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Biomedical subjects

K Gerlach

Publications and source records attributed to K Gerlach.

9 recordsLinked to original sources
PubMed1990

[Invasive pressure measuring for the determination of the aortic opening surface in normal and stenotic left ventricular outflow tracts].

A method of evaluation of the aortic opening area in healthy dogs and dogs with aortic stenosis is described. Through right and left heart catheterisation intraventricular and intravascular pressures were measured. For the determination of cardiac output the thermodilution technique is used. The aortic opening area is calculated by using the GORLIN-formula. Values of normal and stenotic left ventricular outflow opening area are given.

Animals↗
PubMed1990

[Changes in the heart beat of puppies in the first twelve weeks of life].

In 37 healthy pups and seven pups with congenital pulmonic stenosis ECG were recorded and the heart rate determined. Between the first week of life in healthy pups (mean = 230/min) and the twelfth week of life the heart rate in both groups at six weeks was 195/min and 180/min. At the end of the investigation the averaged heart rate was 167/min or 166/min respectively. In single weeks during the investigation a slightly increased heart rate occurred in a few dogs between the fourth and sixth week of life owing to an increased restlessness during this time span. The heart rate of newborn pups at the first day (mean = 215/min) was a little lower than the average in the first week of life.

Aging↗
PubMed1989

Biostability of polyurethanes.

Aside from the medical requirements a material has to fulfill to qualify as biocompatible, for the bioengineer, who is involved in the design, construction and fabrication of prosthetic devices, the mechanical, physical and chemical properties of the material as well as its possible manufacturing procedures and, last but not least, its biostability are of the same importance. In the very aggressive biological environment, the material should behave inertly, showing no surface erosions, molecular chain disruptions, uptake of low molecular weight biological materials, local chemical imbalances, tendency to calcification or negative changes of mechanical properties. With regard to this aspect, different polyurethanes have been evaluated in-vitro and in-vivo as basic materials and already fabricated devices (blood pumps and heart valves). The comparison of the results stresses the necessity of further efforts to achieve a standardized test protocol for the prove of the biostability of polymers, containing appropriate, well-defined in-vitro and in-vivo test methods to establish the necessary data basa for the materials' clinical approval.

Animals↗
PubMed1988

[Localization of the freezing front in tissue by the ultrasound-A picture technic in cryotherapy].

The knowledge of the depth of infiltration of the freezing front in the treated tissue represented an essential demand for an optimal cryotherapy (sprayfreezing and contactfreezing). The hitherto used invasive measuring methods are connected with a tissue traumatisation and therefore only applicable in a limited way. On that account the non-invasive ultrasound-A-picture-technique was applied for defining the freezing front extension. Its qualification was represented in vitro (gelatin), in living biological tissue (muscle of rabbit), and on the human eye (cryotherapy of the primary glaucoma). The use of the sonography in the cryotherapy can be recommended for other special medical branches too.

Animals↗