Fast Retinal Vessel Detection and Measurement Using Wavelets and Edge Location Refinement

The relationship between changes in retinal vessel morphology and the onset and progression of diseases such as diabetes, hypertension and retinopathy of prematurity (ROP) has been the subject of several large scale clinical studies. However, the difficulty of quantifying changes in retinal vessels in a sufficiently fast, accurate and repeatable manner has restricted the application of the insights gleaned from these studies to clinical practice. This paper presents a novel algorithm for the efficient detection and measurement of retinal vessels, which is general enough that it can be applied to both low and high resolution fundus photographs and fluorescein angiograms upon the adjustment of only a few intuitive parameters. Firstly, we describe the simple vessel segmentation strategy, formulated in the language of wavelets, that is used for fast vessel detection. When validated using a publicly available database of retinal images, this segmentation achieves a true positive rate of 70.27%, false positive rate of 2.83%, and accuracy score of 0.9371. Vessel edges are then more precisely localised using image profiles computed perpendicularly across a spline fit of each detected vessel centreline, so that both local and global changes in vessel diameter can be readily quantified. Using a second image database, we show that the diameters output by our algorithm display good agreement with the manual measurements made by three independent observers. We conclude that the improved speed and generality offered by our algorithm are achieved without sacrificing accuracy. The algorithm is implemented in MATLAB along with a graphical user interface, and we have made the source code freely available. 

Availability of complementary and alternative medicine for people with cancer in the British National Health Service: Results of a national survey

This study assessed access to Complementary and Alternative Medicine (CAM) therapies for people with cancer within the British National Health Service. CAM units were identified through an internet search in 2009. A total of 142 units, providing 62 different therapies, were identified: 105 (74.0%) England; 23 (16.2%) Scotland; 7 (4.9%) each in Wales and Northern Ireland. Most units provide a small number of therapies (median 4, range 1–20), and focus on complementary, rather than alternative approaches. Counselling is the most widely provided therapy (available at 82.4% of identified units), followed by reflexology (62.0%), aromatherapy (59.1%), reiki (43.0%), massage (42.2%). CAM units per million of the population varied between countries (England: 2.2; Wales: 2.3; Scotland: 4.8; Northern Ireland: 5.0), and within countries. Better publicity for CAM units, greater integration of units in conventional cancer treatment centres may help improve access to CAMs.

Ulysses contracts in medicine

Ulysses contracts are a method by which one person binds himself by agreeing to be bound by others. In medicine such contracts have primarily been discussed as ways of treating people with episodic mental illnesses, where the features of the illness are such that they now judge that they will refuse treatment at the time it is needed. Enforcing Ulysses contracts in these circumstances would require medical professionals to override the express refusal of the patient at the time treatment is required, something that is generally problematic both ethically and legally. In this paper I will argue that despite appearances Ulysses contracts can make it the case that treating a patient in such circumstances is an instance of treating him with his consent, although safeguards are needed to ensure that this is the case. Given the potential benefits to patients I further argue that modified Ulysses contracts should be made legally enforceable.

Spatial updating across saccades during manual interception

We studied the effect of intervening saccades on the manual interception of a moving target. Previous studies suggest that stationary reach goals are coded and updated across saccades in gaze-centered coordinates, but whether this generalizes to interception is unknown. Subjects (n = 9) reached to manually intercept a moving target after it was rendered invisible. Subjects either fixated throughout the trial or made a saccade before reaching (both fixation points were in the range of -10° to 10°). Consistent with previous findings and our control experiment with stationary targets, the interception errors depended on the direction of the remembered moving goal relative to the new eye position, as if the target is coded and updated across the saccade in gaze-centered coordinates. However, our results were also more variable in that the interception errors for more than half of our subjects also depended on the goal direction relative to the initial gaze direction. This suggests that the feedforward transformations for interception differ from those for stationary targets. Our analyses show that the interception errors reflect a combination of biases in the (gaze-centered) representation of target motion and in the transformation of goal information into body-centered coordinates for action.

Prospective control of manual interceptive actions:comparative simulations of extant and new model constructs

Two prospective controllers of hand movements in catching-both based on required velocity control-were simulated. Under certain conditions, this required velocity control led to overshoots of the future interception point. These overshoots were absent in pertinent experiments. To remedy this shortcoming, the required velocity model was reformulated in terms of a neural network, the Vector Integration To Endpoint model, to create a Required Velocity Integration To Endpoint model. Addition of a parallel relative velocity channel, resulting in the Relative and Required Velocity Integration To Endpoint model, provided a better account for the experimentally observed kinematics than the existing, purely behavioral models. Simulations of reaching to intercept decelerating and accelerating objects in the presence of background motion were performed to make distinct predictions for future experiments.