A photo of the Goggle, remote and software screen.

Virtual SVVTM

Subjective visual vertical
testing made virtual

Spatial orientation and sensory-motor coordination rely on the accurate perception of verticality. The vestibular system provides the essential information for these tasks. Virtual SVV™ can functionally assess vestibular and otoneurologic function, while providing detailed quantitative data analysis.
  • Subjective measures with quantitative data analysis
  • Behavioral evaluation of vestibular and otoneurologic function
  • Sensitive to tilt at different head positions
  • Game-like procedure is easy to understand and fun for children

The clinical background behind subjective visual vertical (SVV) testing

The vestibular system consists of three semicircular canals and two otoliths (utricle and saccule) in each ear. The semicircular canals perceive angular acceleration, while the otolith organs perceive linear acceleration. Otolithic dysfunction is typically accompanied by incorrect spatial orientation and postural instability. Thus, patients that suffer from this dysfunction may experience a perception of tilt.
A photo of the Goggle and remote.

Functional testing of the utricles

Virtual SVV™ aids in the diagnosis and rehabilitation of vestibular dysfunction. It provides a non-invasive technique for differential diagnosis of the vestibular apparatus. Virtual subjective visual vertical (SVV) testing is particularly prudent for diagnosing the otolith organs. In particular, SVV testing is a functional test of the utricles.

An efficient test of perceived verticality

An individual with a healthy otolith system perceives verticality with great precision. The estimation of the subjective visual vertical (SVV) thus serves as a behavioral evaluation of utricular function.

The virtual subjective visual vertical (SVV) test in three easy steps


For a true measure of the subjective visual vertical (SVV), the patient must be tested in complete darkness without any ambient light or visual cues. This is enabled by the virtual reality (VR) goggles of Virtual SVV™.


The patient will see a luminous line that is intentionally offset from the true vertical.


The patient manipulates the stimulus clockwise or counterclockwise with the hand-held remote of Virtual SVV™. They manipulate the stimulus until they perceive it is vertical.

Three reasons why you should perform the virtual subjective visual vertical (SVV) test rather than the bucket test


The bucket test does not allow testing in complete darkness. This means the test and its results are influenced by ambient light.


The bucket test offers no quantifiable analysis of data.


The bucket test is not able to test at varying degrees of head tilt.
Open laptop with software screen.

Wireless testing

Virtual SVV™ comes with a cradle, which connects to computers via USB. The cradle communicates with the virtual reality (VR) goggles wirelessly and transfers the measurement data to the software.

Understand your patient's perception of verticality

The Virtual SVV™ software includes a real-time display of your patient's head position and the angle of the luminous line. Throughout the test procedure, the deviation of the luminous line from the true vertical is displayed. Each subjective visual vertical (SVV) estimate confirmed by your patient is entered on a chart against the expected threshold range.

Detailed data analysis

All data is stored and can be exported. The data includes head angles and your patient's subjective visual vertical (SVV) estimations. You can compare this with an expected threshold range.

Luminous candle-lit line

The virtual reality (VR) goggles display a luminous candle-lit line. Your patient simply needs to align the candle to a vertical position, with the flame at the top. This is done by pushing the buttons on the remote control.

A comfortable fit for any patient

The virtual reality (VR) goggles have single-use foam face cushions. They ensure a comfortable and correct fit to any face, while ensuring a sanitary experience for your patients. In addition, the correct fit occludes any ambient light during the virtual subjective visual vertical (SVV) test.

Rechargeable batteries

Virtual SVV™ has a rechargeable battery, which automatically recharges when docked in the cradle. A fully charged battery can test for several hours before the next recharge.

Integrated motion sensor

A unique feature of this special goggle design is the integrated motion sensor. It provides constant and accurate feedback of your patient's head orientation during the subjective visual vertical (SVV) test. This allows you to tilt your patient's head during testing. Testing at different angles will increase the clinical utility of your test.
A photo of a woman smiling.
The game-like nature of the test is intuitive for children. Children love wearing the goggle and using the joystick, which makes it more appealing than the bucket test. Very user-friendly and easier for children to understand the goal of the test. Overcomes the ability of the bucket to take into consideration head position. A great tool, particularly as the role of the subjective visual vertical test in the clinical evaluation is expanding. Excellent tool for behaviorally assessing the impact of vestibular end-organ function. May better estimate the functional impact of vestibular end-organ function.
- Otolaryngologist Hospital for Sick Children Toronto, ON. Dr. Sharon Cushing
Young girl wearing the goggles and operating a remote.
The game-like nature of the test procedure allows for a behavioral measure of vestibular end-organ function in pediatric patients. An average test can be completed in as little as five minutes.
Woman operating a remote under guidance from a clinician.
The goggles are fitted with motion sensors to allow for subjective visual vertical (SVV) testing to be performed at multiple tilt angles.

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