9995821
Testing of droplet-based microelectrofluidic systems
Composite microsystems that integrate mechanical and fluidic components are fast emerging as the next generation of system-on-chip designs. As these systems become widespread in safety-critical biomedical applications, dependability emerges as a critical performance parameter. In this paper, we present a costeffective concurrent test methodology for droplet-based microelectrofluidic systems. We present a classification of catastrophic and parametric faults in such systems and show how faults can be detected by electrostatically controlling and tracking droplet motion. We then present tolerance analysis based on Monte-Carlo simulations to characterize the impact of parameter variations on system performance. To the best of our knowledge, this constitutes the first attempt to define a fault model and to develop a test methodology for droplet-based microelectrofluidic systems.
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.
6635658
High-level synthesis of digital microfluidic biochips
Microfluidic biochips offer a promising platform for massively parallel DNA analysis, automated drug discovery, and real-time biomolecular recognition. Current techniques for full-custom design of droplet-based “digital” biochips do not scale well for concurrent assays and for next-generation system-on-chip (SOC) designs that are expected to include microfluidic components. We propose a system design methodology that attempts to apply classical high-level synthesis techniques to the design of digital microfluidic biochips. We focus here on the problem of scheduling bioassay functions under resource constraints. We first develop an optimal scheduling strategy based on integer linear programming. However, because the scheduling problem is NP-complete, we also develop two heuristic techniques that scale well for large problem instances. A clinical diagnostic procedure, namely multiplexed in-vitro diagnostics on human physiological fluids, is first used to illustrate and evaluate the proposed method. Next, the synthesis approach is applied to a protein assay, which serves as a more complex bioassay application. The proposed synthesis approach is expected to reduce human effort and design cycle time, and it will facilitate the integration of microfluidic components with microelectronic components in next-generation SOCs.
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.
8664918
Automated design of pin-constrained digital microfluidic arrays for lab-on-a-chip applications
Microfluidics-based biochips, also referred to as lab-on-a-chip (LoC), are devices that integrate fluid-handling functions such as sample preparation, analysis, separation, and detection. This emerging technology combines electronics with biology to open new application areas such as point-of-care diagnosis, on-chip DNA analysis, and automated drug discovery. We propose a design automation method for pin-constrained LoCs that manipulate nanoliter volumes of discrete droplets on a microfluidic array. In contrast to the direct-addressing scheme that has been studied thus far in the literature, we assign a small number of independent control pins to a large number of electrodes in the LoC, thereby reducing design complexity and product cost. We apply the proposed method to a microfluidic array for a set of multiplexed bioassays
206846196
Fingerprint Matching With Rotation-Descriptor Texture Features
A novel texture correlation matching method for fingerprint verification using Fourier-Mellin descriptor and phase-only correlation function is proposed in this paper. Fourier-Mellin descriptor correlation is used to align the template and query fingerprint images and a matching score is obtained. Matching takes about 1 second in Celeron 2.0 GHz processor, and the experimental results show that EER is 3.8%; fusion with minutia matching gets a better result
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.
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.
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.
15063481
Eye Location under Various Illumination Conditions
Eye location is an important step in face recognition. Locate eyes under various illumination conditions is also an important step especially for most of illumination normalization algorithms. In this paper, an algorithm uses a group of eigenfeature templates and Gabor feature templates to locate eye under various illumination conditions is proposed. Experiment results show that the performance of this algorithm is good and robust under widely changed illumination conditions