117 research outputs found

    The centrifugo-pneumatic Lab-on-a-Disk (LoaD) platform: towards robust flow control for larger-scale functional integration

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    This work shows for the first time how unavoidable tolerances in manufacturing and experimental input parameters have a decisive influence on the reliability of flow control in Lab-on-a-Disk (LoaD) platforms and must therefore be considered towards larger scale fluidic integration (LSI)

    Isolation of white blood cells using paper-triggered dissolvable-film valves on a centrifugal platform

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    The inherent centrifugation capability of the so-called ‘Lab-on-a-Disc’ (LoaD) platforms is widely used for blood processing during sample preparation. Here we introduce a valving technique which ena-bles rotational control of paper wetting to actuate dissolvable film (DF) valves. This mechanism is applied to the separation of whole blood into its chief constituents; plasma, leukocytes and erythrocytes

    Logistic Changes to Production and some Impacts on Transportation and Materials Handling

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    There is presently a trend to "internalize" external transport links within the framework of large production system networks. This is made possible by the rapidly increasing capability to swiftly exchange huge masses of data within such networks and the availability of a deregulated transport sector, where the highly competitive trucking industry sets the rules. The result is new forms of logistics systems, designed to meet a set of service requirements which go beyond low cost. The impact of such systems on the evolution of material handling technologies is discussed. Details of one operational Just in Time system and one hypothetical JIT transport system connecting two production plants with particularly unmanned operations are included for the purpose of illustration

    Design features for enhancing optical detection on lab-on-a-disc platforms

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    Centrifugal microfluidics has undergone a massive growth surge over the past 15 years, evident by the number of comprehensive reviews currently available, with special regard towards Lab-On-A-Disc (LOAD) diagnostic solutions.1–3 The potential of a LOAD system is dependent on its ability to mimic the specific laboratory protocols with which are required to conduct sample-to-answer analysis. This would include sample handling and manipulation (such as mixing and separation), sample modification (including heating and redox reactions), as well as reaction detection (such as optical, electrochemical, or as required by user). Optical detection strategies on LOAD platforms has been largely successful in both the fields of biological and chemical sensing.4 Herein, will demonstrate the optical optimisations which were carried out on a biological fluorescent-based5 and a chemical absorbance-based6 LOAD detection platforms. This will include the identification and optimisation of LED-photodiode selection, the effects of detection orientation and pathway-length fluorophore selection. Also covered will be a comparison between the microfluidic architecture for incorporating either detection methods as well as their reported limits of detection

    Reciprocating, buoyancy-driven radial pumping on centrifugal microfluidic platforms

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    Centrifugal microfluidic systems bear great potential for applications where ruggedness, portability, ease-of-use, and cost efficiency are critical. However, due to the unidirectional nature of the centrifugal pumping force, the number of sequential process steps which can be integrated on these “Lab-on-a-Disc” (LoaD) devices is limited by their finite radial extension. To significantly widen this bottleneck and thus expand the scope of applications that can be ported on these LoaD platforms, various groups have developed a range of centripetal pumping mechanisms. Here, we present two advancements over our previous efforts in this area by combining buoyancy-based pumping with dissolvable film (DF) valves. First, we present a buoyancy-driven, reciprocating flow of a dense liquid initially located an upper reservoir and a sample in a peripheral reservoir. Secondly, we combine buoyancy-driven centripetal pumping with sample discretization and metering to fully integrate and automate a liquid handling protocol towards implementing a multi-parameter bioassay on a disc

    Rotational-pulse actuated dissolvable-film valves for automated purification of total RNA from E. Coli

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    In this work we report for the first time on a repertoire of valving technologies which are combined to enable automated purification of total RNA from cell homogenate. Process control is implemented us-ing rotational-pulse actuated dissolvable-film (DF) valves; where the order of valve actuation is deter-mined by the disc architecture while the timing of valve actuation is governed by pulses in the spin rate. Selective liquid routing is enabled by combining a heavy, inert and immiscible liquid plug with a DF. The combination of these technologies enables bead-based extraction of amplifiable RNA, with a yield comparable to gold-standard bench-top protocols

    A portable centrifugal analyser for liver function screening

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    Mortality rates of up to 50% have been reported after liver failure due to drug-induced hepatotoxicity and certain viral infections(Gao et al. 2008). These adverse conditions frequently affect HIV and tuberculosis patients on regular medication in resource-poor settings. Here, we report full integration of sample preparation with read-out of a 5-parameter liver assay panel (LAP) on a portable, easy-to-use, fast and cost- efficient centrifugal microfluidic analysis system (CMAS). Our unique, dissolvable-film based centrifugo- pneumatic valving was employed to provide sample-to-answer fashion automation for plasma extraction (from finger-prick of blood), metering and aliquoting into separate reaction chambers for parallelized colorimetric quantification during rotation. The entire LAP completes in less than 20 minutes while using only a tenth the reagent volumes when compared with standard hospital laboratory tests. Accuracy of in-situ liver function screening was validated by 96 separate tests with an average coefficient of variance (CV) of 7.9% compared to benchtop and hospital lab tests. Unpaired two sample statistical t-tests were used to compare the means of CMAS and benchtop reader, on one hand; and CMAS and hospital tests on the other. The results demonstrate no statistical difference between the respective means with 94% and 92% certainty of equivalence, respectively. The portable platform thus saves significant time, labour and costs compared to established technologies, and therefore comply with typical restrictions on lab infrastructure, maintenance, operator skill and costs prevalent in many field clinics of the developing world. It has been successfully deployed in a centralised lab in Nigeria

    Advances in Microfluidics Technology for Diagnostics and Detection

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    Microfluidics and lab-on-a-chip have, in recent years, come to the forefront in diagnostics and detection. At point-of-care, in the emergency room, and at the hospital bed or GP clinic, lab-on-a-chip offers the potential to rapidly detect time-critical and life-threatening diseases such as sepsis and bacterial meningitis. Furthermore, portable and user-friendly diagnostic platforms can enable disease diagnostics and detection in resource-poor settings where centralised laboratory facilities may not be available. At point-of-use, microfluidics and lab-on-chip can be applied in the field to rapidly identify plant pathogens, thus reducing the need for damaging broad spectrum pesticides while also reducing food losses. Microfluidics can also be applied to the continuous monitoring of water quality and can support policy-makers and protection agencies in protecting the environment. Perhaps most excitingly, microfluidics also offers the potential to enable entirely new diagnostic tests that cannot be implemented using conventional laboratory tools. Examples of microfluidics at the frontier of new medical diagnostic tests include early detection of cancers through circulating tumour cells (CTCs) and highly sensitive genetic tests using droplet-based digital PCR.This Special Issue on “Advances in Microfluidics Technology for Diagnostics and Detection” aims to gather outstanding research and to carry out comprehensive coverage of all aspects related to microfluidics in diagnostics and detection

    Technology-Based Feedback and Its Efficacy in Improving Gait Parameters in Patients with Abnormal Gait: A Systematic Review

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    This systematic review synthesized and analyzed clinical findings related to the effectiveness of innovative technological feedback for tackling functional gait recovery. An electronic search of PUBMED, PEDro, WOS, CINAHL, and DIALNET was conducted from January 2011 to December 2016. The main inclusion criteria were: patients with modified or abnormal gait; application of technology-based feedback to deal with functional recovery of gait; any comparison between different kinds of feedback applied by means of technology, or any comparison between technological and non-technological feedback; and randomized controlled trials. Twenty papers were included. The populations were neurological patients (75%), orthopedic and healthy subjects. All participants were adults, bar one. Four studies used exoskeletons, 6 load platforms and 5 pressure sensors. The breakdown of the type of feedback used was as follows: 60% visual, 40% acoustic and 15% haptic. 55% used terminal feedback versus 65% simultaneous feedback. Prescriptive feedback was used in 60% of cases, while 50% used descriptive feedback. 62.5% and 58.33% of the trials showed a significant effect in improving step length and speed, respectively. Efficacy in improving other gait parameters such as balance or range of movement is observed in more than 75% of the studies with significant outcomes. Conclusion: Treatments based on feedback using innovative technology in patients with abnormal gait are mostly effective in improving gait parameters and therefore useful for the functional recovery of patients. The most frequently highlighted types of feedback were immediate visual feedback followed by terminal and immediate acoustic feedback.Universidad de Sevilla, Telefonica Chair "Intelligence in Networks
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