Pain killer VR

2 minute read

10 year old Blaine Baxter injured his arm in a go karting accident last year. Painful daily dressing changes at the hospital made him so anxious he had to be sedated. Not only was the sedation costing money, but Blaine was still anxious before the sedation.

Two weeks into his stay at Lucile Packard Children’s Hospital Stanford, a team of pain management specalists suggested he tried playing games using the Samsung Gear VR. This was such an effective distraction that Blaine didn’t need sedation anymore.

This is one case of many where virtual reality has been used to replace sedation or painkillers in a hospital. In the UK, the NHS spends £700 million on over the counter pain medicines such as paraceatamol every year.

Sure, VR systems cost money. The overall cost to implement VR may be well over £1 bln but their yearly costs are a lot lower than painkillers.

How does VR work?

Virtual reality tricks your brain into believing you are in a 3D world. VR does this using many different ways. The first way VR does this is with a steroscopic display. This works by displaying two different angles of the world to each eye, simulating depth.

Looking at this image, as you can see, the angle of the weapon is slightly different on each side. But when you put on the headset and play the game, everything looks perfect.

The second way is using parallax. Parallax means that the further an object is to you, the slower it moves.

Other ways include shading the world, or manipulating field of view. Humans have a field of view of about 180 degrees when looking straight, but 270 degrees with eye movement.

Humans are very good at noticing vision imperfections, with tunnel vision being an example of such a phenomena.

The human eye is very good at noticing vision imperfections, with tunnel vision being an example of such a phenomena. Even if a VR headset had a 180 degree FOV, you may still be able to tell a difference. The Vive and Rift both have 110 degree FOVs, Cardboard has 90, the GearVR has 96 and it is rumored that Daydream may have as much as 120. This should, generally speaking, greatly affect the VR experience and could make or break a certain headset for people, not to mention any health issues that we will get into later.

Latency is also a factor that can make or break VR, with anything over 20 milliseconds not being fast enough to trick your brain into thinking you are in a different world. There are a bunch of variables that go into latency, including CPU, GPU, the screen, cables and so on. The screen will have an average latency, around 4-5 ms depending on the screen for example. The time it takes a full pixel to switch is another 3 ms and the engine could also take a few. With just three variables, you are looking at latency in the double digits in some cases. The key to decreasing latency is the refresh rate of the monitor. The formula is as follows: 1000 (ms) / refresh rate (hz). So while the latency issue could be solved with a 90hz monitor instead of a 60hz monitor, it isn’t that easy as we have discussed. Later we will talk about the PC hardware requirements for virtual reality.

Not meeting an acceptable frame rate, FOV or latency can cause motion sickness. This happens enough to actually coin its own name, known as “cybersickness”. All three of these concepts need to be met to cut down on the changes of cybersickness. Without the correct frames per second with the refresh rate of the display, frame skipping, micro stutters and lag are possible. Latency may even be a bigger problem, with movement and interaction lag caused by slow response times of the hardware, it is possible to completely lose your sense of direction and become disoriented. Field of view, while important, shouldn’t cause as many issues as the others mentioned, but will definitely take away from the experience and may cause some disorientation.

The need to find a replacement for painkillers

The NHS spends £80 million on over the counter painkillers every year This is not needed when

Most people get prescribed painkillers they can buy for 35p.

Painkillers have been a problem

painkiller VR

The future