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Human immunodeficiency virus (HIV) weakens a person’s immune system by destroying cells which are important to fighting the disease and infection. HIV is a major global public health issue with an estimated 38 million people living with HIV at the end of 2019. There is no cure for HIV. However, increased access to effective prevention, diagnosis and treatment has enabled people living with HIV to lead healthy lives. Rapid diagnosis forms an important part of the WHO’s strategy for ensuring those who are HIV positive have immediate access to care. Perhaps more critical however is that effective diagnostic testing informs individuals of their HIV status, reducing the risk of transmission. HIV prevalence within the US is disproportionately high amongst Black/African American and Hispanic/Latino American populations who often have limited access to advanced medical clinics. In this paper, we present a lateral flow device designed to detect miR-150-5p; an emerging biomarker of HIV. Based on our preliminary results shown here, we are capable of detecting the miRNA sequence at sub-ng uL-1 using colorimetric analysis, without prior amplification of the target material. We have also detailed our initial results obtained from surface-enhanced Raman scattering measurements made at the device capture line, whilst the standard deviations are large, the technique shows lots of promise for lowering the detection limit in the future.

In the process of knowing and understanding the world, the traditional media of books and paper have always played a very important role. However, with the emergence of new media and the skilled use of digital media technology, the traditional medium of book and paper media has gradually faded away in the eyes of mankind. Stereoscopic paper media is a three-dimensional paper media that can display three-dimensional virtual scenes on the display device based on the traditional paper books by using the camera of the display device to identify the logo card or the real scene, and then collect the virtual information and the real scene. In this paper, under Windows 10 operating system, the program is written by VC++ and ARtoolKit software development kit development tool, and based on augmented reality technology, virtual 3D scenes are built through 3D model modeling to achieve matching and integration with real scenes of paper books and realize 3D interaction. Based on this, a 3D interactive augmented reality system with a high degree of realism is realized. The main research contents include: customizing the paper media markers, reducing the system's misjudgment rate of the markers by combining the single-response matrix and calculating the image matching value with an optimization algorithm, realizing and tracking the recognition of the markers in real time; and optimizing the image segmentation method of the ARtoolKit software development kit, using the marker card to rotate 45° relative to the camera's position to simulate the situation when the scene has changed significantly. We use the minimum error method to calculate the gaps in real time to realize augmented reality; build a 3D model with animation effects based on the ARtoolKit software development tool and Unity development platform; accurately align the recognized markers with the virtual 3D model; add audio to the 3D model to match the content and add interactive functions to realize the control of 3D animation. Stereoscopic paper media breaks the traditional paper book book reading method, no longer just read the content of paper books, you can see and content-related virtual information on the display device of the mobile terminal, such as three-dimensional scenes, videos and so on. Stereoscopic paper media improves the reader's interest in reading and gives the reader a vivid and realistic reading experience.

Colorimetric analysis is being broadly applied in chemical sensing today; however, detection ranges and resolution limits are typically modest. In this paper, we introduce a methodology to quantify the colorimetric chemical response on a paper-based microfluidic device that enables high-resolution colorimetric detection over a broad pH range. We have achieved this by combining data from various indicators displaying sensitivity on partially overlapping small pH ranges and training machine learning classification models to the colorimetric output. The training dataset consists of images taken from the colorimetric response of three different pH indicators previously deposited on circular spots of a multilayer paper-based device, captured with a reference lab-grade camera. Instead of restricting the use of each pH indicator to their linear response regime within the RGB space, the models are trained against data spanning the entire range of pH values, from 3 to 9, in increments of 0.1, exploring the optimum combination of feature engineering and classification model to maximize the overall model accuracy. The combined analysis of image data captured simultaneously with the three indicators resulted in a pH detection accuracy above 85% with over the entire pH range with resolution down to 0.2 pH points. The demonstrated detection range and resolution are well-suited to support various applications in environmental and industrial analysis.

Colorimetric detection using microfluidic paper-based analytical devices (µPADs) and smartphones enable lowcost mobile chemical analysis solutions. However, variable illumination conditions and phone characteristics (i.e. camera hardware and software capabilities) limit the accurate interpretation and reproducibility of quantitative results. In this paper, we describe a method to automatically compensate an image captured by a smartphone camera under variable illumination conditions. By incorporating a two-step algorithm, we approximate the mobile camera picture color distribution to resemble a laboratory-grade measurement under reference illumination conditions. For every test image, the algorithm first applies a color mapping step that performs histogram matching of a set of color reference spots printed on the device to a laboratory reference measurement. After this initial correction step, a transformation matrix is computed via a least-square fit to minimize the differences between the device and the laboratory references. This matrix is then applied to the RGB channel values obtained from a µPAD to correct for illumination variations. The methodology was tested by correcting a test dataset captured using a smartphone to approximate to a calibration dataset acquired using a lab-grade camera. After correction, the relative error between the datasets fell to 10-20%, leading to an increase in classification accuracy between 12-33%. This approach enables colorimetric chemical analysis with smartphones outside the lab, removing the need to control external lighting conditions.

We show photonic responses of selected two-dimensional photonic crystals that are based on a combination of geometrical design and spatial self-similarity. Structures based on multi-layer circles, squares, and triangles are studied, finding a range of local band gaps that can be varied with the self-similarity of the photonic crystal patterns. Selected photonic modes are shown that couple to different geometrical features of the photonic crystal. The role of boundary sharpness between the two dielectric components is emphasized.

Here we report a novel approach to create tunable and reconfigurable microwave metamaterials using metal ink printing on a paper. Our approach enables easy-to-fabricate but still highly functional and tunable elements. An array of asymmetric split ring resonators was printed on a photopaper to induce Fano resonances in the microwave region (~ 10 GHz). Then, the printed paper was cut line by line and folded, so that a step height between neighboring unit cells can be created and tuned. With the varying step height between neighboring cells, our sample demonstrates significant spectral shifts and resonance tuning despite its simple geometry. Depending on the cutting direction, we observe either spectral redshift or blueshift. We explain our experimental observations based on the interactions between electric/magnetic dipoles in the neighboring unit cell. Moreover, we observe phase singularity at the zero amplitude position of the Fano resonance spectrum. The spectral phase exhibits a drastic change at this singularity point, and the phase spectrum can be also largely tuned with the geometry change in our sample. The drastic changes in phase could be very useful for various applications, such as optical sensing and beam steering.

We present an ultra-high frequency radio frequency identification based wireless communication set-up for paper-based point-of-care diagnostic applications, based on a sensing radio frequency identification chip. Paper provides a low-cost, disposable platform for ease of fluidic handling without bulky instrumentation, and is thus ideally suited for point-ofcare applications; however, result communication – a crucial aspect for healthcare to be implemented effectively – is still lacking. Printing of radio frequency identification antennas and electronic circuitry for sensing on paper are presented, with read out of the results using a radio frequency identification reader illustrated, demonstrating the feasibility of developing integrated, all-printed solutions for point-of-care diagnosis in resource-limited settings.

In this study, we demonstrate a novel wax-patterned paper-polymer centrifugal optical system for performing multiple biomedical tests. The system consists of a detector (photodiode, LED), a diagnostic disc (paper, plastic) and a DC motor, allowing monitoring of changes in real time absorbance. Here, a wax printer was used to form hydrophobic channels on paper. The diagnostic disc can be prepared by attaching wax-patterned paper to a plastic disc. After the diagnostic disc is mounted on the dc motor, the fluid first wets the wax-patterned paper by centrifugal force, slowly moves by capillary action, and the reaction proceeds in the reaction zone with enzyme and color indicator. Microfluidic devices prepared in the wax-patterned paper have several attractive features such as low cost, ease of use, disposability and portability. In addition, the centrifugal disk-based platform can provide a solution for high-efficiency analysis that can process multiple reactions in parallel and monitor reactions in real time. To demonstrate the usability of this system, we performed realtime monitoring of glucose, an important indicator of blood glucose. The detection results could be delivered with the calibration curve within 10 seconds and no complex image analysis was required. The developed wax-patterned paperpolymer centrifugal optical system is promising for clinical multianalyte point-of-care testing due to its ease of manufacture, ease of operation, low cost and high sensitivity.

Copyright: 2016 SPIE. Due to copyright restrictions, the attached PDF file only contains the abstract of the full text item. For access to the full text item, please consult the publisher's website.

There are significant challenges in global healthcare delivery at the moment. Some countries have abundant services, but are stuck with a rather nimble and expensive system that focuses on incremental innovations. Other geographies are still in need of basic tools, infrastructure and require completely different, inexpensive, and with that more disruptive solutions to satisfy their healthcare needs. Next Generation Healthcare systems with a focus on prevention / early detection and pro-active therapy will employ exponential technologies (AI, Big Data, Blockchain, Sensor Technology, Synthetic Biology, Tissue Engineering, Robotics, 3D Printing, ...) that will surely lead to significant changes in the way we experience, think about, and deliver healthcare and in which a digitally empowered patient will play a more important role. In the coming years/decades we will experience a shift from the current SICK-CARE provision to real HEALTHCARE to a focus on personal HEALTH, supported by an integration of patient generated health data with other external diagnostic and therapeutic data components creating a digital health twin as a base for prevention and patient centered precision medicine. Education and training of Biomedical Engineers needs to be adjusted to these developments focussing on solving unmet clinical needs, which requires a solid understanding of current health problems (regional, global), future technologies, economic realities and global health markets. The paper will present and discuss some of these future global innovation needs and the subsequent need for a change in the biomedical engineering curriculum that needs to include learning- (creativity, critical thinking, collaboration) and life skills (flexibility, leadership, social), as well as basic economic and entrepreneurial training — all of which are currently not taught or emphasized.