A technique for avoidance of hypothermia during prolonged mechanical circulatory support with centrifugal pumps.

Systemic hypothermia became a major problem in one of our patients undergoing postcardiotomy mechanical circulatory support with a centrifugal pump. We have developed a technique to prevent systemic hypothermia in this setting by applying an adapted topical cardiac cooling device to the centrifugal pump heads.

Characteristics and measurements of an aperture-limited in-line hologram image.

The intensity distribution in the neighborhood of the real image reconstructed from an in-line Fraunhofer hologram was investigated. Assuming a finite amount of information recorded on the hologram in terms of a limiting aperture, the image is shown to possess intensity variations that are dependent on the argument of a first-order Bessel function recorded on the hologram. The theoretical results are presented on isophote diagrams and are verified experimentally. Three measurements of the image width are presented, and the inherent errors are found. The focal tolerance of the aperture-limited image relative to the recording parameters is discussed.

[Aorto-enteral fistula--pathogenesis, clinical aspects and therapy]. / Aorto-enterische Fisteln--Pathogenese, Klinik und Therapie.

This report is based on 14 own observations and 166 patients collected from the literature. The most frequent location both of primary and secondary aortic-enteric fistulas (AEF) is the end part of the duodenum (60-70%). In the group of secondary AEF the paraprothetic type represents the most frequent morphological finding. The best diagnostic approach should be seen in a gastroduodenoscopy. The choice of surgical repair is still controversal. Most of the surgeons insist on a radical repair (Type A: restoration of the intestinal tract, complete removal of the vascular prosthesis, blind closure of the infrarenal aortic stump, axillo-bifemoral bypass). Type A repair is loaded with a high operative mortality (52%) and a number of secondary complications (e.g. recurrent AEF; bleeding from the aortic stump). As an alternative surgical approach the authors present an in-situ-repair (Type B: closing of the intestinal defect, partial exchange of inserted vascular prosthesis, a circular omentum sleeve covering the prosthesis and anastomosis). The Type B repair offers a time saving procedure with a reduced operative mortality (29%) and a better outcome for the patients. This method is only contraindicated in the presence of a spread infection of the retroperitoneal space including the vascular prosthesis.

Holographic techniques for the study of dynamic particle fields.

The techniques of small particle holography are extended in an elementary way to show that multiple exposure holography can be used to study the dynamic properties of particle fields. Experimental techniques for performing such a study are then described. Finally, as a typical example, a multiple exposure hologram of an aerosol is presented with a portion of the data extracted from it. The hologram exhibits a vast amount of information including the determination of the velocity and density field, size distribution, flow structure, and diffusion rate.