Retinal Vessel Detection and Measurement for Computer-aided Medical Diagnosis

Since blood vessel detection and characteristic measurement for ocular retinal images is a fundamental problem in computer-aided medical diagnosis, automated algorithms/systems for vessel detection and measurement are always demanded. To support computer-aided diagnosis, an integrated approach/solution for vessel detection and diameter measurement is presented and validated. In the proposed approach, a Dempster–Shafer (D–S)-based edge detector is developed to obtain initial vessel edge information and an accurate vascular map for a retinal image. Then, the appropriate path and the centerline of a vessel of interest are identified automatically through graph search. Once the vessel path has been identified, the diameter of the vessel will be measured accordingly by the algorithm in real time. To achieve more accurate edge detection and diameter measurement, mixed Gaussian-matched filters are designed to refine the initial detection and measures. Other important medical indices of retinal vessels can also be calculated accordingly based on detection and measurement results. The efficiency of the proposed algorithm was validated by the retinal images obtained from different public databases. Experimental results show that the vessel detection rate of the algorithm is 100 % for large vessels and 89.9 % for small vessels, and the error rate on vessel diameter measurement is less than 5 %, which are all well within the acceptable range of deviation among the human graders.     

Effectiveness of a National Transitional Care Program in Reducing Acute Care Use

This study evaluated the effectiveness of a national transitional care program for elderly adults with complex care needs and limited social support. The Aged Care Transition (ACTION) Program was designed to improve coordination and continuity of care and reduce rehospitalizations and visits to emergency departments (EDs). Dedicated care coordinators provided coaching to help individuals and families understand the individuals' conditions, effectively articulate their preferences, and enable self‐management and care planning. Participants were individuals aged 65 and older hospitalized and enrolled from five public general hospitals in Singapore between February 2009 and July 2010 (N = 4,132). The coordinators worked with participants during hospitalization and followed up with telephone calls and home visits for 1 to 2 months after discharge and coordinated placements with appropriate community service providers. Unplanned rehospitalization and ED visit (up to 6 months after discharge) rates were compared with those of a comparator group of individuals who did not receive care coordination using propensity score‐based weighting. Participant and caregiver surveys on quality of life and self‐rated health were also administered. Recipients of the ACTION program had fewer unplanned rehospitalizations and ED visits after discharge. Propensity score–adjusted odds ratios of participants versus control for number of unplanned rehospitalization and ED visits were 0.5 (95% confidence interval (CI) = 0.5–0.6) and 0.81 (95% CI = 0.72–0.90) 30 days after discharge and 0.6 (95% CI = 0.6–0.7) and 0.90 (95% CI = 0.82–0.99) 180 days after discharge. Quality of life and self‐rated health were better 4 to 6 weeks after discharge than 1 week after discharge. These findings confirm the effectiveness of the ACTION program in improving the transition of vulnerable older adults from hospital to community. Such transitional care should be considered as an integral part of care integration.     

An overview of hypertension and cardiac involvement in Asia: Focus on heart failure

Cardiovascular Disease (CVD) is the leading cause of deaths worldwide, contributing to about 30% of all deaths. Half of the cases of CVD are estimated in Asia, the world's most populous continent. Hypertension, a major modifiable risk factor for CVD, results in more deaths than any other CV risk factors in the Asian regions. The total number of patients with hypertension is likely to grow as the population ages. The proportion of the elderly population aged 65 years or more in Asia is expected to increase from 7.4% in 2015 to 10.9% in 2030. It is important to note that more than half (54%) of the world's population live in Asia. Aside of being the biggest single risk factor for global deaths, hypertension is also an important precursor and most common risk factor of heart failure (HF). An increase in HF prevalence is clearly related to the rapid epidemiological transition caused by changes in lifestyle in Asian countries. However, the availability of data on HF burden and health care delivery is limited in Asia compared with Europe and North America. This reality has driven the working group of Asian experts for example the HOPE Asia Network to concentrate on hypertension as risk factors for CVD, with the mission to improve the management of hypertension resulting in organ protection toward a goal of achieving “ZERO” CV event in Asia. This paper aims to give an overview regarding the heart problems caused by hypertension in Asia, focus on HF.     

Current status of ambulatory blood pressure monitoring in Asian countries: A report from the HOPE Asia Network

Ambulatory blood pressure monitoring (ABPM) can measure 24‐hour blood pressure (BP), including nocturnal BP and diurnal variations. This feature of ABPM could be of value in Asian populations for preventing cardiovascular events. However, no study has yet investigated regarding the use of ABPM in actual clinical settings in Asian countries/regions. In this study, 11 experts from 11 countries/regions were asked to answer questionnaires regarding the use of ABPM. We found that its use was very limited in primary care settings and almost exclusively available in referral settings. The indications of ABPM in actual clinical settings were largely similar to those of home BP monitoring (HBPM), that is, diagnosis of white‐coat or masked hypertension and more accurate BP measurement for borderline clinic BP. Other interesting indications, such as nighttime BP patterns, including non‐dipper BP, morning BP surge, and BP variability, were hardly adopted in daily clinical practice. The use of ABPM as treatment guidance for detecting treated but uncontrolled hypertension in the Asian countries/regions didn't seem to be common. The barrier to the use of ABPM was primarily its availability; in referral centers, patient reluctance owing to discomfort or sleep disturbance was the most frequent barrier. ABPM use was significantly more economical when it was reimbursed by public insurance. To facilitate ABPM use, more simplified indications and protocols to minimize discomfort should be sought. For the time being, HBPM could be a reasonable alternative.     

Diversity of and initiatives for hypertension management in Asia—Why we need the HOPE Asia Network

The Hypertension Cardiovascular Outcome Prevention and Evidence in Asia (HOPE Asia) Network was set up to improve the management of hypertension in Asia with the ultimate goal of achieving “zero” cardiovascular events. Asia is a diverse continent, and the prevalence of hypertension has increased over the last 30 years. There are a number of Asia‐specific features of hypertension and hypertension‐related cardiovascular complications, which means that a region‐specific approach is needed. White‐coat hypertension will become more of an issue over time as Asian populations age, and masked hypertension is more prevalent in Asian than in Western countries. Identifying and treating masked hypertension is important to reduce cardiovascular risk. Abnormal patterns of blood pressure (BP) variability common in Asia include exaggerated early morning BP surge and nocturnal hypertension. These are also important cardiovascular risk factors that need to be managed. Home blood pressure monitoring (HBPM) is an important tool for detecting white‐coat and masked hypertension, and monitoring BP variability, and practices in Asia are variable. Use of HBPM is important given the Asia‐specific features of hypertension, and strategies are needed to improve and standardize HBPM usage. Development of HBPM devices capable of measuring nocturnal BP along with other information and communication technology‐based strategies are key developments in the widespread implementation of anticipation medicine strategies to detect and prevent cardiovascular events in patients with hypertension. Region‐wide differences in hypertension prevalence, control, and management practices in Asia highlight the importance of information sharing to facilitate best practices.     

A novel technique of detecting MRI‐negative lesion in focal symptomatic epilepsy: Intraoperative ShearWave Elastography

Focal symptomatic epilepsy is the most common form of epilepsy that can often be cured with surgery. A small proportion of patients with focal symptomatic epilepsy do not have identifiable lesions on magnetic resonance imaging (MRI). The most common pathology in this group is type II focal cortical dysplasia (FCD), which is a subtype of malformative brain lesion associated with medication‐resistant epilepsy. We present a patient with MRI‐negative focal symptomatic epilepsy who underwent invasive electrode recordings. At the time of surgery, a novel ultrasound‐based technique called ShearWave Elastography (SWE) was performed. A 0.5 cc lesion was demonstrated on SWE but was absent on B‐mode ultrasound and 3‐T MRI. Electroencephalography (EEG), positron emission tomography (PET), and magnetoencephalography (MEG) scans demonstrated an abnormality in the right frontal region. On the basis of this finding, a depth electrode was implanted into the lesion. Surgical resection and histology confirmed the lesion to be type IIb FCD. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here .     

Bi-doping improves the magnetic properties of zinc oxide nanowires

Room-temperature ferromagnetism in the large and direct bandgap diluted magnetic semiconductor zinc oxide (ZnO) is attributed to the intrinsic defects and p-orbital–p-orbital (p–p) coupling interaction. However, due to oxidation, the ferromagnetism induced by defects is unstable. In the present work, the solution process synthesis route was utilized to grow pristine and bismuth-doped, highly crystalline ZnO nanowire (ZnO NW)-based samples. The FE-SEM images showed that the grown ZnO NWs have a preferred orientation along the c-axis in the (001) direction due to the anisotropic crystal nature of ZnO. X-ray photoelectron spectroscopy (XPS) confirmed the presence of Bi, and at a higher doping content, the bismuth oxide phase appeared. The XRD patterns showed the wurtzite crystal structure, and the large intensity of the (002) peak suggests that most of the reflection was from the top hexagonal face of the NWs, and thus, the wires are predominantly aligned along the c-axis. The TEM analysis further confirmed the crystal growth direction along the (001) direction. The UV-Visible absorption and PL measurements also showed a decrease in the bandgap with an increase in doping concentration, which may be associated with the sp–d exchange interaction between the localized d-electrons and band electrons of the Bi ions. Bi-doping tended to increase the PL intensity in the visible region. The magnetic properties measured by SQUID at 4 and 300 K showed ferromagnetic behaviour for both the pristine and Bi-doped samples. However, the saturation magnetization for the Bi-doped samples was higher compared to that of the pristine ZnO samples until the threshold doping value. The obtained results demonstrated that Bi-doping can be used to tune both the optical and magnetic properties of ZnO NWs, hence paving the way for future spintronics and spin-polarized optoelectronics applications.

Room-temperature ferromagnetism in the large and direct bandgap diluted magnetic semiconductor zinc oxide (ZnO) is attributed to the intrinsic defects and p-orbital–p-orbital (p–p) coupling interaction.