Design and Development of Microfluidic Lab-On-Chip Bioimpedance Analyzer

Impedance analysis for biological samples has proved to be one of the most powerful non-invasive techniques developed so far, for understanding the electrophysiological properties of the tissues. Presently all the impedance analyzer systems that are available in the market are large and expensive. There is a need of small, portable, low-cost system which can be used commercially. In this context, an attempt has been made to design and develop a Lab-On-Chip Bioimpedance Analyzer System. For this purpose, the portable microfluidic platform for impedance analysis was prepared on cupper print laminated board by chemical etching. The device was successfully operated and had a sensitivity output value in terms of frequency ranging from 50 Hz to 10 KHz. The impedance analysis was done for various samples such as PBS, NaCl solution, cell culture medium(DMEM) and bacterial cell culture. However, all the samples were shown a capacitive response. Optimization of the platform was done on the basis of the electrode spacing, diameter and flow rate so as to bring accuracy in impedance analysis measurement. The device was designed in such a way so that the analysis can be made even at a reduced sample volume, moreover portability of the device makes it stand out among commercially available systems in the marke

Communication system for a tooth-mounted RF sensor used for continuous monitoring of nutrient intake

In this Thesis, the communication system of a wearable device that monitors the user’s diet is studied. Based in a novel RF metamaterial-based mouth sensor, different decisions have to be made concerning the system’s technologies, such as the power source options for the device, the wireless technology used for communications and the method to obtain data from the sensor. These issues, along with other safety rules and regulations, are reviewed, as the first stage of development of the Food-Intake Monitoring projectOutgoin

Toxic level hypergolic vapor detection sensor development

Development of an electrochemical sensor technology capable of PPB level hypergolic vapor sensing is reported. A portable instrument capable of meeting the design goals is described

Southwest Research Institute assistance to NASA in biomedical areas of the technology utilization program

The activities are reported of the NASA Biomedical Applications Team at Southwest Research Institute between 25 August, 1972 and 15 November, 1973. The program background and methodology are discussed along with the technology applications, and biomedical community impacts

Distributed chemical sensor networks for environmental sensing

Society is increasingly accustomed to instant access to real-time information, due to the ubiquitous use of the internet and web-based access tools. Intelligent search engines enable huge data repositories to be searched, and highly relevant information returned in real time. These repositories increasingly include environmental information related to the environment, such as distributed air and water quality. However, while this information at present is typically historical, for example, through agency reports, there is increasing demand for real-time environmental data. In this paper, the issues involved in obtaining data from autonomous chemical sensors are discussed, and examples of current deployments presented. Strategies for achieving large-scale deployments are discussed

A Portable Impedance Biosensing System based on a Laptop with LabVIEW for Rapid Detection of Avian Influenza Virus

Avian Influenza Virus (AIV) H5N1 is a highly pathogenic virus found not only in birds but also in human. Rapid and sensitive detection method is needed to help prevent the spread of AIV H5N1. In this study, a portable impedance biosensing system based on a laptop with LabVIEW software was developed for detection of AIV H5N1. First, a virtual instrument was programmed with LabVIEW software to form a platform for impedance measurement, data processing and control. The audio card of a laptop was used as a function generator while a data acquisition card was used with the signal channels for data communication. A gold interdigitated microelectrode was coated with specific aptamers to bind H5N1 virus and used in a microflow cell to obtain changes in impedance with desired accuracy and sensitivity. A sampling delivery unit consisted of a pump and three valves and was controlled by the virtual instrument to provide automated operation with adjustable flow rate. Results of the impedance measured with this biosensing system were compared with a commercial IM 6 impedance analyzer, and the error was less than 5%. The experiments on AIV H5N1 virus showed a linear relationship between the impedance change and the concentration of AIV H5N1 in a detection range from 2 to 16HAU.The specificity for detection of AIV H5N1 was confirmed with three non-target AIV subtypes, H1N1, H5N2, and H5N3.The biosensing system is portable and automated and has great potential to serve as a diagnostic and epidemiological tool for in-field rapid detection of AIV and other pathogens

Assessment of Human Arm Bioelectrical Impedance using Microcontroller Based System

Background and aims: In a wide field of research, the devices available based on long-established methods for measurement of bioelectrical impedance are large in size, expensive and low in accuracy. In this research, a system is developed for the measurement of the segmental bioelectrical impedance of the human body with high accuracy and small of a size. Methods: Developed method uses multi-frequency to measure segmental bioelectrical impedance that follows four electrodes segmental measurement technique and is equipped with an impedance analyzer with a touch screen. Multi-frequency signals flow to the human body to measure bioelectrical impedance and also compare data measured by developing a device to standard device. Results: Data have been collected through a developed device and is being analyzed. The outcomes show that the relative error of measured amplitude at multi-frequency is less than 1.50% while the absolute error of phase is up to 10. Comparison between two devices shows that the accuracy parameter of the developed device is more than 98% with the standard device. A compatible correlation (~ 0.9993) can be seen between both devices that they measure a nearly equal impedance of left and right arm at the same frequency. Conclusions: Use of the developed device for the measurement of segmental bioelectrical impedance using multi-frequency, adequately enhances all trait of measurement as state-of-the-art facilities, small size and liberated to use due to simplicity

Designing of a variable frequency standalone impedance analyzer for in vitro biological applications

Maximum biological samples have some electrical property, which gave us a new dimension in the field of biomedical engineering. Now-a-days measurement of impedance by applying an electrical voltage/current, has a broader application for analyzing different biological samples. Most of the devices used for the measurement of bio-impedance are bulky and much costlier. This approach will help us to design a portable, standalone, multi frequency (10Hz – 10kHz) bio-impedance monitoring device with acceptable accuracy and resolution for in-vitro studies of biological cells and tissue

High frequency electronic ballast provides line frequency lamp current

Most electronic ballasts for fluorescent lamps provide a sinusoidal lamp current at the switching frequency. The high-frequency current flowing through the lamp can generate significant radiated noise, which is unacceptable in noise-sensitive applications, such as fluorescent lights in airplanes. Using shielded enclosures for the lamps may solve the problem, but it is expensive. A discontinuous conduction mode (DCM) electronic ballast topology is presented which drives the lamp with line frequency current, just like a magnetic ballast. However, compared to a magnetic ballast, its weight is substantially reduced due to operation at 40 kHz switching frequency. The topology also ensures unity power factor at the input and stable lamp operation at the output