2409697
Droplet Routing in the Synthesis of Digital Microfluidic Biochips
Recent advances in microfluidics are expected to lead to sensor systems for high-throughput biochemical analysis. CAD tools are needed to handle increased design complexity for such systems. Analogous to classical VLSI synthesis, a top-down design automation approach can shorten the design cycle and reduce human effort. We focus here on the droplet routing problem, which is a key issue in biochip physical design automation. We develop the first systematic droplet routing method that can be integrated with biochip synthesis. The proposed approach minimizes the number of cells used for droplet routing, while satisfying constraints imposed by throughput considerations and fluidic properties. A real-life biochemical application is used to evaluate the proposed method
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
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.
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.
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.
1293291
Microfluidics-Based Biochips: Technology Issues, Implementation Platforms, and Design-Automation Challenges
Microfluidics-based biochips are soon expected to revolutionize clinical diagnosis, deoxyribonucleic acid (DNA) sequencing, and other laboratory procedures involving molecular biology. In contrast to continuous-flow systems that rely on permanently etched microchannels, micropumps, and microvalves, digital microfluidics offers a scalable system architecture and dynamic reconfigurability; groups of unit cells in a microfluidics array can be reconfigured to change their functionality during the concurrent execution of a set of bioassays. As more bioassays are executed concurrently on a biochip, system integration and design complexity are expected to increase dramatically. This paper presents an overview of an integrated system-level design methodology that attempts to address key issues in the synthesis, testing and reconfiguration of digital microfluidics-based biochips. Different actuation mechanisms for microfluidics-based biochips, and associated design-automation trends and challenges are also discussed. The proposed top-down design-automation approach is expected to relieve biochip users from the burden of manual optimization of bioassays, time-consuming hardware design, and costly testing and maintenance procedures, and it will facilitate the integration of fluidic components with a microelectronic component in next-generation systems-on-chips (SOCs).
23911088
Robust Ridge Following in Fingerprints
In this paper, we presented an improved approach of minutiae detection by following the ridges Our algorithm is based on the two characteristics of the ridge points on the same ridge: connectivity and randomicity Because our algorithm takes full advantage of the characteristics of the ridge points, it is robust to noise Using our algorithm, good quality ridge images can be obtained which can be used to assist minutiae-based fingerprint matching, or directly used for fingerprint matching Experimental results are included.
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.
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.
1341088
An optical characterization technique for hygroscopic expansion of polymers and plastic packages
In this paper, we have described a new simultaneous 3-D optical system for characterizing electronic packages. This optical system is able to capture high resolution, online whole field data set. We are able to use this optical system to determine the coefficient of hygroscopic expansion (CHE) in moulding compound by correlating the weight gain and hygro-strain information obtained. In this study, we have used this optical system to evaluate the hygroscopic expansion of a fully cured moulding compound, XJA-9. We have also studied the effect of moisture diffusion on the deformation of plastic IC package. It was found that moisture diffusion could reverse the warpage of the plastic package. The study showed that moisture may cause severe changes to the internal stress field of plastic packages that would usually occur unnoticed or underestimated.
13557739
A Robust Fingerprint Minutiae Matching Algorithm Based on the Support Model
A novel method to match two minutiae point-sets based on the support model we proposed is presented in this paper. In this method, coarse matching is first performed from a number of seeds, and the results are then fused to obtain a constrained corresponding relationship of minutiae in two point-sets. By using the support degree of the elements in the constrained relations, the one-to-one correspondence is finally determined by comparison of similarity of local structures. Experiments show that this algorithm is robust and can deal with the translation, rotation, distortion and outlier problems well.