scholarly journals Thin Flexible Lab-on-a-Film for Impedimetric Sensing in Biomedical Applications

2021 ◽  
Author(s):  
Amina Farooq ◽  
Fezan Hayat ◽  
Sobia Zafar ◽  
Nauman Zafar Butt
Keyword(s):  
Bond Strength ◽  
Signal To Noise Ratio ◽  
Point Of Care ◽  
Flexible Substrate ◽  
Pulse Amplitude ◽  
Medical Diagnostics ◽  
Design Guidelines ◽  
Covalent Crosslinking ◽  
Point Of Care Diagnostics ◽  
Wide Range

Abstract Microfluidic cytometers based on coulter principle have recently shown a great potential for point of care biosensors for medical diagnostics. Here, we explore the design of an impedimetric microfluidic cytometer on flexible substrate. Two coplanar microfluidic geometries are compared to highlight the sensitivity of the device to the microelectrode positions relative to the detection volume. We show that the microelectrodes surface area and the geometry of the sensing volume for the cells strongly influence the output response of the sensor. Reducing the sensing volume decreases the pulse width but increases the overall pulse amplitude with an enhanced signal-to-noise ratio (~max. SNR=38.78dB). For the proposed design, the SNR was adequate to enable good detection and differentiation of 10 µm diameter polystyrene beads and leukemia cells (~6-21 µm). Also, a systematic approach for irreversible & strong bond strength between the thin flexible surfaces that make up the biochip is explored in this work. We observed the changes in surface wettability due to various methods of surface treatment can be a valuable metric for determining bond strength. We observed permanent bonding between microelectrode defined polypropylene surface and microchannel carved PDMS due to polar/silanol groups formed by plasma treatment and consequent covalent crosslinking by amine groups. These experimental insights provide valuable design guidelines for enhancing the sensitivity of coulter based flexible lab-on-a-chip devices which have a wide range of applications in point of care diagnostics.

scholarly journals Flexible Substrate-Based Devices for Point-of-Care Diagnostics

2016 ◽  
Vol 34 (11) ◽  
pp. 909-921 ◽  
Author(s):  
ShuQi Wang ◽  
Thiruppathiraja Chinnasamy ◽  
Mark A. Lifson ◽  
Fatih Inci ◽  
Utkan Demirci
Keyword(s):  
Point Of Care ◽  
Flexible Substrate ◽  
Point Of Care Diagnostics

Fabrication Techniques for Production of Thermoplastic-Based Microfluidics Devices

2016 ◽  
Vol 04 (03) ◽  
pp. 1640016 ◽  
Author(s):  
Zhenfeng Wang
Keyword(s):  
Point Of Care ◽  
Emerging Market ◽  
Science Research ◽  
Polymer Materials ◽  
Microfluidic Chips ◽  
Face Lift ◽  
Point Of Care Diagnostics ◽  
Wide Range ◽  
The Face ◽  
Micro Tooling

Microfluidics is a multidisciplinary technology which enables the face-lift crossing a wide range of applications such as life science research, point-of-care diagnostics and personal medicine. Polymer materials, especially thermoplastics, are dominating this emerging market due to the low material cost and the ease of mass production. This paper reviews the major fabrication technologies for making polymer, especially thermoplastic microfluidic chips, such as micro tooling, injection molding, bonding and surface treatment. The paper also summarizes the key challenges in fulfilling the needs of next generation microfluidic products.

scholarly journals Energy Detection of Multilevel PAM Signals with Systematic Threshold Mismatch

2009 ◽  
Vol 2009 ◽  
pp. 1-4 ◽  
Author(s):  
Antti Anttonen ◽  
Adrian Kotelba ◽  
Aarne Mämmelä
Keyword(s):  
Signal To Noise Ratio ◽  
Pulse Amplitude ◽  
Energy Detection ◽  
Symbol Error Rate ◽  
Threshold Selection ◽  
Selection Scheme ◽  
Efficient Energy ◽  
System Parameters ◽  
Wide Range ◽  
The Relationship

We address a symbol decision problem with spectrally efficient energy detected multilevel pulse amplitude modulated (PAM) signals. First, we analytically quantify the relationship between a systematic threshold mismatch and the required increase of the average signal-to-noise ratio to preserve a desired symbol error rate. For the case in which such an increase is not tolerable, we present a novel near-optimal multilevel threshold selection scheme, which is accurate for a wide range of system parameters.

scholarly journals Self-Powered Portable Electronic Reader for Point-of-Care Amperometric Measurements

Sensors ◽  
2019 ◽  
Vol 19 (17) ◽  
pp. 3715 ◽  
Author(s):  
Yaiza Montes-Cebrián ◽  
Albert Álvarez-Carulla ◽  
Jordi Colomer-Farrarons ◽  
Manel Puig-Vidal ◽  
Pere Ll. Miribel-Català
Keyword(s):  
Low Power ◽  
Point Of Care ◽  
Power Source ◽  
Laboratory Equipment ◽  
Fuel Concentration ◽  
Point Of Care Diagnostics ◽  
External Power Source ◽  
Wide Range ◽  
External Power ◽  
Self Powered

In this work, we present a self-powered electronic reader (e-reader) for point-of-care diagnostics based on the use of a fuel cell (FC) which works as a power source and as a sensor. The self-powered e-reader extracts the energy from the FC to supply the electronic components concomitantly, while performing the detection of the fuel concentration. The designed electronics rely on straightforward standards for low power consumption, resulting in a robust and low power device without needing an external power source. Besides, the custom electronic instrumentation platform can process and display fuel concentration without requiring any type of laboratory equipment. In this study, we present the electronics system in detail and describe all modules that make up the system. Furthermore, we validate the device’s operation with different emulated FCs and sensors presented in the literature. The e-reader can be adjusted to numerous current ranges up to 3 mA, with a 13 nA resolution and an uncertainty of 1.8%. Besides, it only consumes 900 µW in the low power mode of operation, and it can operate with a minimum voltage of 330 mV. This concept can be extended to a wide range of fields, from biomedical to environmental applications.

scholarly journals Biosensors in Health Care: The Milestones Achieved in Their Development towards Lab-on-Chip-Analysis

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Suprava Patel ◽  
Rachita Nanda ◽  
Sibasish Sahoo ◽  
Eli Mohapatra
Keyword(s):  
Point Of Care ◽  
Medical Diagnostics ◽  
Point Of Care Testing ◽  
Lab On Chip ◽  
Testing Facility ◽  
Wide Range ◽  
On Chip ◽  
Huge Challenge ◽  
Chip Analysis ◽  
Higher Sensitivity

Immense potentiality of biosensors in medical diagnostics has driven scientists in evolution of biosensor technologies and innovating newer tools in time. The cornerstone of the popularity of biosensors in sensing wide range of biomolecules in medical diagnostics is due to their simplicity in operation, higher sensitivity, ability to perform multiplex analysis, and capability to be integrated with different function by the same chip. There remains a huge challenge to meet the demands of performance and yield to its simplicity and affordability. Ultimate goal stands for providing point-of-care testing facility to the remote areas worldwide, particularly the developing countries. It entails continuous development in technology towards multiplexing ability, fabrication, and miniaturization of biosensor devices so that they can provide lab-on-chip-analysis systems to the community.

scholarly journals Nanozymes in Point-of-Care Diagnosis: An Emerging Futuristic Approach for Biosensing

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Bhaskar Das ◽  
Javier Lou Franco ◽  
Natasha Logan ◽  
Paramasivan Balasubramanian ◽  
Moon Il Kim ◽  
...  
Keyword(s):  
Surface Chemistry ◽  
Point Of Care ◽  
Low Cost ◽  
Metal Organic Framework ◽  
World Health ◽  
Point Of Care Diagnostics ◽  
Enzyme Mimicking ◽  
Wide Range ◽  
Metal Metal

AbstractNanomaterial-based artificial enzymes (or nanozymes) have attracted great attention in the past few years owing to their capability not only to mimic functionality but also to overcome the inherent drawbacks of the natural enzymes. Numerous advantages of nanozymes such as diverse enzyme-mimicking activities, low cost, high stability, robustness, unique surface chemistry, and ease of surface tunability and biocompatibility have allowed their integration in a wide range of biosensing applications. Several metal, metal oxide, metal–organic framework-based nanozymes have been exploited for the development of biosensing systems, which present the potential for point-of-care analysis. To highlight recent progress in the field, in this review, more than 260 research articles are discussed systematically with suitable recent examples, elucidating the role of nanozymes to reinforce, miniaturize, and improve the performance of point-of-care diagnostics addressing the ASSURED (affordable, sensitive, specific, user-friendly, rapid and robust, equipment-free and deliverable to the end user) criteria formulated by World Health Organization. The review reveals that many biosensing strategies such as electrochemical, colorimetric, fluorescent, and immunological sensors required to achieve the ASSURED standards can be implemented by using enzyme-mimicking activities of nanomaterials as signal producing components. However, basic system functionality is still lacking. Since the enzyme-mimicking properties of the nanomaterials are dictated by their size, shape, composition, surface charge, surface chemistry as well as external parameters such as pH or temperature, these factors play a crucial role in the design and function of nanozyme-based point-of-care diagnostics. Therefore, it requires a deliberate exertion to integrate various parameters for truly ASSURED solutions to be realized. This review also discusses possible limitations and research gaps to provide readers a brief scenario of the emerging role of nanozymes in state-of-the-art POC diagnosis system development for futuristic biosensing applications.

scholarly journals Evolution of Wearable Devices with Real-Time Disease Monitoring for Personalized Healthcare

Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 813 ◽  
Author(s):  
Kyeonghye Guk ◽  
Gaon Han ◽  
Jaewoo Lim ◽  
Keunwon Jeong ◽  
Taejoon Kang ◽  
...  
Keyword(s):  
Real Time ◽  
Health Monitoring ◽  
Point Of Care ◽  
Monitoring And Evaluation ◽  
The Elderly ◽  
Wearable Devices ◽  
Medical Diagnostics ◽  
Biomedical Monitoring ◽  
Wide Range ◽  
Barriers And Challenges

Wearable devices are becoming widespread in a wide range of applications, from healthcare to biomedical monitoring systems, which enable continuous measurement of critical biomarkers for medical diagnostics, physiological health monitoring and evaluation. Especially as the elderly population grows globally, various chronic and acute diseases become increasingly important, and the medical industry is changing dramatically due to the need for point-of-care (POC) diagnosis and real-time monitoring of long-term health conditions. Wearable devices have evolved gradually in the form of accessories, integrated clothing, body attachments and body inserts. Over the past few decades, the tremendous development of electronics, biocompatible materials and nanomaterials has resulted in the development of implantable devices that enable the diagnosis and prognosis through small sensors and biomedical devices, and greatly improve the quality and efficacy of medical services. This article summarizes the wearable devices that have been developed to date, and provides a review of their clinical applications. We will also discuss the technical barriers and challenges in the development of wearable devices, and discuss future prospects on wearable biosensors for prevention, personalized medicine and real-time health monitoring.

scholarly journals Point-of-Care Diagnostics: Molecularly Imprinted Polymers and Nanomaterials for Enhanced Biosensor Selectivity and Transduction

2020 ◽  
Vol 4 (4) ◽  
pp. 184-206
Author(s):  
Daniel J. Denmark ◽  
Subhra Mohapatra ◽  
Shyam S. Mohapatra
Keyword(s):  
Molecularly Imprinted Polymers ◽  
Point Of Care ◽  
Medical Diagnostics ◽  
Biomedical Science ◽  
Molecularly Imprinted ◽  
Imprinted Polymers ◽  
Point Of Care Diagnostics ◽  
Physical And Chemical ◽  
Global Population ◽  
Excellent Stability

AbstractSignificant healthcare disparities resulting from personal wealth, circumstances of birth, education level, and more are internationally prevalent. As such, advances in biomedical science overwhelmingly benefit a minority of the global population. Point-of-Care Testing (POCT) can contribute to societal equilibrium by making medical diagnostics affordable, convenient, and fast. Unfortunately, conventional POCT appears stagnant in terms of achieving significant advances. This is attributed to the high cost and instability associated with conventional biorecognition: primarily antibodies, but nucleic acids, cells, enzymes, and aptamers have also been used. Instead, state-of-the-art biosensor researchers are increasingly leveraging molecularly imprinted polymers (MIPs) for their high selectivity, excellent stability, and amenability to a variety of physical and chemical manipulations. Besides the elimination of conventional bioreceptors, the incorporation of nanomaterials has further improved the sensitivity of biosensors. Herein, modern nanobiosensors employing MIPs for selectivity and nanomaterials for improved transduction are systematically reviewed. First, a brief synopsis of fabrication and wide-spread challenges with selectivity demonstration are presented. Afterward, the discussion turns to an analysis of relevant case studies published in the last five years. The analysis is given through two lenses: MIP-based biosensors employing specific nanomaterials and those adopting particular transduction strategies. Finally, conclusions are presented along with a look to the future through recommendations for advancing the field. It is hoped that this work will accelerate successful efforts in the field, orient new researchers, and contribute to equitable health care for all.

scholarly journals Machine Learning-Based HIV Risk Estimation Using Incidence Rate Ratios

2021 ◽  
Vol 3 ◽  
Author(s):  
Oliver Haas ◽  
Andreas Maier ◽  
Eva Rothgang
Keyword(s):  
Machine Learning ◽  
Incidence Rate ◽  
Clinical Data ◽  
Hiv Risk ◽  
Point Of Care ◽  
Risk Estimation ◽  
Expert Opinions ◽  
Point Of Care Diagnostics ◽  
Wide Range ◽  
Hiv Aids

HIV/AIDS is an ongoing global pandemic, with an estimated 39 million infected worldwide. Early detection is anticipated to help improve outcomes and prevent further infections. Point-of-care diagnostics make HIV/AIDS diagnoses available both earlier and to a broader population. Wide-spread and automated HIV risk estimation can offer objective guidance. This supports providers in making an informed decision when considering patients with high HIV risk for HIV testing or pre-exposure prophylaxis (PrEP). We propose a novel machine learning method that allows providers to use the data from a patient's previous stays at the clinic to estimate their HIV risk. All features available in the clinical data are considered, making the set of features objective and independent of expert opinions. The proposed method builds on association rules that are derived from the data. The incidence rate ratio (IRR) is determined for each rule. Given a new patient, the mean IRR of all applicable rules is used to estimate their HIV risk. The method was tested and validated on the publicly available clinical database MIMIC-IV, which consists of around 525,000 hospital stays that included a stay at the intensive care unit or emergency department. We evaluated the method using the area under the receiver operating characteristic curve (AUC). The best performance with an AUC of 0.88 was achieved with a model consisting of 53 rules. A threshold value of 0.66 leads to a sensitivity of 98% and a specificity of 53%. The rules were grouped into drug abuse, psychological illnesses (e.g., PTSD), previously known associations (e.g., pulmonary diseases), and new associations (e.g., certain diagnostic procedures). In conclusion, we propose a novel HIV risk estimation method that builds on existing clinical data. It incorporates a wide range of features, leading to a model that is independent of expert opinions. It supports providers in making informed decisions in the point-of-care diagnostics process by estimating a patient's HIV risk.

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