30 research outputs found
Real-Time Unified Trajectory Planning and Optimal Control for Urban Autonomous Driving Under Static and Dynamic Obstacle Constraints
Trajectory planning and control have historically been separated into two
modules in automated driving stacks. Trajectory planning focuses on
higher-level tasks like avoiding obstacles and staying on the road surface,
whereas the controller tries its best to follow an ever changing reference
trajectory. We argue that this separation is (1) flawed due to the mismatch
between planned trajectories and what the controller can feasibly execute, and
(2) unnecessary due to the flexibility of the model predictive control (MPC)
paradigm. Instead, in this paper, we present a unified MPC-based trajectory
planning and control scheme that guarantees feasibility with respect to road
boundaries, the static and dynamic environment, and enforces passenger comfort
constraints. The scheme is evaluated rigorously in a variety of scenarios
focused on proving the effectiveness of the optimal control problem (OCP)
design and real-time solution methods. The prototype code will be released at
https://github.com/WATonomous/control
A sensorless state estimation for a safety-oriented cyber-physical system in urban driving : deep learning approach
In today's modern electric vehicles, enhancing the safety-critical cyber-physical system CPS 's performance is necessary for the safe maneuverability of the vehicle. As a typical CPS, the braking system is crucial for the vehicle design and safe control. However, precise state estimation of the brake pressure is desired to perform safe driving with a high degree of autonomy. In this paper, a sensorless state estimation technique of the vehicle's brake pressure is developed using a deep-learning approach. A deep neural network DNN is structured and trained using deep-learning training techniques, such as, dropout and rectified units. These techniques are utilized to obtain more accurate model for brake pressure state estimation applications. The proposed model is trained using real experimental training data which were collected via conducting real vehicle testing. The vehicle was attached to a chassis dynamometer while the brake pressure data were collected under random driving cycles. Based on these experimental data, the DNN is trained and the performance of the proposed state estimation approach is validated accordingly. The results demonstrate high-accuracy brake pressure state estimation with RMSE of 0.048 MPa.Published versio
May Measurement Month 2018: a pragmatic global screening campaign to raise awareness of blood pressure by the International Society of Hypertension
Aims
Raised blood pressure (BP) is the biggest contributor to mortality and disease burden worldwide and fewer than half of those with hypertension are aware of it. May Measurement Month (MMM) is a global campaign set up in 2017, to raise awareness of high BP and as a pragmatic solution to a lack of formal screening worldwide. The 2018 campaign was expanded, aiming to include more participants and countries.
Methods and results
Eighty-nine countries participated in MMM 2018. Volunteers (≥18 years) were recruited through opportunistic sampling at a variety of screening sites. Each participant had three BP measurements and completed a questionnaire on demographic, lifestyle, and environmental factors. Hypertension was defined as a systolic BP ≥140 mmHg or diastolic BP ≥90 mmHg, or taking antihypertensive medication. In total, 74.9% of screenees provided three BP readings. Multiple imputation using chained equations was used to impute missing readings. 1 504 963 individuals (mean age 45.3 years; 52.4% female) were screened. After multiple imputation, 502 079 (33.4%) individuals had hypertension, of whom 59.5% were aware of their diagnosis and 55.3% were taking antihypertensive medication. Of those on medication, 60.0% were controlled and of all hypertensives, 33.2% were controlled. We detected 224 285 individuals with untreated hypertension and 111 214 individuals with inadequately treated (systolic BP ≥ 140 mmHg or diastolic BP ≥ 90 mmHg) hypertension.
Conclusion
May Measurement Month expanded significantly compared with 2017, including more participants in more countries. The campaign identified over 335 000 adults with untreated or inadequately treated hypertension. In the absence of systematic screening programmes, MMM was effective at raising awareness at least among these individuals at risk
Global variations in diabetes mellitus based on fasting glucose and haemogloblin A1c
Fasting plasma glucose (FPG) and haemoglobin A1c (HbA1c) are both used to diagnose
diabetes, but may identify different people as having diabetes. We used data from 117
population-based studies and quantified, in different world regions, the prevalence of
diagnosed diabetes, and whether those who were previously undiagnosed and detected
as having diabetes in survey screening had elevated FPG, HbA1c, or both. We developed
prediction equations for estimating the probability that a person without previously
diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa.
The age-standardised proportion of diabetes that was previously undiagnosed, and
detected in survey screening, ranged from 30% in the high-income western region to 66%
in south Asia. Among those with screen-detected diabetes with either test, the agestandardised
proportion who had elevated levels of both FPG and HbA1c was 29-39%
across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and
middle-income regions, isolated elevated HbA1c more common than isolated elevated
FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and
underestimate diabetes prevalence. Our prediction equations help allocate finite
resources for measuring HbA1c to reduce the global gap in diabetes diagnosis and
surveillance.peer-reviewe
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Summary
Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally.
Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies
have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of
the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income
countries globally, and identified factors associated with mortality.
Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to
hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis,
exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a
minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical
status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary
intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause,
in-hospital mortality for all conditions combined and each condition individually, stratified by country income status.
We did a complete case analysis.
Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital
diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal
malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome
countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male.
Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3).
Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income
countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups).
Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome
countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries;
p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients
combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11],
p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20
[1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention
(ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety
checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed
(ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of
parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65
[0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality.
Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome,
middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will
be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger
than 5 years by 2030
Sim-to-Real Domain Adaptation for Lane Detection and Classification in Autonomous Driving
While supervised detection and classification frameworks in autonomous
driving require large labelled datasets to converge, Unsupervised Domain
Adaptation (UDA) approaches, facilitated by synthetic data generated from
photo-real simulated environments, are considered low-cost and less
time-consuming solutions. In this paper, we propose UDA schemes using
adversarial discriminative and generative methods for lane detection and
classification applications in autonomous driving. We also present Simulanes
dataset generator to create a synthetic dataset that is naturalistic utilizing
CARLA's vast traffic scenarios and weather conditions. The proposed UDA
frameworks take the synthesized dataset with labels as the source domain,
whereas the target domain is the unlabelled real-world data. Using adversarial
generative and feature discriminators, the learnt models are tuned to predict
the lane location and class in the target domain. The proposed techniques are
evaluated using both real-world and our synthetic datasets. The results
manifest that the proposed methods have shown superiority over other baseline
schemes in terms of detection and classification accuracy and consistency. The
ablation study reveals that the size of the simulation dataset plays important
roles in the classification performance of the proposed methods. Our UDA
frameworks are available at https://github.com/anita-hu/sim2real-lane-detection
and our dataset generator is released at https://github.com/anita-hu/simulanesComment: Accepted by IV 202
Exercise capacity in people with Parkinson’s disease: which clinical characteristics are important?
Background: People with Parkinson’s (PwP) are suffering from reduced exercise capacity. However, little information is known about clinical correlates of exercise capacity in this population Objective: This study aimed to evaluate correlations between motor and non-motor symptoms with exercise capacity in PwP. Methods: A total of 50 individuals with Parkinson’s disease participated in the study. Exercise capacity was measured by 6 minutes’ walk test (6MWT). Besides, the Movement Disorder Society-Unified Parkinson’s Disease Rating Scale-Part III used to evaluate disease motor severity, Berg Balance Scale to assess balance, Montréal Cognitive Assessment to evaluate cognitive status, hospital anxiety and depression scale to assess depression and anxiety, Modified Fatigue Impact scale to evaluate fatigue, and the Pittsburgh Sleep Quality Index to evaluate sleep quality. Results: The results showed that exercise capacity, when measured by the 6MWT, can be significantly predicted by balance, disease motor severity, anxiety, and age (R2 = 0.61 P < .0001). Conclusion: These results suggest that exercise capacity in PwP is multifactorial and can potentially be predicted by balance, motor severity, anxiety, and age.Open Access funding provided by the Qatar National Library.
The authors would like to acknowledge all the participants of the study. Acknowledgment for funding support is to Jordan University of Science and Technology (Grant number HK-20190320)
Validation of the Arabic Version of the Movement Disorder Society-Unified Parkinson's Disease Rating Scale
Background: The Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) has become the gold standard for evaluating different domains in Parkinson's disease (PD), and it is commonly used in clinical practice, research, and clinical trials. Objectives: The objectives are to validate the Arabic-translated version of the MDS-UPDRS and to assess its factor structure compared with the English version. Methods: The study was carried out in three phases: first, the English version of the MDS-UPDRS was translated into Arabic and subsequently back-translated into English by independent translation team; second, cognitive pretesting of selected items was performed; third, the Arabic version was tested in over 400 native Arabic-speaking PD patients. The psychometric properties of the translated version were analyzed using confirmatory factor analysis (CFA) as well as exploratory factor analysis (EFA). Results: The factor structure of the Arabic version was consistent with that of the English version based on the high CFIs for all four parts of the MDS-UPDRS in the CFA (CFI ≥0.90), confirming its suitability for use in Arabic. Conclusions: The Arabic version of the MDS-UPDRS has good construct validity in Arabic-speaking patients with PD and has been thereby designated as an official MDS-UPDRS version. The data collection methodology among Arabic-speaking countries across two continents of Asia and Africa provides a roadmap for validating additional MDS rating scale initiatives and is strong evidence that underserved regions can be energically mobilized to promote efforts that apply to better clinical care, education, and research for PD. © 2022 International Parkinson and Movement Disorder Society