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The Virtual Meditative Walk: Virtual Reality Therapy
for Chronic Pain Management
Diane Gromala1, Xin Tong1, Amber Choo1, Mehdi Karamnejad1, Chris D. Shaw1
1Simon Fraser University
1250 -13450 102 Avenue
1Surrey, BC V3T 0A3 CANADA
{gromala, tongxint, achoo, mehdi_karamnejad, shaw}@sfu.ca
ABSTRACT
Because the nature of chronic pain is complex,
pharmacological analgesics are often not enough to achieve
an ideal treatment plan. Virtual Reality (VR) technologies
have emerged within medical research in recent years for
treating acute pain, and proved to be an effective strategy
based on pain distraction. This paper describes a VR system
designed for chronic pain patients. The system incorporates
biofeedback sensors, an immersive virtual environment, and
stereoscopic sound titled the “Virtual Meditative Walk”
(VMW). It was designed to enable chronic pain patients to
learn Mindfulness-based stress reduction (MBSR), a form
of meditation. By providing real-time visual and sonic
feedback, VMW enables patients to learn how to manage
their pain. A proof-of-concept user study was conducted to
investigate the effectiveness of the VR system with chronic
pain patients in clinical settings. Results show that the
VMW was more effective in reducing perceived pain
compared to the non-VR control condition.
Author Keywords
Virtual Reality; Chronic Pain; Biofeedback; Mindfulness
Meditation.
INTRODUCTION
An estimated 20% of people in North America [1] and 15-
20% in industrialized nations [2] suffer from chronic pain.
Chronic pain is defined as pain that lasts more than 6
months and persists beyond the healing of its putative
cause. The complexity of this condition involves
neurobiological, psychological and social dimensions, and
as such, no universal treatment exists [3]. Although
pharmacological approaches are the most common
treatment method, they cannot address all aspects of the
condition. Moreover, analgesics such as opioids can have
serious side effects, including dependency and addictive
tendencies [4], and misuse of opioids is a fast-growing
problem among certain patient demographics [5].
One of the standard supplementary or adjuvant approaches
to managing chronic pain is MBSR. The primary goal of
MBSR is to enable patients to reduce stress and improve
their health via improvements in the maintenance of their
psychological states [6]. This is particularly important for
chronic pain patients, as the persistence of pain itself is
stress-inducing. Moreover, because there is currenty no
known cure, and because current treatments present
limitations, many patients are left with a sense of
hopelessness [2].
Hoffman et al. convincingly demonstrated that immersive
Virtual Reality (VR) is an effective way to manage
attention in computer-generated virtual places as a form of
pain distraction [7]. Thus, VR can be used as a powerful
pain control technique and tool for patients to manage and
alleviate their acute or short-term pain [8]. However, it is
not yet known if the analgesic effects of VR persist beyond
the VR sessions. No peer reviewed user studies have yet
been published to investigate whether VR is helpful for
managing chronic pain on a long-term scale.
This paper outlines a novel approach constructed for
managing chronic pain using VR, biofeedback technology
and the MBSR technique. The results of this research
suggest that learning MBSR while immersed in a virtual
environment can lead to further decreases in perceived pain
in contrast to learning MBSR without VR.
RELATED WORK
While treatment of severe chronic pain solely by
pharmacological approaches is limited and problematic [9],
there are alternatives and adjuvant approaches that help
patients manage their long-term pain and reduce its
intensity.
Medical applications of VR have begun to emerge over the
past decade, including rehabilitation, surgical simulators,
and telepresence surgery [10]. In 2003, researchers at the
Georgia Institute of Technology designed an immersive
virtual environment (VE) — the Meditation Chamber — to
train participants to reduce their stress [10]. The researchers
used biofeedback sensors to monitor arousal; this data in
turn affected the visual assets in the VE. Participants were
able to successfully reduce their stress levels while
observing the VE’s continuously changing visual feedback,
and the VE was more effective than biofeedback alone.
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CHI 2015, April 18–23, 2015, Seoul, Republic of Korea.
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http://dx.doi.org/10.1145/2702123.2702344
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VR has also proven to be an effective method to reduce
perceived pain during burn wound care [12]. Hoffman et al.
designed a series of distraction-based VR studies in which
patients reported up to 50% reduction in perceived pain.
Although these studies were small, they have been
replicated and extended since 1999. Several other VR
applications not built upon pain distraction were developed
to mitigate pain. Drawing upon the well-known “mirror
therapy” espoused by neuroscientist V.S. Ramachandran,
Murray et al. deployed VR as a solution to treat phantom
limb pain [11]. Although this study was preliminary, the
users reported they felt sensation in their phantom limb and
reported a decrease in phantom pain.
In 2013, Shiri et al. created a VE and biofeedback system to
treat pediatric headaches [12]. They obtained galvanic skin
response (GSR) levels of patients with chronic headaches
over ten sessions, each lasting 30 minutes. The GSR data
was processed and used to affect the VE that the users were
exposed to. The users were instructed to perform relaxation
techniques; as they became more relaxed, the VE showed a
happier picture of them. The researchers reported that
during the intervention, patients with migraines experienced
a significant decrease in headache pain using Visual Analog
Scale [13]. E. Hudlicka also designed and evaluated a
virtual mindfulness coach for patient education and health
behavior training. Results suggested that coach-based
training was more effective compared to self-administered
approaches for mindfulness practices [14].
These works indicate that VR has been effective for treating
acute pain; however, such VEs present limitations for
managing chronic pain. We must consider the inherent
approach in the use of VR for acute pain is based on pain
distraction. It is impossible to distract chronic pain patients
in a VE for significant and frequent periods of time, or
whenever their pain begins to flare. Thus, our research
focuses on utilizing VR as a therapeutic intervention to
teach MBSR, a well-established pain management
technique, which in turn may enable patients to more easily
develop an effective long-term pain management tool.
VIRTUAL MEDITATIVE WALK: USER STUDY DESIGN
AND METHOD
Virtual Meditative Walk
MBSR, a form of mindfulness meditation, is a technique
that takes time and effort to learn. Initially, it requires a
focus on one’s internal states, rather than on the world. The
design of the Virtual Meditative Walk (VMW) provides a
peaceful, non-distracting and safe environment for users to
immerse themselves in as they learn to achieve a stable
meditative practice as they learn to control (or exert agency
over) the physiological aspects that are necessary to achieve
the positive effects of MBSR. The VMW is a VE where
participants immersed in the virtual reality find themselves
“walking” in a beautiful forest composed primarily of a
deciduous forest and undergrowth. The surrounding area is
relatively mountainous, reminiscent of the trails found
along the northwest coast of North America. The camera
slowly moves along a worn dirt pathway, as if the user is
walking. This allows patients to explore the forest without
requiring physical distractions or attention in order to
achieve further passage. (Figure 1.)
The GSR sensors continuously track the patient’s changing
arousal levels, and in turn modify the VMW’s weather. The
light fog in the forest, for example, recedes as a patient’s
GSR levels start to stabilize in favor of a mindful state.
Alternatively, the fog thickens and draws closer when the
patient’s arousal levels increase. This serves as seamless
visual feedback for patients immersed in the VMW. Figure
2 shows how the VE changes according to variabile
changes in the patients’ biofeedback data.
Figure 1. Path design in VMW virtual environment.
Figure 2. As patients approach an inferred meditative
state, the fog begins to dissipate (left to right), and sounds
become more audible and spatial.
Study Intent
This proof-of-concept study was designed to determine if a
Virtual Environment, combined with MBSR training and
biofeedback, helps pain patients better manage their long-
term chronic pain, given the limitations of VR pain
distraction. Will patients fare better using the VMW to
learn MBSR, compared to patients who learn MBSR
without immersive VR? If such a VR intervention is able to
reduce perceived pain levels among chronic pain patients in
a clinical setting, it may be possible that the long-term
benefits for patients learning MBSR to better manage their
long-term persistent pain could be significantly improved.
Our focus groups and participatory design sessions made it
clear that the use of VR itself may impose limitations that
require greater investigation. For example, we found that
some patients cannot sit for more than 20 minutes, that
others cannot tolerate the weight or pressure of a head-
mounted display (HMD) like the Oculus Rift, and that the
planned use of a treadmill was too problematic to use in this
initial stage. And so the study not only served as a proof-of-
concept experiment, but it provided us further insight into
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how future studies can be better designed to accommodate
customized patient needs.
Participants & Procedures
Initially, the study included twenty participants. However,
because seven participants refused to fill out the pain
assessment forms, their data was excluded. The participants
who were included comprised thirteen patients from the
Greater Vancouver area, ranging from 35 to 55 years of age
(mean = 49, SD = 8.2); each had a diagnosis of chronic
pain. Six participants (3 male, 3 female) were randomly
assigned to the control group, and the other seven (3 male,
4 female) were assigned to the VR group. The experimenter
introduced each participant to the study, and then attached
the GSR sensors. Participants in the control group were
required to listen to the MBSR training audio track.
Participants in the VR group listened to the same MBSR
training audio track while immersed in the VMW. Firsthand
Technology’s DeepStream VR viewer was used. Patients in
both groups participated in the MBSR training for twelve
minutes.
Figure 3. A participant in the VMW study using the
DeepStream stereoscopic viewer.
Apparatus
The construction of the physical setup for the VMW
required the use of the DeepStream VR viewer, which was
installed in a room in a pain clinic for the study. The
DeepStream is a stereoscopic VR viewer compatible with
PC or Mac computers; it is mounted on a movable arm to
ensure flexibility and to maximize patient comfort. The
DeepStream rests directly in front of the participant’s eyes
and does not grip the head, unlike HMDs such as the
Oculus Rift, which may cause unnecessary discomfort or
pain with this particular participant demographic. The GSR
sensors, which are small clips, were gently put onto two of
the patient’s fingertips; none of the participants reported
discomfort from their use.
Instruments
A simple statistical analysis was conducted before and after
the study session in order to compare perceived reported
pain levels. Study investigators used an 11-point Numerical
Rating Scale (NRS) in which patients self-report their pain
levels between the numerical values 0 and 10; 10 equates to
the worst pain possible and 0 equates to no pain felt. The
NRS instrument was chosen because of its simplicity of
understanding and ease of use, and because the
investigators wanted to avoid distressing the pain patients
with complex and lengthy questionnaires. Prior experience
taught us that these participants, who may already be
feeling some discomfort, end studies prematurely when
confronted with the same lengthy questionnaires that they
are compelled to fill out for most of their clinical visits.
RESULTS AND ANALYSIS
In this study, time and condition were two independent
variables. Time was a within-subjects factor, as every
participant was measured before and after their MBSR
experience. The study used a between-subjects design; a
participant either belonged to the VR group or to the control
group. Therefore, a two-way mixed ANOVA was run to
analyze the collected data. We found a significant main
effect of Time, F(1, 11) = 10.44, p < .01, r = .61. The main
effect of Condition was not significant, F(1, 11) = 1.53, p >
.05, r = .25. This indicated that when the time at which NRS
was measured is ignored, the initial pain level in the VR
group was not significantly different than that in the control
group. There was a significant Time x Condition interaction
(as shown in Figure 4), F(1, 11) = 8.16, p < .05, r = .54,
indicating that the changes in the pain level in the VR group
were significantly different compared to the change in the
control group. Specifically, there was a significant drop in
NRS ratings in the VR group, t(6) = 2.86, p < .05, r = .57,
but a very weak drop in the control group, t(5) = 1.24, p >
.05, r = .26. These findings indicate that the VMW (VR
paired with biofeedback for MBSR training) was
significantly more effective than MBSR alone at reducing
reported pain levels among participants. LS Means test
results are shown in Figure 4.
Figure 4. VR and Control Groups NRS Rating LS mean
value before and after experiment
DISCUSSION
It is promising to examine the pain reduction reported by
participants in the VMW study, as the impact the VR had
on chronic pain patients occurred after such a short amount
of time. Compared to the control group, the VR group
experienced a reduction of pain, on average, equalling 2.6
on the NRS scale. One must also consider that the patients
themselves were only immersed in the VR for twelve
minutes, which is a short amount of time for an MBSR
session. Future studies with longer immersion times and a
focus on how long the analgesic effect may linger after the
meditative session is the natural next step in continuing this
line of inquiry. The introduction of more detailed reporting
methods of perceived pain, such as the use of the McGill
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Pain Questionnaire, could also yield new insights into the
details surrounding perceived reported pain after the VR
intervention. This will require greater effort put towards the
understanding of pain patient experience within the context
of the clinic to ensure their comfort and stamina are not
negatively impacted.
Although the single trial outlined does not speak to the
effectiveness of potential long-term capabilities for VR
chronic pain management, the VMW enables chronic pain
patients to consider that their pain experiences could be
further managed through MBSR practiced over the long-
term. By multiple training sessions and regularized practice,
patients can learn to more easily situate the psychophysical
mediation of their internal experiences into everyday life.
The pain reduction reported by the NRS data is an early
step in proving that VR and biofeedback systems may be an
effective first step in promoting this behavioural change.
The VMW was designed using a cross-platform game
engine that enables researchers or patients to run the VMW
on a wide variety of devices, including handheld phones
and tablets. These could enable patients to enhance their
MBSR skills in a more easily accessible manner outside of
clinical settings. This would also allow researchers and
health practitioners to extend the use of VR technology
from research and clinical settings to patient homes. To
achieve this goal, a key approach would be to migrate the
current VE to devices patients already own. Smaller,
portable stereoscopic viewers could also be used with
mobile devices such as Google Cardboard or the FOV2GO,
both of which are low-budget stereoscopic viewing devices;
this approach is currently being investigated by the study
investigators for future work.
CONCLUSION
In this paper, we discussed how a VR intervention, in
conjunction with MBSR and biofeedback, was better able
to invoke positive results in chronic pain patients, compared
to MBSR alone. This approach could be an effective non-
pharmacological alternative or supplementary method to
existing pain management strategies. By teaching
mindfulness meditation to patients in this context, we
believe that pain patient health may be improved over time.
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