We present a neural stimulator chip with an output stage (electrode driving circuit) that is fail-safe under single-fault conditions without the need for off-chip blocking-capacitors. To miniaturize the stimulator output stage two novel techniques are introduced. The first technique is a new current generator circuit reducing to a single step the translation of the digital input bits into the stimulus current, thus minimizing silicon area and power consumption compared to previous works. The current generator uses voltage-controlled resistors implemented by MOS transistors in the deep triode region. The second technique is a new stimulator output stage circuit with blocking-capacitor safety protection using a high-frequency current-switching (HFCS) technique. Unlike conventional stimulator output stage circuits for implantable functional electrical stimulation (FES) systems which require blocking-capacitors in the microfarad range, our proposed approach allows capacitance reduction to the picofarad range, thus the blocking-capacitors can be integrated on-chip. The prototype four-channel neural stimulator chip was fabricated in XFAB's 1-mum silicon-on-insulator CMOS technology and can operate from a power supply between 5-18 V. The stimulus current is generated by active charging and passive discharging. We obtained recordings of action potentials and a strength-duration curve from the sciatic nerve of a frog with the stimulator chip which demonstrate the HFCS technique. The average power consumption for a typical 1-mA 20-Hz single-channel stimulation using a book electrode, is 200 muW from a 6 V power supply. The silicon area occupation is 0.38 mm(2) per channel.

Benign acute childhood myositis (BACM) is a rare transient condition usually occurring at the early convalescent phase of a viral upper respiratory tract illness, normally influenza A, and, more frequently, influenza B infection. It is characterized by acute-onset difficulty in walking as a result of severe bilateral calf pain and by elevated muscle enzymes including creatinine kinase. It is self-limiting because there is rapid full recovery usually within 1 week. We describe the first case of BACM in association with the new pandemic influenza A (H1N1) virus infection in an 11-year-old boy from Cyprus. The child had the typical clinical and laboratory characteristics of this clinical syndrome. Prompt diagnosis of this clinical entity is essential to prevent unnecessary investigations and therapeutic interventions and to reassure the patient and parents of the excellent prognosis.

Wireless power transfer systems, particularly those based on inductive coupling, provide an increasingly attractive method to safely deliver power to biomedical implants. Although there exists a large body of literature describing the design of inductive links, it generally focuses on single aspects of the design process. There is a variety of approaches, some analytic, some numerical, each with benefits and drawbacks. As a result, undertaking a link design can be a difficult task, particularly for a newcomer to the subject. This tutorial paper reviews and collects the methods and equations that are required to design an inductive link for biomedical wireless power transfer, with a focus on practicality. It introduces and explains the published methods and principles relevant to all aspects of inductive link design, such that no specific prior knowledge of inductive link design is required. These methods are also combined into a software package (the Coupled Coil Configurator), to further simplify the design process. This software is demonstrated with a design example, to serve as a practical illustration.

and Demosthenous, Andreas (2018) A high frame rate wearable EIT system using active electrode ASICs for lung respiration and heart rate monitoring. IEEE transactions on circuits and systems. I, Fundamental theory and applications, 65 (11). pp. 3810-3820.

Abstract-This paper discusses certain important issues involved in the design of a nerve signal preamplifier for implantable neuroprostheses. Since the electroneurogram signal measured from cuff electrodes is typically on the order of 1 V, a very low-noise interface is essential. We present the argument for the use of BiCMOS technology in this application and then describe the design and evaluation of a complete preamplifier fabricated in a 0.8-m double-metal double-poly process. The preamplifier has a nominal voltage gain of 100, a bandwidth of 15 kHz, and a measured equivalent input-referred noise voltage spectral density of 3.3 nV Hz at 1 kHz. The total input-referred rms noise voltage in a bandwidth 1 Hz-10 kHz is 290 nV, the power consumption is 1.3 mW from 2.5-V power supplies, and the active area is 0.3 mm 2 .

A highly integrated, wearable electrical impedance tomography (EIT) belt for neonatal thorax vital multiple sign monitoring is presented. The belt has sixteen active electrodes. Each has an application specific integrated circuit (ASIC) connected to an electrode. The ASIC contains a fully differential current driver, a high-performance instrumentation amplifier (IA), a digital controller and multiplexors. The belt features a new active electrode architecture that allows programmable flexible electrode current drive and voltage sense patterns under simple digital control. It provides intimate connections to the electrodes for the current drive and to the IA for direct differential voltage measurement providing superior common-mode rejection ratio. The ASIC was designed in a CMOS 0.35-µm high-voltage technology. The high specification EIT belt has an image frame rate of 122 fps, a wide operating bandwidth of 1 MHz and multifrequency operation. It measures impedance with 98% accuracy and has less than 0.5 Ω and 1 o variation across all possible channels. The image results confirmed the advantage of the new active electrode architecture and the benefit of wideband, multifrequency EIT operation. The system successfully captured high quality lung respiration EIT images, breathing cycle and heart rate. It can also provide boundary shape information using an array of MEMS sensors interfaced to the ASICs.

Following the first imported case in a tourist in Cyprus on 2 June 2009, the influenza A(H1N1)v virus has spread on the island affecting mainly young adults and children. We describe here the first 45 cases in children. Fever, cough, rhinorrhoea and sore throat were the most common symptoms of infection. Half of the children had fever for one day or only for a few hours. Five children were hospitalised, and overall their symptoms were mild. Adherence to oseltamivir treatment was very high, with low frequency of gastrointestinal side effects such as nausea and vomiting. Camping places and summer schools played a significant role in spreading the infection among children of school age.

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