This book shows how Bohmian mechanics overcomes the need for a measurement postulate involving
wave function collapse. The measuring process plays a very important role in quantum mechanics.
It has been widely analyzed within the Copenhagen approach through the Born and von Neumann
postulates with later extension due to Lüders. In contrast much less effort has been invested
in the measurement theory within the Bohmian mechanics framework. The continuous measurement
(sharp and fuzzy or strong and weak) problem is considered here in this framework. The authors
begin by generalizing the so-called Mensky approach which is based on restricted path integral
through quantum corridors. The measuring system is then considered to be an open quantum system
following a stochastic Schrödinger equation. Quantum stochastic trajectories (in the Bohmian
sense) and their role in basic quantum processes are discussed in detail. The decoherence
process is thereby described in terms of classical trajectories issuing from the violation of
the noncrossing rule of quantum trajectories.