The use of stroboscopy in
the voice clinic has been associated with an improved
knowledge of the dynamics of voice production and
has had direct payback to patients in the development
of microsurgical techniques capable of preserving
or reconstructing the essential features of the
delicate vibrating structures which are responsible
for the generation of good voice.
The Lx Precision Stroboscopy
program (LxStrobe3) is an enhanced version of the
Lx Digital Video capture
program which intelligently controls the Lx Light
Source and provides the extra precision and additional
benefits of a state of the art software controlled
stroboscopy system.
Lx Precision Stroboscopy
has been optimized for obtaining stroboscopic sequences
for even the most difficult subjects with fast capturing,
reviewing and animating options. Precision synchrony
with triggering waveforms permits greater security
in the interpretation of the images.
Benefits
-
Automatic switch from continuous
to slow motion stroboscopic view when phonation
starts
-
No change in colour balance
between continuous and stroboscopic light.
-
Footswitch control of video
acquisition
-
Fast capture option of image
sequences representing one vocal fold cycle
(within 300ms)
-
Footswitch to mark points of
interest
-
Instantaneous review of marked
sections
-
Optional save of marked sections
only
-
Rapid animation of simulated
vocal fold cycles
-
Cross correlation of Stroboscopic
and Lx (EGG) and speech processing techniques
and measures.
-
Speech
Studio, a connected speech analysis and
outcome measurement system, can be added as
a software option.
Features
-
Triggering from Speech or Laryngograph®
signals.
-
Instantaneous tracking of fundamental
frequency and, period by period (unsmoothed)
calculation of triggering point under DSP control.
-
Single flash per video field
avoids blurring due to multiple exposures. (50
or 60Hz)
-
Synchrony markers linking image
and Lx or Speech cycle and phase. The complete
acoustic waveform for the entire captured sequence
can be viewed with the precise period and phase
at which the corresponding images were taken.
This permits critical evaluation of the validity
of the stroboscopic sequences and gives a context
for the interpretation of images sequences,
even where vibration is irregular and stroboscopic
motion gives a false impression of the real
motion.
-
Full software control of light
source and stroboscopic functions
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The image above is taken
from a movie of the vocal folds captured using Precision
Stroboscopy. Click the image to download the full
movie. 800KB avi file. (NB a media player like Real
Player or Quick Time Player will be needed to view
the avi file)
Speech and Laryngograph®
waveforms are marked at the precise period and phase
where the flash was fired. In this case one complete
period is represented by 8 consecutive video images
The eight
images are automatically selected and displayed
with the associated flash marker on the Laryngograph®
waveform.
Cycling through
the image sequence provides a full screen, slow
motion animation.
The number
of images chosen to represent one cycle can be set
in software. the mucosal wave, vocal fold symmetry,
amplitude, periodicity, and completeness of closure
can be observed.
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