Investigation into the verification of the Synapsys videonystagmography (VNG) Ulmer calibration system.
OBJECTIVE
To assess the accuracy and stability of the Synapsys VNG Ulmer calibration system when the goggles and infrared camera are repositioned, and the accuracy of the equipment's geometric calibration system.


METHODS
Prospective data collection involved participants conducting the system's horizontal calibration test. Eye measurements were then recorded for a 60° deviation (looking from 30° right to -30° left) and repeated after the goggles and infrared camera were removed/repositioned. Participants' eye measurements were also recorded after the geometric calibration had been activated.


METHODS
Twenty-two participants with no history of visual or vestibular pathology were recruited for this study.


RESULTS
No significant differences were found when the goggles were removed and replaced (p = 0.21); when the infrared camera was repositioned within the goggles (p = 0.50); or when the goggles were removed and the camera repositioned (p = 0.18) after horizontal calibration. A significant difference was found during the assessment of geometric calibration (p < 0.01).


CONCLUSIONS
Calibration is not affected by removal or repositioning of the goggles and/or infrared camera within the goggles, therefore suggesting recalibration may not be necessary. Caution should be exercised when using the equipment's geometric calibration and should only be used when the patient is unable to conduct the system's horizontal calibration test.
Audiology Department, Betsi Cadwaladr University Health Board , Wrexham , UK.
Natalie
N
Corless
Susannah
S
Goggins
D000328:Adult; D000465:Algorithms; D002138:Calibration; D004867:Equipment Design; D053483:Eye Movement Measurements / Q000295:instrumentation / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D008422:Materials Testing; D009760:Nystagmus, Physiologic; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D014159:Transducers; D014724:Vestibular Function Tests / Q000295:instrumentation / Q000592:standards*; D014722:Vestibule, Labyrinth / Q000502:physiology*; D014741:Video Recording / Q000295:instrumentation / Q000592:standards*
Calibration; videonystagmography/VNG