603 research outputs found

    Finding the future:evolving interaction design

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    The main aim of this project is to design and prototype a simplified example of a mobile operating system that makes use of both edge swipe control and 'smart' graphical instructions. The research will consider how these methods can be used to design a truly inclusive and accessible interface. The effectiveness of these features will be validated through user experiments and focus groups over the course of the project, with the findings of user testing used to inform design practice

    How to extend Roberts' Law for eccentrically driven, inverted slider-cranks

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    The extension of Roberts' Law concerns inverted slider-cranks with an eccentricity and a general tracing-point attached to the moving plane of the slider. As both curve-cognates degenerate in this case, the infinite turning-joint has first been replaced by a finite far-away joint, but such that the coupler-plane also meets two accuracy-positions of the erstwhile slider. One of the curve-cognates may then be adapted or modified until up to six accuracy positions are met. They seem to be sufficient to attain an extraordinary good approximation of the entire branch of the original curve. Besides, even the transmission-angle attains a value about twice as large as the one obtained with the auxiliary four-bar representing the first approximation. Cases, where the inverted slider-crank turns into a crank-and-rocker, into a double crank or even into a stretchable four-bar, are shown. The latter corresponds with one of Grashofs border cases for the inverted slider-crank. Roberts' Law then ensures that each inverted slider-crank, having a fully revolving crank, possesses three four-bar branchcognates this way

    Control of cellular automata

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    We study the problem of master-slave synchronization and control of totalistic cellular automata (CA) by putting a fraction of sites of the slave equal to those of the master and finding the distance between both as a function of this fraction. We present three control strategies that exploit local information about the CA, mainly, the number of nonzero Boolean derivatives. When no local information is used, we speak of synchronization. We find the critical properties of control and discuss the best control strategy compared with synchronization

    The diagnostic accuracy of a single CEA blood test in detecting colorectal cancer recurrence: Results from the FACS trial

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    Objective: To evaluate the diagnostic accuracy of a single CEA (carcinoembryonic antigen) blood test in detecting colorectal cancer recurrence. Background: Patients who have undergone curative resection for primary colorectal cancer are typically followed up with scheduled CEA testing for 5 years. Decisions to investigate further (usually by CT imaging) are based on single test results, reflecting international guidelines. Methods: A secondary analysis was undertaken of data from the FACS trial (two arms included CEA testing). The composite reference standard applied included CT-CAP imaging, clinical assessment and colonoscopy. Accuracy in detecting recurrence was evaluated in terms of sensitivity, specificity, likelihood ratios, predictive values, time-dependent area under the ROC curves, and operational performance when used prospectively in clinical practice are reported. Results: Of 582 patients, 104 (17.9%) developed recurrence during the 5 year follow-up period. Applying the recommended threshold of 5”g/L achieves at best 50.0% sensitivity (95% CI: 40.1-59.9%); in prospective use in clinical practice it would lead to 56 missed recurrences (53.8%; 95% CI: 44.2-64.4%) and 89 false alarms (56.7% of 157 patients referred for investigation). Applying a lower threshold of 2.5”g/L would reduce the number of missed recurrences to 36.5% (95% CI: 26.5-46.5%) but would increase the false alarms to 84.2% (924/1097 referred). Some patients are more prone to false alarms than others – at the 5”g/L threshold, the 89 episodes of unnecessary investigation were clustered in 29 individuals. Conclusion: Our results demonstrated very low sensitivity for CEA, bringing to question whether it could ever be used as an independent triage test. It is not feasible to improve the diagnostic performance of a single test result by reducing the recommended action threshold because of the workload and false alarms generated. Current national and international guidelines merit re-evaluation and options to improve performance, such as making clinical decisions on the basis of CEA trend, should be further assessed

    Extended scope of nursing practice: a multicentre randomised controlled trial of appropriately trained nurses and pre-registration house officers in pre-operative assessment in elective general surgery

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    Aim/ Principal Research Question:1) To determine whether pre-operative assessment carried out by an appropriately trained nurse (ATN) is equivalent in quality to that carried out by a pre-registration house officer (PRHO).2) To assess whether pre-assessments carried out by ATNs and PRHOs are equivalent in terms of cost.3) To determine whether assessments carried out by ATNs are acceptable to patients.4) To investigate the quality of communication between senior medical staff and ATNs.Factors of Interest:The extended role of appropriately trained nurses and pre-registration house officers in pre-operative assessment in elective general surgery.Methods:The study design was principally a prospective randomised equivalence trial but was accompanied by additional qualitative assessment of patient and staff perceptions, and an economic evaluation.The intervention consisted of a pre-operative assessment carried out by either an ATN or a PRHO. Of the patients who completed the study with a full evaluation, 926 patients were randomised to the PRHO arm of the trial and 948 to the ATN arm. Three ATNs took part in the study, one from each centre, together with a total of 87 PRHOs.Immediately following the initial assessment of a patient by a PRHO or an ATN, one of a number of clinical research fellows, all specialist registrars in anaesthetics, repeated the assessment and recorded it on a study form, together with a list of investigations required. The clinical research fellow then evaluated the competency of the initial assessor by comparing the quality of their assessment with their own. Any deficiencies in ordering of investigations and referral to other specialities were met in order to maximise patient care.Sample groups:All patients attending at one site for assessment prior to general anaesthetic for elective general, vascular, urological or breast surgery were potentially included in the study. Of 1907 patients who were randomised, 1874 completed the study with a full evaluation.The study was carried out at four NHS hospitals, three of which were teaching hospitals, in three NHS Trusts in Southampton, Sheffield and Doncaster.Outcome measures:Three areas of ATN and PRHO performance were judged separately, history taking, examination and ordering of tests, and each was graded into one of four categories, the most important of which was under-assessment, which would possibly have affected peri-operative management. In the case of ordering of tests, it was possible to have both over- and under-assessed a patient on different tests.Findings:The pre-operative assessments carried out by the ATNs were essentially equivalent to those performed by the PRHOs in terms of under-assessment that might possibly have affected peri-operative management, although there was variation between the ATNs in terms of the quality of history taking. This may be related to the low number of patients seen at one study site.PRHOs ordered significantly more unnecessary tests than the ATNs. The substitution of ATNs for PRHOs was calculated to be cost neutral.The results of the qualitative assessment showed that the use of ATNs for pre-operative assessment was acceptable to patients; however, there was no evidence that communication between senior medical staff and those carrying out pre-operative assessments was improved by their introduction.Conclusions:This study demonstrated no reason to inhibit the development of fully nurse-led pre-operative assessment, provided that the nurses are appropriately trained and maintain sufficient workload to retain skills.Implications for Further Research:Further research is needed in the following areas:1) the extent and type of training needed for nurses undertaking the pre-operative assessment role2) the use, costs and benefits of routine pre-operative testing.<br/
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