2012年1月13日 星期五

Pain Relief Through VR Technology


Virtual Reality, VR in short is a very advanced technology, which is an integration of computer science, robotics, instrumentation, multimedia, sensors, optics, 3-D technology etc. Each technology, which converges to form VR, is itself very sophisticated and hi-tech. VR is a powerful user interface technology. This current technology does not even require physical presence of a person. Information is important and this promising technology provides the best way to visualize it and enabling the user to directly interact with it.

VR has its full-blown applications in industries like automobile and aviation. Its implementations are now been expanded to fields like education and medicine. In education, Mutual Telexistence has emerged which is the convergence of VR and robotics. In medicine, very advanced softwares have been developed for patients to treat growing number of painful procedures like wound care of burn patients, endoscopic therapy after Single Event Multilevel Surgery (SEMLS) for cerebral palsy, dental pain and anxiety and pain/anxiety during injections. VR is also used to overcome phobias like spider phobias; to treat various anxiety disorders like Post-traumatic Stress Disorder (PTSD) and in artificial limb development.

Virtual Reality

According to the American Heritage Dictionary, virtual means, existing in essence or effect though not in actual fact or form.

VR is a computer-generated, multidimensional sensory, artificial environment that users experience via interference tools that enable them to immerse themselves in the new environment, navigate within it and interact with objects and characters inhabiting the environment.

We live in a world whose properties we have come to know well through long familiarity. A display connected to a digital computer gives us a chance to gain familiarity with concepts not realizable in the physical world. It is a looking glass into a mathematical world. The ultimate display is a room within which a computer can control the existence of matter. The cardinal virtue of virtual reality is the ability to give users the sense that they are somewhere else, which ipso facto has become of great value in a medical setting.

VR can be classified on the basis of display technology into the following types:

Adventure games.

Applications of VR

The fields in which VR has been implemented are summarized below:

Education and conferencing.
Civilian and military training simulators.
Business and scientific visualization.
Architecture, design, prototyping (Research and Industry).
Art and leisure.
Surgery and rehabilitation.
Telexistence, tele-immersion and Immersive 3D virtual environments (IVR).
SnowWorld, SpiderWorld, ChocolateWorld, SuperSnowWorld.

Pain and its Cure

In this world, human beings suffer from various types of aches and pains. Is there any difference between ache and pain? Yes, there is. All aches are pains but all pains are not aches. A disturbed sensation causing suffering or distress is known as pain. Ache is any constant or fixed pain, which may be dull to severe in character.

Pains may be classified according to various criteria like fast and slow or, referred and visceral. Fast pain occurs within 0.1 second when a pain stimulus is applied and is transmitted through type Ad pain fibers. Slow pain begins only after a second or more and then increases slowly over a period of many seconds or even minutes. They are transmitted through type C fibers. Fast pain has many alternative names, such as sharp pain, pricking pain, acute pain, electric pain etc. It is caused by prick of needle, cut by a knife, when skin is subjected to electric shock etc. It is not felt in deeper tissues of the body. Slow pain is also known as burning pain, aching pain, throbbing pan, nauseous pain and chronic pain. It is associated with tissue destruction. e.g.: - burn pain. It can become excruciating leading to prolonged, unbearable suffering and can occur both in skin and internal tissues or organs.

Painful lesions of muscles or viscera, which give pain in overlying skin or remote cutaneous area is known as referred pain and are, carried through afferent pain fibres. Since, these painful sensations seem not to be coming from viscus involved but from body surface, it is also known as pseudovisceral pain. e.g.: -pain felt in right spatula due to gall bladder disease, headache etc. Pain carrying impulses, which arise from abdominal organs due to excessive contraction of plain muscle, is known as visceral pain and are carried through afferent fibres and sympathetic nerves. e.g.: -pancreatic pain. Visceral pain impulses arising due to distention of hollow organs or inflammation of their evolving membranes (such as peritoneum) are carried by somatic afferents.

Pains are also acquainted by the organ in which they occur. e.g.: - pain in head-headache; pain in abdomen-spasmodic pain; spasms in involuntary muscles-colic pain; pain in arm-arm pain; pain in back-back pain; pain in leg-leg pain. Nature of these pains may be from dull or mild to acute or severe or excruciating or chronic.

There are 5 regions of the brain that are known to be involved in the perception of pain: the thalamus, the insula, the primary and secondary somatosensory cortex (SS1 and SS2) and the affective division of the anterior cingulate cortex (ACC). It is these 5 areas, which report large increase in pain-related activity, shown by fMRI scans.

Patients suffering from physiological and/or psychological pain can be medicated by in taking analgesics like ibuprofen, paracetamol, morphine, pethidine, phenytoin, amitriptyline etc. Listening to music, performing yoga and last but not the least by Virtual Reality are the new ways of relief. Dosage amounts of analgesics are limited by side effects like nausea, constipation, interference with appetite, sleep cycle etc. Patients especially of burn cases report severe to excruciating pain, which can be relieved only to some extents by these analgesics. To further control the pain other methods have to be used among which VR is very promising.

Pain has a strong psychological component. The intensity of the pain is interpreted by what the patient is thinking. The same pain can be exacerbated by anxiety and expectations and on the other hand, can be declined by traditional distraction. Thus, burn patients, who report severe to excruciating pain, are now allowed to escape mentally into an immersive virtual world, which can help reduce their pain experience.

SnowWorld is the first virtual world custom-designed software/hardware for burn patients. Patients don a VR helmet, which blocks their view of the burn wound care. Since, patients often report of reliving their original burn experience during wound care, a glacial landscape is designed in SnowWorld to help put out the fire. Patients float through a virtual icy 3-D canyon with a river and frigid waterfall during severe burn wound care or physical therapy sessions. Aiming with head-tracked gaze, patients shoot snowballs at arctic characters like snowmen, igloos, and penguins or at robots. When hit by snowball, the snowmen and igloos disappear in a puff of powder, the penguins flip upside down with a quack and robots explode with 3-D animations and sound effects and collapse into a heap of metal.

Neural correlates of VR analgesia

In fMRI brain scan, it has been observed that in pain-related brain activity in the 5 regions-of-interest of brain (SS1, SS2, ACC, insula and thalamus) showed large reductions i.e., 50% to 97%, depending on the neural area observed, when in SnowWorld. Such remarkable reduction in pain was observed in these 5 regions of brain by VR analgesia as compared to no VR. VR changes the way the patients' brains process incoming nociceptive signals.

When a brain center is activated, there is a rapid momentary increase in blood flow to the area. The increase in circulation brings an increase in oxygen. fMRI detects increases in blood flow in areas of heightened neuronal activity by detection of oxygenated hemoglobin. Spurts of neuronal activity are associated with anaerobic brain metabolism. Thus, increased oxyhemoglobin at the sites of increased neuronal activity produces an increased signal that can be interpreted to show the structures activated by visceral stimulus.

Pain requires conscious attention, which is like a spotlight. Human attention is likened to a spotlight, which selects some information to process and ignore everything else because there is a limit to how many sources of information one can handle at one time. VR acts as powerful nonpharmacologic analgesic by distracting the brain from processing pain signals from the body and less attention is paid to them. More distraction means less pain. VR, by drawing a person into another world, drains conscious attention away from processing pain signals and spend much less time thinking about their pain during wound care.


VR hitherto plays a dramatic role in automobile and aviation industry. Since, in these industries software for VR are custom-designed, they are not published. The exact details of procedures and working of VR are not well known. Lab work of VR is not sufficient. Due to less research on this promising technology, less articles and researches are published, which only give a general exposure.

Though VR technology proves to be excellent in any field, yet it is not very popular. The reason behind this disadvantage of VR is that its setup is very expensive. When the cost of VR setup will decline to an affordable price then, its applications will broaden to a larger number of fields. More number of patients will go in for VR technology. In the next 5 years, VR technology will become wireless and patient won't have to be tethered to a computer- allowing them to be treated at home. If wireless VR technology also becomes available to the masses at an affordable price then, we can envision people having a VR station at home and being connected through a telepresence to a therapist, just like at present each person has one or more cell phones in his/her pocket(s).

Khushbu Arora
D/o Dr. Bimal K. Arora
BSc (Ewing Christian College, Allahabad), A-Level (s/w) from DOEACC, India and, OCP (Oracle Forms Developer Certified Professional).

Currently doing MCA (Master of Computer Application) from Ewing Christian Institute of Management and Technology, Allahabad.

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