vHIT for iPhone (vHIT96da)

vHIT96da is a vHIT application that runs on the iPhone. vHIT96da requires a goggles to hold the iPhone in front of the face. How to make the goggles is described at the bottom of this page. It works well on a lightweight iPod-touch(7th), iPhone-SE(1th) and iPhone12mini.

The leftmost picture shows the iPhone fixed to the face with goggles and the app launched. Pressing the camera button in the lower right corner of the screen activates the camera, resulting in the second photo from the left. You will need to set the LED lighting and focal length only once the first time, but the settings will be saved and you won't need to set them the second time. Press the start button at the bottom center to start recording.
The center of the screen is the recording screen, where the vHIT test is performed and recorded. In parallel with the recording, the gyro sensor data is also recorded. When the recording is finished, press the large stop button at the bottom center. The second screen from the right appears. Align the green frame with the reflection point on the cornea of the LED light, tell the app which part to analyze, and press the Analyze button.
The screen on the far right shows the vHIT waveform from the eye video and the iPhone gyro sensor data. You can save the resulting image with a name or send it by e-mail.

The first step is to fixate on a single point in front of you for calibration and move your head to the left or right several times as quickly as possible. After that, we do the vHIT test. The video on the left is a screenshot from the end of the recording. If the imaginary image of LED lighting is out of the black eye area, it cannot be analyzed, so please perform the vHIT so that the imaginary image of LED lighting is in the black eye area.
If the imaginary image of LED lighting is not in the center of the green frame, it cannot be analyzed. During the analysis, the head and eye speed are shown in black and red respectively in the lower white window, and the vHIT waveform is shown in the upper white window.
When the analysis is finished, you can adjust the display. Use the blue slide bar to align it with the waveform where you are shaking your head left and right for calibration. Pan the left 1/3 of the lower white window up and down to adjust the eye waveform. The right 1/3 can be used to adjust the head waveform. Pan the lower white frame to the left or right to adjust the time gap between the eye and head waveforms. The above operations are used to align the eye and head waveforms during calibration of the lower white window. Finally, pan the center 1/3 of the lower white window up and down to change both the eye and head heights and adjust the height of the vHIT waveform.

The vHIT waveform is displayed in the upper white window. vHIT waveform is detected by checking only the head rotation, and the part of the waveform is displayed. In the movie on the left, the user blinks during the vHIT test, but even if the user blinks or the imaginary image of the LED illumination is out of the black eye area, it is still displayed in the upper white window. If you use the blue slide bar to move the waveform in the lower white window, the vHIT waveform in the center of the lower white window will be highlighted in the upper white window. Tap the bottom white window when the waveform that is not properly analyzed is highlighted to delete the vHIT waveform.

Due to the weight of the iPhone, the rapid head rotation of the vHIT inevitably causes misalignment between the face and the goggles, making it impossible to get an accurate VOR gain. If I fasten the iPod touch (7th) with the headband of the goggles very tightly, it seems to be okay, but still there seems to be a little bit of misalignment.

If you are using an iPhone, you can tap the QR code to go to the download site.

Goggles for iPhone Fixation

3D data is available in stl, wrl and 123dx extensions. Please download and use them.( contain the 3D data of the teeth-shaped brace)
3Ddata/ for iPodTouch(7th) - download
3Ddata/ for iPhoneSE(1th) - download
3Ddata / for iPhone12mini - download
To complete the project, you will need sunglasses (Daiso), a tying band, and double-sided tape. iPhoneSE (1th) and iPodTouch (7th generation) LED flashes are too bright, so two sheets of copy paper are stacked with double-sided tape and attached to the lens. Use a rubber band or other rubber to fix the goggles on face.
Please make it referring to the picture below.

Teeth-shaped brace to hold iPhone in place

Attach a split tooth or disposable wooden spoon to the dental brace, place a piece of cardboard over it, and bite down to secure the iPhone. 3D data is included with the iPhone fixing goggles data above.

Smartphone RING

Attach an anti-drop phone ring to the iPhone, put a piece of cardboard over it, and bite it. This way you can perform vHIT.