Non-invasive healthcare technologies are increasingly pivotal in research anddevelopment due to their affordability and the convenience they offer to bothhealthcare recipients and providers. Alongside traditional non-invasive methodssuch as ultrasound imaging, a variety of innovative non-invasive devices havebeen developed. These include cardiovascular diagnostic systems, bioimpedancebasedscales, and various types of analyzers. These analyzers, which can be fluidlessor fluid-based, are capable of measuring not just physical parameters of thebody but also key biomarkers like glucose and lactate. This comprehensive andtransdisciplinary thesis encompasses three distinct yet interconnected segments:1) Advanced ultrasound imaging (Papers I and II): The first explored vortexformation time in female athletes and the second detailed investigations of thesuperficial venous systems of apparently healthy volunteers.2) Validation and application of commercially available fluid-less bloodanalyzers (Papers IV-VI). These papers focus on non-invasive blood glucosemonitoring (Paper IV) and the general use of non-invasive healthcaretechnologies among female participants from socioeconomicallydisadvantaged areas (Papers V and VI).3) Design and testing of novel, fluid-based sensors, and biosensors (Papers II andIII): Paper II delves into biosensing of viruses, and paper III deals withcontinuous ex vivo glucose sensing in human blood using an enzymatic sensorin a vein replica.Each of these segments contribute to the broader understanding and advancementof non-invasive healthcare technologies, highlighting the significant role suchtechnologies play in modern healthcare research. The thesis's transdisciplinaryapproach, spanning from advanced imaging techniques to the development ofnovel biosensors, exemplifies the dynamic and evolving nature of medicaltechnology research.

Regular, vigorous physical activity can have a significant impact on cardiac function, leading to cardiac morphological alterations that may be challenging to distinguish from pathological changes. Therefore, new screening methods are needed to accurately differentiate between adaptive changes and pathological alterations in athletes. Vortex formation time (VFT) is an emerging method that shows potential in this regard, as it involves the formation of a rotating vortex ring in the left ventricle during the early filling phase of diastole. In this study, we investigated the difference in VFT between two groups of women: professional handball players and healthy middle-aged female athletes, along with their corresponding control groups. By using echocardiography-Doppler analysis of the heart, VFT was calculated based on the left ventricular ejection fraction, the ratio between the end-diastolic volume and the diameter of the mitral annulus, and the ratio of the atrial contraction volume to the total inflow via the mitral valve. The study reveals a significant increase in VFT in both professional handball players and middle-aged female athletes compared to their respective control groups. Moreover, statistically significant differences between handball players and middle-aged female athletes were observed, indicating that the level of physical activity may affect the VFT. These results suggest that VFT could be a promising screening tool for identifying cardiac adaptations due to long-term vigorous training, potentially enabling more accurate diagnoses of cardiac morphological alterations in athletes. Representation of the graphical abstract of the conducted research.

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.

When compared to the general population, socioeconomically disadvantaged communitiesfrequently experience compromised health. Monitoring the divide is challenging since standardizedbiomedical tests are linguistically and culturally inappropriate. The aim of this study was to developand test a unique mobile biomedical testbed based on non-invasive analysis, as well as to explorethe relationships between the objective health measures and subjective health outcomes, asevaluated with the World Health Organization Quality of Life survey. The testbed was evaluated in asocioeconomically disadvantaged neighborhood in Malmö, which has been listed as one of the twelvemost vulnerable districts in Sweden. The study revealed that compared to conventional protocolsthe less intrusive biomedical approach was highly appreciated by the participants. Surprisingly, thecollected biomedical data illustrated that the apparent health of the participants from the ethnicallydiverse low-income neighborhood was comparable to the general Swedish population. Statisticallysignificant correlations between perceived health and biomedical data were disclosed, even thoughthe dependences found were complex, and recognition of the manifest complexity needs to beincluded in further research. Our results validate the potential of non-invasive technologies incombination with advanced statistical analysis, especially when combined with linguistically andculturally appropriate healthcare methodologies, allowing participants to appreciate the significanceof the different parameters to evaluate and monitor aspects of health.

Sweat is a promising biofluid in allowing for non-invasive sampling. Here, we investigate the use of a voltammetric electronic tongue, combining different metal electrodes, for the purpose of non-invasive sample assessment, specifically focusing on sweat. A wearable electronic tongue is presented by incorporating metal electrodes on a flexible circuit board and used to non-invasively monitor sweat on the body. The data obtained from the measurements were treated by multivariate data processing. Using principal component analysis to analyze the data collected by the wearable electronic tongue enabled differentiation of sweat samples of different chemical composition, and when combined with 1H-NMR sample differentiation could be attributed to changing analyte concentrations.

Non-invasive healthcare technologies are an important part of research and development nowadays due to the low cost and convenience offered to both healthcare receivers and providers. This work overviews the recent advances in the field of non-invasive electrochemical biosensors operating in secreted human physiological fluids, viz. tears, sweat, saliva, and urine. Described electrochemical devices are based on different electrochemical techniques, viz. amperometry, coulometry, cyclic voltammetry, and impedance spectroscopy. Challenges that confront researchers in this exciting area and key requirements for biodevices are discussed. It is concluded that the field of non-invasive sensing of biomarkers in bodily fluid is highly convoluted. Nonetheless, if the drawbacks are appropriately addressed, and the pitfalls are adroitly circumvented, the approach will most certainly disrupt current clinical and self-monitoring practices.