247 research outputs found
Technical design of complex vision-tactile navigation system for using of blind persons navigation
ArticleThis article presents the system used for navigation and orientation of blind persons in
an unknown terrain. This system called
‘
Tactile Navigation System
’
constitutes a compensation
instrument for blind persons. It is composed from three basic elements: a
camera, a control unit
and a tactile activator. The tactile navigation system converts the image from the camera to the
tactile information and it transfers this information to the blind person. The blind person can
recognize by vibration of the tactile a
ctivator placed on the antebrachium whether he comes on
an impediment or if he can continue free walking. The main advantage of this system is the
possibility of detecting any individual impediment earlier than using other common compensation
tools, such a
s a simple blind stick, which is not a competitor with this device, but a helper. This
way the system facilitates the orientation of a blind person an in an unknown terrain. The article
describes in detail the overall composition and functionality of the s
ystem as well as the principle
and funct
ion of its individual elements
Verification of mathematical model of pressure distribution in artificial knee joint
ArticleThe paper deals with pressure distribution measurement in knee arthroplasty, which is
an artificial replacement of human knee joint. The scope of the article is to verify the accuracy of
a mathematical model by real measurements. The calculated pressure values basing on the
mathematical model are compared with actually measured pressure values in the contact area of
the joint. Hereby maximal load the in the contact area, the distribution of the pressure and any
potentially dangerous pressure deviations during the walk cycle are checked. To enable accurate
pressure distribution measurement without interfering into human’s body, a sophisticated
measuring setup was created: the contact area of the joint was equipped with several pressure
sensors and a machine simulating the human walk cycle was used. The measured pressure data
are finally compared with those from the mathematical model and with the strength limit of the
used material, to verify the accuracy of the mathematical model experimentally
Plantograf V18 – new construction and properties
ArticleThe article describes Plantograf
V18, a planar tactile transducer, which converts the
applied pressure into electric signal and enables a graphical presentation of the measured data;
the new version V18 comes with some significant improvements and modifications. The device
may be used ev
erywhere where the pressure distribution between an object and surface is to be
determined, e.g. in medicine or automotive industry. The article contains the detailed description
of the transducer design and its electronic control circuits, as well as the
yet unpublished
measurements of pressure sensitivity with 3.5
mm electrodes
Rossiisko-Germanskoi proekt "KAL'MAR": kompleksnye issledovaniya Kurilo-Kamchatskoi i Aleutskoi zon subduktsii = The Russian-German project KALMAR: complex investigations of the Kurile-Kamchatka and Aleutian subduction zones [in kyrill. Schr., russ.]
Nanoporous monolithic microsphere arrays have anti-adhesive properties independent of humidity
Bioinspired artificial surfaces with tailored adhesive properties have
attracted significant interest. While fibrillar adhesive pads mimicking gecko
feet are optimized for strong reversible adhesion, monolithic microsphere
arrays mimicking the slippery zone of the pitchers of carnivorous plants of the
genus Nepenthes show anti-adhesive properties even against tacky counterpart
surfaces. In contrast to the influence of topography, the influence of relative
humidity (RH) on adhesion has been widely neglected. Some previous works deal
with the influence of RH on the adhesive performance of fibrillar adhesive
pads. Commonly, humidity-induced softening of the fibrils enhances adhesion.
However, little is known on the influence of RH on solid anti-adhesive
surfaces. We prepared polymeric nanoporous monolithic microsphere arrays
(NMMAs) with microsphere diameters of a few 10 {\mu}m to test their
anti-adhesive properties at RHs of 2 % and 90 %. Despite the presence of
continuous nanopore systems through which the inner nanopore walls were
accessible to humid air, the topography-induced anti-adhesive properties of
NMMAs on tacky counterpart surfaces were retained even at RH = 90 %. This
RH-independent robustness of the anti-adhesive properties of NMMAs
significantly contrasts the adhesion enhancement by humidity-induced softening
on nanoporous fibrillar adhesive pads made of the same material
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