Robot Therapy for Elders Affected by Dementia - IEEE Pulse

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BY KAZUYOSHI WADA,
TAKANORI SHIBATA,
TOSHIMITSU MUSHA,
AND SHIN KIMURA
Dementia is one of the most important issues in the
care of the elderly. According to Alzheimer’s Disease
International (ADI), an estimated 24.4 million
people suffer from dementia worldwide, and the
number will increase to 82 million by 2040. Dementia is a
progressive disabling neurological condition that occurs in a
wide variety of diseases. The most common cause of dementia
is Alzheimer’s disease (AD), which accounts for approximately
half of the people with dementia. Other causes include
vascular disease, Lewy body dementia, and many other
diseases [1]. Psychiatric and behavioral disturbances such as
personality change, hallucinations, paranoid ideas, aggression,
wandering, and incontinence are common features of
dementia and are leading causes of the need for long-term care
[2]. Unfortunately, there is no permanent cure for dementia at
this time. Recent data suggest that art, music, and learning,
which stimulate the patients’ emotions and brain, can help prevent
the development of dementia [3]–[5]. However, there is
room for improvement in all such treatments.
Interaction with animals has long been known to benefit
people emotionally. The effects of animals on humans have
been applied to medical treatment. Especially in the United
States, animal-assisted therapy (AAT) and animal-assisted
activities (AAAs) are becoming widely used in hospitals
and nursing homes [6], [7]. AAT has particular therapeutic
goals designed by doctors, nurses, or social workers, in cooperation
with volunteers. In contrast, AAA refers to patients interacting
with animals without particular therapeutic goals and
depends on volunteers. AAT and AAA generally have three
effects: 1) psychological effects (e.g., relaxation and motivation),
2) physiological effects (e.g., improvement of vital signs),
and 3) social effects (e.g., stimulation of communication among
inpatients and caregivers).
However, most hospitals and nursing homes, especially in
Japan, do not accept animals, even though they acknowledge
the positive effects of AAT and AAA. They fear the negative
effects of animals on humans, such as allergy, infection, bites,
and scratches.
We proposed robot therapy, which uses robots as substitutes
for animals in AAT and AAA [8]–[26]. To that end, we have
Digital Object Identifier 10.1109/MEMB.2008.919496
Robot Therapy for Elders
Affected by Dementia
Using Personal Robots for
Pleasure and Relaxation
studied and developed mental commitment robots—personal
robots that aim to engender mental effects such as pleasure
and relaxation. Robot therapy has two aspects: robot-assisted
therapy, which has therapy programs designed by doctors,
nurses, or social workers; and robot-assisted activity, which
has patients interacting with robots without particular therapeutic
goals. However, unlike AAA, robot-assisted activity
does not depend on volunteers but is conducted by the staff of
the facility.
Paro, a seal-type mental commitment robot, was designed
for therapy. She is covered with soft white artificial antibacterial
fur, and her artificial intelligence allows genuine animallike
behavior using tactile, visual, auditory, and posture sensors
as well as several actuators.
Robot therapy using Paro was conducted at pediatric wards
and elderly institutions in several countries [13]–[22]. The
results showed that interaction with Paro improved patients’
and elderly people’s moods, making them more active and
communicative with each other and their caregivers. Results
of urine tests revealed that interaction with Paro reduced stress
among the elderly [17], [20]. In addition, we investigated
long-term interaction between Paro and the elderly and found
that the effects of interaction with Paro lasted for more than a
year [19].
In this study, we discuss the application of seal robots in the
therapy of patients with dementia and observe their neuropsychological
effects through electroencephalogram (EEG) analysis.
The next section describes mental commitment robots, which is
followed by the section describing the real robot that was used
for robot therapy. The ‘‘Diagnosis Method of Neuronal Dysfunction’’
section explains the evaluation methods used for assessing
the brain activity of patients with dementia, and the ‘‘Robot Therapy
for Patients with Dementia’’ section discusses the experimental
methods and explains the effects of robot therapy. The
‘‘Discussion’’ section presents the current results of robot therapy
as well as future work.
Mental Commitment Robots
Industrial robots have been widely used in manufacturing
industries since the early 1960s. Typical tasks for industrial
robots include welding, assembly, painting, packaging, and
palletizing in automotive manufacturing and other industries.
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Industrial robots accomplish their tasks very quickly and accurately.
They must be taught by a human operator and a specific
environment must be designed for them to accomplish their
tasks. Most industrial robots are considered potentially dangerous
to humans, and so they are kept isolated from people.
On the other hand, the rapid development of high technology
has produced robots not only for factories but also for homes,
hospitals, museums, etc. In particular, human interactive robots
for psychological enrichment are one of the new applications of
robotics, and this field of application has research and commercial
potential [26]. Human interactive robots are designed for
entertainment, communication (social activity), guides, education,
welfare and mental therapy, and other purposes. Various
types of robots, such as humanoids, animals, and those with a
unique appearance, have been developed.
These robots are more interactive with humans than industrial
robots. They are evaluated not only in terms of objective
measures, such as speed and accuracy, but also in terms of
subjective measures for interacting with humans, such as joy
and comfort. Entertainment robots are good examples of the
importance of their subjective value (Figure 1).
There are four categories of human interactive robots for
psychological enrichment in terms of their relationship with
humans: 1) performance robots; 2) teleoperated performance
robots; 3) operation, building, programming, and control
robots; and 4) interactive autonomous robots.
Performance Robots
Performance robots have a long history and are able to perform
movements that express meanings to humans, mostly for
fun. Mechanical puppets that could play an organ, make pictures,
and write letters were developed in Switzerland in the
18th century. Karakuri dolls were developed to perform dances,
magic, and so on in Japan during the same era. Recently,
many performance robots have been used at exhibitions,
museums, movies, and amusement parks such as Disney Land
and Universal Studios. Recent humanoid robots such as Honda’s
ASIMO and Sony’s QRIO can be included in this category
[27], [28]. A performance robot can amuse a sizeable
audience at any time. However, their movements will probably
be preprogrammed and mostly repetitive, and so they are
not usually very interactive with humans. A high degree of
Automatic Machine
Objective Evaluation
Fast
Accurate
Cheap
Medical Robot
Welfare Robot
Industrial Robot
Working with
Human
Home
Appliance
Entertainment
Fig. 1. Objective and subjective measures for evaluating artifacts.
complexity is important in performance robots to keep
humans amused.
Teleoperated Performance Robots
Teleoperated performance robots are controlled remotely by a
hidden operator. Their movements can appear reactive to their
audience or to the humans who interact with them because the
operator senses their current actions and sends commands to
the robot to simulate reactive behavior. At exhibitions or
amusement parks, for example, human-type robots are used as
teleoperated performance robots.
Operating, Building, Programming,
and Controlling Robots
Humans derive much fun and joy from operating, building,
programming, and controlling robots. Moreover, we can watch
the performance of the robot that we are operating. A simple
example of this is the UFO Catcher, a stuffed animal game
machine, at amusement centers. Building and programming a
robot is also included in this category. Contests between
robots, such as Micro-mouse, RoboCup, and RoboOne, are
popular examples [29], [30]. LEGO, Mindstorms, and I-Blocks
are some other examples. Because building and programming
robots can stimulate children’s creativity, this activity combines
entertainment with education and is often referred to as
edutainment [31], [32].
Interactive Autonomous Robots
Interactive autonomous robots interact with humans in the
physical world. They use verbal and nonverbal communication
depending on the functions of the robots. Contrary to robots in
the other categories, the interactions between humans and these
robots are mostly personal. For example, Sony’s dog robot,
AIBO, which is designed for entertainment, has a mechanical
appearance and attracts people’s interest by using nonverbal
communication [33]. The communication robot, ifbot, produces
conversation by using facial expressions and a huge data of prepared
conversation scenes [34]. The human-friendly information
terminal, PaPeRo, can control home electric appliances,
collect information via the Internet by voice command, and
entertain people by dancing and playing games [35]. Guide
robots in museums and exhibitions [36] the and mental commitment
robots discussed in this article
belong to this category.
Mental commitment robots
are not intended for offering
people physical work or service.
Aesthetic Objects
Subjective Evaluation
Interesting
Beautiful
Comfortable
Their function is to engender
mental effects, such as pleasure
and relaxation, in their role as
personal robots. These robots act
independently with purpose and
motives while receiving stimulation
from the environment, mimicking
living organisms. Actions
that manifest during interactions
with people can be interpreted as
if the robots have feelings.
A basic psychological experiment
was conducted on the
subjective interpretation and
evaluation of robot behavior
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following interactions between robots and people [12]. This
showed the importance of appropriately stimulating the human
senses and extracting associations. Sensor systems, such as
visual, aural, and tactile senses for robots, were studied and
developed. A plane tactile sensor using an air bag was developed
to cover the robot to enhance bodily contact between people and
robots. It detects the position and calculates the force when there
is contact, and at the same time, provides a soft texture. Dog,
cat, and seal robots were developed using these sensors.
Paro the Seal Robot
Paro, a seal robot, is shown in Figure 2. Its appearance resembles
a baby harp seal, a nonfamiliar animal. Therefore, people
can accept Paro easily without preconceptions. The fur has a
soft, natural feel, and the newly developed soft tactile sensors,
named ubiquitous surface tactile sensors, were inserted
between the hard inner skeleton and the fur over the whole
body surface to permit measurement of human contact [23].
Paro is equipped with four primary senses, i.e., sight (light sensor),
auditory (determination of sound source direction and
speech recognition), balance, and the tactile sense mentioned
previously. Its moving parts are designed to provide vertical
and horizontal neck movements, front and rear paddle movements,
and independent movements of each eyelid, which is
important for creating facial expressions. Paro weighs approximately
2.8 kg. Its operating time with the installed battery is
approximately 1 h. However, a charger, which resembles a
dummy (pacifier), can be used for continuous operation of
Paro. For therapy use, its artificial fur is hygienic with an antibacterial,
soil-resistant finish, and hair loss is prevented. Paro
has an electromagnetic shield, and so it can be used by people
with a pacemaker. Paro’s reliability and durability have been
improved through voltage, drop, and stroking tests over 10,000
times, and a long-term commissioning test in a nursing home.
Paro has a behavior generation system (Figure 3) consisting of
two hierarchical layers of processes: proactive and reactive.
These two layers generate three types of behavior: proactive,
reactive, and physiological.
Proactive Behavior
Paro has two layers to generate
proactive behavior: a behavior
planning layer and a behavior
generation layer. By addressing
its internal states of stimulation,
desires, and rhythm, Paro generates
proactive behavior.
Behavior Planning Layer
This has a state transition network
based on Paro’s internal
states and desire, produced by
its internal rhythm. Paro has
internal states that can be
described with words indicating
emotions. Each state has a
numerical level, which changes
according to the stimulation.
Moreover, each state decays
with time. Interaction changes
its internal states and creates
the character of Paro. The
Stimulation
Light
Auditory
Tactile
Posture
Internal
Rhythm
behavior planning layer sends basic behavioral patterns to the
behavior generation layer. The basic behavioral patterns
include several poses and movements. Here, although the term
proactive is used, the proactive behavior is very primitive compared
with that of humans. We programmed Paro such that its
behavior (blinking eyes, movement of neck and flippers, etc.)
was similar to that of a real seal. We visited the harp seal’s habitat
in Canada and observed its behavior. In particular, the
noises made by Paro are based on actual seal vocalizations.
Behavior Generation Layer
This layer generates control references for each actuator to perform
the determined behavior. The control reference depends on
the magnitude of the internal states and their variations. For
example, various parameters can change the motion speed and
number of instances of the same behavior. Therefore, although
the number of basic patterns is finite, the number of emerging
behaviors is infinite because of the varying number of parameters.
This creates life-like behavior. In addition, to gain attention,
the behavior-generation layer adjusts the parameters according
to the priority of reactive and proactive behaviors based on the
magnitude of the internal states. This function allows the behavioral
situation of Paro to be unpredictable to a subject.
Fig. 2. Paro, the seal robot.
Evaluation
of Value
State Transition
Network
Internal States
Desire
Control Reference
Speed
Number of Behavior
Reactive Behavior 1
Reactive Behavior M
Fig. 3. The behavior generation system of Paro.
Proactive Processes
Reactive Processes
Behavior Planning Layer
Basic Behavior
Pattern 1
Basic Behavior
Pattern N
Behavior Generation Layer
Behavior
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Long-Term Memory
Paro has the property of reinforcement learning, and it assigns
values to the relationship between stimulation and behavior. It
places a positive value on preferred stimulation, such as stroking,
and a negative value on undesired stimulation, such as beating.
Users are prevented from changing its behavior program
manually; however, Paro can be gradually tuned to the preferred
behavior of its owner. (Paro is not tuned to be obedient to
its owner when it is beaten frequently. In such a case, Paro
would be a prickly character.) In addition, Paro can memorize a
frequently articulated word as its new name. The user can give
Paro his or her preferred name during natural interaction.
Reactive Behavior
Paro reacts to sudden stimulation. For example, when it hears
a sudden loud sound, Paro pays attention to it and looks in the
direction of the sound. There are several patterns of combination
of stimulation and reaction. These patterns emulate the
unconditioned reflex of animals.
Physiological Behavior
Paro has a diurnal rhythm. It has several spontaneous needs,
such as sleep, based on this rhythm.
For investigating how people evaluate the robot, studies
were conducted using questionnaires at exhibitions held in six
countries: Japan, United Kingdom, Sweden, Italy, Korea, and
Brunei. The results showed that the seal robot was widely
accepted, regardless of cultural differences [24]–[26].
Diagnosis Method of Neuronal Dysfunction
There are various methods for the assessment of cognitive
function. Neuropsychological tests, such as minimental state
(MMSE) and clinical dementia rating (CDR), are handy and
useful [37], [38], although their sensitivity depends on the
measuring procedure and their time resolution is low.
Functional neuroimaging techniques [single photon emission
computed tomography (SPECT), positron emission tomography
(PET), and functional magnetic resonance imaging (fMRI)] are
useful for the early diagnosis of dementia [39]. However, they
are prohibitively expensive and require huge measuring equipment
and/or injection of radioactive tracer compounds.
On the other hand, electrophysiological tests, such as the EEG
and event-related potential (ERP), directly measure the cortical
T3
F7
100,000 (s)
F3
15
Fp2 Fp2
Fp1 Fp3 Fp1 Fp3
Fz
F4
F2
C3 Cz C4 T2 T3 C3 Cz C4 T2
P3
P4
T5
Pz
T6
10
5
0
–5
–10
F7 F3
O1 Oz O2 O1 Oz O2
–15
activity of specific neuronal populations [40], [41] and have high
time resolution. However, these methods are difficult to quantify.
In addition, ERP requires a well-designed test battery.
Diagnosis method of neuronal dysfunction (DIMENSION),
an EEG analysis method, has high time resolution and quantifiability
and does not require a test battery [42]. It can detect lack
of smoothness of the scalp potential distribution due to cortical
neuronal impairment by analyzing spontaneous EEG alpha components
recorded with 21 electrodes. This technique is applicable
for the mass screening of people with early stage dementia.
When neurons within a specific cortical area are depolarized,
electric currents flow perpendicularly to the cortical surface,
producing a scalp potential. In a normal brain, the active
current generators produce the distributions of neurons that
are approximately equally activated. This activation produces
1) uniform electric current density at the cortical surface,
2) electric currents within cortical sulci that cancel each other,
and 3) a uniform distribution of the resulting scalp potential
[43]. However, when cortical (and possibly subcortical) damage
exists, randomly oriented electric current sources arise
because sulcal currents do not cancel each other, and the scalp
potential becomes less uniform [44] (Figure 4).
Musha et al. defined mean alpha diporality (D a)todetermine
the loss of uniformity of an observed scalp EEG alpha potential
distribution. D a approaches unity without cortical sulcal lesions,
whereas a brain with randomly distributed cortical sulcal lesions
has Da values well below unity. Especially, as shown by the
results from SPECT analysis, Da has a strong correlation with a
decreasing regional cerebral blood flow (RCBF), which is a particular
symptom of the early stage of AD.
A basic experiment showed that the rough criterion Da @ 0.95
separates normal subjects and AD patients. Reproducibility
of this result was examined in normal subjects, and the error
is 0.005inrepeatedmeasurements after 1 h. Therefore,
positive efficacy is observed when an increment d of the D a
value after treatment is larger than 0.005.
Robot Therapy for Patients with Dementia
As for the interaction between Paro and patients with dementia in
nursing homes, behavioral improvements were observed in several
cases. For example, a patient who moaned continuously was able to
relax and then started to talk with the therapist [22]. Moreover, on
playing with Paro, another patient who often tried to return home
stopped doing so, and her wandering
decreased. In this study, we
aimed to investigate the neuropsy-
10
chological influence of Paro.
8
100,160 (s)
Fz
F4
F2
P3
P4
T5
Pz
T6
(a) (b)
Fig. 4. a-waves of the scalp electrical potential distribution.
6
4
2
0
–2
–4
–6
–8
–10
Methods of Robot Therapy
Seal robots named Paro were
used at Kimura Clinic, a cranial
nerve clinic in Japan, where
patients with mild to moderately
severe dementia were
treated. After obtaining informed
consent of patients and/or their
families, a 20-min robot therapy
was conducted in accordance
with the ethical committee of the
National Institute of Advanced
Industrial Science and Technology
(AIST).
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We designed two seal robots and placed them in the center of
tables. Five to ten patients were arranged around the tables
(Figure 5). They interacted with the seal robots freely during
the robot therapy. Before and after the robot therapy, a 5-min
EEG recording was performed with the patient at rest with
closed eyes. The recorded EEG was analyzed by DIMENSION.
In addition, a questionnaire about their impressions of Paro
was conducted after the 20-min interaction. The questionnaire
consisted of four items evaluated in five grades (Table 1). All
the answers to the questions were scored as follows: most positive
answer ¼ 2, positive ¼ 1, no opinion ¼ 0, negative ¼ 1,
and most negative ¼ 2. The impression of Paro was evaluated
by the total score of the questionnaire. The examiner
heard each question to the subject.
Results of Robot Therapy
We examined 29 patients (including 11 men, 62–90 years).
Some of these patients were rejected because they were subnormal
or normal according to the DIMENSION analysis. In
such cases, no improvement was expected by robot therapy. In
some other cases, the patients were rejected because they were
unable to close their eyes during the EEG recording. The number
of available subjects was reduced to 14. Their basic attributes
are shown in Table 2.
Figure 6 presents the results. The Y-axis, D r, denotes the
standard deviation of fluctuations of D a. The fan beam area
denotes the rough standard of levels of neuronal activity.
Arrows indicate displacements after the 20-min robot therapy.
The green arrows indicate positive displacements. The robot
therapy was effective for seven patients. In particular, one
patient improved from impaired to normal, and two other
patients improved to subnormal.
As for the questionnaire on the impressions of Paro, we were
able to obtain data from 11 of the 14 available subjects. Figure
7 shows the scores of their questionnaires and changes of D a.
Four patients whose total score was eight showed improvement.
In contrast, no improvement was observed in patients
whose score was lower than seven (except for patient B).
As for their interactions with Paro, for example, patient K
treated Paro like her grandchild. She hugged and spoke to it
while smiling during the robot therapy (Figure 8). She felt Paro
was so cute that she recommended it to a patient seated at her
side. She said, ‘‘I want to sleep with Paro,’’ and ‘‘I’m never tired
of Paro.’’ On the other hand, patient A did not try to interact with
Paro, and said, ‘‘It seems to be alive, but it is not a real animal.’’
Fig. 5. A scene of robot therapy.
Cortical neuron activity of two patients, F and G, who
achieved the same total scores on the impression questionnaire,
was opposite after the robot therapy. In response to
the question about their lives, we found that patient F had
owned pets, but G had not. Patient G felt that animals were
fearful, dirty, and stinky, but commented ‘‘Paro never bit
me, and it’s very clean. I want this one! I feel as if Paro is
alive.’’ On the other hand, patient F said this was well made,
even though she was dandling Paro on her knee during the
robot therapy.
To clarify the effects, we inactivated Paro so that it appeared
to be a stuffed toy and applied it to subjects whose neuronal
activities had been improved by Paro. We obtained data from
Table 1. Questionnaire of the impression of the seal robot.
1. Is Paro cute/ugly?
a) very
cute
b) cute c) no
opinion
2. Do you like/dislike Paro?
a) like it
very
much
b) like c) no
opinion
3. Is playing with Paro fun or boring?
a) very
fun
b) fun c) no
opinion
4. Do you want to play more with Paro?
a) more b) a little
more
c) no
opinion
d) ugly e) very
ugly
d) dislike e) dislike it
very
much
d) boring e) very
boring
d) not too
eager
Table 2. Basic attributes of the 14 subjects.
e) no
more
Sex
Male 4
Female 10
Age (avg. SD) 79.2 4.5
MMSE (avg. SD) 16.6 2.9
D σ : SD of Smoothness Fluctuation
0.0350
0.0300
0.0250
0.0200
0.0150
0.0100
0.0050
0.0000
0.8000
0.8200
Before
After
0.8400
0.8600
0.8800
0.9000
0.9200
Subnormal
0.9400
0.9600
Normal
0.9800
1.0000
D α : Smoothness of Scalp Electrical Potential Distribution
Fig. 6. The change of cortical neuron activity of 14 patients
before and after robot therapy.
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D of D α
0.0500
0.0400
0.0300
0.0200
0.0100
0.0000
–0.0100
–0.0200
Subject
(Gender, Age)
[MMSE Score]
Score of
Impression of
Paro
A
(M, 72)
[20]
–3
B
(M, 80)
[14]
0
C
(M, 84)
[15]
4
D
(F, 80)
[14]
5
E
(M, 76)
[13]
F
(F, 82)
[18]
6 7
G
(F, 74)
[18]
H
(F, 81)
[17]
I
(F, 79)
[18]
J
(F, 81)
[16]
8
K
(F, 81)
[16]
Fig. 7. The relationship between the impression of seal robot, Paro, and its efficacy on 11
patients.
Fig. 8. Patient K holding a seal robot. She treated it like her
grandchild.
D of D α
0.0550
0.0400
0.0300
0.0200
0.0100
0.0000
–0.0100
–0.0200
Subject
B (M, 80) G (F, 74) J (F, 81) K (F, 81) K (F, 79)
(Gender, Age)
[MMSE Score]
[14] [18] [16] [16] [18]
Score of
Impression
of Paro
–4 3 5 6 7
Fig. 9. The relationship between the impression of Paro and
the efficacy of inactivated Paro on five patients whose neuronal
activities improved by the activated Paro.
five subjects: B, G, I, J, and K
(Figure 9). Neuronal activities of
subjects K and I, whose impressions
of Paro were relatively high,
were improved by the interaction
with the inactivated Paro. However,
the changes of D a were
smaller than when they interacted
with the activated Paro. In fact,
their interactions with the inactivated
Paro were quite different
from those with the activated
Paro. They rarely touched it, and
never spoke to it. In addition,
none of them said, ‘‘I want to play
more with Paro.’’
Discussion
Art therapy [3], music therapy,
animal therapy, and so on are
known to be effective in delaying
the onset of dementia. However,
these therapies require welltrained
therapists. In addition,
animal therapy has problems of safety and sanitation. Learning
therapy requires patient effort for continuation. Pharmaceutical
treatment is also available to prevent the progress of
dementia but has side effects. In contrast, robot therapy using
the seal robot Paro is safe, convenient, and does not require
special skills, places, or other tools.
In Figure 5, the four patients whose impression of Paro was
most positive were all women. Women interacted with Paro
willingly and treated it as if it was a real puppy or kitten. On
the other hand, most males just watched Paro’s behavior and
did not interact with it positively, even though they commented
that it was cute. One man commented, ‘‘It is boring
because it is not a real animal.’’ Moreover, males generally
feel that playing with stuffed toys is girlish. We considered
that these differences influenced the effects of Paro.
Influences of robot therapy on patients F and G were opposite,
even though their total scores of their impressions of Paro
were the same. Patient G disliked animals but wanted to interact
with Paro. This desire might enhance the effects of Paro,
and she immediately accepted Paro as if it was a real animal.
On the other hand, patient F felt Paro was an artificial thing in a
part of her mind, even though she treated it like a child. We
consider that this difference resulted in opposing influences on
their cortical neuron activity. As for patient B, his cortical neuron
activity improved by robot therapy despite his poor score
on his impression of Paro. When the experimenter was listening
to patient B’s impression of Paro, people around him
laughed at his negative answer because he interacted with Paro
very happily. His answers to the questionnaire might have
been influenced by embarrassment.
As for the inactivated Paro, neuronal activities improved
in two subjects whose impression of Paro was relatively
high. Harlow examined the reactions of a child monkey to
two surrogate mother monkeys consisting of only hard wire
or hard wire-covered with a soft blanket [45]. He found that
the child monkey was more attracted to the soft surrogate
mother monkey, and often hugged it. Softness brought the
child monkey comfort and peace. This experiment showed us
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theimportanceoftouch.Paroappearstobeababyharpseal,
averycuteanimal,anditssurfaceiscoveredbysoftbushy
fur. In addition, ubiquitous surface tactile sensors also
provide softness. The appearance and feel of Paro might
bring neuropsychological improvements in patients. However,
the extent of that improvement was smaller than when
they interacted with the activated Paro. Moreover, their interaction
with the inactivated Paro was passive. We consider
that the reactions to the touch and speech from the patients
were very important to attract their interest and brought
about the effects of robot therapy.
With regard to other research groups, Dautenhahn used
mobile robots and Robins used robotic dolls for treating
autistic children [46], [47]; and robot therapy using commercially
available animal-type robots, such as AIBO and
the cat robot named NeCoRo [48], has been attempted [49]–
[53]. For example, Yokoyama used AIBO in a pediatric
ward and observed the interaction between children and the
robot [49]. He pointed out that when people met AIBO for
the first time, they were interested in it for a brief period.
However, AIBO never produced relaxation effects, such as
those obtained from petting a real dog. In other examples,
Libin introduced NeCoRo to a nursing home and observed
patient interaction with it [50]. Ohokubo used AIBO,
NeCoRo, etc. at pediatric wards using volunteers and then
investigated its influences by observation and with questionnaires
[51]. Kanamori et al. examined the effects of
AIBO on the elderly in a nursing home [52]. By measuring
hormones in saliva, they found that stress decreased after a
one-hour interaction with AIBO and patient loneliness
improved after 20 sessions over a seven-week period.
Tamura et al. compared the effects of a toy dog with those
obtained when patients were exposed to AIBO [53]. They
found that AIBO encouraged less interaction and required
more intervention from the occupational therapist.
Robots such as AIBO and NeCoRo break easily during
interaction with people because they were not originally
designed for therapy. Therefore, it is important to consider the
robot as a system that includes its usage and design it specifically
for therapeutic uses.
In our first experiment, which investigated the neuropsychological
effects on patients with dementia, we evaluated the
subjects’ neuron activities before and after the robot therapy
session and obtained data from 14 subjects. The number of
subjects was very limited because of the restricted experimental
environment. However, current results show that robot
therapy has a high potential for improving the brain activity of
patients with dementia and helping to prevent the development
of such disorders in healthy people.
A case study to investigate the effects more precisely will
be performed in the future. Further experiments are needed to
investigate the repeatability and durability of the effects and
the relationship between the functions of the robots and their
effects on patients suffering from dementia.
Conclusions
We used the seal robot, Paro, for therapy of patients suffering
from dementia at a cortical neuron clinic. The efficacy of the
robot therapy was evaluated by DIMENSION, which detects
patient’s cortical neuron activity from a 21-channel EEG. The
results from preliminary experiments show that robot therapy
has a high potential to improve the condition of brain activity
in patients suffering from dementia. This is especially true for
patients who like Paro very much. In Japan, the cost of care
for a patient with dementia is about US$33,000 per year, and
their life expectancy is about eight years. This represents an
enormous burden for those municipalities that provide longterm
care insurance. Useful and convenient methods for the
prevention of dementia are strongly needed. Several municipalities
in Japan anticipate the effects of Paro and support its
introduction. For example, Nanto city, Toyama, bought
eight Paros and introduced them to day service centers in the
city. In addition, Tsukuba city, Ibaraki, established a subsidy
for purchasing Paro. We hope Paro will be widely used
and provide help to people with dementia.
Kazuyoshi Wada received his B.Eng. and
M.Eng. degrees in mechanical and control
engineering from the University of Electrocommunications,
Tokyo, Japan, in 1998
and 2000, respectively, and he received his
Ph.D. degree in engineering from the
University of Tsukuba, Japan, in 2004. He
was a research staff member at Intelligent
Systems Research Institute, AIST, from 2004 to 2007. He has
been an associate professor with the faculty of system design,
Tokyo Metropolitan University since 2007. His current
research interests include intelligent robotics, human-robot
interaction, and robot-assisted therapy. He is a member of the
Robotics Society of Japan and the Human Interface Society.
Takanori Shibata received his B.S., M.S.,
and Ph.D. degrees in electromechanical
engineering from Nagoya University in
1989, 1991, 1992, respectively. He was a
visiting researcher at the Artificial Intelligence
Lab, University of Zurich, in 1996
and at the Artificial Intelligence Lab,
Massachusetts Institute of Technology, in
1998. From 1998 to 2001, he was a senior research scientist at
the Mechanical Engineering Lab, AIST, and since 2007 he
has been with the Intelligent Systems Research Institute,
AIST. Concurrently, he has been a research scientist for the
Interaction and Intelligence Project of Solution-Oriented
Research Science and Technology, Japan Science and
Technology Agency (SORST, JST). He is a Member of the
IEEE as well as of other scientific and technical societies. His
research interests include human-robot interaction, human
interactive robot, emotional robot, robot therapy, and humanitarian
demining. He has published many papers and books.
He was certified as the inventor of a seal robot named Paro,
the world’s most therapeutic robot, by the Guinness World
Records in 2002. He has received many awards including the
Outstanding Young Person (TOYP) of the World award in
2004 and the Japanese Prime Minister’s award in 2003.
Toshimitsu Musha graduated from the
Department of Physics, University of
Tokyo, in 1954, He worked for the Electrocommunication
Lab of Nippon Telegraph
and Telephone Corporation, Japan;
the Research Lab of Electronics, MIT; the
Royal Institute of Technology; and Tokyo
Institute of Technology. After retirement,
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60
he established the Brain Functions Lab, Inc., where he has
developed new diagnostic tools for numerical estimation of
human emotional state (ESAM), which has been used in
developing new industrial products, and the neuronal impairment
in the human brain (DIMENSION), which allows early
detection of dementia.
Shin Kimura received his medical degree
from Nihon University, Tokyo, Japan, in
1990. He was an instructor of neurosurgery
at the Department of Neurosurgery, Nihon
University, from 1989 to 2002. He has been
the director of Kimura clinic and Art Brut
in which people affected by dementia have
been treated with art therapy since 2003.
Address for Correspondence: Kazuyoshi Wada, National
Institute of Advanced Industrial Science and Technology, 1-1-1
Umezono, Tsukuba, Ibaraki, 305-8561, Japan. E-mail: k-wada@
aist.go.jp.
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