Biomedical Engineering Reference
In-Depth Information
1.10.2 Proprioceptive Sense
Proprioception (from Latin proprius) means 'one's own' and refers to perception of
proprioceptive senses. Proprioceptive sense provides the inner information of the body,
such as joint angle or muscle contractile force and it keeps track of primarily internal
information about body position and movement through the combination of inputs from
both the kinesthetic and vestibular senses [51 - 54]. Kinesthesia informs about the position
of body parts with respect to each other, while the vestibular sense details the position of
the body part in the world through sensing gravity and acceleration.
1.11 Tactile Display Requirements
The main challenges to the ideas of remote manipulation are those that seek to confer, to
the operator, the same sense of touch and proprioception as is felt by the hand (end effec-
tor) on a robot manipulator (i.e., temperature, pressure distribution, vibrations, contact
geometry). Nowadays, remote manipulation systems provide a comprehensive visual and
handling force feedback to the operators. The latest research in this area show that the
greatest haptic feedback for the user is provided by combining tactile and kinesthetic
feedbacks.
According to the high sensitivity of the human tactile sense at the fingertips, tactile
display elements must match different requirements, concerning, for example, the distance
of the stimulator elements (spatial resolution), their displacement, temporal resolution,
and exerted forces [55]. The most important capabilities of the tactile sense, based on
psycho-physiological investigations, are summarized below. The two-point discrimination
threshold describes the minimum distance of two stimulation points that a human can still
distinguish.
Figure 1.5 shows the two-point discrimination threshold at different regions of the hand,
given in [56]. Its value at the fingertips is between 1 mm [57] and 2 mm [58] for vibrational
stimulation. For stimulation of the whole area of an average-sized hand, including the palm
2 mm
4 mm
10 mm
Figure 1.5
Values for the two-point discrimination threshold at different regions of the hand [56]
