A microfabricated electrode with hollow microneedles for ECG measurement
ABSTRACT This paper proposes a novel micromachined physiological recording electrode with hollow microneedles for electrocardiography (ECG) measurement. Compared to the standard commercial wet electrode, a unique characteristic of this device is that a hollow microneedle array, which is made of silicon, can pierce through the outer skin surface, lowering the electrode-skin-electrode impedance (ESEI) and eliminating the need for skin preparation. Furthermore, instead of the conventional electrolytic gel, NaCl solution is used to fill the hollow microneedles and the reservoir etched in the backside of the silicon die; it is more comfortable, easy to acquire and imposes no side-effects on human. Test results of this electrode showed that this device could acquire typical structures of ECG signal with high signal to noise ratio, which provides a potential for routine and repetitive measurement with convenience, and comfort for home health care management of aged population.
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ABSTRACT: This work describes a bio-potential acquisition system for portable ubiquitous healthcare applications using flexible polydimethylsiloxane dry electrodes (FPDEs) and a low-power recording circuit. This novel FPDE used Au as the skin contact layer, which was made using a CO laser and replica method technology. The FPDE was revised from a commercial bio-potential electrode with a conductive snap using dry electrodes rather than wet electrodes that proposed reliable and robust attachment for the purpose of measurement, and attaching velcro made it wearable on the forearm for bio-potential applications. Furthermore, this study proposes a recording device to store bio-potential signal data and provides portability and low-power consumption for the proposed acquisition system. To acquire differential bio-potentials, such as electrocardiogram (ECG) signals, the proposed recording device includes a low-power front-end acquisition chip fabricated using a complementary metal-oxide-semiconductor (CMOS) process, a commercial microcontroller (MSP430F149), and a secure digital (SD) card for portable healthcare applications. The proposed system can obtain ECG signals efficiently and are comfortable to the skin. The power consumption of the system is about 85 mW for continuous working over a 3 day period with two AA batteries. It can also be used as a compact Holter ECG system.Sensors 01/2013; 13(3):3077-91. · 1.95 Impact Factor
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ABSTRACT: Lab-on-a-chip technology is an emerging field evolving from the recent advances of micro- and nanotechnologies. The technology allows the integration of various components into a single microdevice. Microfluidics, the science and engineering of fluid flow in microscale, is the enabling underlying concept for lab-on-a-chip technology. The present paper reviews the design, fabrication and characterization of drug delivery systems based on this amazing technology. The systems are categorized and discussed according to the scales at which the drug is administered. Starting with the fundamentals on scaling laws of mass transfer and basic fabrication techniques, the paper reviews and discusses drug delivery devices for cellular, tissue and organism levels. At the cellular level, a concentration gradient generator integrated with a cell culture platform is the main drug delivery scheme of interest. At the tissue level, the synthesis of smart particles as drug carriers using lab-on-a-chip technology is the main focus of recent developments. At the organism level, microneedles and implantable devices with fluid-handling components are the main drug delivery systems. For drug delivery to a small organism that can fit into a microchip, devices similar to those of cellular level can be used.Advanced drug delivery reviews 05/2013; · 11.96 Impact Factor
- Sensors and Actuators A Physical 01/2012; 180:177-186. · 1.84 Impact Factor