In-Body Energy Harvesting Power Management Interface for Post Heart Transplantation Monitoring

Deep tissue energy harvesters are of increasing interest in the development of battery-less implantable devices. This paper presents a fully integrated ultra-low quiescent power management interface. It has power optimization and impedance matching between a piezoelectric energy harvester and the functional load that could be potentially powered by the heart's mechanical motions. The circuit has been designed in 0.18-µm CMOS technology. It dissipates 189.8 nW providing two voltage outputs of 1.4 V and 4.2 V. The simulation results show an output power 8.2x times of an ideal full-bridge rectifier without an external power supply. The design has the potential for use in self-powered heart implantable devices as it is capable providing stable output voltages from a cold startup

Design of a Power Management Circuit for an Opto-Electro Stimulator

This paper presents the design of an integrated power management circuit for use in an implantable opto-electro stimulator. It features an active rectifier with pulse width modulation (PWM) regulation to generate a 3.3 V regulated output, and a 3-stage high voltage charge pump (CP) that generates a 12 V output from a 3.3 V input with a 20 MHz, two-phase non-overlapping clock generator. The circuits were designed in a 0.18-µm CMOS technology requiring a chip area of 0.048 mm 2 . Simulation results show that the regulating rectifier has a voltage conversion efficiency of 94.3% and 92.8% with an ac input magnitude of 3.5 V and 3.6 V, respectively. The peak power transfer efficiency of the regulated 3.3V output voltage is 70.7% with a maximum output power of 30.3 mW. The CP with an overall on-chip capacitance is 60 pF

Efficient Dual Output Regulating Rectifier and Adiabatic Charge Pump for Biomedical Applications Employing Wireless Power Transfer †

A power management unit (PMU) is an essential block for diversified multi-functional low-power Internet of Things (IoT) and biomedical electronics. This paper includes a theoretical analysis of a high current, single-stage ac-dc, reconfigurable, dual output, regulating rectifier consisting of pulse width modulation (PWM) and pulse frequency modulation (PFM). The regulating rectifier provides two independently regulated supply voltages of 1.8 V and 3.3 V from an input ac voltage. The PFM control feedback consists of feedback-driven regulation to adjust the driving frequency of the power transistors through adaptive buffers in the active rectifier. The PWM/PFM mode control provides a feedback loop to adjust the conduction duration accurately and minimize power losses. The design also includes an adiabatic charge pump (CP) to provide a higher voltage level. The adiabatic CP consists of latch-up and power-saving topologies to enhance its power efficiency. Simulation results show that the dual regulating rectifier has 94.3% voltage conversion efficiency with an ac input magnitude of 3.5 Vp. The power conversion efficiency of the regulated 3.3 V output voltage is 82.3%. The adiabatic CP has an overall voltage conversion efficiency (VCE) of 92.9% with a total on-chip capacitance of 60 pF. The circuit was designed using 180 nm CMOS technology

DRIVERS AFFECTING THE SUCCESSFUL IMPLEMENTATION OF ORGANIZATIONAL STRATEGIES: THE CASE OF THE OIL & GAS INDUSTRY IN QATAR

The oil and gas industry in Qatar stands out as one of the world's most prosperous sectors. This success comes from the excellent decision-making and practical implementations accumulated over the years. A literature review underscores the need for further exploration and consideration of the factors influencing organizational strategy implementation within this sector. This research discusses the factors affecting successful strategy implementation in Qatar's oil and gas industry and sheds light on the interplay among these elements. Factors are organizational culture, risk management, achievable goals, employee engagement, knowledge management, leadership support, and resource allocation. To assess the hypothesis of the relationship among factors, a quantitative research approach was employed involving a Likert scale questionnaire distributed to employees currently working in organizations within the oil and gas sector in Qatar where 292 participants were selected for the survey, ranging from top, middle, and first-line managers and employees. Data collected were analysed using the SPSS. Results revealed that organizational culture, risk management, achievable goals, and employee engagement exhibit significant and direct relationships with successful strategy implementation. In contrast, the remaining variables, leadership support, knowledge management, and resource allocation were identified as indirect influencers on successful strategy implementation, operating through mediators

Time Stamp – A Novel Time-to-Digital Demodulation Method for Bioimpedance Implant Applications

Bioimpedance analysis is a noninvasive and inexpensive technology used to investigate the electrical properties of biological tissues. The analysis requires demodulation to extract the real and imaginary parts of the impedance. Conventional systems use complex architectures such as I-Q demodulation. In this paper, a very simple alternative time-to-digital demodulation method or ‘time stamp’ is proposed. It employs only three comparators to identify or stamp in the time domain, the crossing points of the excitation signal, and the measured signal. In a CMOS proof of concept design, the accuracy of impedance magnitude and phase is 97.06% and 98.81% respectively over a bandwidth of 10 kHz to 500 kHz. The effect of fractional-N synthesis is analysed for the counter-based zero crossing phase detector obtaining a finer phase resolution (0.51˚ at 500 kHz) using a counter clock frequency ( fclk = 12.5 MHz). Because of its circuit simplicity and ease of transmitting the time stamps, the method is very suited to implantable devices requiring low area and power consumption

An integrated bidirectional multi-channel opto-electro arbitrary waveform stimulator for treating motor neurone disease

This paper presents a prototype integrated bidirectional stimulator ASIC capable of mixed opto-electro stimulation and electrophysiological signal recording. The development is part of the research into a fully implantable device for treating motor neurone disease using optogenetics and stem cell technology. The ASIC consists of 4 stimulator units, each featuring 16-channel optical and electrical stimulation using arbitrary current waveforms with an amplitude up to 16 mA and a frequency from 1.5 Hz to 50 kHz, and a recording front-end with a programmable bandwidth of 1 Hz to 4 kHz, and a programmable amplifier gain up to 74 dB. The ASIC was implemented in a 0.18μm CMOS technology. Simulated performance in stimulation and recording is presented

Emergency medicine in Oman: current status and future challenges

The Sultanate of Oman has a relatively young national health care system that could demonstrate its high performance at an international level. Emergency medicine as a specialty has developed rapidly in the country over the last decade. This has involved the parallel development of local emergency residency training, prehospital emergency care, and emergency nursing programs. This article reviews the progress of emergency care practice in this country from a general primary care system toward becoming an established specialty in hospital, prehospital, and private emergency care settings. It also describes aspects of undergraduate, postgraduate, and continuous emergency medicine education in the country. Further, a glimpse into academic emergency medicine and emergency nursing is provided. Since it describes a developing specialty, the article also attempts to address briefly major future challenges and their importance to the future development of the specialty in Oman

The Effectiveness of E-Mentoring Program to Develop Mothers Awareness of Protecting their Children from Sexual Harassment in Kindergarten

The research aims to measure the effectiveness of an E-mentoring program to educate mothers about the mechanisms of protecting children from sexual harassment and to identify the symptoms and methods that must be followed when kindergarten children are subjected to harassment, in order to answer the research questions, the semi- experimental approach was used because it is the most appropriate for the nature of the research to rely on changing something and studying the impact of this change on something else, and a random sample of mothers of children enrolled in kindergarten. The research tools consist of an electronic counselling program to develop mothers awareness on mechanisms to protect their children from sexual harassment in kindergarten by researchers, as well as a questionnaire to measure mothers awareness of mechanisms to protect their children from sexual harassment in kindergartens prepared by researchers. One of the most prominent findings of the research is that the indicative level of mothers awareness of the symptoms of sexual harassment of their children in kindergarten, their protection mechanisms, and the methods to be followed when sexually harassing children was less than 0.05, which indicates that there are differences in favor of the dimensional measurement, which proves the effectiveness of the program in improving mothers awareness of mechanisms to protect their children from sexual harassment in kindergarten

A New Zn(II) Metal Hybrid Material of 5-Nitrobenzimidazolium Organic Cation (C7H6N3O2)2[ZnCl4]: Elaboration, Structure, Hirshfeld Surface, Spectroscopic, Molecular Docking Analysis, Electric and Dielectric Properties

The slow solvent evaporation approach was used to create a single crystal of (CHNO)[ZnCl] at room temperature. Our compound has been investigated by single-crystal XRD which declares that the complex crystallizes in the monoclinic crystallographic system with the P2/c as a space group. The molecular arrangement of the compound can be described by slightly distorted tetrahedral ZnCl anionic entities and 5-nitrobenzimidazolium as cations, linked together by different non-covalent interaction types (H-bonds, Cl…Cl, π…π and C–H…π). Hirshfeld’s surface study allows us to identify that the dominant contacts in the crystal building are H…Cl/Cl…H contacts (37.3%). FT-IR method was used to identify the different groups in (CHNO)[ZnCl]. Furthermore, impedance spectroscopy analysis in 393 ≤ T ≤ 438 K shows that the temperature dependence of DC conductivity follows Arrhenius’ law. The frequency–temperature dependence of AC conductivity for the studied sample shows one region (E = 2.75 eV). In order to determine modes of interactions of compound with double stranded DNA, molecular docking simulations were performed at molecular level

Amino acid residues in five separate HLA genes can explain most of the known associations between the MHC and primary biliary cholangitis.

Primary Biliary Cholangitis (PBC) is a chronic autoimmune liver disease characterised by progressive destruction of intrahepatic bile ducts. The strongest genetic association is with HLA-DQA1*04:01, but at least three additional independent HLA haplotypes contribute to susceptibility. We used dense single nucleotide polymorphism (SNP) data in 2861 PBC cases and 8514 controls to impute classical HLA alleles and amino acid polymorphisms using state-of-the-art methodologies. We then demonstrated through stepwise regression that association in the HLA region can be largely explained by variation at five separate amino acid positions. Three-dimensional modelling of protein structures and calculation of electrostatic potentials for the implicated HLA alleles/amino acid substitutions demonstrated a correlation between the electrostatic potential of pocket P6 in HLA-DP molecules and the HLA-DPB1 alleles/amino acid substitutions conferring PBC susceptibility/protection, highlighting potential new avenues for future functional investigation