ABSTRACT
Extensive testing of populations against COVID-19 has been suggested as a game-changer quest to control the spread of this contagious disease and to avoid further disruption in our social, healthcare and economical systems. Nonetheless, testing millions of people for a new virus brings about quite a few challenges. The development of effective tests for the new coronavirus has become a worldwide task that relies on recent discoveries and lessons learned from past outbreaks. In this work, we review the most recent publications on microfluidics devices for the detection of viruses. The topics of discussion include different detection approaches, methods of signalling and fabrication techniques. Besides the miniaturization of traditional benchtop detection assays, approaches such as electrochemical analyses, field-effect transistors and resistive pulse sensors are considered. For emergency fabrication of quick test kits, the local capabilities must be evaluated, and the joint work of universities, industries, and governments seems to be an unequivocal necessity.
ABSTRACT
Resistive pulse sensors (RPS) are based on the detection principle of partial and non-permanent obstruction of an electrically conducting channel. The integration of RPS in microfluidics has the potential for detections at the molecular level. Current challenges involve limitations in fabrication technology, most notably the finite structure accuracy and fabrication repeatability, which have a direct and strong impact on RPS device performance. In this work, we analyzed the geometrical structure and performance of a nanofabricated RPS device and iteratively used the experimental data to propose an adequate numerical model which also accounts for fabrication imperfections beyond the optical resolution limit. The proposed model for a nano-RPS was validated and able to augment the understating of the structure and operation of a microdevice.Clinical Relevance- This work is part of a greater effort to bring microfluidics devices closer to patients for bedside analysis of blood, or other human fluids, for instance. These devices can potentially perform screening for multiple targets in one sample. New devices often need to go through design, prototyping and bench tests, simulation models as the one presented can increase the chances of the device to get to the market in reduced time.
Subject(s)
Microfluidic Analytical Techniques , Nanopores , Heart Rate , Humans , MicrofluidicsABSTRACT
Electrochemotherapy is an anticancer treatment based on applying electric field pulses that reduce cell membrane selectivity, allowing chemotherapy drugs to enter the cells. In parallel to electrochemotherapy clinical tests, in silico experiments have helped scientists and clinicians to understand the electric field distribution through anatomically complex regions of the body. In particular, these in silico experiments allow clinicians to predict problems that may arise in treatment effectiveness. The current work presents a metastatic case of a mast cell tumor in a dog. In this specific treatment planning study, we show that using needle electrodes has a possible pitfall. The macroscopic consequence of the electroporation was assessed through a mathematical model of tissue electrical conductivity. Considering the electrical and geometrical characteristics of the case under study, we modeled an ellipsoidal tumor. Initial simulations were based on the European Standard Operating Procedures for electrochemotherapy suggestions, and then different electrodes' arrangements were evaluated. To avoid blind spots, multiple applications are usually required for large tumors, demanding electrode repositioning. An effective treatment electroporates all the tumor cells. Partially and slightly overlapping the areas increases the session's duration but also likely increases the treatment's effectiveness. It is worth noting that for a single application, the needles should not be placed close to the tumor's borders because effectiveness is highly likely to be lost.
