Jacob Max Rabbie, an internationally renowned social psychologist and a founding member of the European Association of Social Psychology (EASP), died on June 29, 2013. Jaap was born in Haarlem, the Netherlands, on October 4, 1927. Jaap studied social psychology at the University of Amsterdam and became the face of Dutch social psychology. His later research focused on aggression between individuals and groups, his early work attempted to isolate the minimal conditions that suffice to generate discriminatory ingroup-outgroup attitudes. Jaap was a dedicated and passionate scientist, oriented to getting things right even when this meant going against the current stream.
Einthoven not only designed a high quality instrument, the string galvanometer, for recording the ECG, he also shaped the conceptual framework to understand it. He reduced the body to an equilateral triangle and the cardiac electric activity to a dipole, represented by an arrow (i.e. a vector) in the triangle's center. Up to the present day the interpretation of the ECG is based on the model of a dipole vector being projected on the various leads. The model is practical but intuitive, not physically founded. Burger analysed the relation between heart vector and leads according to the principles of physics. It then follows that an ECG lead must be treated as a vector (lead vector) and that the lead voltage is not simply proportional to the projection of the vector on the lead, but must be multiplied by the value (length) of the lead vector, the lead strength. Anatomical lead axis and electrical lead axis are different entities and the anatomical body space must be distinguished from electrical space. Appreciation of these underlying physical principles should contribute to a better understanding of the ECG. The development of these principles by Burger is described, together with some personal notes and a sketch of the personality of this pioneer of medical physics.
Verzamelaars (personen): Johannes Herman Kernkamp ; J. J. Poelhekke
Liesbeth Wytzes in gesprek met godsdiensthistoricus Pieter van der Horst