Why did the software freeze during a VNG test?


Why did the software freeze during a VNG test?

What causes a freeze and how to fix it

Check the Visiobox to laptop internet connection

On some occasions, you may experience software freezing. Typically this occurs during the Smooth Pursuit test, but may also happen on Random Saccades, Optokinetic, and rarely during calibration tests.  Let's look at what may be the cause and what you can do to fix it and complete testing your patient.

If you have a NysStar I, NysStar II, or Headstar, it includes the Visiobox module. Visiobox is a mini-computer that assists the laptop power calibration, peripheral stimulation and oscillating tracking tests.  Visiobox helps the screen from buffering or creating erratic screen images.

If you have Headstar E-Z VNG, it does not have Visiobox, but does have VisioX internally.  We will discuss Headstar E-Z systems in an upcoming post.

Two connection options

Difra Visiobox premium VNG

Difra's Visiobox functions as a mini computer

Visiobox has two connection options to connect the Visiobox to the computer.  The first is a wireless WiFi adapter that is used as an internet connection without internet access.  It only allows for communication between the laptop and the Visiobox.  Once set up properly, it will show up as WiFi-2 in your network and internet settings.  WiFi-1 is your standard internet access connection.

Consider a wireless extender

Typically, the wireless connection works great, but if you often experience freezing, erratic behavior or lose your internet connection on the laptop, you may need to consider a couple of options.  If you have several devices connected to your router or your building has heavy, thick walls, long hallways, concrete or brick walls, plus some distance from your router to the laptop, you may need to install a simple router extender to push a stronger signal to the Visiobox and laptop.

Most extenders plug into a wall outlet, then you simply follow the product's instructions to pair the extender to your router.  When connected, this will strengthen your signal, allowing your Visiobox to function much better.  Extenders can be purchased at many electronics stores or Amazon for between $25 to $100.  Personally, I use an extender in the $50 to $70 range, I find these work great while the more expensive ones tend to be more complicated to set up.

An ethernet cable directly connects Visiobox to the laptop

If an extender still does not completely help, then we can go to the second type of Visiobox connection, using an ethernet cable that directly connects the Visiobox and laptop.  First, check your laptop to make sure it has an ethernet port.  Most all of the newer computers have them, but make sure before going any further.  The ethernet port looks like a larger phone cable connection.

You will have another cable to manage, but you will also have much-improved connectivity and consistency to offset the inconvenience of another cable.

To complete a changeover to an ethernet connection, you will need to contact my office at 260.804.4041 or by email to premiumvng@gmail.com and schedule a time that I can remote access your computer to complete the ethernet set up.

This process does not take long, maybe 15 minutes providing everything goes as planned. I will be changing your default from the wireless connection to the ethernet option, plus making a change to the IP address to facilitate the ethernet connections, then disconnecting your WiFi connection for Visiobox only.

It is best to schedule this during a time without patients.

Once the ethernet connection is completed, you should experience no further freezing due to the Visiobox connection. 

Other factors that may cause a freeze

There are other factors that may cause a freeze, mostly, one of which may be due to the overuse of the computer's RAM memory.  You can try to redo the test by stopping the test, then on the lower left of the software screen, click on the test to redo and start over.  Many times, this will help clear the test up, allowing for you to complete the test.  

If that does not clear things up, exit and reboot the system.  I know, not fun, but it might be necessary to clear the cache and RAM.  If Windows was in the middle of an update, it will need to finish before everything works properly again.  I highly suggest changing the schedule for Windows updates to happen overnight so as not to interrupt your testing schedule and for your best overall computer performance.  

If you have questions or just want to talk about this post or you have any other questions, please contact me.  I look forward to hearing from you.

Stay Healthy,

Dan Scherer

CEO, Secure Health, Inc.

260.804.4041 / premiumvng@gmail.com

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Troubleshooting: An overview of common VNG technical issues

Troubleshooting Difra VNG Equipment

An overview of common VNG equipment technical issues

Over the years, we've assisted many health care professionals to troubleshoot their VNG equipment via remote access online and over the phone. Issues range from very easy fixes, changing settings or other software or hardware corrections that need a straightforward adjustment. However, at times, it is necessary to have the hardware professionally evaluated due to years of handling and use. I've compiled an overview of common technical issues to help troubleshoot as well as links to service bulletins that are also included in your online manual.


The most common issue that we encounter has more to do with driver compatibility and not software per se.  All of the computers we have supplied with our VNG devices in the last several years utilize the most current Windows 10 operating system. As you likely know, Microsoft continually runs updates for Windows 10. Most of the time these are security updates to thwart malicious hackers from accessing our computers.  

Occasionally, after an update, your video camera that is housed with the goggles does not show up.  Everything seems to be fine otherwise, but there is no eye view visible.  A large portion of the time this is related to a driver being out of date or deleted during the Windows 10 update.  The solution is for the driver to be reinstalled. It is best to contact us for assistance via online remote access.



While it is rare, we do encounter some hardware issues. I suggest one simple premise in diagnosing any technical issue, look for the most obvious and basic problem first. If that does not resolve your issue, try the next obvious and so forth.  Do not assume it is the most extreme problem right away.

An example of checking the most basic problem first: the highest incidence of tech support we get calls about is a dark image on the computer screen of the eye/s. The first and most basic issue is to make sure the lens cap is removed from the camera lens. For monocular cameras, there may be a small black cap that slides over the lens to help keep it clean and protected. And yes, this does happen more than you would think, so I'm not judging or making fun of anyone, it just happens sometimes. As the old saying goes, never assume.


Secondly, try to adjust the luminance and focus of the camera. It is less likely this will be the problem, but again, let's not assume. Depending on the camera model, the focus knob may vary. The NysStar I monocular assembly requires focusing the camera by twisting the camera itself slightly clockwise or counterclockwise.  It does not take much to adjust, so don't overdo it.

The Headstar and NysStar II binocular camera assemblies have a knob that facilitates the adjustment.  Again, small movements are best.

If you want to make sure you have the correct adjustment method, refer to your Difra product manuals for directions.  If you can't locate your manuals, contact us.


If the issue still exists, one last thing to try on your own is to unplug the camera USB cable and reinsert it in another USB port.  Sometimes, the USB ports will become faulty or go to sleep and switching to another USB port will possibly clear up the image problem.


Now, if the issue still exists, it's time to contact us.  At this point, we will likely need the camera to be shipped to us for repair. We will need your model information and serial number, which are located on the decal tag on your product. We will issue you a Repair Order with shipping instructions and a general estimate of repair charges or if the unit is under the manufacturer's warranty or not.

Once received, our highly qualified technical team will conduct diagnostic tests to identify the problem.  Prior to any repair being completed, we will send you a revised Repair Order with actual repair costs and/or warranty information.  We require payment with your approval prior to completing any repair that is not a warranty issue. 

With your Repair Order, we will send you a credit card authorization form to complete and return with your payment and approval. Turn-around times are dependent on the type of service you select and the number of repairs ahead of yours. Generally, once we receive your product, standard repairs are completed in business five days.  We do not always have loaner units available, but if we try to do what we can to accommodate your request.


Please contact us anytime you have questions or problems that arise.  We are typically always available and want your equipment to function properly.  We will do our best to keep your downtime to an absolute minimum.  We do understand the importance of you and your patient's time.


Look for future blog posts where I will devote some time to various Service Bulletins explaining how to complete different software adjustments, fixes and other troubleshooting procedures.  In a future post, I will include a link to our Dropbox folder to reference for PDF's of the service manuals and other pertinent information to help make your experience with Difra and Secure Health the very best.  


We offer live hands-on training several times a year as well as private training in person or online. Please contact us for additional information, rates, and schedules.

For more information on all of the products or discuss a specific application,  please contact me at premiumvng@gmail.com or by calling 260.804.4041.  I would appreciate hearing from you.

--Dan Scherer, CEO

Secure Health, Inc.

260.804.4041 or premiumvng@gmail.com








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