User modelling for adaptive training in high performance driving

User model creation is a fundamental component for the development of intelligent personalised systems. This thesis proposes an adaptive user modelling framework that uses a combination of unobtrusive task-related and physiological data with the aim of identifying strengths and weaknesses in user performance in the defined task. The research is focused on utilising the framework to provide personalised content adaptation in car racing games. Our system adopts concepts from the Trace Theory (TT) framework, and uses machine learning techniques to extract specific features from the user and the game. These metrics are then transformed and evaluated into higher level abstractions such as experience, exploration and physiological attention by utilising the educational theoretical frameworks of Flow and Zone Theory. The end result is to provide new game paths utilising the user’s model. We demonstrate that this procedural generation of user-tailored content drives the self-motivating behaviour of players to immerse and engage themselves in the game’s virtual world. Collection of data and feedback from multiple users (52) allowed us to associate the model’s outcomes to the user responses, as well as device multiple trial scenarios to verify their training and engagement. We have also evaluated the algorithms for the generation of new tracks for their suitability on the skill’s profile of 41 of our subjects and race track diversity among the evolved paths. We have also designed a method for predicting the states of the user-controlled system by combining information from both sources – vehicle and user – via Gaussian Processes (GPs). In the context of high speed car racing we showed that the forthcoming position and speed of the car can be predicted with high accuracy by our trained user models. This opens up future possibilities of generating better personalised tracks for individuals or even real-time share-control of the car to optimally assist the users in dangerous situations.Open Acces

Is the Routine Use of Drainage After Elective Laparoscopic Cholecystectomy Justified? A Randomized Trial

Background: Laparoscopic cholecystectomy (LC) is the gold standard for the surgical treatment of cholelithiasis. However, the use of drainage after elective LC in literature remains controversial. Methods: A randomized study was performed in Larnaka General Hospital. The purpose of the study was to evaluate drainage of the gallbladder bed after elective LC. One hundred sixteen patients were randomly allocated in two groups, sustained an uneventful LC, and were included in the study after an informed consent was obtained. Sixty-three patients were included in drainage group (YD) and 53 patients in nondrainage group (ND). Drain tubes, made of polyethylene, were placed at the end of the procedure in the patients of YD group. Postoperative pain was assessed using two scales: a 10-point visual analog scale and a 5-point verbal response scale. The two groups were evaluated and compared regarding postoperative pain, the time needed for surgery, length of postoperative hospital stay, the postoperative collection of fluid in the subhepatic space, and the incidence of postoperative complications. Chi-square and t-tests were used to evaluate the data, and statistical significance was established at P < .05. Results: The mean operative time in YD patients was 6.9 minutes longer compared with ND patients (P = .056). The postoperative pain was higher in the YD group by more than one point on the average in the visual analog scale both at 6 and 24 hours (P = .01 and < .001, respectively). When measured with the verbal response scale, the difference in the reported pain was very significant at 24 hours (mean level for YD 1.24 and for ND 0.75). The proportion of patients staying in hospital for > 2 days was higher in the YD group: 28.6% of the patients versus 13.2% in the ND group (P = .05). Subhepatic fluid was more often observed in the YD group (47% versus 34% in the ND), but the difference was not statistically significant. There was no statistical difference in the rate of wound infections, shoulder pain, nausea, vomiting, and respiratory infections between the two groups. Conclusions: Our results indicate that routine drainage of gallbladder bed after elective LC may not be justified. Drainage causes more postoperative pain, prolongs the operative time and hospital stay, increases the occurrence of fluid in the subhepatic space, and does not protect from other complications

Genotypes at the matrix metalloproteinase (MMP) loci for MMP9 and MMP12 are associated with carotid IMT measures of plaque stability

Abstarct paper presented in the XIV International Symposium on Atherosclerosis, 2006, Rome, Italy, 18–22 Jun

ApoB/ApoA1 ratio and subclinical atherosclerosis

Aim. It has been demonstrated that an increased apolipoprotein B (ApoB)/apolipoprotein A-I (ApoA1) ratio is associated with atherogenic low density lipoprotein (LDL) particles and the development of clinical cardiovascular disease. The aim of this study was to test the hypothesis that ApoB/ApoA1 ratio is associated with early subclinical atherosclerosis as demonstrated by ultrasonic measurements. Methods. Both common carotid and common femoral bifurcations have been scanned with high-resolution ultrasound in 767 volunteers over the age of 40. The latter consisted of 95% of the population of two randomly selected areas. IMTcc, IMTmax (including plaques), total plaque thickness (TPT) (the sum of the thickest plaques present at each bifurcation in cm) and black plaque burden (BPB) (TPT means plaque type) using the Widder classification with type 1 being the most hyperechoic and calcified and type 5 the most hypoechoic plaque were recorded. A medical history was taken with emphasis on risk factors present and a fasting lipid profile including ApoB and ApoA1 was determined. Results. In the total population (N.=767) the mean (±SD) ApoB/ApoA1 ratio was 0.85 (±0.22). In linear regression analysis, the Apob/ApoA1 ratio was significantly associated with all the ultrasonic measurements of early atherosclerosis (intima media thickness, IMTcc, IMTmax, TPT and BPB). These findings remained significant after correcting for age, gender, smoking, hypertension and diabetes (P<0.001 for all). Conclusion. The results indicate that a high ApoB/ApoA1 ratio is associated not only with early atherosclerosis but also with hypoechoic (BPB) and by inference unstable plaques

Association of genotypes at the matrix metalloproteinase (MMP) loci with carotid IMT and presence of carotid and femoral atherosclerotic plaques

We aimed to test the association between matrix metalloproteinase (MMP) genetic polymorphisms and (a) intima-media thickness in the common carotid (IMTcc) and (b) the presence of plaques in the carotid and femoral bifurcations. Carotid and femoral bifurcations were scanned with ultrasound in 762 Cypriot community dwellers (46% men) over the age of 40 years. IMTcc and the presence of plaques were recorded. The MMP1 1G/2G, MMP3 5A/6A, MMP7 -181A>G, MMP9 R279Q, and MMP12 -82A>G polymorphisms were determined with the TaqMan method. In men, the presence of plaques in any bifurcation was associated with the MMP9 279Q allele (ORadjusted=4.50; 95% CI=2.0 to 10.1; p<0.001) and the MMP7 -181A allele was associated with the presence of femoral plaques (ORadjusted=2.61; 95% CI=1.36 to 4.99; p=0.004). In women, the presence of femoral plaques was associated with the MMP12 -82G allele (ORadjusted=1.9; 95% CI=1.14 to 3.16; p=0.014). Our results suggest that the effect of common MMP genotypes on plaque presence may be site- and sex-dependent

Heritability of ultrasonic measurements of subclinical atherosclerosis

Abstract presented in the XV International Symposium on Atherosclerosis, 2009, Boston, USA, 14–18 Jun

Association of LP-PLA2 activity and PAF-AH ALA379VAL genotype and early atherosclerosis. results from the Cyprus study

Abstract of the paper presented in the 77 Congress of the European Atherosclerosis Society, 2008, Istanbul, Turkey, 26–29 Apri

Performance of SCORE2 and SCORE2-OP Risk Algorithms in a Cypriot Cohort

SCORE2 and SCORE2-OP algorithms and associated online calculators provide a new and easy method of estimating the 10-year cardiovascular risk in apparently healthy Europeans. The aim of the study was to determine the performance of these algorithms in terms of discrimination and calibration in the cohort of the Cyprus Epidemiological Study on Atherosclerosis (CESA), not only for the 10-year risk for myocardial infarction (MI), stroke and cardiovascular death, but also for all types of atherosclerotic cardiovascular events (ASCVE)