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Biomedical subjects

S Oswald

Publications and source records attributed to S Oswald.

27 records · Page 2Linked to original sources
PubMed1980

Determination of left ventricular dimensions with ultrasound.

A new ultrasonic measuring system (UM 3) is described. In addition, the construction of simple piezoelectric transducers is outlined. These can be implanted either in the epicardium or in the endocardium of the left ventricle in anesthetized or conscious dogs. The total system has a high accuracy and linearity, and zero drift is small. An automatically controlled floating window excludes most artifacts due to unwanted echoes. Together with a modified delay-time measuring circuit, better recordings of dimensions are obtained. Sources of error due to the technique of implantation or due to electrical disturbances are described. A modified technique of implantation of endocardial transducers is presented.

Animals↗
PubMedDate not supplied

Influence of the ischemic coronary bed on collateral blood flow.

The purpose of this study was to determine the influence of the resistance of the terminal vascular bed of an occluded coronary artery on collateral blood flow and collateral resistance. In 6 anesthetized dogs, left anterior descending coronary artery (LAD) was ligated, cannulated, and the terminal vascular bed was occluded by latex microspheres (diameter: 25 mu). Retrograde flow was measured using a new technique, which allowed control of outflow pressure of retrograde flow (PRF) at the LAD cannula. When retrograde flow was interrupted, pressure in the occluded vessel represented collateral perfusion pressure (CPP) within the border zone of the ischemic vessel. Collateral resistance was determined dividing the pressure difference across the collateral bed (CPP-PRF) by retrograde flow. Variation of PRF was used as a model for changes in resistance of the ischemic bed. Retrograde flow fell when PRF was increased from 11.0 +/- 3.0 ml X min-1 X 100 g-1 (PRF = 0) to 8.3 +/- 2.4 (p less than 0.01)(PRF = 24.6 +/- 6 mm Hg). For the same PRF range, collateral resistance fell from 9.68 +/- 2.96 to 8.30 +/- 2.50 mm Hg X ml-1 X min X 100 g (p less than 0.01). These results indicate that the vascular resistance of the terminal ischemic bed may considerably influence collateral blood flow and resistance.

Animals↗
PubMedDate not supplied

Efficiency experts. Hospitals can improve performance by starting in the human resources department.

In our changing economic environment, efficient human resource (HR) management is especially crucial to hospitals. Has the emphasis on HR activities responded to this changing environment? We studied 165 hospitals to determine whether they are making good use of HR. The results of our study show that HR activities remain important during these turbulent times. The emphasis hospitals place on HR activities increased slightly between 1985 and 1986. Performance evaluation ranked the highest in emphasis; job redesign and analysis were also high ranking. These are important mechanisms for improving performance and productivity. Respondents also rated HR activities by importance. Several categories that ranked high in change in emphasis ranked low in importance, and vice versa. One reason for this discrepancy between emphasis and importance is that HR activities that directors consider important may have already received a great deal of emphasis, leaving no room for increase. Also, circumstances may dictate increased emphasis on an activity (e.g., layoffs) even though HR directors consider it unimportant.

Attitude of Health Personnel↗