CytoSensor : an application for distributed bio-sensor networks

• Main Author: Boichon, Bertrand
• Other Authors: Kolodziej, Wojtek J.
• Language: en_US
• Published: 2012
• Subjects: Cytosensor; Sensor networks > Design; Biosensors > Design and construction
• Online Access: http://hdl.handle.net/1957/32478

The purpose of the thesis is to design and develop a network of automated, distributed, living cell-based sensors, called CytoSensors. Their main role is to detect a variety of biological and chemical toxins. The system is designed to help researchers to carry out multitude of experiments, in order to build a practical knowledge base in toxin detection. The network is developed in accordance with industry standards, to be used and deployed for prevention in inhospitable environments such as battlefields, toxic urban locations or polluted agricultural regions. The sensor is composed of a processing unit (processor and memory), an archiving unit (permanent data storage), a communication unit, input devices attached to a data acquisition unit, and control devices. The CytoSensor is specifically designed to acquire and analyze visual information about the living cells: hence cameras are used as input devices and frame grabbers are used as the digitizers. The control devices are additional external devices developed to help control and automate the process of data acquisition: they comprise light intensity control USB boards to provide the correct amount of light to view the cells, touch panels for user-instrument interaction, and bar code readers to identify vials and experiments. The software, on the other hand, is a complex mosaic of different elements, each of which has a specific task to accomplish. These building blocks include the real-time acquisition, archiving, networking, processing, modelling, sensor output presentation and user interfaces. Our goal is to develop, integrate and optimize all these components to produce a viable and working device. The prototypes evolved from an offline, portable sensor equipped with a single high-resolution CCD camera and high-quality optics, to distributed online sensors with multiplexed CCD cameras and affordable optics. The acquisition board digitizes in real time the images from one to twelve multiplexed high resolution cameras. Several operational requirements must be met. First, a fault-tolerant and stable control over the input devices and control devices must be provided. Secondly, acquisition timing errors should be minimized as a trade-off between performance and the use of a low-cost, general-purpose, industry-standard operating system such as Microsoft Windows NT. Finally, in order to reduce development time and increase code reusability, a common abstraction layer is designed to provide for flexible use with various types of digitizers and cameras. As part of a distributed detection network, each sensor is able to exchange data with other "trusted" sensors and users, and to allow remote control of certain tasks. The sensor may be seen as a node capable of transmitting and receiving acquired or processed data to a distant device (another sensor, a workstation or a PDA) for visualization, inspection and decision-making by a front-end user. Each node on the network provides a set of complementary services including data acquisition, data processing, communication and system. The mandatory system service monitors the local system performance and manages data archiving. The communication service connects the various services on the network by enabling message-passing, file transfer and caching. The sensor network integrates a lightweight, interoperable and flexible RPC (Remote Procedure Call) protocol to achieve real-time control and monitoring of these distributed resources. A reliable embedded database system is used to store metadata bound to acquired and processed images. This database is also used to maintain information on neighbor nodes, and to check access credentials of available local services. Finally, by adding store-and-forward messaging capabilities, the application can be extended to work in wireless and mobile networks. === Graduation date: 2003