Publications by authors named "Sungkyu Seo"

18 Publications

  • Page 1 of 1

Detection of Particulate Matters with a Field-Portable Microscope Using Side-Illuminated Total Internal Reflection.

Sensors (Basel) 2021 Apr 13;21(8). Epub 2021 Apr 13.

Department of Electronics and Information Engineering, Korea University, Sejong 30019, Korea.

Field-portable observation and analysis of particulate matter (PM) is required to enhance healthy lives. Various types of the PM measurement methods are in use; however, each of these methods has significant limitations in that real time measurement is impossible, the detection system is bulky, or the measurement accuracy is insufficient. In this work, we introduce an optical method to perform a fast and accurate PM analysis with a higher-contrast microscopic image enabled by a side-illuminated total internal reflection (TIR) technique to be implemented in a compact device. The superiority of the proposed method was quantitatively demonstrated by comparing the signal-to-noise ratio of the proposed side-illuminated TIR method with a traditional halogen lamp-based transmission microscope. With the proposed device, signal-to-noise ratios (SNRs) for microbeads (5~20 µm) and ultrafine dust particles (>5 µm) increased 4.5~17 and 4~10 dB, respectively, compared to the conventional transmission microscope. As a proof of concept, the proposed method was also applied to a low-cost commercial smartphone toy microscope enabling field-portable detection of PMs. We believe that the proposed side-illuminated TIR PM detection device holds significant advantages over other commonly used systems due to its sufficient detection capability along with simple and compact configuration as well as low cost.
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http://dx.doi.org/10.3390/s21082745DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8070112PMC
April 2021

A Field-Portable Cell Analyzer without a Microscope and Reagents.

Sensors (Basel) 2017 Dec 29;18(1). Epub 2017 Dec 29.

Department of Electronics and Information Engineering, Korea University, Sejong 30019, Korea.

This paper demonstrates a commercial-level field-portable lens-free cell analyzer called the NaviCell (No-stain and Automated Versatile Innovative cell analyzer) capable of automatically analyzing cell count and viability without employing an optical microscope and reagents. Based on the lens-free shadow imaging technique, the NaviCell (162 × 135 × 138 mm³ and 1.02 kg) has the advantage of providing analysis results with improved standard deviation between measurement results, owing to its large field of view. Importantly, the cell counting and viability testing can be analyzed without the use of any reagent, thereby simplifying the measurement procedure and reducing potential errors during sample preparation. In this study, the performance of the NaviCell for cell counting and viability testing was demonstrated using 13 and six cell lines, respectively. Based on the results of the hemocytometer ( standard), the error rate (ER) and coefficient of variation (CV) of the NaviCell are approximately 3.27 and 2.16 times better than the commercial cell counter, respectively. The cell viability testing of the NaviCell also showed an ER and CV performance improvement of 5.09 and 1.8 times, respectively, demonstrating sufficient potential in the field of cell analysis.
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http://dx.doi.org/10.3390/s18010085DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5795886PMC
December 2017

Flexible heartbeat sensor for wearable device.

Biosens Bioelectron 2017 Aug 8;94:250-255. Epub 2017 Mar 8.

Department of Electronics and Information Engineering, Korea University, Sejong, Republic of Korea. Electronic address:

We demonstrate a flexible strain-gauge sensor and its use in a wearable application for heart rate detection. This polymer-based strain-gauge sensor was fabricated using a double-sided fabrication method with polymer and metal, i.e., polyimide and nickel-chrome. The fabrication process for this strain-gauge sensor is compatible with the conventional flexible printed circuit board (FPCB) processes facilitating its commercialization. The fabricated sensor showed a linear relation for an applied normal force of more than 930 kPa, with a minimum detectable force of 6.25Pa. This sensor can also linearly detect a bending radius from 5mm to 100mm. It is a thin, flexible, compact, and inexpensive (for mass production) heart rate detection sensor that is highly sensitive compared to the established optical photoplethysmography (PPG) sensors. It can detect not only the timing of heart pulsation, but also the amplitude or shape of the pulse signal. The proposed strain-gauge sensor can be applicable to various applications for smart devices requiring heartbeat detection.
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http://dx.doi.org/10.1016/j.bios.2017.03.016DOI Listing
August 2017

A Human Serum-Based Enzyme-Free Continuous Glucose Monitoring Technique Using a Needle-Type Bio-Layer Interference Sensor.

Sensors (Basel) 2016 Sep 24;16(10). Epub 2016 Sep 24.

Department of Biotechnology and Bioinformatics, Korea University, Sejong 30019, Korea.

The incidence of diabetes is continually increasing, and by 2030, it is expected to have increased by 69% and 20% in underdeveloped and developed countries, respectively. Therefore, glucose sensors are likely to remain in high demand in medical device markets. For the current study, we developed a needle-type bio-layer interference (BLI) sensor that can continuously monitor glucose levels. Using dialysis procedures, we were able to obtain hypoglycemic samples from commercial human serum. These dialysis-derived samples, alongside samples of normal human serum were used to evaluate the utility of the sensor for the detection of the clinical interest range of glucose concentrations (70-200 mg/dL), revealing high system performance for a wide glycemic state range (45-500 mg/dL). Reversibility and reproducibility were also tested over a range of time spans. Combined with existing BLI system technology, this sensor holds great promise for use as a wearable online continuous glucose monitoring system for patients in a hospital setting.
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http://dx.doi.org/10.3390/s16101581DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5087370PMC
September 2016

A review of recent progress in lens-free imaging and sensing.

Biosens Bioelectron 2017 Feb 1;88:130-143. Epub 2016 Aug 1.

Department of Electronics and Information Engineering, Korea University, Sejong, Republic of Korea. Electronic address:

Recently, lens-free imaging has evolved as an alternative imaging technology. The key advantages of this technology, including simplicity, compactness, low cost, and flexibility of integration with other components, have facilitated the realization of many innovative applications, especially, in the fields of the on-chip lens-free imaging and sensing. In this review, we discuss the development of lens-free imaging, from theory to applications. This article includes the working principle of lens-free digital inline holography (DIH) with coherent and semi coherent light, on-chip lens-free fluorescence imaging and sensing, lens-free on-chip tomography, lens-free on-chip gigapixel nanoscopy, detection of nanoparticles using on-chip microscopy, wide field microscopy, and lens-free shadow image based point-of-care systems. Additionally, this review also discusses the lens-free fluorescent imaging and its dependence on structure and optical design, the advantage of using the compact lens-free driven equilibrium Fourier transform (DEFT) resolved imaging technique for on-chip tomography, the pixel super-resolved algorithm for gigapixel imaging, and the lens-free technology for point-of-care applications. All these low-cost, compact, and fast-processing lens-free imaging and sensing techniques may play a crucial role especially in the fields of environmental, pharmaceutical, biological, and clinical applications of the resource-limited settings.
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http://dx.doi.org/10.1016/j.bios.2016.07.115DOI Listing
February 2017

Automated Micro-Object Detection for Mobile Diagnostics Using Lens-Free Imaging Technology.

Diagnostics (Basel) 2016 May 5;6(2). Epub 2016 May 5.

Department of Electronics and Information Engineering, Korea University, Sejong 30019, Korea.

Lens-free imaging technology has been extensively used recently for microparticle and biological cell analysis because of its high throughput, low cost, and simple and compact arrangement. However, this technology still lacks a dedicated and automated detection system. In this paper, we describe a custom-developed automated micro-object detection method for a lens-free imaging system. In our previous work (Roy et al.), we developed a lens-free imaging system using low-cost components. This system was used to generate and capture the diffraction patterns of micro-objects and a global threshold was used to locate the diffraction patterns. In this work we used the same setup to develop an improved automated detection and analysis algorithm based on adaptive threshold and clustering of signals. For this purpose images from the lens-free system were then used to understand the features and characteristics of the diffraction patterns of several types of samples. On the basis of this information, we custom-developed an automated algorithm for the lens-free imaging system. Next, all the lens-free images were processed using this custom-developed automated algorithm. The performance of this approach was evaluated by comparing the counting results with standard optical microscope results. We evaluated the counting results for polystyrene microbeads, red blood cells, and HepG2, HeLa, and MCF7 cells. The comparison shows good agreement between the systems, with a correlation coefficient of 0.91 and linearity slope of 0.877. We also evaluated the automated size profiles of the microparticle samples. This Wi-Fi-enabled lens-free imaging system, along with the dedicated software, possesses great potential for telemedicine applications in resource-limited settings.
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http://dx.doi.org/10.3390/diagnostics6020017DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4931412PMC
May 2016

Low-cost telemedicine device performing cell and particle size measurement based on lens-free shadow imaging technology.

Biosens Bioelectron 2015 May 18;67:715-23. Epub 2014 Oct 18.

Department of Electronics and Information Engineering, Korea University, Sejong, Republic of Korea. Electronic address:

Recent advances in lens-free shadow imaging technology have enabled a new class of cell imaging platform, which is a suitable candidate for point-of-care facilities. In this paper, we firstly demonstrate a compact and low-cost telemedicine device providing automated cell and particle size measurement based on lens-free shadow imaging technology. Using the generated shadow (or diffraction) patterns, the proposed approach can detect and measure the sizes of more than several hundreds of micro-objects simultaneously within a single digital image frame. In practical experiments, we defined four types of shadow parameters extracted from each micro-object shadow pattern, and found that a specific shadow parameter (peak-to-peak distance, PPD) demonstrated a linear relationship with the actual micro-object sizes. By using this information, a new algorithm suitable for operation on both a personal computer (PC) and a cell phone was also developed, providing automated size detection of poly-styrenemicro-beads and biological cells such as red blood cells, MCF-7, HepG2, and HeLa. Results from the proposed device were compared with those of a conventional optical microscope, demonstrating good agreement between two approaches. In contrast to other existing cell and particle size measurement approaches, such as Coulter counter, flow-cytometer, particle-size analyzer, and optical microscope, this device can provide accurate cell and particle size information with a 2 µm maximum resolution, at almost no cost (less than 100 USD), within a compact instrumentation size (9.3×9.0×9.0 cm(3)), and in a rapid manner (within 1 min). The proposed lens-free automated particle and cell size measurement device, based on shadow imaging technology, can be utilized as a powerful tool for many cell and particle handling procedures, including environmental, pharmaceutical, biological, and clinical applications.
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http://dx.doi.org/10.1016/j.bios.2014.10.040DOI Listing
May 2015

A simple and low-cost biofilm quantification method using LED and CMOS image sensor.

J Microbiol Methods 2014 Dec;107:150-6

Department of Electronics and Information Engineering, Korea University, Sejong 339-700, Republic of Korea.

A novel biofilm detection platform, which consists of a cost-effective red, green, and blue light-emitting diode (RGB LED) as a light source and a lens-free CMOS image sensor as a detector, is designed. This system can measure the diffraction patterns of cells from their shadow images, and gather light absorbance information according to the concentration of biofilms through a simple image processing procedure. Compared to a bulky and expensive commercial spectrophotometer, this platform can provide accurate and reproducible biofilm concentration detection and is simple, compact, and inexpensive. Biofilms originating from various bacterial strains, including Pseudomonas aeruginosa (P. aeruginosa), were tested to demonstrate the efficacy of this new biofilm detection approach. The results were compared with the results obtained from a commercial spectrophotometer. To utilize a cost-effective light source (i.e., an LED) for biofilm detection, the illumination conditions were optimized. For accurate and reproducible biofilm detection, a simple, custom-coded image processing algorithm was developed and applied to a five-megapixel CMOS image sensor, which is a cost-effective detector. The concentration of biofilms formed by P. aeruginosa was detected and quantified by varying the indole concentration, and the results were compared with the results obtained from a commercial spectrophotometer. The correlation value of the results from those two systems was 0.981 (N = 9, P < 0.01) and the coefficients of variation (CVs) were approximately threefold lower at the CMOS image-sensor platform.
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http://dx.doi.org/10.1016/j.mimet.2014.10.004DOI Listing
December 2014

Lens-free shadow image based high-throughput continuous cell monitoring technique.

Biosens Bioelectron 2012 Oct-Dec;38(1):126-31. Epub 2012 May 27.

Department of Electronics and Information Engineering, Korea University, Jochiwon, Republic of Korea.

A high-throughput continuous cell monitoring technique which does not require any labeling reagents or destruction of the specimen is demonstrated. More than 6000 human alveolar epithelial A549 cells are monitored for up to 72 h simultaneously and continuously with a single digital image within a cost and space effective lens-free shadow imaging platform. In an experiment performed within a custom built incubator integrated with the lens-free shadow imaging platform, the cell nucleus division process could be successfully characterized by calculating the signal-to-noise ratios (SNRs) and the shadow diameters (SDs) of the cell shadow patterns. The versatile nature of this platform also enabled a single cell viability test followed by live cell counting. This study firstly shows that the lens-free shadow imaging technique can provide a continuous cell monitoring without any staining/labeling reagent and destruction of the specimen. This high-throughput continuous cell monitoring technique based on lens-free shadow imaging may be widely utilized as a compact, low-cost, and high-throughput cell monitoring tool in the fields of drug and food screening or cell proliferation and viability testing.
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http://dx.doi.org/10.1016/j.bios.2012.05.022DOI Listing
December 2012

Flexible glucose sensor using CVD-grown graphene-based field effect transistor.

Biosens Bioelectron 2012 Aug-Sep;37(1):82-7. Epub 2012 May 9.

Components and Materials R&D Division, Korea Electronics Technology Institute, Seongnam, Republic of Korea.

A flexible glucose sensor using a CVD-grown graphene-based field-effect-transistor (FET) is demonstrated. The CVD-grown graphene was functionalized with linker molecules in order to immobilize the enzymes that induce the catalytic response of glucose. Polyethylene terephthalate (PET) was employed as the substrate material to realize a flexible sensor. The fabricated graphene-based FET sensor showed ambipolar transfer characteristics. Through measurements of the Dirac point shift and differential drain-source current, the fabricated FET sensor could detect glucose levels in the range of 3.3-10.9 mM, which mostly covers the reference range of medical examination or screen test for diabetes diagnostic. This CVD-grown graphene-based FET sensor, which provides excellent fitting to a model curve even when deformed, high resolution, and continuous real-time monitoring, holds great promise, especially for portable, wearable, and implantable glucose level monitoring applications.
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http://dx.doi.org/10.1016/j.bios.2012.04.042DOI Listing
September 2012

Generation of midfield concentrated beam arrays using periodic metal annular apertures.

Appl Opt 2012 Mar;51(8):1076-85

Department of Electronics and Information Engineering, Korea University, Jochiwon, South Korea.

Generation of minimally diffracting beam arrays in the midfield region using periodic metal annular apertures is investigated. The relations between the patterns of the diffraction fields and the structural parameters of the periodic metal annular aperture are numerically analyzed. Material dependent transmission characteristics are also studied with finite difference time-domain simulation. The results reveal that the beam concentration efficiency and axial intensity uniformity have a trade-off restriction due to strong inter-aperture interference and surface plasmon mediates the transmission efficiency of the periodic annular apertures. The design criteria of the metal annular aperture to achieve the strong and uniform beam arrays are addressed.
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http://dx.doi.org/10.1364/AO.51.001076DOI Listing
March 2012

High-throughput lens-free blood analysis on a chip.

Anal Chem 2010 Jun;82(11):4621-7

Electrical Engineering Department, University of California, Los Angeles, California 90095, USA.

We present a detailed investigation of the performance of lens-free holographic microscopy toward high-throughput on-chip blood analysis. Using a spatially incoherent source that is emanating from a large aperture, automated counting of red blood cells with minimal sample preparation steps at densities reaching up to approximately 0.4 x 10(6) cells/muL is presented. Using the same lens-free holographic microscopy platform, we also characterize the volume of the red blood cells at the single-cell level through recovery of the optical phase information of each cell. We further demonstrate the measurement of the hemoglobin concentration of whole blood samples as well as automated counting of white blood cells, also yielding spatial resolution at the subcellular level sufficient to differentiate granulocytes, monocytes, and lymphocytes from each other. These results uncover the prospects of lens-free holographic on-chip imaging to provide a useful tool for global health problems, especially by facilitating whole blood analysis in resource-poor environments.
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http://dx.doi.org/10.1021/ac1007915DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2892055PMC
June 2010

Compact, light-weight and cost-effective microscope based on lensless incoherent holography for telemedicine applications.

Lab Chip 2010 Jun 19;10(11):1417-28. Epub 2010 Apr 19.

Electrical Engineering Department, University of California, Los Angeles, CA 90095, USA.

Despite the rapid progress in optical imaging, most of the advanced microscopy modalities still require complex and costly set-ups that unfortunately limit their use beyond well equipped laboratories. In the meantime, microscopy in resource-limited settings has requirements significantly different from those encountered in advanced laboratories, and such imaging devices should be cost-effective, compact, light-weight and appropriately accurate and simple to be usable by minimally trained personnel. Furthermore, these portable microscopes should ideally be digitally integrated as part of a telemedicine network that connects various mobile health-care providers to a central laboratory or hospital. Toward this end, here we demonstrate a lensless on-chip microscope weighing approximately 46 grams with dimensions smaller than 4.2 cm x 4.2 cm x 5.8 cm that achieves sub-cellular resolution over a large field of view of approximately 24 mm(2). This compact and light-weight microscope is based on digital in-line holography and does not need any lenses, bulky optical/mechanical components or coherent sources such as lasers. Instead, it utilizes a simple light-emitting-diode (LED) and a compact opto-electronic sensor-array to record lensless holograms of the objects, which then permits rapid digital reconstruction of regular transmission or differential interference contrast (DIC) images of the objects. Because this lensless incoherent holographic microscope has orders-of-magnitude improved light collection efficiency and is very robust to mechanical misalignments it may offer a cost-effective tool especially for telemedicine applications involving various global health problems in resource limited settings.
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http://dx.doi.org/10.1039/c000453gDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2902728PMC
June 2010

Lensfree holographic imaging of antibody microarrays for high-throughput detection of leukocyte numbers and function.

Anal Chem 2010 May;82(9):3736-44

Department of Biomedical Engineering, University of California, Davis, CA 95616, USA.

Characterization of leukocytes is an integral part of blood analysis and blood-based diagnostics. In the present paper, we combine lensless holographic imaging with antibody microarrays for rapid and multiparametric analysis of leukocytes from human blood. Monoclonal antibodies (Abs) specific for leukocyte surface antigens (CD4 and CD8) and cytokines (TNF-alpha, IFN-gamma, IL-2) were printed in an array so as to juxtapose cell capture and cytokine detection antibody (Ab) spots. Integration of Ab microarrays into a microfluidic flow chamber (4 muL volume) followed by incubation with human blood resulted in capture of CD4 and CD8 T-cells on specific Ab spots. On-chip mitogenic activation of these cells induced release of cytokine molecules that were subsequently captured on neighboring anticytokine Ab spots. The binding of IL-2, TNF-alpha, and IFN-gamma molecules on their respective Ab spots was detected using horseradish peroxidase (HRP)-labeled anticytokine Abs and a visible color reagent. Lensfree holographic imaging was then used to rapidly ( approximately 4 s) enumerate CD4 and CD8 T-lymphocytes captured on Ab spots and to quantify the cytokine signal emanating from IL-2, TNF-alpha, and IFN-gamma spots on the same chip. To demonstrate the utility of our approach for infectious disease monitoring, blood samples of healthy volunteers and human immunodeficiency virus (HIV)-infected patients were analyzed to determine the CD4/CD8 ratio, an important HIV/AIDS diagnostic marker. The ratio obtained by lensfree on-chip imaging of CD4 and CD8 T-cells captured on Ab spots was in close agreement with conventional microscopy-based cell counting. The present paper, describing tandem use of Ab microarrays and lensfree holographic imaging, paves the way for future development of miniature cytometry devices for multiparametric blood analysis at the point of care or in a resource-limited setting.
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http://dx.doi.org/10.1021/ac100142aDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2864520PMC
May 2010

Lensless on-chip imaging of cells provides a new tool for high-throughput cell-biology and medical diagnostics.

J Vis Exp 2009 Dec 14(34). Epub 2009 Dec 14.

Electrical Engineering Department, University of California, Los Angeles, CA, USA.

Conventional optical microscopes image cells by use of objective lenses that work together with other lenses and optical components. While quite effective, this classical approach has certain limitations for miniaturization of the imaging platform to make it compatible with the advanced state of the art in microfluidics. In this report, we introduce experimental details of a lensless on-chip imaging concept termed LUCAS (Lensless Ultra-wide field-of-view Cell monitoring Array platform based on Shadow imaging) that does not require any microscope objectives or other bulky optical components to image a heterogeneous cell solution over an ultra-wide field of view that can span as large as approximately 18 cm(2). Moreover, unlike conventional microscopes, LUCAS can image a heterogeneous cell solution of interest over a depth-of-field of approximately 5 mm without the need for refocusing which corresponds to up to approximately 9 mL sample volume. This imaging platform records the shadows (i.e., lensless digital holograms) of each cell of interest within its field of view, and automated digital processing of these cell shadows can determine the type, the count and the relative positions of cells within the solution. Because it does not require any bulky optical components or mechanical scanning stages it offers a significantly miniaturized platform that at the same time reduces the cost, which is quite important for especially point of care diagnostic tools. Furthermore, the imaging throughput of this platform is orders of magnitude better than conventional optical microscopes, which could be exceedingly valuable for high-throughput cell-biology experiments.
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http://dx.doi.org/10.3791/1650DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3149969PMC
December 2009

Lensfree holographic imaging for on-chip cytometry and diagnostics.

Lab Chip 2009 Mar 5;9(6):777-87. Epub 2008 Dec 5.

Electrical Engineering Department, University of California, Los Angeles, CA 90095, USA.

We experimentally illustrate a lensfree holographic imaging platform to perform on-chip cytometry. By controlling the spatial coherence of the illumination source, we record a 2D holographic diffraction pattern of each cell or micro-particle on a chip using a high resolution sensor array that has approximately 2 microm pixel size. The recorded holographic image is then processed by using a custom developed decision algorithm for matching the detected hologram texture to existing library images for on-chip characterization and counting of a heterogeneous solution of interest. The holographic diffraction signature of any microscopic object is significantly different from the classical diffraction pattern of the same object. It improves the signal to noise ratio and the signature uniformity of the cell patterns; and also exhibits much better sensitivity for on-chip imaging of weakly scattering phase objects such as small bacteria or cells. We verify significantly improved performance of this holographic on-chip cytometry approach by automatically characterizing heterogeneous solutions of red blood cells, yeast cells, E. coli and various sized micro-particles without the use of any lenses or microscope objectives. This lensless on-chip holography platform will especially be useful for point-of-care cytometry and diagnostics applications involving e.g., infectious diseases such as HIV or malaria.
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http://dx.doi.org/10.1039/b813943aDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3931575PMC
March 2009

Multi-angle LUCAS for high-throughput on-chip cytometry.

Annu Int Conf IEEE Eng Med Biol Soc 2008 ;2008:1854-5

Electrical Engineering Department, University of California, Los Angeles, CA 90095, USA.

We illustrate that by recording under-sampled diffraction patterns of cells at different illumination angles, we can achieve high-throughput on-chip characterization of a heterogeneous cell solution over an ultra large volume of approximately 5 ml. This platform, termed multi-angle LUCAS, is especially promising for cost-effective point-of-care cell counting applications.
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http://dx.doi.org/10.1109/IEMBS.2008.4649543DOI Listing
May 2009

High-throughput lensfree imaging and characterization of a heterogeneous cell solution on a chip.

Biotechnol Bioeng 2009 Feb;102(3):856-868

Electrical Engineering Department, University of California, P.O. Box 951594, Los Angeles, California 90095.

A high-throughput on-chip imaging platform that can rapidly monitor and characterize various cell types within a heterogeneous solution over a depth-of-field of approximately 4 mm and a field-of-view of approximately 10 cm(2) is introduced. This powerful system can rapidly image/monitor multiple layers of cells, within a volume of approximately 4 mL all in parallel without the need for any lenses, microscope-objectives or any mechanical scanning. In this high-throughput lensless imaging scheme, the classical diffraction pattern (i.e., the shadow) of each micro-particle within the entire sample volume is detected in less than a second using an opto-electronic sensor chip. The acquired shadow image is then digitally processed using a custom developed "decision algorithm" to enable both the identification of the particle location in 3D and the characterization of each micro-particle type within the sample volume. Through experimental results, we show that different cell types (e.g., red blood cells, fibroblasts, etc.) or other micro-particles all exhibit uniquely different shadow patterns and therefore can be rapidly identified without any ambiguity using the developed decision algorithm, enabling high-throughput characterization of a heterogeneous solution. This lensfree on chip cell imaging platform shows a significant promise especially for medical diagnostic applications relevant to global health problems, where compact and cost-effective diagnostic tools are urgently needed in resource limited settings.
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http://dx.doi.org/10.1002/bit.22116DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4183348PMC
February 2009