Koneoppimistekniikoiden soveltaminen radiografisten kuvien luokitteluun NDT-menetelmissä

Tiivistelmä. Tämän tutkielman tarkoituksena oli tutkia tekoälyn ja koneoppimisen tekniikoita teollisuuden NDT-menetelmien parissa. Tutkielman motiivina toimi NDT-tarkastajan tehtävässä hankkimani työkokemus ja sitä kautta syntynyt mielenkiinto alan uusimpia tekniikoita ja virtauksia kohtaan. NDT-menetelmistä keskityttiin erityisesti radiografiseen tarkastukseen ja radiografisten kuvien luokitteluun käytettävien koneoppivien algoritmien käyttöön. Tavoitteena oli tiedon lisääminen oppivien algoritmien mahdollisuuksista radiografisten kuvien tulkinnassa erityisesti pienillä opetusaineistoilla. Tutkielma toteutettiin kirjallisten lähteiden avulla, vertaamalla keskenään aiheesta toteutettuja tutkimuksia ja niistä saatuja tuloksia. Tutkielman tuloksena saatiin tietoa kolmen erilaisen algoritmin suorituskyvystä radiografisten kuvien luokittelussa ja vikojen segmentoinnissa. Tuloksista selvisi, että kahdella keskenään verratulla algoritmillä, tukivektorikoneella ja monikerrosperseptronilla, päästään keskenään liki samanlaisiin luokittelutuloksiin, tukivektorikoneen ollessa tuloksissa näistä kahdesta keskimäärin parempi algoritmi. Kolmantena mukana olleen syväoppivan konvolutiivisen neuroverkon tutkimustuloksissa keskityttiin pienimmän mahdollisen vikakoon löytämiseen kyseisen algoritmin avulla ja tutkimuksen mukaan menetelmä täyttää vaativimmatkin NDT-menetelmän herkkyydelle teollisuudessa asetetut vaatimukset. Tutkimusaineiston mukaan, koneoppivilla algoritmeillä on täydet valmiudet toimia tarkastajan apuna mm. vika-alueiden paikantamisessa, segmentoimisessa ja vikojen tilastoinnissa jo tällä hetkellä. Alan tutkimus on viime aikoina vahvasti painottunut konvolutiivisten neuroverkkojen suuntaan ja niiden merkitys teollisuuden NDT-menetelmien automatisoinnissa tulee epäilemättä olemaan näistä kolmesta koneoppivasta tekniikasta suurin

Maternal childbirth experience and time of delivery : a retrospective 7-year cohort study of 105 847 parturients in Finland

Objectives To explore how the time of delivery influences childbirth experience. Design A retrospective cohort study. Setting Childbirth in the four Helsinki and Uusimaa Hospital District hospitals, Finland, from 2012 to 2018. Participants 105 847 childbirths with a singleton live fetus. Main outcome measures Childbirth experience measured by Visual Analogue Scale (VAS). Results The major difference in average childbirth experience measured by VAS was between primiparas (8.03; 95% CI 8.01 to 8.04) and multiparas (8.47; 95% CI 8.45 to 8.48). Risk ratio (RR) of the low VAS ( Conclusion The maternal childbirth experience depended on the time of delivery. Giving birth during the evening led to impaired childbirth experience in both primiparas and multiparas, compared with delivery at other times. The impact of labour induction on childbirth experience should be further examined. The reorganisation of delivery services and the reduction of birth preparations might affect annual VAS. VAS is a simple method of measuring the complex entity of childbirth experience, and our results indicate its ability to capture temporal variation.Peer reviewe

Maternal childbirth experience and pain relief methods: a retrospective 7-year cohort study of 85 488 parturients in Finland

Objectives The aim of this study was to analyse the relation between the used labour pain relief and childbirth experience measured by Visual Analogue Scale (VAS).Design A retrospective cohort study.Setting Childbirth in five Helsinki University Hospital delivery units from 2012 to 2018.Primary outcome measure Childbirth experience measured by VAS and classified in three groups (negative VAS=1textendash5, positive VAS=6textendash8 and highly positive=9textendash10).Results The use of epidural or non-epidural compared with non-medical pain relief methods decreased the likelihood to experience highly positive childbirth for primiparous (adjusted OR (aOR)EPIDURAL=0.64, 95.57 to 0.73; and aORNON-EPIDURAL=0.76, 95.66 to 0.87) and multiparous (aOREPIDURAL=0.90, 95.84 to 0.97 and aORNON-EPIDURAL=0.80, 95.74 to 0.86) parturients. The effects of epidural differed between primiparas and multiparas. In multiparas epidural was associated with decreased odds for experiencing negative childbirth compared with the non-medical group (aOR=0.70, 95.57 to 0.87), while the effect of epidural was considered insignificant in primiparas (aOR=1.28, 95.93 to 1.77).Conclusion While the use of medicaltextemdashepidural and non-epiduraltextemdashpain relief methods were not associated with odds for experiencing negative childbirth in primiparas, using epidural helps to avoid negative experience in multiparas. However, the odds for experiencing highly positive childbirth were decreased if the parturients used any medical pain relief for both primiparas and multiparas. Consequently, the effect of pain relief on the childbirth experience is strongly confounded by indication. Thus, the use of pain relief per se plays a limited role in the complex formation of the overall childbirth experience.No data are available. The data was granted to use in this study and is not allowed to reuse without other permission.Peer reviewe

Flow-Mediated Vasodilation Is Not Attenuated in Hypertensive Pregnancies Despite Biochemical Signs of Inflammation

Background. Our objective was to evaluate endothelial function and markers of inflammation during and after pregnancy in normal pregnancies compared to pregnancies complicated with hypertension or preeclampsia (PE). Methods and Results. We measured endothelium-dependent brachial artery flow-mediated vasodilation (FMD) and high sensitive C-reactive protein (hsCRP), interleukin-6 (IL-6), and tumour necrosis factor-α (TNF-α) in 32 women with normal pregnancy and in 28 women whose pregnancy was complicated with hypertensive disorder in the second half of pregnancy and minimum 3-month postpartum. Enhancement of endothelial function was greater in hypertensive than normal pregnancies, the mean FMD% being 11.0% versus 8.8% during pregnancy (P = 0.194) and 8.0% versus 7.9% postpartum (P = 0.978). Concentrations of markers of inflammation were markedly increased in pregnant hypertensive group compared to those after delivery (hsCRP 4.5 versus 0.80 mg/L, P = 0.023, IL-6 2.1 versus 1.2 pg/mL, P = 0.006; TNF-α 1.9 versus 1.5 pg/mL, P = 0.030). There were no statistically significant associations between the markers of inflammation and FMD. Conclusions. Brachial artery FMD was not attenuated in the third trimester hypertensive pregnancies compared to normal pregnancies, whereas circulating concentrations of hsCRP and IL-6 and TNF-α reacted to hypertensive complications

Short-term exercise affects cardiac function ex vivo partially via changes in calcium channel levels, without influencing hypoxia sensitivity

Exercise is known to improve cardiac recovery following coronary occlusion. However, whether short-term exercise can improve cardiac function and hypoxia tolerance ex vivo independent of reperfusion injury and the possible role of calcium channels in improved hypoxia tolerance remains unknown. Therefore, in the current study, heart function was measured ex vivo using the Langendorff method at different oxygen levels after a 4-week voluntary wheel-running regimen in trained and untrained male mice (C57Bl/6NCrl). The levels of cardiac Ca2+-channels: L-type Ca2+-channel (CACNA1C), ryanodine receptor (RyR-2), sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA2), and sodium-calcium exchanger were measured using western blot. Trained mice displayed lower cardiac afterload pressure generation capacity (rate and amplitude), but unaltered hypoxia tolerance when compared to untrained mice with similar heart rates. The level of CACNA1C positively correlated with the pressure generation rate and amplitude. Furthermore, the CACNA1C-RYR-2 ratio also positively correlated with the pressure generation rate. While the 4-week training period was not enough to alter the intrinsic cardiac hypoxia tolerance, interestingly it decreased pressure generation capacity and slowed pressure decreasing capacity in the mouse hearts ex vivo. This reduction in pressure generation rate could be linked to the level of channel proteins in sarcolemmal Ca2+-cycling in trained mice. However, the Ca(2+-)channel levels did not differ significantly between the groups, and thus, the level of calcium channels cannot fully explain all the functional alterations, despite the detected correlations. Therefore, additional studies are warranted to reveal further mechanisms that contribute to the reduced intrinsic capacity for pressure production in trained mouse hearts

Maternal childbirth experience and induction of labour in each mode of delivery: a retrospective seven-year cohort study of 95,051 parturients in Finland

Childbirth experience has been shown to depend on the mode of delivery. However, it is unclear how labour induction influences the childbirth experience in different modes of delivery. Thus, we assessed the childbirth experience among mothers with spontaneous and induced labours.Background Childbirth experience has been shown to depend on the mode of delivery. However, it is unclear how labour induction influences the childbirth experience in different modes of delivery. Thus, we assessed the childbirth experience among mothers with spontaneous and induced labours. Design A retrospective cohort study. Setting Childbirths in four delivery hospitals in Helsinki and Uusimaa District, Finland, in 2012-2018. Sample 95051 childbirths excluding elective caesarean sections. Methods Obstetric data combined to maternal childbirth experience measured by Visual Analogue Scale (VAS) was analysed with univariate linear modelling and group comparisons. The primiparas and multiparas were analysed separately throughout the study due to the different levels of VAS. Main outcome measures Maternal childbirth experience measured by VAS. Results The negative effect of labour induction on the childbirth experience was discovered in each mode of delivery. Operative deliveries were perceived more negatively when they were preceded by labour induction. The rate of poor childbirth experience (VASPeer reviewe

Ventilation during continuous compressions or at 30:2 compression-to-ventilation ratio results in similar arterial oxygen and carbon dioxide levels in an experimental model of prolonged cardiac arrest

Background: In refractory out-of-hospital cardiac arrest, transportation to hospital with continuous chest compressions (CCC) from a chest compression device and ventilation with 100% oxygen through an advanced airway is common practice. Despite this, many patients are hypoxic and hypercapnic on arrival, possibly related to suboptimal ventilation due to the counterpressure caused by the CCC. We hypothesized that a compression/ventilation ratio of 30:2 would provide better ventilation and gas exchange compared to asynchronous CCC during prolonged experimental cardiopulmonary resuscitation (CPR).Methods: We randomized 30 anaesthetized domestic swine (weight approximately 50 kg) with electrically induced ventricular fibrillation to the CCC or 30:2 group and bag-valve ventilation with a fraction of inspired oxygen (FiO(2)) of 100%. We started CPR after a 5-min no-flow period and continued until 40 min from the induction of ventricular fibrillation. Chest compressions were performed with a Stryker Medical LUCAS (R) 2 mechanical chest compression device. We collected arterial blood gas samples every 5 min during the CPR, measured ventilation distribution during the CPR using electrical impedance tomography (EIT) and analysed post-mortem computed tomography (CT) scans for differences in lung aeration status.Results: The median (interquartile range [IQR]) partial pressure of oxygen (PaO2) at 30 min was 110 (52-117) mmHg for the 30:2 group and 70 (40-171) mmHg for the CCC group. The median (IQR) partial pressure of carbon dioxide (PaCO2) at 30 min was 70 (45-85) mmHg for the 30:2 group and 68 (42-84) mmHg for the CCC group. No statistically significant differences between the groups in PaO2 (p =0.40), PaCO2 (p = 0.79), lactate (p = 0.37), mean arterial pressure (MAP) (p = 0.47) or EtCO2 (p = 0.19) analysed with a linear mixed model were found. We found a deteriorating trend in PaO2, EtCO2 and MAP and rising PaCO2 and lactate levels through the intervention. There were no differences between the groups in the distribution of ventilation in the EIT data or the post-mortem CT findings.Conclusions: The 30:2 and CCC protocols resulted in similar gas exchange and lung pathology in an experimental prolonged mechanical CPR model.Peer reviewe