QLF-InVitro
advantages
The
purpose of QLF-InVitro is to measure changes
in mineralization of tooth-tissue in a nondestructive way. Tooth-tissue
specimens that are used in in-vitro or in-situ experiments can be measured
repeatedly without the need to cut the specimens as is the case with Transversal
Microradiography (TMR), Longitudinal Microradiography (LMR), Polarized
Light Microscopy or Histology. Because of this nondestructive approach,
in-vitro and in-situ experiments can be designed around smaller amounts
of specimens without loss of analysis power. Also, the time needed to
measure the specimens is reduced dramatically, typically from days to
seconds. No more X-rays, no more film development problems: just take
your specimen, measure it and replace it in the test environment.
QLF-InVitro
results
De-
and remineralization is measured in terms of the change in fluorescence
(ΔF) over an area (A), which is referred to as ΔQ (=ΔF•A).
Optionally, ΔQ values can be converted into Integrated Mineral Loss
(IML) values as used by TMR and LMR. Typically, ΔQ will be measured
longitudinally with respect to a baseline measurement.
QLF-InVitro results are reproducible by using a special calibration specimen with known grayscales. The calibration process, which is fully supported by the software, is part of the installation and ensures that measurements of QLF-InVitro are reproducible and allows comparison of results between different QLF-InVitro systems as well as different video cameras.
 |
|
Click
picture
|
QLF-InVitro
equipment
The
equipment consists of the specimen stage and the system box. The system
box (40 x 34 x 8.1 cm) contains the electronics for the video camera and
the lightsource, the lightsource itself and connectors for the light guide
and videocamera in the specimen stage.
 |
|
Click
picture
|
The
specimen stage (27 x 18 x 30.3 cm) provides 4 degrees of freedom for positioning
specimens relative to the illumination and the video camera (X,Y,Z-translation
and rotation around Z). The design of the stage is such that the rotation
is always around the center of the field of view. Additionally the specimen
can be rotated independently by rotating the specimenholder.
The
stage is designed for quick and reproducible placement of the tissue specimens.
A special curtain shields the specimens from ambient light.
The
stage comes with specimenholders specially
developed to accommodate wide range of tooth-tissue specimens.
S1, the simplest specimenholder provides a flat circular surface to which
the tooth specimen can be fixed with putty. Depending on the thickness
of the specimen and the amount of putty used to fix the specimen, this
specimenholder requires that for each measurement the horizontal and vertical
position of the camera must be checked.
To minimize the need for vertical adjustment, S2 was developed. S2 provides
a large circular opening that can be filled with putty in which specimens
of varying size can be fixed with their surface flush with the top of
the specimenholder.
 |
 |
 |
 |
|
S1
|
S2
|
S3
|
S4
|
S3
was made to accommodate relatively large circular enamel slabs (generally
bovine) of a fixed size and height, that are routinely used in invitro
experiments.
S4 was designed for specimens mounted in perspex (plastic) cylinders.
With S3 and S4 type specimenholders, adjustment time of the stage is limited
to rotational alignment of successive measurements, which is automatically
done by the QLF-InVitro software. The S3
and S4 specimenholders are fitted with a mechanical pin to assist the
removal of the specimens after measurement.
It
is also possible to request customized specimenholders from Inspektor
or to create your own based on one of the available types.
QLF-InVitro
software
 |
|
Click
picture
|
The
PC is fitted with an interface card (frame-grabber) and QLF-InVitro
software. Through the interface card, the software displays and captures
live video images from the specimen on the stage. When the specimen is
correctly positioned and identified, the measurement cycle is started.
While gently rotating the specimenholder, Inspektor's patented repositioning
software automatically selects the image that has the best match with
the baseline image. This process typically takes a few seconds and can
be repeated if necessary. The resulting image is stored in an experiment
database, ordered by specimen-identification and date/time. The specimen
can then be replaced in its testing environment.
The
analysis software allows the computation of ΔQ values with respect
to the baseline image.
QLF-InVitro
hard- and software requirements
QLF-InVitro
will run on any state-of-the-art personal computer that can accommodate
Integral FlashPoint framegrabber as its primary display adapter (contact
your PC retailer or Integral
for more information). Any windows operating system is supported, but
QLF-InVitro has been tested extensively with Windows 98 and Windows 2000.
Large amounts of system memory (>128Mb) and disk storage (>40Gb)
are recommended. Access to a flexible permanent storage device such as
an MO-drive is also advisable.
QLF-InVitro
availability
QLF-InVitro
is now available. Delivery time is 3-6 months. Subject to
demand. Contact Inspektor
for more information.