Sensors

Research

22 pages, 14018 KiB

Open AccessArticle

A Computer Vision-Based System to Help Health Professionals to Apply Tests for Fall Risk Assessment

by Jesús Damián Blasco-García, Gabriel García-López, Marta Jiménez-Muñoz, Juan Antonio López-Riquelme, Jorge Juan Feliu-Batlle, Nieves Pavón-Pulido and María-Trinidad Herrero

Sensors 2024, 24(6), 2015; https://doi.org/10.3390/s24062015 - 21 Mar 2024

Cited by 4 | Viewed by 2502

Abstract

The increase in life expectancy, and the consequent growth of the elderly population, represents a major challenge to guarantee adequate health and social care. The proposed system aims to provide a tool that automates the evaluation of gait and balance, essential to prevent [...] Read more.

The increase in life expectancy, and the consequent growth of the elderly population, represents a major challenge to guarantee adequate health and social care. The proposed system aims to provide a tool that automates the evaluation of gait and balance, essential to prevent falls in older people. Through an RGB-D camera, it is possible to capture and digitally represent certain parameters that describe how users carry out certain human motions and poses. Such individual motions and poses are actually related to items included in many well-known gait and balance evaluation tests. According to that information, therapists, who would not need to be present during the execution of the exercises, evaluate the results of such tests and could issue a diagnosis by storing and analyzing the sequences provided by the developed system. The system was validated in a laboratory scenario, and subsequently a trial was carried out in a nursing home with six residents. Results demonstrate the usefulness of the proposed system and the ease of objectively evaluating the main items of clinical tests by using the parameters calculated from information acquired with the RGB-D sensor. In addition, it lays the future foundations for creating a Cloud-based platform for remote fall risk assessment and its integration with a mobile assistant robot, and for designing Artificial Intelligence models that can detect patterns and identify pathologies for enabling therapists to prevent falls in users under risk. Full article

(This article belongs to the Special Issue Sensing and Measurement Technologies in Healthcare, Medicine, and Biosciences)

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15 pages, 596 KiB

Open AccessArticle

A High-Resolution LED Stimulator for Steady-State Visual Stimulation: Customizable, Affordable, and Open Source

by Mónica Otero, Yunier Prieur-Coloma, Wael El-Deredy and Alejandro Weinstein

Sensors 2024, 24(2), 678; https://doi.org/10.3390/s24020678 - 21 Jan 2024

Viewed by 1616

Abstract

Visually evoked steady-state potentials (SSVEPs) are neural responses elicited by visual stimuli oscillating at specific frequencies. In this study, we introduce a novel LED stimulator system explicitly designed for steady-state visual stimulation, offering precise control over visual stimulus parameters, including frequency resolution, luminance, [...] Read more.

Visually evoked steady-state potentials (SSVEPs) are neural responses elicited by visual stimuli oscillating at specific frequencies. In this study, we introduce a novel LED stimulator system explicitly designed for steady-state visual stimulation, offering precise control over visual stimulus parameters, including frequency resolution, luminance, and the ability to control the phase at the end of the stimulation. The LED stimulator provides a personalized, modular, and affordable option for experimental setups. Based on the Teensy 3.2 board, the stimulator utilizes direct digital synthesis and pulse width modulation techniques to control the LEDs. We validated its performance through four experiments: the first two measured LED light intensities directly, while the last two assessed the stimulator’s impact on EEG recordings. The results demonstrate that the stimulator can deliver a stimulus suitable for generating SSVEPs with the desired frequency and phase resolution. As an open source resource, we provide comprehensive documentation, including all necessary codes and electrical diagrams, which facilitates the system’s replication and adaptation for specific experimental requirements, enhancing its potential for widespread use in the field of neuroscience setups. Full article

(This article belongs to the Special Issue Sensing and Measurement Technologies in Healthcare, Medicine, and Biosciences)

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14 pages, 2524 KiB

Open AccessArticle

A Non-Invasive Technique for Long-Term Monitoring of Gastroesophageal Reflux—A Pilot Study

by Marco Laracca, Gianfranco Miele, Luca Podestà and Silvia Sangiovanni

Sensors 2023, 23(23), 9459; https://doi.org/10.3390/s23239459 - 28 Nov 2023

Viewed by 1664

Abstract

Many people suffer from gastric or gastroesophageal reflux disorder (GERD) due to a malfunction of the cardia, the valve between the esophagus and the stomach. GERD is a syndrome caused by the ascent of gastric juices and bile from the stomach. This article [...] Read more.

Many people suffer from gastric or gastroesophageal reflux disorder (GERD) due to a malfunction of the cardia, the valve between the esophagus and the stomach. GERD is a syndrome caused by the ascent of gastric juices and bile from the stomach. This article proposes a non-invasive impedance measurement method and demonstrates the correlation between GERD and impedance variation between appropriately chosen points on the patient’s chest. This method is presented as an alternative to the most widely accepted diagnostic techniques for reflux, such as pH-metry, pH-impedance measurement, and esophageal manometry, which are invasive because they use a probe that is inserted through a nostril and reaches down to the esophagus. Full article

(This article belongs to the Special Issue Sensing and Measurement Technologies in Healthcare, Medicine, and Biosciences)

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14 pages, 2440 KiB

Open AccessArticle

Cranial Electrode Belt Position Improves Diagnostic Possibilities of Electrical Impedance Tomography during Laparoscopic Surgery with Capnoperitoneum

by Kristyna Koldova, Ales Rara, Martin Muller, Tomas Tyll and Karel Roubik

Sensors 2023, 23(20), 8644; https://doi.org/10.3390/s23208644 - 23 Oct 2023

Viewed by 1593

Abstract

Laparoscopic surgery with capnoperitoneum brings many advantages to patients, but also emphasizes the negative impact of anesthesia and mechanical ventilation on the lungs. Even though many studies use electrical impedance tomography (EIT) for lung monitoring during these surgeries, it is not clear what [...] Read more.

Laparoscopic surgery with capnoperitoneum brings many advantages to patients, but also emphasizes the negative impact of anesthesia and mechanical ventilation on the lungs. Even though many studies use electrical impedance tomography (EIT) for lung monitoring during these surgeries, it is not clear what the best position of the electrode belt on the patient’s thorax is, considering the cranial shift of the diaphragm. We monitored 16 patients undergoing a laparoscopic surgery with capnoperitoneum using EIT with two independent electrode belts at different tomographic levels: in the standard position of the 4th–6th intercostal space, as recommended by the manufacturer, and in a more cranial position at the level of the axilla. Functional residual capacity (FRC) was measured, and a recruitment maneuver was performed at the end of the procedure by raising the positive end-expiratory pressure (PEEP) by 5 cmH₂O. The results based on the spectral analysis of the EIT signal show that the ventilation-related impedance changes are not detectable by the belt in the standard position. In general, the cranial belt position might be more suitable for the lung monitoring during the capnoperitoneum since the ventilation signal remains dominant in the obtained impedance waveform. FRC was significantly decreased by the capnoperitoneum and remained lower also after desufflation. Full article

(This article belongs to the Special Issue Sensing and Measurement Technologies in Healthcare, Medicine, and Biosciences)

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11 pages, 1884 KiB

Open AccessArticle

by Naama Karniel, Eden Shimon, Noam Gemer, Rotem Zivion and Sigal Portnoy

Sensors 2023, 23(18), 7747; https://doi.org/10.3390/s23187747 - 8 Sep 2023

Viewed by 1313

Abstract

Background: Cognitive bias may appear in occupational therapists’ interpretation of physical examinations. Since different strategies for decision making have been shown to reduce bias, its quantification is an essential first step towards awareness and bias reduction. Our aims: (1) quantify cognitive bias by [...] Read more.

Background: Cognitive bias may appear in occupational therapists’ interpretation of physical examinations. Since different strategies for decision making have been shown to reduce bias, its quantification is an essential first step towards awareness and bias reduction. Our aims: (1) quantify cognitive bias by testing the differences in occupational therapists’ assessment of lateral pinch force modulation between young and older adults, and between women and men; and (2) to test for a correlation between the tendency to bypass an intuitive response and the degree of cognitive bias. Methods: Occupational therapists (n = 37; age 40.3 ± 11.4 years) used a visual analogue scale to rate pre-recorded simulations of the digital output of lateral pinch modulation videos of different levels of abilities coupled with videos of young/old men/woman pressing the force sensor. They filled out the Cognitive Reflection Test and the Rational-Experiential Inventory-40. Results: Subjects showed higher bias towards old individuals compared to young ones (p < 0.001), but with no sex bias (p = 0.119). Rational ability correlated with cognitive bias of assessment of lateral pinch modulation in old individuals (r = 0.537, p < 0.001). Discussion: Occupational therapists might underestimate the physical abilities of older adults. Biased evaluation might cause assignment of redundant exercises and therefore loss of time, effort, and resources. Full article

(This article belongs to the Special Issue Sensing and Measurement Technologies in Healthcare, Medicine, and Biosciences)

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26 pages, 6324 KiB

Open AccessArticle

Functional Enhancement and Characterization of an Electrophysiological Mapping Electrode Probe with Carbonic, Directional Macrocontacts

by Radu C. Popa, Cosmin-Andrei Serban, Andrei Barborica, Ana-Maria Zagrean, Octavian Buiu, Niculae Dumbravescu, Alexandru-Catalin Paslaru, Cosmin Obreja, Cristina Pachiu, Marius Stoian, Catalin Marculescu, Antonio Radoi, Silviu Vulpe and Marian Ion

Sensors 2023, 23(17), 7497; https://doi.org/10.3390/s23177497 - 29 Aug 2023

Viewed by 1671

Abstract

Electrophysiological mapping (EM) using acute electrode probes is a common procedure performed during functional neurosurgery. Due to their constructive specificities, the EM probes are lagging in innovative enhancements. This work addressed complementing a clinically employed EM probe with carbonic and circumferentially segmented macrocontacts [...] Read more.

Electrophysiological mapping (EM) using acute electrode probes is a common procedure performed during functional neurosurgery. Due to their constructive specificities, the EM probes are lagging in innovative enhancements. This work addressed complementing a clinically employed EM probe with carbonic and circumferentially segmented macrocontacts that are operable both for neurophysiological sensing (“recording”) of local field potentials (LFP) and for test stimulation. This paper illustrates in-depth the development that is based on the direct writing of functional materials. The unconventional fabrication processes were optimized on planar geometry and then transferred to the cylindrically thin probe body. We report and discuss the constructive concept and architecture of the probe, characteristics of the electrochemical interface deduced from voltammetry and chronopotentiometry, and the results of in vitro and in vivo recording and pulse stimulation tests. Two- and three-directional macrocontacts were added on probes having shanks of 550 and 770 μm diameters and 10–23 cm lengths. The graphitic material presents a ~2.7 V wide, almost symmetric water electrolysis window, and an ultra-capacitive charge transfer. When tested with clinically relevant 150 μs biphasic current pulses, the interfacial polarization stayed safely away from the water window for pulse amplitudes up to 9 mA (135 μC/cm²). The in vivo experiments on adult rat models confirmed the high-quality sensing of LFPs. Additionally, the in vivo-prevailing increase in the electrode impedance and overpotential are discussed and modeled by an ionic mobility-reducing spongiform structure; this restricted diffusion model gives new applicative insight into the in vivo-uprisen stimulation overpotential. Full article

(This article belongs to the Special Issue Sensing and Measurement Technologies in Healthcare, Medicine, and Biosciences)

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12 pages, 4644 KiB

Open AccessArticle

Comparative Evaluations on Real-Time Monitoring of Temperature Sensors during Endoscopic Laser Application

by Minh Duc Ta, Van Gia Truong, Seonghee Lim, Byeong-Il Lee and Hyun Wook Kang

Sensors 2023, 23(13), 6069; https://doi.org/10.3390/s23136069 - 30 Jun 2023

Cited by 2 | Viewed by 1830

Abstract

Temperature sensors, such as Fiber Bragg Grating (FBG) and thermocouple (TC), have been widely used for monitoring the interstitial tissue temperature during laser irradiation. The aim of the current study was to compare the performance of both FBG and TC in real-time temperature [...] Read more.

Temperature sensors, such as Fiber Bragg Grating (FBG) and thermocouple (TC), have been widely used for monitoring the interstitial tissue temperature during laser irradiation. The aim of the current study was to compare the performance of both FBG and TC in real-time temperature monitoring during endoscopic and circumferential laser treatment on tubular tissue structure. A 600-µm core-diameter diffusing applicator was employed to deliver 980-nm laser light (30 W for 90 s) circumferentially for quantitative evaluation. The tip of the TC was covered with a white tube (W-TC) in order to prevent direct light absorption and to minimize temperature overestimation. The temperature measurements in air demonstrated that the measurement difference in the temperature elevations was around 3.5 °C between FBG and W-TC. Ex vivo porcine liver tests confirmed that the measurement difference became lower (less than 1 °C). Ex vivo porcine esophageal tissue using a balloon-integrated catheter exhibited that both FBG and W-TC consistently showed a comparable trend of temperature measurements during laser irradiation (~2 °C). The current study demonstrated that the white tube-covered TC could be a feasible sensor to monitor interstitial tissue temperature with minimal overestimation during endoscopic laser irradiation. Further in vivo studies on gastroesophageal reflux disease will investigate the performance of the W-TC to monitor the temperature of the esophageal mucosa surface in real-time mode to warrant the safety of endoscopic laser treatment. Full article

(This article belongs to the Special Issue Sensing and Measurement Technologies in Healthcare, Medicine, and Biosciences)

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18 pages, 7583 KiB

Open AccessArticle

A Novel Dielectric Modulated Gate-Stack Double-Gate Metal-Oxide-Semiconductor Field-Effect Transistor-Based Sensor for Detecting Biomolecules

by Dibyendu Chowdhury, Bishnu Prasad De, Bhargav Appasani, Navaneet Kumar Singh, Rajib Kar, Durbadal Mandal, Nicu Bizon and Phatiphat Thounthong

Sensors 2023, 23(6), 2953; https://doi.org/10.3390/s23062953 - 8 Mar 2023

Cited by 10 | Viewed by 2745

Abstract

In this article, the performance of n-type junctionless (JL) double-gate (DG) MOSFET-based biosensors with and without gate stack (GS) has been studied. Here, the dielectric modulation (DM) method is applied to detect biomolecules in the cavity. The sensitivity of n-type JL-DM-DG-MOSFET and n-type [...] Read more.

In this article, the performance of n-type junctionless (JL) double-gate (DG) MOSFET-based biosensors with and without gate stack (GS) has been studied. Here, the dielectric modulation (DM) method is applied to detect biomolecules in the cavity. The sensitivity of n-type JL-DM-DG-MOSFET and n-type JL-DM-GSDG-MOSFET-based biosensors have also been evaluated. The sensitivity (ΔV_th) improved in JL-DM-GSDG MOSFET/JL-DM-DG-MOSFET-based biosensors for neutral/charged biomolecules is 116.66%/66.66% and 1165.78%/978.94%, respectively, compared with the previously reported results. The electrical detection of biomolecules is validated using the ATLAS device simulator. The noise and analog/RF parameters are compared between both biosensors. A lower threshold voltage is observed in the GSDG-MOSFET-based biosensor. The I_on/I_off ratio is higher for DG-MOSFET-based biosensors. The proposed GSDG-MOSFET-based biosensor demonstrates higher sensitivity than the DG-MOSFET-based biosensor. The GSDG-MOSFET-based biosensor is suitable for low-power, high-speed, and high sensitivity applications. Full article

(This article belongs to the Special Issue Sensing and Measurement Technologies in Healthcare, Medicine, and Biosciences)

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19 pages, 2067 KiB

Open AccessArticle

Measuring the Effectiveness of a Multicomponent Program to Manage Academic Stress through a Resilience to Stress Index

by Carlos Figueroa, Andrés Ayala, Luis A. Trejo, Bertha Ramos, Clara L. Briz, Isabella Noriega and Alejandro Chávez

Sensors 2023, 23(5), 2650; https://doi.org/10.3390/s23052650 - 28 Feb 2023

Cited by 6 | Viewed by 4677

Abstract

In this work, we evaluate the effectiveness of a multicomponent program that includes psychoeducation in academic stress, mindfulness training, and biofeedback-assisted mindfulness, while enhancing the Resilience to Stress Index (RSI) of students through the control of autonomic recovery from psychological stress. Participants are [...] Read more.

In this work, we evaluate the effectiveness of a multicomponent program that includes psychoeducation in academic stress, mindfulness training, and biofeedback-assisted mindfulness, while enhancing the Resilience to Stress Index (RSI) of students through the control of autonomic recovery from psychological stress. Participants are university students enrolled in a program of excellence and are granted an academic scholarship. The dataset consists of an intentional sample of 38 undergraduate students with high academic performance, 71% (27) women, 29% (11) men, and 0% (0) non-binary, with an average age of 20 years. The group belongs to the “Leaders of Tomorrow” scholarship program from Tecnológico de Monterrey University, in Mexico. The program is structured in 16 individual sessions during an eight-week period, divided into three phases: pre-test evaluation, training program, and post-test evaluation. During the evaluation test, an assessment of the psychophysiological stress profile is performed while the participants undergo a stress test; it includes simultaneous recording of skin conductance, breathing rate, blood volume pulse, heart rate, and heart rate variability. Based on the pre-test and post-test psychophysiological variables, an RSI is computed under the assumption that changes in physiological signals due to stress can be compared against a calibration stage. The results show that approximately 66% of the participants improved their academic stress management after the multicomponent intervention program. A Welch’s t-test showed a difference in mean RSI scores (t = −2.30, p = 0.025) between the pre-test and post-test phases. Our findings show that the multicomponent program promoted positive changes in the RSI and in the management of the psychophysiological responses to academic stress. Full article

(This article belongs to the Special Issue Sensing and Measurement Technologies in Healthcare, Medicine, and Biosciences)

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13 pages, 5681 KiB

Open AccessArticle

Classification of Heart Sounds Using Chaogram Transform and Deep Convolutional Neural Network Transfer Learning

by Ali Harimi, Yahya Majd, Abdorreza Alavi Gharahbagh, Vahid Hajihashemi, Zeynab Esmaileyan, José J. M. Machado and João Manuel R. S. Tavares

Sensors 2022, 22(24), 9569; https://doi.org/10.3390/s22249569 - 7 Dec 2022

Cited by 16 | Viewed by 3902

Abstract

Heart sounds convey important information regarding potential heart diseases. Currently, heart sound classification attracts many researchers from the fields of telemedicine, digital signal processing, and machine learning—among others—mainly to identify cardiac pathology as quickly as possible. This article proposes chaogram as a new [...] Read more.

Heart sounds convey important information regarding potential heart diseases. Currently, heart sound classification attracts many researchers from the fields of telemedicine, digital signal processing, and machine learning—among others—mainly to identify cardiac pathology as quickly as possible. This article proposes chaogram as a new transform to convert heart sound signals to colour images. In the proposed approach, the output image is, therefore, the projection of the reconstructed phase space representation of the phonocardiogram (PCG) signal on three coordinate planes. This has two major benefits: (1) it makes possible to apply deep convolutional neural networks to heart sounds and (2) it is also possible to employ a transfer learning scheme by converting a heart sound signal to an image. The performance of the proposed approach was verified on the PhysioNet dataset. Due to the imbalanced data on this dataset, it is common to assess the results quality using the average of sensitivity and specificity, which is known as score, instead of accuracy. In this study, the best results were achieved using the

I n c e p t i o n V 3

model, which achieved a score of 88.06%. Full article

(This article belongs to the Special Issue Sensing and Measurement Technologies in Healthcare, Medicine, and Biosciences)

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18 pages, 13746 KiB

Open AccessArticle

Optimized Acoustic Phantom Design for Characterizing Body Sound Sensors

by Valerie Rennoll, Ian McLane, Mounya Elhilali and James E. West

Sensors 2022, 22(23), 9086; https://doi.org/10.3390/s22239086 - 23 Nov 2022

Cited by 2 | Viewed by 2521

Abstract

Many commercial and prototype devices are available for capturing body sounds that provide important information on the health of the lungs and heart; however, a standardized method to characterize and compare these devices is not agreed upon. Acoustic phantoms are commonly used because [...] Read more.

Many commercial and prototype devices are available for capturing body sounds that provide important information on the health of the lungs and heart; however, a standardized method to characterize and compare these devices is not agreed upon. Acoustic phantoms are commonly used because they generate repeatable sounds that couple to devices using a material layer that mimics the characteristics of skin. While multiple acoustic phantoms have been presented in literature, it is unclear how design elements, such as the driver type and coupling layer, impact the acoustical characteristics of the phantom and, therefore, the device being measured. Here, a design of experiments approach is used to compare the frequency responses of various phantom constructions. An acoustic phantom that uses a loudspeaker to generate sound and excite a gelatin layer supported by a grid is determined to have a flatter and more uniform frequency response than other possible designs with a sound exciter and plate support. When measured on an optimal acoustic phantom, three devices are shown to have more consistent measurements with added weight and differing positions compared to a non-optimal phantom. Overall, the statistical models developed here provide greater insight into acoustic phantom design for improved device characterization. Full article

(This article belongs to the Special Issue Sensing and Measurement Technologies in Healthcare, Medicine, and Biosciences)

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18 pages, 1110 KiB

Open AccessArticle

Development and Assessment of a Movement Disorder Simulator Based on Inertial Data

by Chiara Carissimo, Gianni Cerro, Luigi Ferrigno, Giacomo Golluccio and Alessandro Marino

Sensors 2022, 22(17), 6341; https://doi.org/10.3390/s22176341 - 23 Aug 2022

Cited by 10 | Viewed by 2206

Abstract

The detection analysis of neurodegenerative diseases by means of low-cost sensors and suitable classification algorithms is a key part of the widely spreading telemedicine techniques. The choice of suitable sensors and the tuning of analysis algorithms require a large amount of data, which [...] Read more.

The detection analysis of neurodegenerative diseases by means of low-cost sensors and suitable classification algorithms is a key part of the widely spreading telemedicine techniques. The choice of suitable sensors and the tuning of analysis algorithms require a large amount of data, which could be derived from a large experimental measurement campaign involving voluntary patients. This process requires a prior approval phase for the processing and the use of sensitive data in order to respect patient privacy and ethical aspects. To obtain clearance from an ethics committee, it is necessary to submit a protocol describing tests and wait for approval, which can take place after a typical period of six months. An alternative consists of structuring, implementing, validating, and adopting a software simulator at most for the initial stage of the research. To this end, the paper proposes the development, validation, and usage of a software simulator able to generate movement disorders-related data, for both healthy and pathological conditions, based on raw inertial measurement data, and give tri-axial acceleration and angular velocity as output. To present a possible operating scenario of the developed software, this work focuses on a specific case study, i.e., the Parkinson’s disease-related tremor, one of the main disorders of the homonym pathology. The full framework is reported, from raw data availability to pathological data generation, along with a common machine learning method implementation to evaluate data suitability to be distinguished and classified. Due to the development of a flexible and easy-to-use simulator, the paper also analyses and discusses the data quality, described with typical measurement features, as a metric to allow accurate classification under a low-performance sensing device. The simulator’s validation results show a correlation coefficient greater than 0.94 for angular velocity and 0.93 regarding acceleration data. Classification performance on Parkinson’s disease tremor was greater than 98% in the best test conditions. Full article

(This article belongs to the Special Issue Sensing and Measurement Technologies in Healthcare, Medicine, and Biosciences)

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Review

Jump to: Research, Other

25 pages, 664 KiB

Open AccessReview

Indirect Calorimetry in Spontaneously Breathing, Mechanically Ventilated and Extracorporeally Oxygenated Patients: An Engineering Review

by Sebastiaan Priem, Joop Jonckheer, Elisabeth De Waele and Johan Stiens

Sensors 2023, 23(8), 4143; https://doi.org/10.3390/s23084143 - 20 Apr 2023

Cited by 3 | Viewed by 5354

Abstract

Indirect calorimetry (IC) is considered the gold standard for measuring resting energy expenditure (REE). This review presents an overview of the different techniques to assess REE with special regard to the use of IC in critically ill patients on extracorporeal membrane oxygenation (ECMO), [...] Read more.

Indirect calorimetry (IC) is considered the gold standard for measuring resting energy expenditure (REE). This review presents an overview of the different techniques to assess REE with special regard to the use of IC in critically ill patients on extracorporeal membrane oxygenation (ECMO), as well as to the sensors used in commercially available indirect calorimeters. The theoretical and technical aspects of IC in spontaneously breathing subjects and critically ill patients on mechanical ventilation and/or ECMO are covered and a critical review and comparison of the different techniques and sensors is provided. This review also aims to accurately present the physical quantities and mathematical concepts regarding IC to reduce errors and promote consistency in further research. By studying IC on ECMO from an engineering point of view rather than a medical point of view, new problem definitions come into play to further advance these techniques. Full article

(This article belongs to the Special Issue Sensing and Measurement Technologies in Healthcare, Medicine, and Biosciences)

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28 pages, 4852 KiB

Open AccessReview

Electromagnetic Sensing Techniques for Monitoring Atopic Dermatitis—Current Practices and Possible Advancements: A Review

by Alexandar Todorov, Russel Torah, Mahmoud Wagih, Michael R. Ardern-Jones and Steve P. Beeby

Sensors 2023, 23(8), 3935; https://doi.org/10.3390/s23083935 - 12 Apr 2023

Cited by 7 | Viewed by 3553 | Correction

Abstract

Atopic dermatitis (AD) is one of the most common skin disorders, affecting nearly one-fifth of children and adolescents worldwide, and currently, the only method of monitoring the condition is through an in-person visual examination by a clinician. This method of assessment poses an [...] Read more.

Atopic dermatitis (AD) is one of the most common skin disorders, affecting nearly one-fifth of children and adolescents worldwide, and currently, the only method of monitoring the condition is through an in-person visual examination by a clinician. This method of assessment poses an inherent risk of subjectivity and can be restrictive to patients who do not have access to or cannot visit hospitals. Advances in digital sensing technologies can serve as a foundation for the development of a new generation of e-health devices that provide accurate and empirical evaluation of the condition to patients worldwide. The goal of this review is to study the past, present, and future of AD monitoring. First, current medical practices such as biopsy, tape stripping and blood serum are discussed with their merits and demerits. Then, alternative digital methods of medical evaluation are highlighted with the focus on non-invasive monitoring using biomarkers of AD—TEWL, skin permittivity, elasticity, and pruritus. Finally, possible future technologies are showcased such as radio frequency reflectometry and optical spectroscopy along with a short discussion to provoke research into improving the current techniques and employing the new ones to develop an AD monitoring device, which could eventually facilitate medical diagnosis. Full article

(This article belongs to the Special Issue Sensing and Measurement Technologies in Healthcare, Medicine, and Biosciences)

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14 pages, 428 KiB

Open AccessReview

Parasitic Effects on Electrical Bioimpedance Systems: Critical Review

by David William Cordeiro Marcôndes, Aleksander Sade Paterno and Pedro Bertemes-Filho

Sensors 2022, 22(22), 8705; https://doi.org/10.3390/s22228705 - 11 Nov 2022

Cited by 6 | Viewed by 3172

Abstract

Parasitic capacitance represents the main error source in measurement systems based on electrical impedance spectroscopy. The capacitive nature of electrodes’ impedance in tetrapolar configuration can give origin to phase errors when electrodes are coupled to parasitic capacitances. Nevertheless, reactive charges in tissue excitation [...] Read more.

Parasitic capacitance represents the main error source in measurement systems based on electrical impedance spectroscopy. The capacitive nature of electrodes’ impedance in tetrapolar configuration can give origin to phase errors when electrodes are coupled to parasitic capacitances. Nevertheless, reactive charges in tissue excitation systems are susceptible to instability. Based on such a scenario, mitigating capacitive effects associated with the electrode is a requirement in order to reduce errors in the measurement system. A literature review about the main compensation techniques for parasitic capacitance was carried out. The selected studies were categorized into three groups: (i) compensation in electronic instrumentation; (ii) compensation in measurement processing, and (iii) compensation by negative impedance converters. The three analyzed methods emerged as effective against fixed capacitance. No method seemed capable of mitigating the effects of electrodes’ capacitance, that changes in the frequency spectrum. The analysis has revealed the need for a method to compensate varying capacitances, since electrodes’ impedance is unknown. Full article

(This article belongs to the Special Issue Sensing and Measurement Technologies in Healthcare, Medicine, and Biosciences)

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32 pages, 7099 KiB

Open AccessReview

Overview of Biofluids and Flow Sensing Techniques Applied in Clinical Practice

by Carlos Yáñez, Gerard DeMas-Giménez and Santiago Royo

Sensors 2022, 22(18), 6836; https://doi.org/10.3390/s22186836 - 9 Sep 2022

Cited by 11 | Viewed by 5700

Abstract

This review summarizes the current knowledge on biofluids and the main flow sensing techniques applied in healthcare today. Since the very beginning of the history of medicine, one of the most important assets for evaluating various human diseases has been the analysis of [...] Read more.

This review summarizes the current knowledge on biofluids and the main flow sensing techniques applied in healthcare today. Since the very beginning of the history of medicine, one of the most important assets for evaluating various human diseases has been the analysis of the conditions of the biofluids within the human body. Hence, extensive research on sensors intended to evaluate the flow of many of these fluids in different tissues and organs has been published and, indeed, continues to be published very frequently. The purpose of this review is to provide researchers interested in venturing into biofluid flow sensing with a concise description of the physiological characteristics of the most important body fluids that are likely to be altered by diverse medical conditions. Similarly, a reported compilation of well-established sensors and techniques currently applied in healthcare regarding flow sensing is aimed at serving as a starting point for understanding the theoretical principles involved in the existing methodologies, allowing researchers to determine the most suitable approach to adopt according to their own objectives in this broad field. Full article

(This article belongs to the Special Issue Sensing and Measurement Technologies in Healthcare, Medicine, and Biosciences)

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Other

Jump to: Research, Review

1 pages, 158 KiB

Open AccessCorrection

Correction: Todorov et al. Electromagnetic Sensing Techniques for Monitoring Atopic Dermatitis—Current Practices and Possible Advancements: A Review. Sensors 2023, 23, 3935

by Alexandar Todorov, Russel Torah, Mahmoud Wagih, Michael R. Ardern-Jones and Steve P. Beeby

Sensors 2023, 23(24), 9888; https://doi.org/10.3390/s23249888 - 18 Dec 2023

Viewed by 927

Abstract

**Mahmoud Wagih** was not included as an author in the original publication [...] Full article

(This article belongs to the Special Issue Sensing and Measurement Technologies in Healthcare, Medicine, and Biosciences)

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