Search

Background: Digitalisation is rapidly changing health care processes and the health care sector, thus increasing the need to improve the digital competence of future health care professionals. Purpose: The aim of this study was to describe the attitudes of medical and nursing students towards digital health based on self-evaluation as well as to compare the differences in perceptions between the two student groups. Methods: A cross-sectional study was conducted as an online survey using the Webropol in April 2021 at the University of Oulu and Oulu University of Applied Sciences in Finland. The survey questionnaire consisted of seven background questions and 16 statements on a five-point Likert scale (fully disagree to fully agree) to survey student attitudes towards eHealth, and their digital capabilities. Results: A total of 250 medical and nursing students were invited to participate in the study and 170 of them took the survey (response rate 68 %). Of those answered, 38 % (n = 64) were nursing and 32 % (n = 106) medical students. Students generally had a positive attitude towards eHealth and health care digitalisation. The differences in perceptions and preparedness between medical and nursing students were surprisingly small in the two student groups. There was a statistically significant difference between the two groups in three out of 16 statements: these were related to changes in the roles of health care professionals and patients as well as the students’ knowledge of information contained in the national patient portal. Conclusions: The results of this study provide a good starting point for further harmonisation of the curriculum for both health professional groups regarding the teaching of eHealth and telemedicine.

Health information exchange (HIE) is the mobilization of health care information electronically across organizations within a region, community, or hospital system. Nordic countries have been developing their health portals including national HIE services systematically. In Finland HIE begun with various regional health information exchange (RHIE) pilots in since 1998. The Kanta patient data repository component in the national HIE has been adopted in routine use since 2012. The current role of non-Kanta RHIE in relation to Kanta services is somewhat unclear. Our research questions are following: 1) Has the availability of RHIE services changed during 2017–2020? 2) What functional types of RHIE are there in Finland in 2020? 3) From the point of view of healthcare provider organizations, at what level is the availability to combine regional information seamlessly into the same view of local patient record systems? Data used in this study were collected using web-based questionnaires in 2017 and 2020 as part of the surveys for monitoring and assessment of social welfare and health care information system services in Finland. This study reported in this article covers all 21 public hospital districts and nearly all public primary health care centers. The quantitative data provided by the organizations were analyzed using SPSS software (version 25). The availability of a particular service or function was calculated as a percentage of all respondents in each sector. The results of this study show that the overall availability of RHIE services has not markedly changed 2017–2020. Functional types of RHIE meaning the role, use and types of RHIE in hospital districts in Finland varies greatly in 2020. We recognized three different types of non-Kanta RHIE in the non-combination organizations (one-way, symmetrical, full symmetrical). Seamless integration of at least some Kanta data into the same view as the main patient health record system data was more common than

Background: eHealth increasingly affects the delivery of health care around the world and the quest for more efficient health systems. In Finland, the development of eHealth maturity has been systematically studied since 2003, through surveys conducted every 3 years. It has also been monitored in several international studies. The indicators used in these studies examined the availability of the electronic patient record, picture archiving and communication system, health information exchange, and other key eHealth functionalities. Objective: The first aim is to study the national development in the maturity level of eHealth in primary health care and specialized care between 2011 and 2020 in Finland. The second aim is to clarify the regional differences in the maturity level of eHealth among Finnish hospital districts in 2020. Methods: Data for this study were collected in 2011, 2014, 2017, and 2020, using web-based questionnaires from the Use of information and communication technology surveys in Finnish health care project. In total, 16 indicators were selected to describe the status of eHealth, and they were based on international eHealth studies and Finnish eHealth surveys in 3 areas: applications, regional integration, and data security and information and communications technology skills. The indicators remain the same in all the study years; therefore, the results are comparable. Results: All the specialized care organizations (21/21, 100%) in 2011, 2014, 2017, and 2020 participated in the study. The response rate among primary health care organizations was 86.3% (139/161) in 2011, 88.2% (135/153) in 2014, 85.8% (121/141) in 2017, and 95.6% (130/136) in 2020. At the national level, the biggest developments in eHealth maturity occurred between 2011 and 2014. The development has since continued, and some indicators have been saturated. Primary health care lags behind specialized care organizations, as measured by all the indicators and throughout the

Tiivistelmä Lähtökohdat: Suomessa tuli 1.5.2019 voimaan niin sanottu toisiolaki eli Laki sosiaali- ja terveystietojen toissijaisesta käytöstä. Kyselytutkimuksemme tarkoitus oli selvittää kliinikkotutkijoiden kokemuksia toisiolain vaikutuksista ja käytännön toteutuksesta. Menetelmät: Suomalaisia kliinikkotutkijoita pyydettiin arvioimaan Webropol-alustalla toisiolain aiheuttamia aikataulumuutoksia, talousvaikutuksia, tutkimusyhteistyössä tapahtuneita muutoksia, mahdollisia esteitä ja hyötyjä lain voimaantuloon liittyen sekä muita lain aiheuttamia positiivisia ja negatiivisia vaikutuksia. Tulokset: Vastaajista (n = 430) 64,4 % raportoi, että tutkimustoiminnan kustannukset ovat nousseet toisiolain mukana. Vastaajista 38,4–45,6 % oli jättänyt tutkimusprojekteja käynnistämättä joko lupahakemuksen hinnan tai etäkäyttöympäristön kustannusten sekä sen käyttövaatimuksen vuoksi. Päätelmät: Tutkimuksemme perusteella on syytä epäillä, että toisiolain soveltaminen vaikuttaa heikentävästi julkaisujen määrään ja laatuun ja heikentää Suomen kilpailukykyä etenkin tutkijalähtöisessä tutkimuksessa. Toisiolain seuraukset kohdistuvat erityisesti suomalaisiin potilaisiin, heidän hoitonsa laatuun sekä hoidon tasavertaisuuteen., Background: The Act on the Secondary Use of Health and Social Data (Secondary Use Act) came into effect in Finland in May 2019. The purpose of our survey was to evaluate clinical researchers’ experiences with the implementation and effects of the act. Methods: The survey, directed to clinical researchers in Finland, was conducted on the Webropol platform. The respondents evaluated the effects and consequences of the Secondary Use Act, including scheduling, financing, and collaborating in research. Potential benefits, barriers and other positive and negative effects of this act were also assessed. Results: A total of 430 respondents completed the survey. Of these, 64.4% reported higher costs of research following implementation of the Secondary Use Act while 38.4–45.6% of respondents reported that the act had prevented starting new research projects due to application costs, demand for the use of remote access and mandatory costs associated with its use. Conclusions: According to our survey, the Secondary Use Act has had alarming effects and consequences in Finnish clinical research, reducing the number of research outputs, the quality of research, and the competitiveness of Finnish research internationally, especially in researcher-driven science. The consequences of the Secondary Use Act negatively impact Finnish patients, quality of care, and equality of care.

The physiological underpinnings of the necessity of sleep remain uncertain. Recent evidence suggests that sleep increases the convection of cerebrospinal fluid (CSF) and promotes the export of interstitial solutes, thus providing a framework to explain why all vertebrate species require sleep. Cardiovascular, respiratory and vasomotor brain pulsations have each been shown to drive CSF flow along perivascular spaces, yet it is unknown how such pulsations may change during sleep in humans. To investigate these pulsation phenomena in relation to sleep, we simultaneously recorded fast fMRI, magnetic resonance encephalography (MREG), and electroencephalography (EEG) signals in a group of healthy volunteers. We quantified sleep-related changes in the signal frequency distributions by spectral entropy analysis and calculated the strength of the physiological (vasomotor, respiratory, and cardiac) brain pulsations by power sum analysis in 15 subjects (age 26.5 ± 4.2 years, 6 females). Finally, we identified spatial similarities between EEG slow oscillation (0.2–2 Hz) power and MREG pulsations. Compared with wakefulness, nonrapid eye movement (NREM) sleep was characterized by reduced spectral entropy and increased brain pulsation intensity. These effects were most pronounced in posterior brain areas for very low-frequency (≤0.1 Hz) vasomotor pulsations but were also evident brain-wide for respiratory pulsations, and to a lesser extent for cardiac brain pulsations. There was increased EEG slow oscillation power in brain regions spatially overlapping with those showing sleep-related MREG pulsation changes. We suggest that reduced spectral entropy and enhanced pulsation intensity are characteristic of NREM sleep. With our findings of increased power of slow oscillation, the present results support the proposition that sleep promotes fluid transport in human brain.

Respiratory brain pulsations have recently been shown to drive electrophysiological brain activity in patients with epilepsy. Furthermore, functional neuroimaging indicates that respiratory brain pulsations have increased variability and amplitude in patients with epilepsy compared to healthy individuals. To determine whether the respiratory drive is altered in epilepsy, we compared respiratory brain pulsation synchronicity between healthy controls and patients. Whole brain fast functional magnetic resonance imaging was performed on 40 medicated patients with focal epilepsy, 20 drug-naïve patients and 102 healthy controls. Cerebrospinal fluid associated respiratory pulsations were used to generate individual whole brain respiratory synchronization maps, which were compared between groups. Finally, we analyzed the seizure frequency effect and diagnostic accuracy of the respiratory synchronization defect in epilepsy. Respiratory brain pulsations related to the verified fourth ventricle pulsations were significantly more synchronous in patients in frontal, periventricular and mid-temporal regions, while the seizure frequency correlated positively with synchronicity. The respiratory brain synchronicity had a good diagnostic accuracy (ROCAUC = 0.75) in discriminating controls from medicated patients. The elevated respiratory brain synchronicity in focal epilepsy suggests altered physiological effect of cerebrospinal fluid pulsations possibly linked to regional brain water dynamics involved with interictal brain physiology.

Primary central nervous system lymphoma (PCNSL) is an aggressive brain disease where lymphocytes invade along perivascular spaces of arteries and veins. The invasion markedly changes (peri)vascular structures but its effect on physiological brain pulsations has not been previously studied. Using physiological magnetic resonance encephalography (MREGBOLD) scanning, this study aims to quantify the extent to which (peri)vascular PCNSL involvement alters the stability of physiological brain pulsations mediated by cerebral vasculature. Clinical implications and relevance were explored. In this study, 21 PCNSL patients (median 67y; 38% females) and 30 healthy age-matched controls (median 63y; 73% females) were scanned for MREGBOLD signal during 2018–2021. Motion effects were removed. Voxel-by-voxel Coefficient of Variation (CV) maps of MREGBOLD signal was calculated to examine the stability of physiological brain pulsations. Group-level differences in CV were examined using nonparametric covariate-adjusted tests. Subject-level CV alterations were examined against control population Z-score maps wherein clusters of increased CV values were detected. Spatial distributions of clusters and findings from routine clinical neuroimaging were compared [contrast-enhanced, diffusion-weighted, fluid-attenuated inversion recovery (FLAIR) data]. Whole-brain mean CV was linked to short-term mortality with 100% sensitivity and 100% specificity, as all deceased patients revealed higher values (n = 5, median 0.055) than surviving patients (n = 16, median 0.028) (p < .0001). After adjusting for medication, head motion, and age, patients revealed higher CV values (group median 0.035) than healthy controls (group median 0.024) around arterial territories (p ≤ .001). Abnormal clusters (median 1.10 × 10₅mm₃) extended spatially beyond FLAIR lesions (median 0.62 × 10₅mm₃) with differences in volumes (p = .0055).

The physiological pulsations that drive tissue fluid homeostasis are not well characterized during brain activation. Therefore, we used fast magnetic resonance encephalography (MREG) fMRI to measure full band (0–5 Hz) blood oxygen level-dependent (BOLDFB) signals during a dynamic visual task in 23 subjects. This revealed brain activity in the very low frequency (BOLDVLF) as well as in cardiac and respiratory bands. The cardiovascular hemodynamic envelope (CHe) signal correlated significantly with the visual BOLDVLF response, considered as an independent signal source in the V1-V2 visual cortices. The CHe preceded the canonical BOLDVLF response by an average of 1.3 (± 2.2) s. Physiologically, the observed CHe signal could mark increased regional cardiovascular pulsatility following vasodilation.

Accumulation of amyloid-β is a key neuropathological feature in brain of Alzheimer’s disease patients. Alterations in cerebral haemodynamics, such as arterial impulse propagation driving the (peri)vascular CSF flux, predict future Alzheimer’s disease progression. We now present a non-invasive method to quantify the three-dimensional propagation of cardiovascular impulses in human brain using ultrafast 10 Hz magnetic resonance encephalography. This technique revealed spatio-temporal abnormalities in impulse propagation in Alzheimer’s disease. The arrival latency and propagation speed both differed in patients with Alzheimer’s disease. Our mapping of arterial territories revealed Alzheimer’s disease-specific modifications, including reversed impulse propagation around the hippocampi and in parietal cortical areas. The findings imply that pervasive abnormality in (peri)vascular CSF impulse propagation compromises vascular impulse propagation and subsequently glymphatic brain clearance of amyloid-β in Alzheimer’s disease.

Tiivistelmä Digitalisaation myötä terveydenhuollon toiminnot muuttuvat nopeasti, ja sähköiset työkalut sekä palvelut ovat jo arkipäivää. Vaikutukset näkyvät koulutustarpeena, koska terveydenhuollon ammattilaisten digiosaaminen tulee turvata. Lääkärien peruskoulutuksen tulisi sisältää etälääketiedettä ja sähköisen terveydenhuollon palveluja (e-health) koskevaa opetusta. Kansallisessa MEDigi-hankkeessa määriteltiin suomalaisen e-health-opetuksen aihealueet ja tehtiin niille ydinainesanalyysi. Työryhmän työn perusteella määräytyi kaksitoista e-health-opetukseen soveltuvaa aihealuetta lääketieteen ja hammaslääketieteen peruskoulutuksessa. Niiden sisältämien opetusaiheiden keskeisyys määriteltiin kolmiportaisesti. Tuloksia sovellettiin pilottina Oulun yliopistossa lääketieteen viidennen vuosikurssin opiskelijoille toteutettuun teemapäivään, jonka opetussisältö muokattiin vastaamaan ydinainesanalyysin tuloksia. Opetus toteutettiin koronapandemian takia kokonaan etäopetuksena. Jatkossa tavoitteena on kansallisesti integroida ydinainesanalyysiin perustuva e-health-opetus suomalaiseen lääkärikoulutukseen.

Several industrial activities produce metal sulfates, which are controlled by strict limitations for wastewater concentrations of sulfate. One emerging area where these activities occur is the production of lithium-ion battery chemicals in which sodium sulfates are formed because of cathode precursor co-precipitation. Several solutions for sulfate removal exist, but one option is to reuse the sulfate side stream in other processes to increase circular economy and atom efficiency. In this paper, the reuse of sodium sulfate solution in a steel industry pickling solution is considered. Neutral electrolytic pickling experiments were carried out to compare the pickling behavior of the electrolyte dissolved from pure sodium sulfate and the electrolyte diluted from a side stream solution. Effect of impure electrolyte was evaluated using field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectrometry (EDS). Concentrations of the metal ions were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES). The results indicated a slight increase in current efficiency with the side stream electrolyte solution, while overall the pickling behavior remained similar. This suggests that a side stream sodium sulfate solution could be used as a pickling electrolyte, reducing the need for pure reagents.

Previously, schizophrenia is found to be related to the variability of the functional magnetic resonance imaging (fMRI) signal in the white matter. However, evidence about the relationship between genetic vulnerabilities and physiological fluctuation in the brain is lacking. We investigated whether familial risk for psychosis (FR) and polygenic risk score for schizophrenia (PRS) are linked with physiological fluctuation in fMRI data. We used data from the Oulu Brain and Mind study (n = 140−149, aged 20−24 years) that is a substudy of the Northern Finland Birth Cohort 1986. The participants underwent a resting-state fMRI scan. Coefficient of variation (CV) of blood oxygen level dependent (BOLD) signal (CVBOLD) was used as a proxy of physiological fluctuation in the brain. Familial risk was defined to be present if at least one parent had been diagnosed with psychosis previously. PRS was computed based on the results of the prior GWAS by the Schizophrenia Working Group. FR or PRS were not associated with CVBOLD in cerebrospinal fluid, white matter, or grey matter. The findings did not provide evidence for the previous suggestions that genetic vulnerabilities for schizophrenia become apparent in alterations of the variation of the BOLD signal in the brain.

Biomarkers sensitive to prodromal or early pathophysiological changes in Alzheimer’s disease (AD) symptoms could improve disease detection and enable timely interventions. Changes in brain hemodynamics may be associated with the main clinical AD symptoms. To test this possibility, we measured the variability of blood oxygen level-dependent (BOLD) signal in individuals from three independent datasets (totaling 80 AD patients and 90 controls). We detected a replicable increase in brain BOLD signal variability in the AD populations, which constituted a robust biomarker for clearly differentiating AD cases from controls. Fast BOLD scans showed that the elevated BOLD signal variability in AD arises mainly from cardiovascular brain pulsations. Manifesting in abnormal cerebral perfusion and cerebrospinal fluid convection, present observation presents a mechanism explaining earlier observations of impaired glymphatic clearance associated with AD in humans.

Background: Physiological brain pulsations have been shown to play a critical role in maintaining interstitial homeostasis in the glymphatic brain clearance mechanism. We investigated whether psychotic symptomatology is related to the physiological variation of the human brain using fMRI. Methods: The participants (N = 277) were from the Northern Finland Birth Cohort 1986. Psychotic symptoms were evaluated with the Positive Symptoms Scale of the Structured Interview for Prodromal Syndromes (SIPS). We used the coefficient of variation of BOLD signal (CVBOLD) as a proxy for physiological brain pulsatility. The CVBOLD-analyses were controlled for motion, age, sex, and educational level. The results were also compared with fMRI and voxel-based morphometry (VBM) meta-analyses of schizophrenia patients (data from the Brainmap database). Results: At the global level, participants with psychotic-like symptoms had higher CVBOLD in cerebrospinal fluid (CSF) and white matter (WM), when compared to participants with no psychotic symptoms. Voxel-wise analyses revealed that CVBOLD was increased, especially in periventricular white matter, basal ganglia, cerebellum and parts of the cortical structures. Those brain regions, which included alterations of physiological fluctuation in symptomatic psychosis risk, overlapped <6% with the regions that were found to be affected in the meta-analyses of previous fMRI and VBM studies in schizophrenia patients. Motion did not vary as a function of SIPS. Conclusions: Psychotic-like symptoms were associated with elevated CVBOLD in a variety of brain regions. The CVBOLD findings may produce new information about cerebral physiological fluctuations that have been out of reach in previous fMRI and VBM studies.

Tiivistelmä Oulussa järjestettiin 13.6.2018 lääketieteen ja hammaslääketieteen tohtorintutkinnon konsensuskokous, jossa käytiin läpi vallitsevia käytäntöjä ja muutostarpeita. Ohjeellinen tutkinnon laajuus on neljä vuotta kokopäiväistä työtä, ja muodollisesti tutkinnon myöntää yhtä yliopistoa lukuun ottamatta aina vastaava tiedekunta. Ohjaajia on tyypillisesti kahdesta kolmeen, ja yksi on pääohjaaja. Seurantaryhmä on käytössä tai ollaan ottamassa käyttöön kaikissa yliopistoissa. Aktiivinen seurantaryhmä tukee merkittävästi ohjausprosessia. Väitöskirjojen asiantuntijoina toimivat esitarkastajat ja vastaväittäjät ovat yleensä muualta kuin suorituspaikan yliopistosta. Osittain tästä syystä suuria eroja eri yliopistojen tohtorintutkinnon vaatimusten välillä ei todettu. Haasteena väitöskirjatyössä on kliinisen työn paine ja nuorten kollegoiden ruuhkavuosien kuormittuminen, mitkä heikentävät mahdollisuuksia tutkimustyöhön. Myönteisiä muutoksia ovat olleet tohtoriopintojen systematisoituminen sekä ohjaamisen tason ja väitöskirjantekijöiden tuen paraneminen. Kaikki osallistuneet kannattivat käytäntöjen vakiinnuttamista ja yhtenäistämistä säännöllisellä konsensuskokoustyöskentelyllä., On June 13, 2018 a consensus meeting of the PhD degree in medicine and dentistry was held in Oulu to review the prevailing practices and assess the needs for change. The PhD degree should be completed in four years of full-time work and, except for one university, is formally awarded by the respective faculty. There are typically two or three supervisors, one acting as the principal supervisor. The follow-up group is or is being implemented in all universities and provides support to the process. To ensure objectivity, pre-examiners and opponents are not usually affiliated to the university granting the degree. This in part explains the relatively similar requirements. One of the challenges in PhD studies is how to combine time-consuming clinical work and requirements of the daily family life with research work. Recent positive changes include the systematization of doctoral studies and improvement in the level of guidance and support from both supervisors and follow-up committees. All participants of the consensus meeting supported the goal to consolidate and harmonize the doctoral training practices in Finland.

As the production of stainless steel increases, environmental concerns due to an increasing demand of production capacity, require an efficient use of energy and materials. Efficient removal of otherwise slow‐to‐dissolve chromium oxide layer can be achieved with electrochemical pre‐pickling before final mixed acid pickling. Neutral electrolytic pickling can be used to rapidly dissolve chromium oxides but suffers from low current efficiency of both the reaction and the system. In order to study the effect of critical parameters for the current efficiency of the system, a pickling device was assembled. A system current efficiency factorial analysis of bipolar neutral electrolytic pickling was conducted for temperature, electrolyte concentration, cell potential, and electrode‐to‐sample distance. Lowering the concentration of electrolytes shows potential to increase current efficiency significantly as conductivity can be used to reduce electrode‐to‐electrode short‐circuiting, which is the biggest cause of decreased efficiency in neutral electrolytic pickling. Increasing the temperature has a positive effect on efficiency, despite increased conductivity, possibly from increasing reaction kinetics.

Objective: Epilepsy causes measurable irregularity over a range of brain signal frequencies, as well as autonomic nervous system functions that modulate heart and respiratory rate variability. Imaging dynamic neuronal signals utilizing simultaneously acquired ultra-fast 10 Hz magnetic resonance encephalography (MREG), direct current electroencephalography (DC-EEG), and near-infrared spectroscopy (NIRS) can provide a more comprehensive picture of human brain function. Spectral entropy (SE) is a nonlinear method to summarize signal power irregularity over measured frequencies. SE was used as a joint measure to study whether spectral signal irregularity over a range of brain signal frequencies based on synchronous multimodal brain signals could provide new insights in the neural underpinnings of epileptiform activity. Methods: Ten patients with focal drug-resistant epilepsy (DRE) and ten healthy controls (HC) were scanned with 10 Hz MREG sequence in combination with EEG, NIRS (measuring oxygenated, deoxygenated, and total hemoglobin: HbO, Hb, and HbT, respectively), and cardiorespiratory signals. After pre-processing, voxelwise SEMREG was estimated from MREG data. Different neurophysiological and physiological subfrequency band signals were further estimated from MREG, DC-EEG, and NIRS: fullband (0–5 Hz, FB), near FB (0.08–5 Hz, NFB), brain pulsations in very-low (0.009–0.08 Hz, VLFP), respiratory (0.12–0.4 Hz, RFP), and cardiac (0.7–1.6 Hz, CFP) frequency bands. Global dynamic fluctuations in MREG and NIRS were analyzed in windows of 2 min with 50% overlap. Results: Right thalamus, cingulate gyrus, inferior frontal gyrus, and frontal pole showed significantly higher SEMREG in DRE patients compared to HC. In DRE patients, SE of cortical Hb was significantly reduced in FB (p = .045), NFB (p = .017), and CFP (p = .038), while both HbO and HbT were significantly reduced in RFP (p = .038, p = .045, respectively). Dynamic SE of HbT was reduced in DRE patients in RF

Low image sampling rates used in resting state functional magnetic resonance imaging (rs-fMRI) may cause aliasing of the cardiorespiratory pulsations over the very low frequency (VLF) BOLD signal fluctuations which reflects to functional connectivity (FC). In this study, we examine the effect of sampling rate on currently used rs-fMRI FC metrics. Ultra-fast fMRI magnetic resonance encephalography (MREG) data, sampled with TR 0.1 s, was downsampled to different subsampled repetition times (sTR, range 0.3–3 s) for comparisons. Echo planar k-space sampling (TR 2.15 s) and interleaved slice collection schemes were also compared against the 3D single shot trajectory at 2.2 s sTR. The quantified connectivity metrics included stationary spatial, time, and frequency domains, as well as dynamic analyses. Time domain methods included analyses of seed-based functional connectivity, regional homogeneity (ReHo), coefficient of variation, and spatial domain group level probabilistic independent component analysis (ICA). In frequency domain analyses, we examined fractional and amplitude of low frequency fluctuations. Aliasing effects were spatially and spectrally analyzed by comparing VLF (0.01–0.1 Hz), respiratory (0.12–0.35 Hz) and cardiac power (0.9–1.3 Hz) FFT maps at different sTRs. Quasi-periodic pattern (QPP) of VLF events were analyzed for effects on dynamic FC methods. The results in conventional time and spatial domain analyses remained virtually unchanged by the different sampling rates. In frequency domain, the aliasing occurred mainly in higher sTR (1–2 s) where cardiac power aliases over respiratory power. The VLF power maps suffered minimally from increasing sTRs. Interleaved data reconstruction induced lower ReHo compared to 3D sampling (p < 0.001). Gradient recalled echo-planar imaging (EPI BOLD) data produced both better and worse metrics. In QPP analyses, the repeatability of the VLF pulse detection becomes linearly reduced with increasing sTR. In co

The brain is cleaned from waste by glymphatic clearance serving a similar purpose as the lymphatic system in the rest of the body. Impairment of the glymphatic brain clearance precedes protein accumulation and reduced cognitive function in Alzheimer’s disease (AD). Cardiovascular pulsations are a primary driving force of the glymphatic brain clearance. We developed a method to quantify cardiovascular pulse propagation in the human brain with magnetic resonance encephalography (MREG). We extended a standard optical flow estimation method to three spatial dimensions, with a multi-resolution processing scheme. We added application-specific criteria for discarding inaccurate results. With the proposed method, it is now possible to estimate the propagation of cardiovascular pulse wavefronts from the whole brain MREG data sampled at 10 Hz. The results show that on average the cardiovascular pulse propagates from major arteries via cerebral spinal fluid spaces into all tissue compartments in the brain. We present an example, that cardiovascular pulsations are significantly altered in AD: coefficient of variation and sample entropy of the pulse propagation speed in the lateral ventricles change in AD. These changes are in line with the theory of glymphatic clearance impairment in AD. The proposed non-invasive method can assess a performance indicator related to the glymphatic clearance in the human brain.

This paper presents a simultaneous high-Q impedance matching and bandpass filtering technique for low-noise amplifiers (LNA) for radio frequency integrated circuit (RFIC) phased array system at 15 GHz, over the bandwidth of 1 GHz. A non-uniform transmission line (NUTL) segment is used as a major building block, which provides feasible integration for multiple antennas. A feeding network for single element receiver is demonstrated. The simulated and measured results show sufficient impedance matching of input feeds with S11 <; -10 dB over a relative bandwidth of 7% at 15 GHz.

Tiivistelmä. Litiumioniakkujen kysyntä on kasvanut vuosia ja kasvu jatkunee hybridi- sekä sähköautojen yleistyessä. Litiumioniakut koostuvat katodista, anodista, niiden välisestä separaattorista ja elektrolyytistä. Anodimateriaaliksi on vakiintunut erilaiset hiiliyhdisteet, kuten grafiitti. Litiumioniakkujen kapasiteettia rajoittavana tekijänä on pitkään ollut katodimateriaalit. Katodimateriaalien toimivuutta rajoittaa litiumionien irrotukseen liittyvä epästabiilius. Perinteisesti käytetyn litiumkobolttioksidi tilalle on etsitty uusia, halvempia ja parempia materiaaleja. Kobolttioksidiin on pitkään sekoitettu nikkeli- ja mangaanioksidia erilaisissa suhteissa, mutta litiumioniakkumateriaaleihin kohdistuvien vaatimusten, kuten käyttöikä ja -jännite, kasvaessa perinteiset metallioksidiseokset eivät riitä. Seostamalla (engl. doping) muita metallioksideja pienissä pitoisuuksissa (alle 5 mol-% metallioksidien kokonaispitoisuudesta) saadaan valmistettua katodimateriaaleja, joiden ominaisuudet ovat puhtaita materiaaleja paremmat. Uudet seostetut katodimateriaalien myötä tutkimus siirtynee esimerkiksi elektrolyytin stabiilisuuteen, kun katodimateriaalin käyttöjännite ylittää elektrolyytin stabiilisuusalueen. Myös elektrodimateriaalien pinnoituksella voidaan estää elektrolyytin reaktioita. Seostetuttuja materiaaleja koskevia julkaisuja on viimevuosina ollut paljon. Materiaalien karakterisointimenetelmät kuitenkin vaihtelevat. Työssä käydään lävitse tutkielman aikana kirjallisuudesta löydettyjä menetelmiä, ja arvioidaan niiden käytön yleisyyttä lähdekirjallisuuden pohjalta. Menetelmien tuloksia kuvaillaan. Tutkielman perusteella yleisimmin käytettyjä menetelmiä ovat akun toimintaan liittyvät sähköiset analyysit, mikroskooppiset menetelmät sekä röntgensädediffraktio. Lisäksi tutkielmassa esitellään lähdekirjallisuuden seostusmenetelmiä ja niiden vaikutuksia litiumioniakkujen toimintaan.

5G system design is a complex process due to a great variety of applications and their diverse requirements. This article describes our experiences in developing a centimeter waves mobile broadband concept satisfying future capacity requirements. The first step in the process was the radio channel measurement campaign and statistical modeling. Then the link level design was performed tightly together with the radio frequency (RF) implementation requirements to allow as large scalability of the air interface as possible. We started the concept development at 10 GHz frequency band and during the project World Radiocommunication Conference 2015 selected somewhat higher frequencies as new candidates for 5G. Thus, the main learning was to gain insight of interdependencies of different phenomena and find feasible combinations of techniques and parameter combinations that might actually work in practice, not only in theory.

Chemotherapy aided by opening of the blood-brain barrier with intra-arterial infusion of hyperosmolar mannitol improves the outcome in primary central nervous system lymphoma. Proper opening of the blood-brain barrier is crucial for the treatment, yet there are no means available for its real-time monitoring. The intact blood-brain barrier maintains a mV-level electrical potential difference between blood and brain tissue, giving rise to a measurable electrical signal at the scalp. Therefore, we used direct-current electroencephalography (DC-EEG) to characterize the spatiotemporal behavior of scalp-recorded slow electrical signals during blood-brain barrier opening. Nine anesthetized patients receiving chemotherapy were monitored continuously during 47 blood-brain barrier openings induced by carotid or vertebral artery mannitol infusion. Left or right carotid artery mannitol infusion generated a strongly lateralized DC-EEG response that began with a 2 min negative shift of up to 2000 μV followed by a positive shift lasting up to 20 min above the infused carotid artery territory, whereas contralateral responses were of opposite polarity. Vertebral artery mannitol infusion gave rise to a minimally lateralized and more uniformly distributed slow negative response with a posterior-frontal gradient. Simultaneously performed near-infrared spectroscopy detected a multiphasic response beginning with mannitol-bolus induced dilution of blood and ending in a prolonged increase in the oxy/deoxyhemoglobin ratio. The pronounced DC-EEG shifts are readily accounted for by opening and sealing of the blood-brain barrier. These data show that DC-EEG is a promising real-time monitoring tool for blood-brain barrier disruption augmented drug delivery.

Wideband fifth generation (5G) systems utilizing high carrier frequency and multiple-input multiple-output (MIMO) raise major challenges for the system design. Wave propagation and practical hardware tradeoffs at higher frequency ranges provide new boundary conditions for the implementation. This paper addresses system performance boundaries and the analysis method towards multibeam communications at mmW. We combine analysis from antennas and propagation to the RF transceiver specifications and beamforming requirements. Realistic propagation model and antenna implementation is used to generate beam-specific path gains and provide a wide variety of user scenarios. Using this approach, system level interdependencies and RF performance boundaries can be verified with different antenna configurations in various propagation environments. As an example, we present MIMO link budget analysis targeting 10 Gbits/s for multiple devices in the office scenario at 27 GHz.

One of the main challenges for wireless body area networks (WBANs) is to evaluate realistic methods to generate channel models for new different purposes and various environments quickly and flexibly. Finite integration technique (FIT) has shown to be promising method for modeling channels characteristics in WBAN deployment scenarios. Applying simulation based channel modeling on the performance evaluations of the concrete-surrounded use scenarios have not been presented in the literature. In this paper, FIT-based channel modeling is applied on the performance evaluation of IEEE 802.15.6 based energy detector (ED) receiver designed for monitoring the symptoms of Parkinson’s disease. The first aim of this paper is to assess and compare the simulated channel impulse responses (CIRs) with the data from a measurement campaign. The second aim is to apply the simulated channel on the performance evaluations of the IEEE 802.15.6 based ED receivers. The obtained bit error rate (BER) performances are compared with BERs obtained using channel measurement data in the simulations. It is shown that performance obtained using FIT-based channel modeling corresponds to performance obtained using channel measurement data based channel modeling. The results of this paper further verify the statements that FIT is sufficiently applicable for WBAN channel modeling.

In this paper, we propose a simple polynomial linearisation technique for nonlinear phased arrays including amplitude control. Due to the large number of antennas and thus power amplifiers in the array, it is inefficient to linearise each power amplifier individually. Therefore, it is demonstrated that the array can be linearised over-the-air using single polynomial. The simulations show that the linearisation is achieved by first linearising the higher driven PAs at the precompression region and then cancelling the compression by the heavily expanding lower driven PAs. The proposed approach offers an alternative way of re-thinking the concept of array linearisation over multiple PAs.

In this paper, an uniaxial anisotropic material block composed of dielectric sheets is examined for the rotation of the tilt angle of the linear polarization. The main objective is to diminish the coupling between two antenna elements. A theoretical model for polarization rotation is briefly introduced. The anisotropic material parameters are derived using electromagnetic mixing formulas. The theoretically predicted operation is verified by 3D EM-simulations using two parallel dipole antennas at the frequency of 1.5 GHz. The simulated transmission coefficient (S21) values between dipoles indicate > 30 dB increase in isolation in comparison with a homogeneous isotropic material sample and in free space. Theoretical and simulation results are promising regardless of the anisotropic material in the near field of the antenna.

Resting-state fMRI results in neurodegenerative diseases have been somewhat conflicting. This may be due to complex partial volume effects of CSF in BOLD signal in patients with brain atrophy. To encounter this problem, we used a coefficient of variation (CV) map to highlight artifacts in the data, followed by analysis of gray matter voxels in order to minimize brain volume effects between groups. The effects of these measures were compared to whole brain ICA dual regression results in Alzheimer’s disease (AD) and behavioral variant frontotemporal dementia (bvFTD). 23 AD patients, 21 bvFTD patients and 25 healthy controls were included. The quality of the data was controlled by CV mapping. For detecting functional connectivity (FC) differences whole brain ICA (wbICA) and also segmented gray matter ICA (gmICA) followed by dual regression were conducted, both of which were performed both before and after data quality control. Decreased FC was detected in posterior DMN in the AD group and in the Salience network in the bvFTD group after combining CV quality control with gmICA. Before CV quality control, the decreased connectivity finding was not detectable in gmICA in neither of the groups. Same finding recurred when exclusion was based on randomization. The subjects excluded due to artifacts noticed in the CV maps had significantly lower temporal signal-to-noise ratio than the included subjects. Data quality measure CV is an effective tool in detecting artifacts from resting state analysis. CV reflects temporal dispersion of the BOLD signal stability and may thus be most helpful for spatial ICA, which has a blind spot in spatially correlating widespread artifacts. CV mapping in conjunction with gmICA yields results suiting previous findings both in AD and bvFTD.

In this dissertation, the operation of planar impulse radio (IR) ultra wideband (UWB) antennas is examined for use in wireless body area networks (WBANs). The objective of the thesis is to consider electromagnetic phenomena due to coupling between an antenna and human body tissues and to analyse the challenges of wideband radiators. The aim is to understand the fundamental behaviour of an antenna in a WBAN, focusing on off-body and on-body communications. The thesis premises follow the international WBAN standard 802.15.6-2012 by the Institute of Electrical and Electronics Engineering (IEEE) and the Federal Communications Commission’s (FCC) UWB regulations (3.1–10.6 GHz). In the examinations, the frequency-dependent modelling of human tissues is considered. The impact of the variation of tissue layer thickness on the performance of an antenna is depicted. The demonstration of the impact of antenna input power is given in terms of generation of heat in tissues and specific absorption rate (SAR). In order to theoretically contemplate the effect of reflections due to tissues on antenna patterns, the opportunities to influence polarization with an artificially anisotropic substrate are derived. With the proposed method, not earlier proposed for WBAN antennas, the smooth patterns without pattern minima can be achieved over the FCC UWB bandwidth. In addition, a theoretical two-path model is applied to the estimation of the antenna pattern shape close to tissues. Various antenna parameters are explored as a function of the use distance to tissue surface to demonstrate the behaviour in the vicinity of a body. The size of the reactive near-field is an important factor for the evaluation of satisfactory on-body performance. The proportions of absorption, mismatch and body losses are analysed close to a body. The connection between the complex input impedance and the dimensions of planar antennas is analysed by using lumped-element equivalent circuits. The impact of t, Tiivistelmä Tässä väitöskirjassa tarkastellaan laajakaistaisten impulssiradioantennien (IR-UWB) toimintaa langattomissa kehoverkoissa (WBAN). Työn tavoitteena on tarkastella antennin ja ihmiskudoksen kytkeytymisestä johtuvia sähkömagneettisia ilmiöitä ja analysoida laajakaistaisen säteilijän haasteet. Päämääränä on ymmärtää antennin suorituskyky kontekstissa ja kohdeympäristöksi on fokusoitu toiminta kehon pinnalla (on-body) ja keholta poispäin seuraavaan liityntäpisteeseen (off-body). Tutkimustyö pohjautuu IEEE802.15.6-2012-standardiin sekä FCC:n UWB -säännöksiin. Väitöstyössä tarkastellaan taajuusriippuvan ihmiskudoksen mallintamista. Ihmiskudoskerrosten paksuuden vaikutusta antennin suorituskykyyn tutkitaan simuloimalla. Lisäksi tarkastellaan antennin syöttötehon vaikutusta kudoksen lämpiämisen ja tehon absorboitumisen näkökulmasta. Kehon aiheuttamien heijastusten vaikutusta säteilykuvioihin tarkastellaan teoreettisesti ja lisäksi esitetään menetelmä vaikuttaa antennin summapolarisaation kautta säteilykuvion muotoon keinotekoisella epäisotrooppisella substraatilla. Ehdotetulla menetelmällä, mitä ei ole aiemmin kirjallisuudessa esitetty kehoantenneille, voidaan minimoida nollakohtia ja saavuttaa tasainen säteilykuvio FCC UWB -taajuuskaistan yli. Kaksitie-mallia sovelletaan säteilykuvion muodon ennustamiseen kehon läheisyydessä. Useita antenniparametreja havainnollistetaan antennin käyttöetäisyyden funktiona ihmiskudoksesta. Antennin reaktiivisen lähikentän koko on tärkeä tekijä kehoantennille riittävän suorituskyvyn saavuttamiseksi. Absorptio-, epäsovitus- ja kehohäviöiden osuudet edelleen eritellään ja analysoidaan työssä. Työssä tutkitaan kompleksisen syöttöimpedanssin ja antennin fyysisten mittojen yhteyttä hyödyntämällä erilliskomponenteilla muodostettuja vastinpiirejä. Ensimmäistä kertaa antennin käytännön leveyden ja pituuden muutos esitetään suhteessa impedanssikäyttäytymiseen. Impedanssin muutos analysoidaan kapasitanssin, induktanssin ja resistanssin funk