Virtual reality and a haptic master-slave set-up in post-stroke upper-limb rehabilitation.

Since the number of stroke patients is ever growing, and since studies show that the patients can benefit from more exercise, the possible use of virtual reality and haptic devices in the rehabilitation of stroke patients is researched. Besides offering more independent and challenging exercise possibilities, the inherent registration capabilities of the haptic devices open up the possibility of monitoring patients' motions in an objective way. This research results in the implementation of a VR mock-up of an exercise in which patients use both hands and a stick to push away a ball that is tossed at them.

Open surgery in VR: inguinal hernia repair according to Lichtenstein.

VREST (Virtual Reality Educational Surgical Tools) is developing a universal and autonomous simulation platform which can be used for training and assessment of medical students and for continuing education of physicians. A workstation consisting of two haptic devices and a 3D vision system is part of the VREST platform. Another part of the platform is a generic software environment in which lessons can be built by the teacher and performed by their students.

The effects of a specific prompting sign on speed reduction.

The purpose of this experiment was to determine whether a specifically worded prompting sign ("BEGIN SLOWING HERE") could reduce speeding where a highway entered an urban area with a residential speed limit. Speed measurements were obtained on vehicles at the start of the residential speed limit zone. Following a baseline period the prompting sign was introduced, removed and reintroduced.

Excretory urography in current practice: evidence against overutilization.

Excretory urography could be performed less frequently if some combinations of genitourinary signs and symptoms were found to be predictive of either a specific disease or normality. To explore this possibility, the authors conducted a prospective study involving more than 3,000 patients at three institutions (a teaching hospital, a community hospital, and a health maintenance organization). Predictive algorithms were obtained by application of a polychotomous logistic regression model but did poorly at differentiating normal from abnormal patients or arriving at a specific diagnosis.

Selection criteria for upper gastrointestinal examinations: attempts at improvement.

An attempt was made to improve upon selection criteria for the performance of upper gastrointestinal (UGI) series in three settings: a teaching hospital, a community hospital, and a health maintenance organization. Two statistical techniques, the polychotomous logistic model (to develop predictive algorithms for the identification of specific diseases) and the maximum attainable discrimination technique, were used to show the relationship between the percentage of patients with any disease detected and the percentage of UGI examinations performed. Results showed that neither technique improved significantly upon selection criteria for identifying patients with abnormal UGI series.

Experimental myocardial ischemia. IV. Shape and volume changes during "isolvolumetric relaxation" in normal and ischemic ventricles.

Shape and volume changes were studied in mongrel dogs between end-systole and mitral valve opening (MVO). Biplane left ventricular cineangiograms were performed at 200 frames/sec. The dogs were studied during the control state and during regional myocardial ischemia produced by balloon occlusion of the left anterior descending coronary artery.

The selection of patients for excretory urography.

Symptoms, signs, and laboratory findings that indicated excretory urography in 1,622 patients, were compared with the radiographs. The chance that an indication would be associated with demonstrable disease was calculated. No "low-likelihood" indications could be identified.

Comparison of observer performance with 16 mm cinefluorography and 70 mm camera fluorography in coronary arteriography.

Clinical 16 mm cinefluorography and 70 mm camera fluorography were compared in 30 unselected patients undergoing coronary arteriography. Accuracy in detecting coronary arterial stenosis and collateral vessels and in assessing the degree of stenosis was similar with the two techniques. With both methods, there were significant inter- and intraobserver differences in estimating the degree of stenosis.

Molasse facies: records of worldwide crustal stresses.

Predominantly nonmarine molasse deposits in the Tethyan and Cordilleran mobile belts record major variations in orogenic activity in latest Cretaceous to earliest Cenozoic, mid-Cenozoic, and latest Cenozoic time. During the same intervals changes in activity also occurred on the sea floor. This coincidence suggests worldwide effects of movement of crustal plates.