 266-279. https://doi-org.ezproxy.massey.ac.nz/10.1002/cta.2074 Abbas Al-Darkazly, Ibtisam A., & Hasan, S. M. Rezaul. (2016). Dual-band waveform generator with ultra-wide low-frequency tuning-range, IEEE Access, 4, 3169-3181. DOI: 10.1109/ACCESS.2016.2557843 Abbas Al-Darkazly, Ibtisam A., & Hasan, S. M. Rezaul. (2017). Optimized low-power CMOS active-electrode-pair for low-frequency multi-channel biomedical stimulation, Microelectronics Journal, 66, 18-24. https://doi-org.ezproxy.massey.ac.nz/10.1016/j.mejo.2017.05.014A biomedical integrated circuit design (IC) is utilized for the development of a novel non-invasive electro-therapy device, for low frequency multi-channel biomedical stimulation to transform immune activity and induce anti-viral state. Biomedical integrated circuit design is an important branch of modern electronic engineering that uses the application of electronic engineering principles for biomedical disciplines, to develop bioelectronics devices that are implanted within the body and for non-invasive devices to improve patient’s lives. These devices use the application of an electric field to stimulate reactions to restore normal cell functions and activate the cells to treat a variety of disorders or disease conditions. Bioelectronics devices can be designed for use as alternative treatments to overcome the deficiencies of several conventional medical treatments. It could potentially assist as drug-free relief when therapeutic drugs become ineffective, costly, with serious side effects and cannot be replaced, loss of future treatment options, and hence, life threatening, as for drug resistant Human immunodeficiency virus (HIV-1) patients. Since the underlying mechanisms of the biological system and disease state is dominated by electrostatic interactions, specifically, the interaction between HIV-1 and the host cell that is predominantly by electrostatic interactions (protein charge-charge interaction) has an important role in its life cycle replication. At given pulses, the charge distribution and polarization of the electro-active protein molecules takes place, inducing conformation change which can enhance immune activity and inhibit the interaction of HIV-1 and host cells, disturbing its life cycle, leading to the mechanisms of the inactivation signal-induced virus death. These electrically induced protein transformations is used in this research as blood-cell treatment and as anti-HIV-1 electrotherapy. Advances in bioelectronics technology, which involve new CMOS IC design, and in bio-electrochemistry science, which include cellular function, electro-active biomolecules and their responses, have contributed to this project to develop the concept of a novel electro-therapy device, for biomedical treatment applications. This involves understanding of the underlying mechanisms of the biological system and disease condition from an electronic engineer’s point of view as well as the interface between the electronic signal and the biological cells, and how electronic devices and circuitry directly communicate with the electro-active body tissue and blood cells. This research project addresses the design and development of a novel energy efficient miniature biomedical device using a new CMOS technology. It can generate, deliver and control an appropriate periodical low frequency electrical pulses, through the low-resistance skin surface to a patient’s blood. The notable feature of such a smart device is its cellular specificity: the parameters of the generated electrical pulse which are designed and selected in order to stimulate only one particular type of tissue (blood) leaving the others unaffected. The device comprises a mixed-signal low power dualband waveform generator (WFG) chip along with a novel two band tuning system. It was fabricated using Global Foundries (GF) 8RF-DM 130-nm CMOS process with a supply voltage of ±1V for the analog circuit and +1V for logic circuits. The WFG core (band I) can be tuned in the range 6.44 kHz - 1003 kHz through bias current adjustment, while a lower frequency (band II) in the range 0.1 Hz to 502 kHz can be provided digitally. Two WFG approaches, that comprise relaxation oscillators with different relaxation timing networks, have been developed for comparison. Since the aim of this work is to transfer electrical signal in a specifically controlled fashion through the tissue, a novel low power active electrode-pair signal delivery system, compatible with human skin with high signal integrity, is developed. The circuit was fabricated in a 130-nm CMOS process using a low supply-voltage of +1.2V to deliver bi-phase square waveform signals from 16 selectable low-frequency channels. The individual active electrode can also be used to deliver mono-phase square/triangular waveform output signals. Accuracy, safety, low power, light-weight, miniature and low-cost characteristics are the main concerns. Being a miniature bioelectronics component with low power consumption, the proposed device is suitable both as a non-invasive and as an implantable biomedical device, in which WFG and electrodes circuitry can communicate with the electro-active biomolecule, strongly stimulating certain events in a complex biological system. A theoretical analysis, experiment design and performance are carried out in invitro environments to examine the effect of the designed signal on human blood cellular proteins. Proteins that display a heterogeneous structure have various conductivities and permittivity (determining the interaction with the electrical field) and possess dielectric properties with a large conformation change, undergoing structural rearrangements in response to cellular signals. The frequency-dependent dielectric present in proteins involves the redistribution and alignment of the proteins charged molecule and its polar molecule in response to an applied external electrical field can also induce conformation change. Interference polarization within proteins could interrupt the interaction between both sides of predominantly host cell proteins and of the HIV-1 infective envelope and its protein particles. This could disturb the signalling proteins for cell activation, and, hence, the virus cannot conjugate with the target cells and control the host cell protein activity. Since the virus is unable to reproduce out of a host cell, hence the virus cannot mutate and develop resistance easily, and use alternative binding and entry mechanisms as in the pharmacological approaches. After carefully studying the interaction of the HIV-1 virus and the host cell, with respect to signal transfer, CD4 receptor, co-receptors CCR5 and nuclear transport factor nucleoporins FGNup153 proteins of the lymphatic system, which are essential targets for HIV-1 infection and its life cycle replication represent an attractive target to investigate in this research project. The activities of the underlying mechanism of the target cell are then examined utilizing immunofluorescence microscopy technique with specific fluorescent labelled antibodies, and accurate results are obtained with relatively low cost. The results demonstrated that the low frequency electrical pulse could inhibit virus attachment and fusion. It is also could provide a permeability barrier, that prevents the import and export of large macromolecule virus particles through the nuclear pore complex. These effects could induce an antiviral state for a period of time, and stope HIV-1 virus replication, with no potential risks and harm to the host cells, compared to the common drugs. This is promising for the conception of HIV-1 treatment in vivo. Although further investigations are required in order to fully use the application of electrical stimulation in vivo for treatment, the result is provides the necessary impetus for the applications of low frequency electrical stimulation on human immune response. This might offer important antiviral therapy against the most devastating pathogens in human history. This doctoral research is not only of academic interest but also highly relevant to medical applications. It is considered potentially beneficial in the development of knowledge in advanced technology for electro-medical treatment devices, their design, structure and applications to extend life, and for future growth in the biotechnology industry, therefore beneficial for the patients, physicians and for humanity

    High voltage bias waveform generator for an RF MEMS microswitch

    Get PDF
    An integrated high voltage bias driver for a Radio Frequency Micro-Electro-Mechanical System (RF MEMS) microswitch is proposed. The design and implementation in a 0.7mum integrated circuit process with high and low voltage transistors is shown along with tested results. High voltage Double-Diffused Metal Oxide Semiconductor (DMOS) transistors in combination with low voltage digital logic provide a non-linear solution that achieves rise and fall times of 1mus while keeping power use to a minimum. System design and tradeoffs are presented for alternate approaches and combinations as well as future integration with Direct Current--Direct Current (DC-DC) voltage conversion and an internally generated clock

    A CMOS self-contained quadrature signal generator for soc impedance spectroscopy

    Get PDF
    This paper presents a low-power fully integrated quadrature signal generator for system-on-chip (SoC) impedance spectroscopy applications. It has been designed in a 0.18 µm-1.8 V CMOS technology as a self-contained oscillator, without the need for an external reference clock. The frequency can be digitally tuned from 10 to 345 kHz with 12-bit accuracy and a relative mean error below 1.7%, thus supporting a wide range of impedance sensing applications. The proposal is experimentally validated in two impedance spectrometry examples, achieving good magnitude and phase recovery results compared to the results obtained using a commercial LCR-meter. Besides the wide frequency tuning range, the proposed programmable oscillator features a total power consumption lower than 0.77 mW and an active area of 0.129 mm2, thus constituting a highly suitable choice as stimulation module for instrument-on-a-chip devices

    DESIGN AND SIMULATE PULSE GENERATOR CIRCUIT

    Get PDF
    The main purpose of the project is to design and simulate pulse generator impulse based for Ultra Wide Band (UWB) applications. The UWB technology is defmed by the Federal Communications Commission's (FCC), the signal must have bandwidth of greater than SOOMHz. The structure of the pulse generator is based on Complementary Metal Oxide Semiconductor (CMOS) and the topology of the circuit is adaptation of CR( RC)" pulse shaping network. The pulse generator circuit consists of variable length rectangle pulse generator, which mingles up cascaded inverter and N-voltage controlled with a CMOS quasi-Gaussian pulse-shaping filter. In this project, the author successfully designed and simulated the pulse generator. The simulation is done using Virtuoso Analog Design Environment (Cadence) which is able for integrated design circuit and used AMI 0.6um transistor technology. The circuit takes lOOMHz pulse as the input. Through the simulation, the author has proved to generate pulse with 660MHz passed frequency. This shows that the topology chosen is able to generate pulse for high frequency purposes

    A Partial-Current-Steering Biphasic Stimulation Driver for Vestibular Prostheses

    No full text
    Published versio

    Ultra-Wideband CMOS Transceiver Front-End for Bio-Medical Radar Sensing

    Get PDF
    Since the Federal Communication Commission released the unlicensed 3.1-10.6 GHz frequency band for commercial use in early 2002, the ultra wideband (UWB) has developed from an emerging technology into a mainstream research area. The UWB technology, which utilizes wide spectrum, opens a new era of possibility for practical applications in radar sensing, one of which is the human vital sign monitoring. The aim of this thesis is to study and research the possibility of a new generation humanrespiration monitoring sensor using UWB radar technology and to develop a new prototype of UWB radar sensor for system-on-chip solutions in CMOS technology. In this thesis, a lowpower Gaussian impulse UWB mono-static radar transceiver architecture is presented. The UWB Gaussian pulse transmitter and receiver are implemented and fabricated using 90nm CMOS technology. Since the energy of low order Gaussian pulse is mostly condensed at lower frequency, in order to transmit the pulse in a very efficient way, higher order Gaussian derivative pulses are desired as the baseband signal. This motivates the advancement of the design into UWB high-order pulse transmitter. Both the Gaussian impulse UWB transmitter and Gaussian higher-order impulse UWB transmitter take the low-power and high-speed advantage of digital circuit to generate different waveforms. The measurement results are analyzed and discussed. This thesis also presents a low-power UWB mono-static radar transceiver architecture exploiting the full benefit of UWB bandwidth in radar sensing applications. The transceiver includes a full UWB band transmitter, an UWB receiver front-end, and an on-chip diplexer. The non-coherent UWB transmitter generates pulse modulated baseband signals at different carrier frequencies within the designated 3-10 GHz band using a digitally controlled pulse generator. The test shows the proposed radar transceiver can detect the human respiration pattern within 50 cm distance. The applications of this UWB radar sensing solution in commercialized standard CMOS technology include constant breathing pattern monitoring for gated radiation therapy, realtime monitoring of patients, and any other breathing monitoring. The research paves the way to wireless technology integration with health care and bio-sensor network

    Adiabatic Approach for Low-Power Passive Near Field Communication Systems

    Get PDF
    This thesis tackles the need of ultra-low power electronics in the power limited passive Near Field Communication (NFC) systems. One of the techniques that has proven the potential of delivering low power operation is the Adiabatic Logic Technique. However, the low power benefits of the adiabatic circuits come with the challenges due to the absence of single opinion on the most energy efficient adiabatic logic family which constitute appropriate trade-offs between computation time, area and complexity based on the circuit and the power-clocking schemes. Therefore, five energy efficient adiabatic logic families working in single-phase, 2-phase and 4-phase power-clocking schemes were chosen. Since flip-flops are the basic building blocks of any sequential circuit and the existing flip-flops are MUX-based (having more transistors) design, therefore a novel single-phase, 2-phase and 4-phase reset based flip-flops were proposed. The performance of the multi-phase adiabatic families was evaluated and compared based on the design examples such as 2-bit ring counter, 3-bit Up-Down counter and 16-bit Cyclic Redundancy Check (CRC) circuit (benchmark circuit) based on ISO 14443-3A standard. Several trade-offs, design rules, and an appropriate range for the supply voltage scaling for multi-phase adiabatic logic are proposed. Furthermore, based on the NFC standard (ISO 14443-3A), data is frequently encoded using Manchester coding technique before transmitting it to the reader. Therefore, if Manchester encoding can be implemented using adiabatic logic technique, energy benefits are expected. However, adiabatic implementation of Manchester encoding presents a challenge. Therefore, a novel method for implementing Manchester encoding using adiabatic logic is proposed overcoming the challenges arising due to the AC power-clock. Other challenges that come with the dynamic nature of the adiabatic gates and the complexity of the 4-phase power-clocking scheme is in synchronizing the power-clock v phases and the time spent in designing, validation and debugging of errors. This requires a specific modelling approach to describe the adiabatic logic behaviour at the higher level of abstraction. However, describing adiabatic logic behaviour using Hardware Description Languages (HDLs) is a challenging problem due to the requirement of modelling the AC power-clock and the dual-rail inputs and outputs. Therefore, a VHDL-based modelling approach for the 4-phase adiabatic logic technique is developed for functional simulation, precise timing analysis and as an improvement over the previously described approaches
    corecore