Pharmakokinetisches Modell



This wonderful analog computer was developed by Rolf Englert at the pharmacological institute at the university Tübingen. It is an implementation of a pharmaco-kinetic model and was used for teaching purposes.

Mr. Englert remembers:

"After finishing my studies in electronics, I started work at the pharmacological institute in Tübingen (Prof. Siess) where my task was to setup an electronics laboratory. Knowing about the Heathkit analog computer from the 1960s, I approached Prof. Siess with the idea of developing an own analog computer to be used in his lectures. This device was intended to simulate the concentration of substances in the blood of a patient. This can be readily modelled by means of differential equations - a task well suited for an analog computer - especially since digital computers were prohibitively expensive back then and did not offer a comparable hands-on-experience like an analog computer.

Thus the first model was built which occupied a 19-inch chassis and featured nine integrators with two time constants suitable for either driving an oscilloscope display or a plotter. Prof. Siess was enthusiastic! This analog computer was used for several semesters during lectures in medicine to show how pharmacological substances are transported and stored in blood, tissue and urine.

One day Prof. Dengler from Bonn came for a visit an saw the analog computer. He was enthusiastic, too, and ordered one for his lectures. A third model was built for Prof. Bock from the institute for toxicology. [This model is shown below:]

The next version followed a substantial different approach. I used a Heathkit oscilloscope as the basis. Its x- and y-amplifiers were replaced by the analog computer's electronic (four integrators with additional components for logarithmic display etc.). Of this model six devices were built over the years. These were used for many years in lectures [...]."

The following pictures show one of these computers based on a Heathkit oscilloscope: