Portable haptic devices allow to implement so-called gravity wells around selected regions of
8.8 FUZZY LOGICS
Fuzzy logic is an emerging ﬁeld for tremor research and therapy (see also Chapter 6). A system
for rehabilitation based on fuzzy assessment of fused features of the tremor movements has been
proposed (Teodorescu et al., 2001). In this method, both classic and nonlinear indices are fused
into a few, easy to represent, and grasp fuzzy measures. The purpose is the creation of a feedback to
help patients to become aware of the characteristics of the tremor of their limbs and help them in
controlling their tremor. One of the main requirements is the ease of use to understand and learn.
FIGURE 8.7: Oscillations of the elbow and the associated power spectral density (PSD), with the mo-
tor in a free mode (left panels) and providing viscosity of 0.2 N m s/rad (right panels) in one ET patient.
Note the strong reduction in the PSD when viscosity is applied. Oscillations are expressed in rad/s and
PSD is expressed in rad
. From Manto et al. (2007), with permission from IPO Publishing Ltd.