18708076
Defect-Aware Synthesis of Droplet-Based Microfluidic Biochips
Recent advances in microfluidics technology have led to the emergence of miniaturized biochip devices for biochemical analysis. A promising category of microfluidic biochips relies on the principle of electrowetting-on-dielectric, whereby discrete droplets ofnanoliter volumes can be manipulated using an array of electrodes. As chemists adapt more bioassays for concurrent execution on such "digital" droplet-based microfluidic platforms, system integration, design complexity, and the need for defect tolerance are expected to increase rapidly. Automated design tools for defect-tolerant and multifunctional biochips are important for the emerging marketplace, especially for low-cost, portable, and disposable devices for clinical diagnostics. We propose a unified synthesis method that combines defect-tolerant architectural synthesis with defect-aware physical design. The proposed approach allows architectural-level design choices and defect- tolerant physical design decisions to be made simultaneously. We use a large-scale protein assay and the polymerase chain reaction procedure as case studies to evaluate the proposed synthesis method. We also carry out simulations based on defect injection to evaluate the robustness of the synthesized biochip design.
16866295
Defect Tolerance Based on Graceful Degradation and Dynamic Reconfiguration for Digital Microfluidics-Based Biochips
Defect tolerance is an important design consideration for microfluidics-based biochips that are used for safety-critical applications. The authors propose a defect-tolerance methodology based on graceful degradation and dynamic reconfiguration. A tile-based biochip architecture is first introduced, which is scalable for large-scale bioassays. A clustered defect model is used to evaluate the graceful-degradation method for tile-based biochips. The proposed schemes ensure that the bioassays mapped to a droplet-based microfluidic array during design can be executed on a defective biochip through operation rescheduling and/or resource rebinding. Real-life biochemical procedures, namely polymerase chain reaction and multiplexed in vitro diagnostics on human physiological fluids, are used to evaluate the proposed defect-tolerance schemes
53235102
Module placement for fault-tolerant microfluidics-based biochips
Microfluidics-based biochips are soon expected to revolutionize clinical diagnosis, DNA sequencing, and other laboratory procedures involving molecular biology. Most microfluidic biochips today are based on the principle of continuous fluid flow and they rely on permanently etched microchannels, micropumps, and microvalves. We focus here on the automated design of “digital” droplet-based microfluidic biochips. In contrast to conventional continuous-flow systems, digital microfluidics offers dynamic reconfigurability; groups of cells in a microfluidics array can be reconfigured to change their functionality during the concurrent execution of a set of bioassays. We present a simulated annealing-based technique for module placement in such biochips. The placement procedure not only addresses chip area, but also considers fault tolerance, which allows a microfluidic module to be relocated elsewhere in the system when a single cell is detected to be faulty. Simulation results are presented for case studies involving the polymerase chain reaction and multiplexed in vitro clinical diagnostics.
712994
Test Planning and Test Resource Optimization for Droplet-Based Microfluidic Systems
Recent years have seen the emergence of droplet-based microfluidic systems for safety-critical biomedical applications. In order to ensure reliability, microsystems incorporating microfluidic components must be tested adequately. In this paper, we investigate test planning and test resource optimization for droplet-based microfluidic arrays. We first formulate the test planning problem and prove that it is NP-hard. We then describe an optimization method based on integer linear programming (ILP) that yields optimal solutions. Due to the NP-hard nature of the problem, we develop heuristic approaches for optimization. Experimental results indicate that for large array sizes, the heuristic methods yield solutions that are close to provable lower bounds. These heuristics ensure scalability and low computation cost.
8296105
Concurrent testing of digital microfluidics-based biochips
We present a concurrent testing methodology for detecting catastrophic faults in digital microfluidics-based biochips and investigate the related problems of test planning and resource optimization. We first show that an integer linear programming model can be used to minimize testing time for a given hardware overhead, for example, droplet dispensing sources and capacitive sensing circuitry. Due to the NP-complete nature of the problem, we also develop efficient heuristic procedures to solve this optimization problem. We apply the proposed concurrent testing methodology to a droplet-based microfluidic array that was fabricated and used to perform multiplexed glucose and lactate assays. Experimental results show that the proposed test approach interleaves test application with the biomedical assays and prevents resource conflicts. The proposed method is therefore directed at ensuring high reliability and availability of bio-MEMS and lab-on-a-chip systems, as they are increasingly deployed for safety-critical applications.
13266891
Unified high-level synthesis and module placement for defect-tolerant microfluidic biochips
Microfluidic biochips promise to revolutionize biosensing and clinical diagnostics. As more bioassays are executed concurrently on a biochip, system integration and design complexity are expected to increase dramatically. This problem is also identified by the 2003 ITRS document as a major system-level design challenge beyond 2009. We focus here on the automated design of droplet-based microfluidic biochips. We present a synthesis methodology that unifies operation scheduling, resource binding, and module placement for such "digital" biochips. The proposed technique, which is based on parallel recombinative simulated annealing, can also be used after fabrication to bypass defective cells in the microfluidic array. A real-life protein assay is used to evaluate the synthesis methodology.
35785382
Multi-UCAV Cooperative Path Planning Using Improved Coevolutionary Multi-Ant-Colony Algorithm
Teams of unmanned combat aerial vehicles (UCAVs) are well suited to perform cooperative mission in hostile environment, and cooperative path planning holds great attention for improving the efficiency of multi-UCAV combating. In this paper, a mathematical formulation for cooperative path planning problem is presented based on the analysis of typical constraints in the scenario. Different from previous studies, the formulation introduces cooperation coefficient to estimate how the UCAV flight paths fulfill the cooperative constraints. Then a coevolutionary multi-ant-colony algorithm is designed and implemented to solve the above-mentioned problem, based on multi-ant-colony algorithm and coevolutionary strategy. The state transition rule and pheromone updating strategy is modified to increase the algorithm performance. Finally, the proposed method is validated to be effective and feasible to solve the cooperative constraints efficiently, and is effective for the multi-UCAV cooperative path planning problem.
41723661
An Adaptive Fingerprint Post-processing Algorithm Based on Mathematical Morphology
In this paper, an adaptive post-processing method using mathematical morphology combined with analyzing the properties of each candidate minutia based on the gray-level image, binary image, local ridge spacing and local orientation is presented to decide whether the minutia is false or true and to eliminate the false one The experiment results demonstrate the effectiveness to reduce the number of false minutiae encountered and improve the thinning fingerprint images at the same time.
973577
Cracking Cancelable Fingerprint Template of Ratha
Cancelable biometrics may be a good approach to address the security and privacy concerns on biometric authentication. It uses some parameterized transforms to convert an original biometric template into a new version for authentication. The security of cancelable biometrics lies on noninvertibility of the transformed template, that is, the transforms should be noninvertible so that the original template can not be recovered. One way to achieve the noninvertibilty is through the use of many-to-one transforms. The idea of Ratha¿s scheme of generating fingerprint templates just depends on this. However, it is revealed in this paper that the form of the transforms and the parameters chosen in his implementation weaken the many-to-one property. This results in the possible recovery of original minutiae from one transformed template.
15905747
Fingerprint Registration Using Minutia Clusters and Centroid Structure 1
In this paper a novel distortion-tolerant fingerprint registration method based on clustering is proposed. In this method, minutiae features of the query fingerprint are divided into various clusters. Several local structure transformations are estimated by local structure sets. Then the global structures (centroid structures) are constructed according to the local structure transformation. The global transformation is determined by the score of local structure transformation together with the similarity level of the global structure. Experimental results show that this algorithm is robust for aligning fingerprints with a small number of minutia and heavy distortions. Such situations are often encountered in forensic applications
11609039
A Hierarchical Fingerprint Matching Method Based on Rotation Invariant Features
A hierarchical matching algorithm based on rotation invariant features to align two fingerprints is proposed in this paper The translation and rotational offsets are extracted using the maximum overlapped fingerprint images The proposed method can reduce the searching space in alignment, and what is more attractive is that it obviates the need for extracting minutiae points or the core point to align the fingerprint images Experimental results show that the proposed method is more robust than using the reference point or using the minutiae to align the fingerprint images.