Biomedical subjects

B Granz

Publications and source records attributed to B Granz.

3 recordsLinked to original sources

PubMed1992

What makes a shock wave efficient in lithotripsy?

The aim of this investigation was the connection of quantitative shock wave parameters to stone fragmentation in lithotripsy. We developed an in vitro procedure where eroded craters in artificial stones could be measured with respect to their geometric outlines. By altering the components of an electrodynamic ultrasonic source we obtained a multitude of shock wave foci with physical parameters covering a wide range. With these foci different craters were formed and measured. With a correlation method the quantitative stone erosion could be connected with single physical parameters of the shock waves. As a result we found strict linear dependence of the volume erosion on the effective energy. On the other hand, the peak pressure in the focus revealed to be a poor parameter to qualify the fragmentation efficiency of a lithotripter. Additionally the contribution of the rise time of the shock wave to stone erosion is of negligible influence.

Equipment Design↗

PubMed1991

Fundamentals for the development of a lithotripter of the new generation. A survey of the principle knowledge and skills contributing to the progress in lithotripter efficiency for a wide scale of application.

An improved shock wave source is required for the extended application of extracorporeal lithotripsy in proven and anticipated novel fields of therapy. Fundamental research was performed in the domains: disintegration efficiency; hydrophone stability; absolute calibration, and source optimization. The combined experiences resulted in the development of a new shock wave source, the Siemens Electromagnetic Acoustic Source (EMAS-C), with considerably improved performance. The compact EMAS-C provides shock wave foci varying over a broad energy range, dedicated to efficient concrement disintegration and to new fields of application in medical therapy.

Calibration↗

PubMedDate not supplied

[Use of an improved transmission ultrasound camera for diagnosis of rheumatic joint diseases].

Transmission (TM) sonography allows a reliable and fast imaging of soft tissues like joint capsules and tendons, especially of hands and feet. Bony structures appear blurred, but serve as landmarks for easy orientation on the ultrasonic images. The quality of imaging allows a reproducible measurement of joint capsule parameters. Inflammatory alterations of joints are recognized earlier than with conventional x-rays. TM sonography contributes to the diagnostic panel for rheumatic diseases, which involve soft tissues and joints of hands and feet. Today, TM sonography cannot compete with conventional reflex sonography in general arthrosonography, but it is an interesting addition. Follow-up studies will show whether objective joint parameters available by TM sonography may help to both indicate disease progression and to monitor therapeutic interventions in rheumatic diseases.

Arthritis, Gouty↗