Interacoustics Virtual SVV, Instructions For Use Manual, Page: 32 / 436

Virtual SVV™ Instructions for Use – EN Page 28
5.4.5 Angle of deviation
The angle of deviation (
Δ
) between the angle of the head tilt and the set angle of the luminous line is
presented graphically and as a numerical value.
Angle of Deviation (
Δ)
= SVV Angle + Angle of Head Tilt
The scale covers a range of -25° to +25°. The orange-colored arrow indicates continuously the angle of
deviation while the patient is adjusting the luminous line. The normal range is modified according to the
current head-tilt angle. This display component permits continuous insight into how well the patient is
performing and able to adjust the luminous line vertically.
For additional orientation the optimal SVV angle is indicated by a small black triangular marker on the
outer ring of the SVV dial.
Figure 5-9 Indication of optimal SVV setting
5.4.6 Results diagram and measurement data table
The head-tilt angle (
α
) and the SVV deviation (
Δ
) are plotted on the results graphical diagram after
completion of each measurement confirmation by the patient with the OK button. The ordinate scale
(angle of deviation
Δ
) can be user-adjusted by the slider on the right-hand edge of the chart.
To assist in interpretation of the results, the threshold response range is indicated in the graphical
diagram. The dark green shaded region represents the 25 – 75% threshold range, while the light green
shaded region represents the 5 – 95% threshold range. These values are based on data from a
population of normal subjects tested in the Vestibular Research Lab of the Charité Berlin, Campus
Benjamin Franklin.
Figure 5-10 Results diagram and table with a single exemplary data point
Source: UWE SCHÖNFELD & ANDREW H. CLARKE
Department of Otorhinolaryngology, Charité Medical School, Campus Benjamin Franklin, Berlin, Germany, 473 participants
The measurement data (
α
and
Δ
) are also entered in the appropriate column of the table below the
graphical diagram. If desired, the table can be minimized to provide a larger image of the results
diagram.