Page 38 - Control Theory in Biomedical Engineering

Modeling and control in physiology 25

Table 3 Some basic sensors and effectors in the human body.
Human Body organs/
transducers tissues Senses/aptitude/action

Sensors Eyes Vision
Nose Smell
Tongue Taste
Ears Hearing/static and dynamic balance
Skin Touch, vibroception, thermoception,
nociception, proprioception...
Effectors Skin and Physical pressure and force
muscles
Sweat glands Produce sweat (increases heat loss)
Pancreas Produces insulin (regulates glucose in blood)
Skeletal Guarantees postural balance
system

Fig. 20 Postural balance via sensors and effectors; (A) schematic model (B) block
diagram. (The figure has been adopted from Kim, S., et al., 2009. Postural feedback
scaling deficits in Parkinson’s disease. J. Neurophysiol. 102 (5), 2910–2920.)

sensors to measure and anticipate external perturbations as is shown in Fig. 21.
An example for voluntary movement via sensory inputs is given in Fig. 22
including feedback and feed-forward loops (Wolpert et al., 2013).
Contrary to negative loops and feed-forward controllers able to counter-
act changes of physiological variables from their target values, positive feed-
back loops amplify their initiating stimuli and move the system away from its