fhit functional Head Impulse Test


The only patented device for assessing functional gaze stabilization skills

Functional Head Impulse Test (fHIT) is a medical device that assesses the functioning of the patient’s vestibular system. fHIT allows to perform an accurate exam of each semicircular canal  to fully investigate the patient’s gaze stabilization abilities.

Main feauteres

Testing performed without measuring eye movements

Patient specific sizing of target images

Exploration of a range of head accelerations

Patient performance directly depending on vestibular function

Simple and quick to perform

No doubts related to gain computations


Seconds to switch ON the device


Seconds to find the static visual acuity


Seconds max for fHIT dynamic testing


Seconds to print the patient’s test


An inertial motion sensor based on a three axis accelerometer and a single axis gyroscope, packed together on a custom 2 cm by 2 cm circuit board, weighing only a few grams. Such assembly was then mounted with an elastic band to the subject’s head, allowing to freely and naturally move his/her head.


Proprietary software that:
- first assesses static visual acuity using an eye chart displayed on the monitor with letter sizes scaled based on the subject’s viewing distance;
- when the imposed head angular acceleration exceeds a defined threshold, an optotype (a character for testing vision by ophthalmologists) briefly displayed on the screen for a defined number of video frames and with a defined time lag;
- characters recognized by subjects are registered and a layout based on the percentage of correct recognitions and normative data is shown;
- the final screen showing results can be easily printed or saved as a pdf file;

fHIT solo tastiera
fHIT hardware parts

Supplied features :

- Not slip strip
- One Sensor
- Mini Keyboard modified with Landolt C
- USB connection and cable
- USB pen drive with software.

Monitor support

Full HD 1920x1080, max response time 5 ms, min refresh rate 60 Hz