Driver sleepiness is a contributing factor in many road fatalities. A long-standing goal driver state research has therefore been to develop robust detection system. It suggested that various heart rate variability (HRV) metrics can be used for classification. However, since modulated not only by but also several other time-varying intra-individual factors such as posture, distress, boredom and relaxation, it relevant highlight the possibilities difficulties involved HRV-based This paper...

Abstract Aims The aim was to investigate the relationship between microvascular function, cardiovascular risk profile, and subclinical atherosclerotic burden. Methods results study enrolled 3809 individuals, 50–65 years old, participating in population-based observational cross-sectional Swedish CArdioPulmonary bioImage Study. Microvascular function assessed forearm skin using an arterial occlusion release protocol determining peak blood oxygen saturation (OxyP). Cardiovascular calculated...

We have determined in vivo optical scattering properties of normal human skin 1734 subjects, mostly with fair type, within the Swedish CArdioPulmonary bioImage Study. The measurements were performed a noninvasive system, integrating spatially resolved diffuse reflectance spectroscopy and laser Doppler flowmetry. Data analyzed an inverse Monte Carlo algorithm, accounting for both scattering, geometrical, absorbing tissue. reduced coefficient was found to decrease from 3.16 ± 0.72 1.13 0.27...

Skin and kidney microvascular functions may be affected independently in diabetes mellitus. We investigated skin microcirculatory function 79 subjects with type 2, where 41 had microalbuminuria 38 not, age-matched controls. The oxygen saturation, fraction of red blood cells speed-resolved perfusion (% × mm/s) divided into three speed regions: 0–1, 1–10 above 10 mm/s, were assessed during baseline after local heating the foot a new device integrating diffuse reflectance spectroscopy laser...

Abstract Background This study aimed to investigate whether changes in capillary refill (CR) time precede macrovascular signs of deterioration a human model blood loss shock. The was conducted at the Department Emergency Medicine Linköping, Sweden, and involved 42 healthy volunteers aged 18–45. Participants were randomized into two provocations applied lower body negative pressure (LBNP): stepwise escalation protocol direct application protocol, simulate gradual acute loss. main outcome...

The objective of this study was to assess normative values for comprehensive forearm skin microcirculatory function: oxygen saturation, tissue fraction red blood cells (RBCs), and speed-resolved perfusion. Furthermore, examine the influence age sex on function. Measurements were performed using a noninvasive probe-based system, including diffuse reflectance spectroscopy laser-Doppler flowmetry, yielding output data in absolute units. conducted within Swedish CArdioPulmonary BioImage Study...

The PeriFlux 6000 EPOS system combines diffuse reflectance spectroscopy (DRS) and laser Doppler flowmetry (LDF) for the assessment of oxygen saturation (expressed in percentage), red blood cell (RBC) tissue fraction as volume fraction, %RBC), perfusion (%RBC × mm / s) microcirculation. It also allows possibility separating into three speed regions (0 to 1, 1 10, >10 s). We evaluate speed-resolved components, i.e., relative amount within each region, using a blood-flow phantom. Human was...

Significance: Tissue simulating phantoms are an important part of validating biomedical optical techniques. pathology in inflammation and oedema involves changes both water hemoglobin fractions. Aim: We present a method to create solid gelatin-based mimicking with adjustable Approach: One store-bought gelatin one research grade were evaluated. Different fractions obtained by varying the water-to-gelatin ratio. Ferrous stabilized human or whole blood was added as absorbers, stability...

Significance: Spatial frequency domain imaging (SFDI) is a quantitative method to measure absorption and scattering of tissue, from which several chromophore concentrations (e.g., oxy-/deoxy-/meth-hemoglobin, melanin, carotenoids) can be calculated. Employing extract additional spectral bands RGB components (that we named cross-channels), designed handheld SFDI device account for these pigments, using low-cost, consumer-grade its implementation characterization. Aim: With only three broad...

Approximately 20–30% of all road fatalities are related to driver sleepiness. A long-lasting goal in state research has therefore been develop a robust sleepiness detection system. Since the alertness level is reflected autonomous nervous system activity, it suggested that various heart rate variability (HRV) metrics can be used as features for classification. modulated by many different factors, and not just sleepiness, relevant question high classification accuracies have occasionally...

Introduction: Systemic lupus erythematosus (SLE) is associated with premature cardiovascular disease (CVD) and mortality, unexplained by traditional risk factors. Impairment of microcirculation vascular hemodynamics may represent early signs affection. We hypothesized that studies pulse waves provide additional information, compared to ultrasound (US) alone, for the detection in SLE. Methods: Sixty well-characterized SLE-patients (52 women, eight men; mean age 43.21 ± 1.3 years)...

The high-density microneedle array patch (HD-MAP) is a promising alternative vaccine delivery system device with broad application in disease, including SARS-CoV-2. Skin reactivity to HD-MAP applications has been extensively studied young individuals, but not the >65 years population, risk group often requiring higher dose vaccines produce protective immune responses. primary aims of present study were characterise local inflammatory responses and barrier recovery HD-MAPs elderly skin. In...

Wound healing assessment is usually performed visually by a trained physician. This type of evaluation very subjective and returns limited information about the wound progression. In contrast, optical imaging techniques are non-invasive ways to quantitatively measure biological parameters. Spatial frequency domain (SFDI) an technique that exploits sinusoidal patterns light with multiple spatial frequencies tissue frequency-specific response, from which absorption scattering coefficient...

SignificanceKnowledge of optical properties is important to accurately model light propagation in tissue, but vivo reference data are sparse.AimThe aim our study was present skin from a large Swedish cohort including 3809 subjects using three-layered and spatially resolved diffuse reflectance spectroscopy (Periflux PF6000 EPOS).ApproachDiffuse spectra (475 850 nm) at 0.4 1.2 mm source–detector separations were analyzed an inverse Monte Carlo method. The had one epidermis layer with variable...

Introduction: Takayasu arteritis (TAK) is a rare inflammatory disease affecting aorta and its major branches. Ultrasound (US) can detect features in the arterial wall, but less known regarding skin microcirculation vascular hemodynamics. The aim was to study if assessment of these variables could add valuable information affection TAK. Methods: 17 patients diagnosed with TAK age- sex-matched healthy controls were included. Microcirculatory peak oxygen saturation (OxyP) after induced ischemia...

Vital signs reflect circulatory function and hence hemodynamics on a macroscopic scale are often unreliable or late indicators of hemodynamic instability. Previous studies support that alterations in the microcirculation may provide early deterioration impending shock. Microcirculation is also restored recovery process. Hence, monitoring important since treatments based normalizing classical vital will not always restore microvascular remain shock although e.g., blood pressure seems normal....

Abstract To enable interactive remote education on electrical safety in biomedical engineering, a real-life problem-based laboratory module is proposed, implemented and evaluated. The was freestanding distance course hospital for three consecutive years based medical devices, where standard equipment existing most hospitals could be used. participants were from total of 42 geographical locations or near Sweden. allow high level interaction, especially among peer students, graphical digital...

SignificanceCurrent methods for wound healing assessment rely on visual inspection, which gives qualitative information. Optical allow quantitative non-invasive measurements of optical properties relevant to healing.AimSpatial frequency domain imaging (SFDI) measures the absorption and reduced scattering coefficients tissue. Typically, SFDI assumes homogeneous tissue; however, layered structures are present in skin. We evaluate a multi-frequency approach process data that estimates...

We present in vivo optical properties of skin tissue assessed using spatially resolved diffuse reflectance spectroscopy. Data was collected a sub-study the Swedish CArdioPulmonary bioImage Study (SCAPIS). Measurements were performed on 3,809 subjects, 50-65 years, volar side forearm with PeriFlux 6000 EPOS system. The analysis consisted an inverse Monte Carlo method where modeled spectra non-linearly fitted to measured at 0.4 and 1.2-mm source-detector fiber separations, respectively,...