Portable Diagnostic Tool Research Articles

Handheld Cough Testing: A Novel Tool for Cough Assessment and Dysphagia Screening.

Aspiration pneumonia is a leading cause of death in Parkinson's disease (PD), occurring as a result of impaired cough and swallowing function. However, portable diagnostic tools for cough assessment and dysphagia screening are limited. Therefore, the aims of this study were to determine if: (1) 'Handheld Cough Testing' (HCT), a novel tool developed for cough assessments, could detect differences in cough airflow and sensation during reflex and voluntary cough tasks; and (2) HCT could screen for dysphagia in PD with high sensitivity. Twenty-two people with PD underwent HCT and swallowing assessments. Cough airflow ('PEFR') and sensation ('UTC') was recorded during reflex and voluntary cough tasks. Flexible endoscopy was used to identify people with and without dysphagia. Within-subject statistical analyses were used to detect differences in PEFR and UTC across cough tasks and between-subject statistical analyses were used to detect differences in cough function between people with and without dysphagia. Results revealed significant differences in PEFR (p < 0.0005) and UTC (p < 0.0005) across cough tasks using HCT. Additionally, reflex cough PEFR was significantly different between people with and without dysphagia (p < 0.05). A cut-off of 42.5 L/min exhibited an excellent ability to predict dysphagia in people with PD (90.9% sensitivity; 80.0% specificity). This study revealed that HCT was a valid tool for cough assessment and dysphagia screening. It identified differences in cough airflow and sensation during reflex and voluntary cough tasks and screened for people with dysphagia in PD with high sensitivity.

Recent advancements in fabrication of nanomaterial based biosensors for diagnosis of ovarian cancer: a comprehensive review.

Ovarian cancer is commonly diagnosed via determination of biomarkers like CA125, Mucin 1, HE4, and prostasin that can be present in the blood. However, there is a substantial need for less expensive, simpler, and portable diagnostic tools, both for timely diagnosis and management of ovarian cancer. This review (with 101 refs.) discusses various kinds of nanomaterial-based biosensors for tumor markers. Following an introduction into the field, a first section covers different kinds of biomarkers for ovarian cancer including CA125 (MUC16), mucin 1 (MUC1), human epididymis protein 4 (HE4), and prostasin. This is followed by a short overview on conventional diagnostic approaches. A large section is then presented on biosensors for determination of ovarian cancer, with subsections on optical biosensors (fluorimetric, colorimetric, surface plasmon resonance, chemiluminescence, electrochemiluminescence), on electrochemical sensors, molecularly imprinted sensors, paper-based biosensors, microfluidic (lab-on-a-chip) assays, chemiresistive and field effect transistor-based sensors, and giant magnetoresistive sensors. Tables are presented that give an overview on the wealth of methods and materials. A concluding section summarizes the current status, addresses current challenges, and gives an outlook on potential future trends. Graphical abstract Schematic representation of the review covering the advancements in the fabrication of various nanomaterial based biosensors for diagnosis of ovarian cancer.

Six decades of lateral flow immunoassay: from determining metabolic markers to diagnosing COVID-19.

Technologies based on lateral flow immunoassay (LFIA), known in some countries of the world as immunochromatographic tests, have been successfully used for the last six decades in diagnostics of many diseases and conditions as they allow rapid detection of molecular ligands in biosubstrates. The popularity of these diagnostic platforms is constantly increasing in healthcare facilities, particularly those facing limited budgets and time, as well as in household use for individual health monitoring. The advantages of these low-cost devices over modern laboratory-based analyzers come from their availability, opportunity of rapid detection, and ease of use. The attractiveness of these portable diagnostic tools is associated primarily with their high analytical sensitivity and specificity, as well as with the easy visual readout of results. These qualities explain the growing popularity of LFIA in developing countries, when applied at small hospitals, in emergency situations where screening and monitoring health condition is crucially important, and as well as for self-testing of patients. These tools have passed the test of time, and now LFIA test systems are fully consistent with the world's modern concept of ‘point-of-care testing’, finding a wide range of applications not only in human medicine, but also in ecology, veterinary medicine, and agriculture. The extensive opportunities provided by LFIA contribute to the continuous development and improvement of this technology and to the creation of new-generation formats. This review will highlight the modern principles of design of the most widely used formats of test-systems for clinical laboratory diagnostics, summarize the main advantages and disadvantages of the method, as well as the current achievements and prospects of the LFIA technology. The latest innovations are aimed at improving the analytical performance of LFIA platforms for the diagnosis of bacterial and viral infections, including COVID-19.

Rapid and on-site simultaneous electrochemical detection of copper, lead and mercury in the Amazon river

In poor and remote zones of the world, such as the Amazon region, the lack of analytical infrastructures prevents regular quality assessments of water systems. The access to affordable, portable and robust analytical technologies for real-time and on-site water monitoring is, therefore, key to safeguard vulnerable communities and the environment. In this context, we have developed and successfully implemented an electrochemical methodology for the rapid (60 s) and effective simultaneous electrochemical detection of heavy metal ions of concern (Pb2+, Cu2+ and Hg2+) in water, with a single screen-printed electrode probe. In particular, we show a wide quantification range for each pollutant (5−300 μg L−1), and detection limits below the Environmental Protection Agency (EPA) maximum contaminant levels for drinking water: 0.015, 1.3 and 0.002 mg L−1 for Pb2+, Cu2+ and Hg2+, respectively. The electrochemical sensors were tested in high temperature and humidity conditions in remote areas of the Amazon river, highly affected by mining-related heavy metal pollution. The field measurements were validated against standard lab-based analytical methods, showing excellent agreement. Our methodology can lead to an affordable and portable diagnostic tool for rapid and on-site monitoring of heavy metals pollution in remote areas.

A Lab-on-a-Chip Device Integrated DNA Extraction and Solid Phase PCR Array for the Genotyping of High-Risk HPV in Clinical Samples.

Point-of-care (POC) molecular diagnostics play a crucial role in the prevention and treatment of infectious diseases. It is necessary to develop portable, easy-to-use, inexpensive and rapid molecular diagnostic tools. In this study, we proposed a lab-on-a-chip device that integrated DNA extraction, solid-phase PCR and genotyping detection. The ingenious design of the pneumatic microvalves enabled the fluid mixing and reagent storage to be organically combined, significantly reducing the size of the chip. The solid oligonucleotide array incorporated into the chip allowed the spatial separation of the primers and minimized undesirable interactions in multiplex amplification. As a proof-of-concept for POC molecular diagnostics on the device, five genotypes of high-risk human papillomavirus (HPV) (HPV16/HPV18/HPV31/HPV33/HPV58) were examined. Positive quality control samples and HPV patient cervical swab specimens were analyzed on the integrated microdevice. The platform was capable of detection approximately 50 copies of HPV virus per reaction during a single step, including DNA extraction, solid-phase PCR and genotype detection, in 1 h from samples being added to the chip. This simple and inexpensive microdevice provided great utility for the screening and monitoring of HPV genotypes. The sample-to-result platform will pave the way for wider application of POC molecular testing in the fields of clinical diagnostics, food safety, and environmental monitoring.

Polydentate Aromatic Nanoparticles Complexed with Cu2+ for the Detection of Cysteamine Using a Smartphone as a Portable Diagnostic Tool

Despite the significant therapeutic use of cysteamine as drug in cystinosis, it also has some serious health issues such as idiopathic intracranial hypertension (IIH), Ehlers–Danlos syndrome, and e...

Wearable Electromagnetic Head Imaging System Using Flexible Wideband Antenna Array Based on Polymer Technology for Brain Stroke Diagnosis.

Given the increased interest in a fast, portable, and on-spot medical diagnostic tool that enables early diagnosis for patients with brain stroke, a new approach of a wearable electromagnetic head imaging system based on the polymer material is proposed. A flexible low-profile, wideband, and unidirectional antenna array with electromagnetic band gap (EBG) and metamaterial (MTM) unit cells reflector is utilized. The designed antenna consists of a 4 × 4 radiating patch loaded with symmetrical extended open-ended U-slots and fed by combination of series and corporate transmission lines. A mushroom-like 10-EBG unit cell arrays are arranged around the feeding network to reduce surface waves, whereas 4 × 4 MTM unit cells are placed on the back-side of the antenna to enable unidirectional radiation. The antenna is designed and embedded on a multilayer low cost, low loss, transparent, and robust polymer poly-di-methyl-siloxane (PDMS) substrate and optimized to operate in contact with the human head. The simulated and measured results show that the antenna has a fractional bandwidth of 53.8% (1.16-1.94GHz), more than 80% of radiation efficiency, and satisfactory field penetration in the head tissues with a safe specific absorption rate. An eight-element array is then configured on 300 × 360 × 4.1 mm3 PDMS material covering an average human head size and used as a worn part of the imaging system. A realistic-shaped 3-D specific anthropomorphic mannequin (SAM) head phantom is used to verify the performance of the designed array. The imaging results indicate the possibility of using the designed conformal array to detect a bleeding inside the brain using a confocal image algorithm.

The digital handheld ultrasound device: A new portable diagnostic tool for healthcare. Will it replace the stethoscope?

The digital handheld ultrasound device: A new portable diagnostic tool for healthcare. Will it replace the stethoscope?

Next-generation diagnostics with CRISPR.

CRISPR-Cas biology promises rapid, accurate, and portable diagnostic tools

A versatile and sensitive lateral flow immunoassay for the rapid diagnosis of visceral leishmaniasis.

Visceral leishmaniasis (VL) is a zoonotic infectious disease with a severe impact on humans and animals. Infection is transmitted by phlebotomine sand flies, and several domestic and wild mammals act as reservoirs for the infection, so the prompt detection of infected hosts is crucial to preventing and controlling the spread of the disease and its transmission to humans. A rapid and portable tool for VL diagnosis based on the lateral flow immunoassay (LFIA) technology is described herein. The device exploits a highly specific chimeric recombinant antigen as the recognition element for capturing anti-leishmanial antibodies, and protein A labelled with gold nanoparticles as the signal reporter. The LFIA shows excellent diagnostic sensitivity (98.4%), specificity (98.9%), and agreement with serological reference methods for diagnosing canine VL. The long-term stability of the LFIA device was confirmed based on six months of storage at room temperature or 4°C, and the qualitative response of the device was not affected by limited thermal stress. The use of the broadly specific protein A means that the LFIA can be readily adapted to diagnose VL in dogs (the main reservoir for human infection) and other mammals, thus further assisting efforts to control the spread of VL. Graphical abstract A rapid and portable diagnostic tool for visceral leishmaniasis (VL) based on lateral flow immunoassay (LFIA) technology. The presence of anti-leishmanial antibodies is revealed through the binding of these antibodies to a highly specific chimeric antigen. Employing a broadly specific signal reporter (protein A labelled with gold nanoparticles) enables the LFIA to be easily adapted to diagnose VL in different animals.

From Healthcare to Warfare and Reverse: How Should We Regulate Dual-Use Neurotechnology?

Recent advances in military-funded neurotechnology and novel opportunities for misusing neurodevices show that the problem of dual use is inherent to neuroscience. This paper discusses how the neuroscience community should respond to these dilemmas and delineates a neuroscience-specific biosecurity framework. This neurosecurity framework involves calibrated regulation, (neuro)ethical guidelines, and awareness-raising activities within the scientific community.

Pragmatic setup for bioparticle responses by dielectrophoresis for resource limited environment application

Various dielectrophoretic responses of bioparticles, including cell-chain, spinning, rotation and clustering, are of high interest in the field due to their benefit into application for biomedical and clinical implementation potential. Numerous attempts using sophisticated equipment setup have been studied to perform those dielectrophoretic responses, however, for development into resource limited environment application, such as portable, sustainable and environmental friendly diagnostic tools, establishment of pragmatic setup using standard, non-sophisticated and low-cost equipment is of important task. Here we show the advantages in the judicious design optimization of tip microelectrode, also with selection of suspending medium and optimization of electric signal configuration in establishing setup that can promote the aforementioned dielectrophoretic responses within standard equipments, i.e. pragmatic setup.

Spacer layer engineering for ultrasensitive Hg(II) detection on surface plasmon-coupled emission platform

AbstractIn this work, we demonstrate for the first time the ultrasensitive detection of Hg2+ ions with femtomolar sensitivity in water samples with the use of the surface plasmon-coupled emission (SPCE) platform. The use of portable network diagnostic tools for water security and integrated water shed management is a topic of recent research interest. In this context, the current study explores Hg2+ monitoring using a rhodamine-6G (Rh6G) derivative bearing a monothiospirolactone mounted onto a SPCE substrate. Thus far, the limit of detection for mercury ions by the conventional fluorescence technique has been 0.15 nm. However, we have achieved 1 fm Hg2+ detection using silver nanoparticle-based spacer layer engineering on an SPCE sensor chip. Using this technology, a field device can be fabricated for rapid, ultrasensitive, multi-analyte detection (of contaminants) in water samples.

Volatile organic compound detection as a potential means of diagnosing cutaneous wound infections.

Chronic cutaneous wound infections and surgical site infections (SSIs) present a huge burden on the healthcare system and can lead to increased morbidity and mortality. Current diagnostic methods of identifying and confirming infection involve culture-based and molecular methods. Both techniques are time-consuming and delays commonly lead to untargeted empirical treatment. An ideal diagnostic method would be noninvasive and highly sensitive and detect pathogenic organisms with a high degree of accuracy to allow targeted treatment. Volatile organic compounds (VOCs) are a diverse group of carbon-based molecules produced and released by humans and microorganisms. VOC detection has the potential in aiding cutaneous wound infection diagnostics using noninvasive and time-efficient methods. This review provides a comprehensive update on VOCs produced and emitted by bacteria commonly associated with chronic wounds and SSIs. VOC sampling has the advantage of being painless, time-efficient, noninvasive, and reproducible. VOCs emitted by these organisms are diverse. In vitro studies have identified potential signature volatile profiles, which can be used in detecting these microorganisms. Combining these profiles with volatile profiles emitted from acute, chronic and surgical wounds in vivo could potentially allow identification of bacterial-specific VOCs. VOC detection has the potential for a relatively inexpensive, portable, noninvasive, and reliable clinical diagnostic tool, which could be used in detecting cutaneous wound infections and guiding their optimal management.

Development of a smartphone-based pulse oximeter with adaptive SNR/power balancing.

Millions worldwide suffer from diseases that exhibit early warnings signs that can be detected by standard clinical-grade diagnostic tools. Unfortunately, such tools are often prohibitively expensive to the developing world leading to inadequate healthcare and high mortality rates. To address this problem, a smartphone-based pulse oximeter is presented that interfaces with the phone through the audio jack, enabling point-of-care measurements of heart rate (HR) and oxygen saturation (SpO2). The device is designed to utilize existing phone resources (e.g., the processor, battery, and memory) resulting in a more portable and inexpensive diagnostic tool than standalone equivalents. By adaptively tuning the LED driving signal, the device is less dependent on phone-specific audio jack properties than prior audio jack-based work making it universally compatible with all smartphones. We demonstrate that the pulse oximeter can adaptively optimize the signal-to-noise ratio (SNR) within the power constraints of a mobile phone (<; 10mW) while maintaining high accuracy (HR error <; 3.4% and SpO2 error <; 3.7%) against a clinical grade instrument.

A Point-of-Need infrared mediated PCR platform with compatible lateral flow strip for HPV detection

With the increasing need of monitoring the epidemiology of serious infectious diseases, food hygiene, food additives and pesticide residues, it is urgent to develop portable, easy-to-use, inexpensive and rapid molecular diagnostic tools. Herein, we demonstrate a prototype of IR mediated Conducting Oil and CarbOn Nanotube circUlaTing PCR (IR-COCONUT PCR) platform for nucleic acid amplification. The presented platform offers a new solution for miniaturized PCR instruments with non-contact heaters by using conducting oil and carbon nanotube as a medium in IR mediated PCR. This novel platform offers accurate and flexible control of temperature through the integration of PID (proportional–integral–derivative) algorithms to manipulate the duty cycle of the voltage signals of IR LED and a peristaltic pump. The ramping rate of the introduced platform in current study is 1.5°C/s for heating speed and −2.0°C/s for cooling speed. This platform fulfills 30 thermal cycles within 50min which is a match to the conventional bench-top PCR thermo cyclers. For demonstration purpose, human papillomavirus (HPV) patient cervical swab specimens were examined. Downstream lateral flow strip (LFS) was also developed to quantity the PCR products from the IR-COCONUT PCR device within 25min. This PCR platform together with the compatible LFS shows great potential for in-field and Point-of-Need (PoN) testing of genetic or contagious diseases.

Electromechanical Coupling Factor of Breast Tissue as a Biomarker for Breast Cancer.

This research aims to validate a new biomarker of breast cancer by introducing electromechanical coupling factor of breast tissue samples as a possible additional indicator of breast cancer. Since collagen fibril exhibits a structural organization that gives rise to a piezoelectric effect, the difference in collagen density between normal and cancerous tissue can be captured by identifying the corresponding electromechanical coupling factor. The design of a portable diagnostic tool and a microelectromechanical systems (MEMS)-based biochip, which is integrated with a piezoresistive sensing layer for measuring the reaction force as well as a microheater for temperature control, is introduced. To verify that electromechanical coupling factor can be used as a biomarker for breast cancer, the piezoelectric model for breast tissue is described with preliminary experimental results on five sets of normal and invasive ductal carcinoma (IDC) samples in the 25-45 temperature range. While the stiffness of breast tissues can be captured as a representative mechanical signature which allows one to discriminate among tissue types especially in the higher strain region, the electromechanical coupling factor shows more distinct differences between the normal and IDC groups over the entire strain region than the mechanical signature. From the two-sample -test, the electromechanical coupling factor under compression shows statistically significant differences ( 0.0039) between the two groups. The increase in collagen density in breast tissue is an objective and reproducible characteristic of breast cancer. Although characterization of mechanical tissue property has been shown to be useful for differentiating cancerous tissue from normal tissue, using a single parameter may not be sufficient for practical usage due to inherent variation among biological samples. The portable breast cancer diagnostic tool reported in this manuscript shows the feasibility of measuring multiple parameters of breast tissue allowing for practical application.

Novel Microwave Torso Scanner for Thoracic Fluid Accumulation Diagnosis and Monitoring

Thoracic fluid accumulation is one of the significant and early-stage manifestations of fatal diseases, such as lung-cancer, liver-failure and congestive heart-failure. Currently, computational-tomography (CT)-Scan is the most widely used tool for the detection of thoracic fluid. Yet, it is unable to detect small amounts of fluid, has ionizing radiation and lacks mobility. On the other hand, microwave imaging systems have emerged as an accurate and portable complementary diagnostic tool. However, there is a lack of a complete clinical platform that can fulfill the requirements of accurate and reliable imaging. Therefore, a microwave torso scanner that is designed to meet those requirements is presented. In this system, two elliptical-arrays of microwave antennas (sensors) transmit signals towards the torso and collect the back-scattered signals. The captured signals are then processed by a frequency-based imaging algorithm to form microwave images that display a possible accumulated fluid. The system successfully detects and localized small volumes (3 mL) of fluid injected at different places inside a torso-phantom. As preparations for future clinical trials, the system is tested on healthy subjects to define the threshold range of healthy scenario images.

Transcranial Doppler Ultrasound Use in Pediatric Traumatic Brain Injury

Transcranial Doppler (TCD) ultrasound is an inexpensive portable diagnostic tool commonly available within most health care systems. A team of trained individuals perform and interpret the test to inform patient care management. The benefit of TCD is well established in adult patients with traumatic brain injury (TBI). However, in children with TBI, it is still considered exploratory, and its use is not a part of the standard of care. This article describes what TCD is, its use in children, and how TCD measurements apply to children and adolescents in an effort to establish criteria for the use of TCD for children with TBI. The benefit of TCD in pediatric TBI is illustrated by two cases of children who participated in a TBI research study. Early indications are that the use of TCD in pediatric cases of TBI may produce unexpected real-time data about the cerebral vasculature and circulation characteristics in children with TBI. TCD ultrasound has the potential for playing an informative diagnostic role in future pediatric TBI management. Ultimately, the goal to promote best outcomes after a TBI requires insights into the multidynamic nature of the injury, and TCD has the ability to support these efforts.

Ex-Vivo Characterization of Bioimpedance Spectroscopy of Normal, Ischemic and Hemorrhagic Rabbit Brain Tissue at Frequencies from 10 Hz to 1 MHz.

Stroke is a severe cerebrovascular disease and is the second greatest cause of death worldwide. Because diagnostic tools (CT and MRI) to detect acute stroke cannot be used until the patient reaches the hospital setting, a portable diagnostic tool is urgently needed. Because biological tissues have different impedance spectra under normal physiological conditions and different pathological states, multi-frequency electrical impedance tomography (MFEIT) can potentially detect stroke. Accurate impedance spectra of normal brain tissue (gray and white matter) and stroke lesions (ischemic and hemorrhagic tissue) are important elements when studying stroke detection with MFEIT. To our knowledge, no study has comprehensively measured the impedance spectra of normal brain tissue and stroke lesions for the whole frequency range of 1 MHz within as short as possible an ex vivo time and using the same animal model. In this study, we established intracerebral hemorrhage and ischemic models in rabbits, then measured and analyzed the impedance spectra of normal brain tissue and stroke lesions ex vivo within 15 min after animal death at 10 Hz to 1 MHz. The results showed that the impedance spectra of stroke lesions significantly differed from those of normal brain tissue; the ratio of change in impedance of ischemic and hemorrhagic tissue with regard to frequency was distinct; and tissue type could be discriminated according to its impedance spectra. These findings further confirm the feasibility of detecting stroke with MFEIT and provide data supporting further study of MFEIT to detect stroke.