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Biomedical subjects

L Lehner

Publications and source records attributed to L Lehner.

5 recordsLinked to original sources
PubMed2000

Grazing collisions of black holes via the excision of singularities.

We present the first simulations of non-head-on (grazing) collisions of binary black holes in which the singularities are excised from the simulation. Initially equal mass m black holes (spinning or not) are separated by approximately 10m and with impact parameter approximately 2m. Evolutions to t approximately 35m are obtained where two separate horizons are present for t approximately 3.8m; then a single enveloping horizon forms indicating that the holes merged. Apparent horizon area estimates suggest gravitational radiation of about 2%-3% of the total mass. The evolutions end after a moderate amount of time because of instabilities.

Journal Article↗
PubMed1996

Data and information requirements for the Department of Veterans Affairs resource allocation systems.

The department of Veterans Affairs (VA) uses a global budgeting process to allocate congressionally appropriated resources to provide medical care to veterans. The Department of Veterans Affairs has developed this process to accommodate the effects of changes in pure inflation, workload, and cost per unit of work in forecasting operating dollars required for facility global budgets. In 1990, VA began shifting to a new method of allocating its global budget called Resource Planning and Management (RPM), based on a capitated system. Facilities receive resources according to their unit costs and the number and type of patients they are expected to serve. A key characteristic of any global budgeting information system is flexibility. The VA information system accesses the portion of each patients's care that is provided at every facility and aggregates this information across all facilities to create a single prorated patient record; the system reconstructs prior years of data into the new patient-centered format to forecast workload. No other health care system in the United States pays for and directly provides such a diverse set of services for such a large population as does VA. Nevertheless, many of the problems VA faces are similar to those of other providers and insurers.

Budgets↗
PubMed1988

Artificial heart and cardiac transplantation: report on the first European combined procedure.

It became necessary to perform a staged procedure by means of total artificial heart followed by cardiac transplantation in a 26-year-old, female patient. The Ellipsoidheart, as an artificial heart, fitted excellently in the chest without compromising the surrounding structures. As soon as the patient recovered with the artificial heart, a consecutive transplantation was performed. This first European clinical experience gained confidence and suggests applying more artificial hearts as a bridge towards transplantation.

Adult↗