Physiological monitoring has become an inherently interdisciplinary field, merging advances in engineering, chemistry, biology, medicine, and data analytics to create sensors that continuously track the vital signals of the body. These developments are enabling more personalized and preventive healthcare, as wearable (bio)sensors and intelligent algorithms can detect subtle physiological changes in real-time. In the Special Issue 'Advances in (Bio)Sensors for Physiological Monitoring', researchers from diverse domains contributed 18 papers showcasing cutting-edge sensor technologies and applications for health and performance monitoring. In this review, we summarize these contributions by grouping them into logical themes based on their focus: (1) cardiovascular and autonomic monitoring, (2) glucose and metabolic monitoring, (3) wearable sensors for movement and musculoskeletal health, (4) neurophysiological monitoring and brain-computer interfaces, and (5) innovations in sensor technology and methods. This thematic organization highlights the breadth of the research, spanning from fundamental sensor hardware to data-driven analytics, and underscores how modern (bio)sensors are breaking traditional boundaries in healthcare.

Background: The COVID-19 pandemic had a significant impact on the public health and the economy of the Swedish population, with disproportionate effects on communities living in socioeconomically diverse neighborhoods. To mitigate these impacts and enhance outreach, COVID-19 diagnostic and prevention services supported by digital health tools were introduced for early diagnosis and prevention. Assessing the perceptions related to utilization of these efforts is essential to ensure they are benefiting the particular populations living in socioeconomically disadvantaged neighborhoods. Therefore, the aim of this study was to demonstrate available COVID-19 diagnostic tools and explore the implementation of COVID-19 diagnostics and the digital support services from the experiences of lay health promoters (LHPs) in a socioeconomically disadvantaged neighborhood in Malmö. Method: Five LHPs participated in an online focus group via Zoom, in May 2021. The session began with an online presentation of testing procedures, followed by discussion to gather user perspectives. The data was analyzed using the Rapid Identification of Themes from Audio recordings method. Results: Health promoters reported a lack of trust in existing COVID self-test procedures due to validity issues and frequent false-negative results. Polymerase chain reaction testing procedures were deemed inadequate because of delays in receiving results. Additionally, the neighborhood faced barriers to vaccination access, including challenges in using digital technology to book test and vaccination, distance to vaccination centers, and unavailability of slots. Conclusion: This study highlights the need for affordable and easy-to-use COVID-19 test alternatives in these neighborhoods. The implementation of digital healthcare solutions during the pandemic faced significant challenges, limiting access to care and support in socioeconomically disadvantaged neighborhoods. Therefore, implementing digital healthcare initiatives for disease diagnosis and prevention at the national level requires strategic planning that considers the needs and capabilities of residents in socioeconomically disadvantaged areas. Furthermore, the importance of increasing targeted vaccination centers and educating community representatives, such as health promoters, to better support their communities during crises, was emphasized.

In recent years, we have witnessed a convergence of disciplines in physiological monitoring [...].

A wireless potentiometric sensor offers a robust platform for detecting microbial growth, which is crucial for managing infected wounds that can lead to serious complications such as tissue spread, systemic infection, or sepsis, potentially resulting in life-threatening conditions. Herein, a solid-state potentiometric working/reference electrode system with a Bluetooth-enabled system on a chip, supporting continuous wireless monitoring of microbial growth is shown. The sensor monitors open circuit potentials (OCPs) in culture media, which significantly decrease due to bacterial growth after inoculation with Gram-positive Staphylococcus aureus, Gram-negative Pseudomonas aeruginosa, and Escherichia coli. Notably, Staphylococcus aureus demonstrates lower electrogenic activity compared with the Gram-negative bacteria, likely owing to its reduced viability. Following thorough in vitro testing, the sensor is also evaluated ex vivo. Stable connections between the sensor and a smartphone receiver ensure reliable data collection and processing, facilitating remote monitoring. A slight decrease in OCP is observed in rat wounds inoculated with Staphylococcus aureus and significant decrease with Pseudomonas aeruginosa. Incorporation of the wireless sensing module for continuous measurement and data collection can greatly enhance early detection capabilities regarding bacterial infections in wounds. This setup offers a convenient and effective method for point-of-care sensing, significantly advancing the management and treatment of wound infections.

Galactose monitoring in individuals allows the prevention of harsh health conditions related to hereditary metabolic diseases like galactosemia. Current methods of galactose detection need development to obtain cheaper, more reliable, and more specific sensors. Enzyme-containing amperometric sensors based on galactose oxidase activity are a promising approach, which can be enhanced by means of their inclusion in a redox polymer coating. This strategy simultaneously allows the immobilization of the biocatalyst to the electroactive surface and hosts the electron shuttling units. An additional deposition of capping polymers prevents external interferences like ascorbic or uric acid as well as biofouling when measuring in physiological fuels. This work studies the protection effect of poly(2-methacryloyloxyethyl phosphorylcholine-co-glycidyl methacrylate (MPC) and polyvinylimidazole-polysulfostyrene (P(VI-SS)) when incorporated in the biosensor design for the detection of galactose in human plasma.

Capacitive humidity sensors typically consist of interdigitated electrodes coated with a dielectric layer sensitive to varying relative humidity levels. Previous studies have investigated different polymeric materials that exhibit changes in conductivity in response to water vapor to design capacitive humidity sensors. However, lipid films like monoolein have not yet been integrated with humidity sensors, nor has the potential use of capacitive sensors for skin hydration measurements been fully explored. This study explores the application of monoolein-coated wireless capacitive sensors for assessing relative humidity and skin hydration, utilizing the sensitive dielectric properties of the monoolein-water system. This sensitivity hinges on the water absorption and release from the surrounding environment. Tested across various humidity levels and temperatures, these novel double functional sensors feature interdigitated electrodes covered with monoolein and show promising potential for wireless detection of skin hydration. The water uptake and rheological behavior of monoolein in response to humidity were evaluated using a quartz crystal microbalance with dissipation monitoring. The findings from these experiments suggest that the capacitance of the system is primarily influenced by the amount of water in the monoolein system, with the lyotropic or physical state of monoolein playing a secondary role. A proof-of-principle demonstration compared the sensor's performance under varying conditions to that of other commercially available skin hydration meters, affirming its effectiveness, reliability, and commercial viability.

Managing blood glucose can affect important clinical outcomes during the intraoperative phase of surgery. However, currently available instruments for glucose monitoring during surgery are few and not optimized for the specific application. Here we report an attempt to exploit an enzymatic sensor in a vein replica that could continuously monitor glucose level in an authentic human bloodstream. First, detailed investigations of the superficial venous systems of volunteers were carried out using ocular and palpating examinations, as well as advanced ultrasound measurements. Second, a tubular glucose-sensitive biosensor mimicking a venous system was designed and tested. Almost ideal linear dependence of current output on glucose concentration in phosphate buffer saline was obtained in the range 2.2-22.0 mM, whereas the dependence in human plasma was less linear. Finally, the developed biosensor was investigated in whole blood under homeostatic conditions. A specific correlation was found between the current output and glucose concentration at the initial stage of the biodevice operation. However, with time, blood coagulation during measurements negatively affected the performance of the biodevice. When the experimental results were remodeled to predict the response without the influence of blood coagulation, the sensor output closely followed the blood glucose level.

An electronic tongue is a powerful analytical instrument based on an array of non-selective chemical sensors with a partial specificity for data gathering and advanced pattern recognition methods for data analysis. Connecting electronic tongues with electrochemical techniques for data collection has led to various applications, mostly within sensing for food quality and environmental monitoring, but also in biomedical research for the analyses of different bioanalytes in human physiological fluids. In this paper, an electronic tongue consisting of six electrodes (viz., gold, platinum, palladium, titanium, iridium, and glassy carbon) was designed and tested in authentic (undiluted, unpretreated) human saliva samples from eight volunteers, collected before and during the COVID-19 pandemic. Investigations of 11 samples using differential pulse voltammetry and a principal component analysis allowed us to distinguish between SARS-CoV-2-free and infected authentic human saliva. This work, as a proof-of-principle demonstration, provides a new perspective for the use of electronic tongues in the field of enzyme-free electrochemical biosensing, highlighting their potential for future applications in non-invasive biomedical analyses.

The lack of culturally and contextually oriented interventions promoting physical activity (PA) has led to increased physical inactivity among women living in disadvantaged neighbourhoods in Sweden. In this study one such intervention informed by community-based participatory research (CBPR) has been evaluated among 34 women from a disadvantaged neighbourhood before and during COVID-19. Health-related quality of life (HRQOL), behavioural and biomedical outcomes were assessed directly prior and post-intervention, followed by evaluations at 6-months and 18-months follow-up during COVID-19. The results revealed that HRQOL, particularly psychological, social, and environmental health significantly increased post-intervention compared to prior to intervention but reversed back at 6-months follow-up. Perceived health satisfaction and environmental health increased at 18-months follow-up during COVID-19. Participation in PA improved post-intervention and at 6-months follow-up. Everyday activities and fruit and vegetable intake continued to increase through all timepoints. Systolic blood pressure significantly decreased post-intervention and 6-months follow-up; blood flow rate increased significantly at all timepoints. Overall, the findings underscores the potential effectiveness of CBPR approaches in promoting and sustaining healthy lifestyles, even during acute situations such as the COVID-19. It may even serve as a future model for promoting health and addressing health disparities in similar groups.