Body Massage Robot Technology

8/18/2019 Body Massage Robot Technology

1/20

Body Massage Robot Technology: A Review | Jignesh Nakrani (2015H141040H) 1

Body Massage Robot Technology: A Review

Jignesh Nakrani

2015H141040H

ME G511 (Mechanism and Robotics)

ME Design Engineering

BITS Pilani, Hyderabad Campus

Abstract

The interest in a healthy and happy life for people has increased of late as the quality of life in

old age has become a issue. Moreover, the interest in health has led industrial companies to

concentrate on massage technology. Body massage robot technology is one of the biggest issuesin the robotics field, and many companies and institutes have sought to develop a massage robot

technology. The massage robot must have certain abilities that would allow it to help a person

mentally and physically. There is no common interface module, however, for body massage

robot platforms, and few robots that have healthcare abilities exist. Therefore, developing a

common interface technology and applying the technology to robot platforms can pave the way

for the development of a technology that could improve the physical and mental health of

humans. This paper introduces the authors‟ research on a massage for different parts of body and

massage service robot platform. First, different body parts including head, feet, back etc. and oral

rehabilitation massage robot area. In conclusion, the intellectual body massage robot is expected

to promote a new field and to pave the way for a new product.

1. Introduction

Robots are needed for tasks and

operations that must be performed with high

speed and accuracy in various industrial

fields. In recent years, however, special

attention has been paid to the need for robots

that can assist human beings with their

health and welfare needs. Robots which can perform these specialized tasks require

complex mechanisms, and the ability to

realize complex motions like those

performed by human beings. [3]

Therapeutic massage is considered

an effective physiological treatment for

human body. Many health benefits can be

achieved through therapeutic massages, such

as improved blood circulation, lowered

blood pressure, reduced heart rate, relief

from fatigue, relaxed muscle tone, etc. In

medical applications, such as clinical patient

care, therapeutic massages are usually

applied for the reduction of pain, stress,

tension and anxiety of patients [2].

Previously, welfare robots such as a

walk support robot, a food tray carrier, and a

meal assistance robot have been developed.


2/20


In addition, there have been a number of

studies on multi-fingered hand robots. A

multi-fingered hand can perform grasping

and manipulating motions to handle objects,

and can imitate the movements of a human

hand. [3]

The development of robot hands is

toward an anthropomorphic design with

multi-finger shape and the utilization of

force/torque sensors and tactile sensor array

to mimic the perception of human hands.

Currently, most multi-finger robot hands are

mainly developed for dexterous

manipulation tasks and as prostheses. In

addition to these applications, the use of

multi-finger robot hand as a massage means

is a feasible application for human health

and welfare. Some research efforts on the

massage issue were presented in literature.

With adequate designs, the multi-finger

robot hand can perform kinds of massage

motions like a massage specialist does, such

as kneading, rubbing, tapping and

acupressure. [2]

Recently, the research in the field of

humanoid robots attracts a lot of attentions

from many researchers in which most of the

studies are focused on the multi-fingered

robot hand. A gripper method and an

impedance control are the outstanding

representative methods among the

researches of humanoid robots. In addition,

in the field of rehabilitation robot, welfareand human supporting robot have also been

reported. Most of the researches are focused

on theoretical problem, but there is only a

few researchers studied about the

application of humanoid robot such as multi-

fingered robot hand. [4]

Examples include such robots

include Toyohashi University of Technology

(TUT), reported feed forward-type and

Neural Networks massage motion control by

off-line learning in the TUT Hand robot.

This research described how a two fingered

hand was applied, but that both the force and

position control were insufficient, because a

feedback controller was not included due to

the lack of a force sensor. Therefore, the

massage motion of this hand was too

limited. Because of this, researchers decided

to design a multi-fingered hand such as a

four-fingered hand. However, it took a great

deal of time to solve the inverse problem presented by Neural Networks. [3]

2. Types of Massage Robots

2.1 ChairBot

The robotic massage chair that uses the

bio information of its human user for health

monitoring is called ChairBot. It estimates

the user‟s body states and analyzes the

massage regions of the body using an

intelligent decision-making system.

ChairBot significantly helps a user

overcome fatigue by providing him or her

with massage services.

Figure (1) The description of ChairBot


3/20


ChairBot utilizes a variety of

technologies: the intellectual massage force

feedback mechanism; the massage control

technique, which applies the robot

mechanism and senses pulses for diagnosis;

an active seat for the user‟s convenience;

and a sensor and interface technology for

healthcare robots (Figure 1). [1]

2.1.1 The Intellectual Massage Force

Feedback Mechanism

A block diagram shown in Figure 2

explains the massage force feedback system.

According to the user‟s health state and

basic information, ChairBot performs itsfunction with the proper user position and

massage strength. It looks for the proper Nth

actuator and an axis controller and could

work efficiently based on the results of the

health management program (HMP). [1]

Figure (2) Block diagram of the intellectual massage

force feedback mechanism

2.1.2 Massage Control Technique

The results obtained from the

intellectual controller present the user‟s

massage pattern or taste. Lower-level

modules are made up of the local controller,

the position/velocity/pressure sensor, and

the biofeedback sensor. The feedback loop

remains firmly in place when the lower-level

modules firmly connect to the sequent work.

Figure (3) Block diagram of the massage control

technique

2.1.3. Act ive Seat Technology for User’sconvenience

The aim of active seat technology is

to give its user an efficient massage. A

sensor was utilized to recognize the

somatotype shown in Figure 4. The sensor is

made up of a probe tip with an accelerationsensor and a load cell. The important

massage points for ChairBot are the neck,

shoulder, and lumbar region. The hands are

massaged repetitively from up downwards

and from left to right, as real hands would.

First, ChairBot scans the whole body

of the user. Second, the seat automatically

adjusts to the proper size of the user‟s

somatotype and then fastens in place. Lastly,

the stiffness of the back area of the bodycould be graphically shown by analyzing the

digitized data regarding the spot on the body

that is suitable for acupuncture. [1]

Figure (4) The block diagram of the active seat

technology


4/20


2.2 Pushing and rubbing massage Multi-

fingered Robot Hand

In recent years, a lot of research on

multi-fingered robot hand has been studied.

A multi-fingered robot hand can perform the

grasping and the manipulating motion to

handle objects, and can imitate the

movement of a human hand. However, these

researches on multi-fingered robot hand

have not given the concrete applications.

Then, the authors have reported the research

on human support and healthcare application

of robotics and also multi-fingered robot

hand. [2]In author‟s group, massage motion

control for human shoulder by teaching-

playback control was developed. Feedback

controllers were corporate with feed forward

linearization compensation of robot‟s

position and force. Based on this concept,

authors reported that position control was

used to control the robot fingertip position,

until it touches shoulder. After touching,

control system was switched from position

control to force one. However, the lateral

position is gradually shifted while doing

force control for the vertical direction of

human skin. Furthermore, in massage

control, exact control for both of position

and force is not necessary for the

disturbance such as finger touches the

human bone, for example. Then, robot

finger is hoped to have compliance like ahuman finger. [4]

Therefore, in this paper, hybrid

impedance control comprised of position-

based and force-based impedance control is

proposed to establish the suitable massage

control system. By using impedance control

technique to control the massage motion, the

lateral position of the robot fingertip is

controlled by position-based impedance

control, while the fingertip force for the

vertical direction of human skin is controlled

by force-based impedance control. Hence,

the massage point in the lateral can be fixed

by position-based impedance control, while

achieving force control of vertical direction

by force based impedance controller. [2]

In this paper, two kinds of massage

motion control are studied, where one is the

pushing massage and another is the rubbingmassage as shown in Figure 5. In the

author‟s previous research, the pushing

massage motion control has only been done.

The rubbing massage motion control is the

first study all over the world in massage

field using maltifingered robot hand. [3]

(a) Pushing (b) Rubbing

Figure (5) Patterns of massage motion

The schematic diagram of massage

system based on the multi-fingered

humanoid type robot hand is shown inFigure 6. The robot hand has 4 fingers with

13 joints. The 1st finger has 4 joints and the

2nd

to 4th

fingers have 3 joints and they are

arranged like the human hands. [3]


5/20


Figure (6) Robot structure and massage system

construction

The actuator for the robot hand is a

small AC servomotor. The servomotor has

an integrated harmonic gear (1/80) and

encoder, and directly drives each joint. In

this paper, the robot hand is controlled using

the velocity mode of the servo driver.

Therefore, the input torque τ of the robot

hand is changed to the voltage by v = Kτ.

Here, v[V] is the voltage supplied to the

motor of robot hand. The constant K is the

coefficient which changes the torque to the

voltage, and was obtained by system

identification. The calculation method of

joint drive torque τ is explained later. [8]

The fingertip force of robot can be

measured by fingertip type of 6-axis force

sensors. For the measurement of a massage

therapist‟s fingertip force, at first, the sheet

type distribution pressure sensor, as shown

in the lower left corner of Figure 5, is put on

the hand of the massage therapist. Then, the

massage therapist‟s fingertip force is

measured when the massage therapistactually massages a human‟s body.

However, this distributed pressure sensor

can measure only the pressure force but can

not measure the direction of pressure force.

So, only one direction of force is considered

in this research. [8]

Figure (7) Robot structure and massage system

construction

2.2.1 Impedance control system

Consider a finger movements

performed by an expert massage therapist

almost consisted of pushing. Pushingmassage is done strongly by fingers and the

fingers are placed on the position of

massage. In actual massage by therapists,

the position of the fingertips does scarcely

change very much, while the force of the

fingertip is depended on the condition of

massage position. But in fact, the massage

object is a human body, so the massage

position moves gradually during the

massage by robot‟s force control. By this

reason, it is difficult to massage by a

fingertip force control with keeping at the

same position by robot. [8]

To solve this problem for both of

force and position control simultaneously, a

hybrid impedance and force control is

proposed for the massage control system by

multi-fingered robot hand. By using this

control, the impedance control is used to fixthe position on the human skin against the

disturbance while executing the force

control on the human skin. Therefore, this

impedance control is suitable to control the

movement of massage. A diagram of


6/20


impedance control of robot hand is shown in

Figure 8. [8]

Figure (8) Conceptual diagram of impedance control

The massage object is a human body,

so the massage position is often shifted

gradually during the massage by robot‟s

force control. Thus, it is difficult to carry out

the force control with keeping at the same

position by finger-tip force control. [3]

To solve this problem for both of

force and position control simultaneously,

the hybrid impedance control is proposed for

the massage control system by multi-

fingered robot hand. In this control method,

the position and force control are realized by

the hybrid position and force impedance

control. Furthermore, when the finger-tip

touches the obstacle like a bone, the

fingertip slip softly against the bone in ordernot to give the damage to the bone like a soft

spring-damper. A conceptual diagram of

impedance control of robot hand is shown in

figure 9. [3]

Figure (9) Conceptual diagram of impedance control

2.2.1.1 Position-based Impedance Control

How to make the fingertip position

of a robot hand follow a target positionusing impedance control is described. The

mathematical formula of the desired

impedance of massage control system with

robot hand is shown in the below: [3]

Where x, ẋ and ẍ are respectively the

fingertip position, velocity and acceleration.And, xd , ẋd and ẍd are the reference position,velocity trajectory and acceleration until

robot finger touches the object. Then , M d ,

Dd , K d and f are the desired mass coefficient,

damper coefficient, spring coefficient and

the action contact force on the fingertip from

the environment, respectively.

A general dynamic equation of robot

manipulator is shown in the below: [3]

Where θ is the joint angle vector, M (θ ) is aninertia matrix, ȟ (θ, θ ̇) is the Corriolis andcentrifugal term, τ is the joint drive torque, Jis a Jacobian matrix.


7/20


Thus, a position-based impedance

control input from Eq.(2) becomes

2.2.1.2 Force-based Impedance Control

It is possible to also make the finger-

tip force follow the target force, realizing the

desired impedance characteristics for the

machine.

The desired impedance of massage

force control system is given not by Eq. (1),

but by Eq.(4), and in stationary state, thefinger-tip force applied to objects agrees

with target force. [3]

Thus, a force-based impedance control input

becomes

2.2.1.3 Hybrid Impedance Control

Hybrid control comprised of

position-based impedance and force-based

impedance is described. Position-based

impedance control is used for the horizontal

direction (y, z axis) of human skin muscle,

and force-based impedance control is usedfor the vertical direction (x-axis) of human

skin.

By performing the position-based

impedance control horizontally, a massage

point does not shift during a massage.

Furthermore, by giving a force reference to

the vertical direction (x-axis) and giving a

position reference to the horizontal direction

(y, z-axis), the rubbing massage motion,

one-type pattern of massage, can be also

realized.

The block diagram of impedance

control of the massage system used in this

paper is shown in Fig.4. Here, f x(θ) is thenotations to transform the variables of θ andθ˙ into the position x and also transform thevelocity ẋ via a Jacobian matrix of robotkinematics.

Reference position, reference force,

desired mass matrix coefficient, damper

coefficient and spring coefficient is given asfollows. [3]

Figure (10) Hybrid impedance control of massage

system

2.2.2 Experimental procedure

For estimating the stiffness of human

skin muscle, at first, fingertip massage force

of the therapist in one direction are read by

the sheet type sensor at the real time and it is


8/20


the input to a robot in order to estimate the

parameter of the various stiffness (softness

and hardness) of the object as shown in

Figure 11. The left hand side in Figure 11 is

the measurement point of soft one. On the

other hand, the measurement point of hard

one is shown in the right side of Figure 11.

(a) Soft Point (b) Hard Point

Figure (11) Measurement point of human body

Reference input force was given

from the data of the expert fingertip force

executed by the therapist using the sheet

sensor with real time measurement and it is

shown in Figure 12 in the case of Figure

11(a). The amplitude of the given input

force was about 10 [N]. The estimation time

was carried out after 1 [s] from the start of

massage. The estimation parameters ofhuman skin muscle in case of the soft point

and the hard point are shown in Table 1. [4]

Table (1) Estimated parameter of human skin muscle

Figure 12 shows the comparison of

the position output response between the

estimated values calculated from the model

of Eq. (11) and the measured position of

robot fingertip in real experiments with the

same input force. Simulation results almost

agree with experimental results, and model

validity was demonstrated. [4]

Figure (12) Estimation and experimental results of

skin model

2.3 Feet Massage

Reflexology is a kind of assisting

physical care through massaging or applying

pressure to parts of the feet where will

reflect an image of the human body in order

to improve general health of the human.

Based on this principle, we propose a new

application of 7-DOF (degree of freedom)

redundant manipulator to do the massaging

work for human feet with the tactile sensor

equipped to the end-effector. To facilitate

the flexible and dexterous manipulation of

redundant manipulator, the hybrid

impedance control is adopted and extended

to include the null space motion, not only to

generate a desired motion of the end-

effector, but also manage the contact force between the end-effector and the human

feet. In order to improve the safety and

comfortability, the reactive forces of the

tactile sensor cells are monitored and

recorded. [14]


9/20


Reflexology, having a very long

history in China, is pressure massage to the

feet or hands in order to stimulate the reflex

points and bring about a balance of the eight

bodily systems in order for the body to work

together in harmony and unison and thus

creating a feeling of well-being and

optimum health. The human body is

completely reflected in the feet in a three-

dimensional form, and a point on the foot

which maps to an area on the body is called

a reflex as shown in Figure 13. The benefits

of reflexology will be the reduction of stress,

relaxation, pain reduction, amelioration of

symptoms for health concerns, rejuvenationof tired feet, improvement in blood flow,

etc.

Figure (13) The system setup of massaging based on

reflexology

In this topic, a redundant

manipulator with tactile sensor equipped

end-effector is applied to massage the

human feet as shown in Figure 13. Then the

reflex properties are analyzed. After that thesystem modeling is discussed with the

introduction of tactile sensor and modeling

of human skin. After that the impedance

control is extended to control both the main

task and null space motion. Simulations and

experiments are made and several subjects

are discussed later. [14]

2.3.1 The analysis of reflex properties

As the reflexology theory indicates,

practitioners believe that the foot is divided

into a number of reflex zones corresponding

to many parts of the body, and the practice

of massaging or applying pressure to parts

of the feet will produce a beneficial effect on

corresponding parts of the body, such as

lung, shoulder, pancreas, kidneys and so on.

Pressure applied to the feet generates a

signal through the peripheral nervoussystem. From there it enters the central

nervous system where it is processed in

various parts of the brain. It is then relayed

to the internal organs to allocate the

necessary adjustments in fuel and oxygen.

Finally a response is generated that is sent

on to the motoric system. This message is

fed forward to adjust the body‟s tone or

overall tension level. [14]

Figure (14) System modeling and human skin model

The massaging gestures of

practitioners always involve the pressing,

kneading, rubbing or tapping. In this topic,


10/20


the action of pressing will be performed by a

robotic arm with a series of forces exerted.

Massaging the feet reflexology by

the robotic arm, will not only save the labor

to do repeated work, but also guarantee the

steady and standard practice, which will

certainly be helpful to improve the quality of

massaging work.

2.3.2 Modeling of the system and skin

It is very difficult to determine skin

properties and to model its behavior, since

human skin is a non-homogeneous,

anisotropic, non-linear viscoelastic materialwhose properties also vary with age and

individual, which is a very complex

biological structure to study. Therefore in

this paper, the variances of skin properties

are not considered and we consider only

different kinds of skin surfaces and different

reflex points in the experiments. [14]

2.3.2.1 System modeling

The massaging action needs both the

position control and the orientation control,

therefore a lower-DOF manipulator is not

sufficient. The 7-DOF redundant

manipulator is applied to massage the

human feet as the setup of system shown in

Figure 14. The tactile sensor is installed at

the tip of the endeffector in order to get the

pressure of contact points. The tactile sensor

is chosen as the module type of DSA 9210

with the shell-like shape, having a size of

50mm×25mm, which provides a spatial

resolution of 3.4mm with 70 sensor cells.

The working principle of the tactile sensors

depends on an interface effect between

metal electrodes and a conductive polymer

covering the sensing electrodes, and the

resistance between a common electrode and

a sensor cell electrode is a function of the

applied load changing with time. The output

voltage of a resistive sensor cell in the

electrical circuit can be detected on real-

time, and the pressure on it will be obtained

from the transducer characteristics. Then the

forces exerted on the sensor cell can be

achieved easily by transforming the sensor

pressure. [14]

2.3.2.2 Three contact types

In general, based on the shape of

human feet, three types of contact can be

divided considering different surfaces as

convex, flat and concave surfaces as shown

in Figure 15(a), Figure 15(c) and Figure

15(e) respectively. The experiments are

made on three different parts of feet to get

the performances of tactile sensor. The

corresponding pressures measured on the

contacted tactile sensor cells are shown inFigure 15(b), Figure 15(d) and Figure 15(f)

respectively. Comparing among the

experiment results, it is easily found that the

reactive forces of the sensor cells are

different although the same force at the end

of the end-effector is exerted. The biggest

reactive pressures of the contacted sensor

cells appear in the convex type as shown in

Figure 15(b), but the concave type has

relatively the smallest pressures of contacted

sensor cells in three contact types as shown

in Figure 15(f), since it has more contact

areas than others. As expected, the flat type

arrives at a compromise. [14]


11/20


2.3.2.3 Derivation of human skin elasticity

Skin can be divided into two separate

layers, the epidermis and dermis, and the

studies show that the dermis is primarily

made of collagen, elastic and reticulin fibers,

Figure (15) Three contact models of human skinsurface

which all contribute to the mechanical

behavior of skin, though the epidermis is

stiffer than the dermis. In a soft

environment, the human feet skin is

modeled as the mass-spring-damper system

in the control scheme and the contact model

between the end-effector with the tactile

sensor equipped and the human feet skin is built up as shown in Figure 14, where M m is

the inertia of the end-effector including the

tactile sensor, K k and Dk are skin elasticity

and damping coefficients while K m and Dm

are stiffness and dumping parameters of

impedance control.

In the simplified model, the reaction

force Fe can be expressed as

(11)

Where Fe is the external force in thedynamic model of the massage motion and it

can be obtained easily from the impedance

control discussed in the next section. X i is an

initial position where Fe becomes zero.

Based on reflexology, the feet

massage topic represent a way of massaging

human feet by a 7-DOF redundant

manipulator with tactile sensor installed at

the end-effector. Since the human skin is

very complicated and difficult to determine

its properties, it is simply modeled as the

mass-spring-damper system. Impedance

control is extended to manage both the task

motion and the null space of the redundant

manipulator. Several key subjects are

discussed, such as the contact types, human

skin elasticity and so on. Simulations and

real experiments are made respectively totrack the desired massaging trajectory and

the results are compared while several

factors influencing the experimental

performances are considered and analyzed

carefully. [14]

2.4 Oral Rehabilitation Robot

The expected Japan's future elderly

society will undoubtedly increase the needs

of medical and dental treatment and

rehabilitation. Due to the increase need of

medical care for patients and elderly

persons, more trained experts and financial

resources are required for providing services

effectively. This causes a big problem for


12/20


the both government and hospitals.

Therefore, it becomes necessary the

introduction of advanced tools designed for

providing treatment to patients and elderly

persons. Such concept was based within the

framework of cooperation between

engineers and medical workers. This

concept was based fundamentally in the

following two points: [7]

1. In the physiotherapy, treatment

procedures by means of robotic

systems enable to evaluate the

efficacy of the treatment objectively.

In contrast, it is difficult forconventional manual treatments to

compare between the subjective

strength of stimulation and

effectiveness. Because the

conventional manual manipulation is

based on the experience and intuition

of experts.

2. Develop a new physiatrist

manipulation technique that is taking

advantages of robot system. Robotic physiatric manipulations bring

solution to cope with the increased

demands of therapy by expert

physiatrician.

Based upon their experience on

developing dental robotics, they proposed

the development of a new rehabilitation

robot designed to provide massage of the

maxillofacial region. The estimated

prevalence of oral health problems such as

dry-mouth, temporomandibular joint (TMJ)

disorders and swallowing disorders in Japan

is over ten million persons in all. Massage

therapy to specifically target organ, such as

masticatory muscles and salivary glands, is

effective to reduce the symptoms from these

conditions. Therefore, they set the purpose

of present study to develop a robot system

that provides massage therapy to

maxillofacial region. In this topic, the design

concept of the Waseda-Asahi Oral-

Rehabilitation Robot No. 1 (WAO-1), which

is composed by two 6-degree of freedom

(DOF) arms and plungers attached to the

end-effectors in order to provide effective

massage to patients. Furthermore, the details

of the control system and safety features of

WAO-1 are introduced. [9]

2.4.1 Maxillofacial massage therapy for dry

mouth

The disease of dry mouth, also

known as Xerostomia, is characterized by an

abnormal dryness of the mouth due to the

reduced capability of the patient to produce

saliva. Such condition can be provoked by

several reasons, such as diabetes mellitus,

kidney diseases, stress, drugs, etc. The main

symptoms are dehydration, pain in the oralcavity, and the abnormalities on the

sensation of tasting. In severe cases, patients

complain about difficulties to swallow and

even to speaking. Nowadays, the

pharmacotherapy and physiotherapy are the

main procedures of treatment to patients for

stimulating the production of saliva. In

addition, dental treatment and physiotherapy

are also provided. [9]

For better understanding of the

maxillofacial massage, we mention about

the human anatomy. The saliva is produced

mainly from three sorts of glands:

sublingual, submandibular and parotid. In

general, the maxillofacial tissue massage is


13/20


provided to the parotid gland due to its great

contribution on the production of saliva

(Figure 16). The therapy treatment consists

of providing massage to the parotid gland

and its excretory ducts in order to stimulate

the salivary flow. The massage includes the

both petrissage and effleurage manipulation

techniques. The petrissage manipulation is

useful to stimulate the specifically target

organ directly. The effleurage manipulation

provides indirect stimulation by rubbing the

skin surface. [10]

Figure (16) Maxillofacial tissue massage consists on

providing stimuli around the parotid gland, musculus

temporalis and masseter

2.4.2 System description

2.4.2.1 Design Concept

In order to provide effective massage to

patients, the development of WAO-1 is

based on the following design

specifications:

1. Working area: As we described

previously, the target organ of the

massage therapy for dry mouth is

parotid gland. Similarly, temporal

and masseter muscle are deemed as

the target of massage for TMJ

disorders. Therefore, the working

area of WAO-1 should be designed

to include above anatomical

structures, as shown in Figure 17.

2. Mechanism: In order to perform

massage on both Zone A and Zone

B, the WAO-1 mechanism should

consist of two-arm manipulators

that are utilized to control the

position/orientation of plunger

devices (attached to the end-

effector). Of course, it is desirable

that the driving mechanism of the

arms is located out from the

patient's visual field.

3. Applied Force: Using a head model

that we will describe later, we

measured the dynamic force on

patient's head during the massage ofmaxillofacial region by skilled

physiatrician. Thus we defined a

maximum force of 4 [kgfl to

massage around patient face.

Therefore, WAO-1 designed to

apply the same force to

physiatricians. [9]

Figure(17). Musculus temporalis is defined as zone A

and parotid gland and masseter are defined as zone B.

2.4.2.2 System Description

The mechanism of WAO-1 consists of

two main parts: robot arms and the plunger

device. Robot arms consist of two 6-DOF

manipulators used to control the movement

of the plunger device attached to the end-

effector of each manipulator. The plunger

device is the only part of the robot having

direct contact with the patient face (Figure


14/20


18a). In the following paragraphs, a more

detail description of each of the parts of

WAO- 1 will be provided:

1. Robot arms. Each of the arms of WAO-

1 is composed by a 6-DOF manipulator(Figure 18b). Each arm consists of two

translational DOF on the base and four

rotational DOF at the each joint of the

arm. Due to this DOF arrangement, the

robot arms do not obstruct the patient's

field of view while providing massage.

Each translational DOF consists of a ball

screws and a DC servo motors which

assures high positioning accuracy. Each

rotational DOF consists of a harmonic

drive gears and a DC servo motors with

no backlash.

(a)

(b)

Figure (18) System configuration of WAO-l: a) WAO-l is

composed by two 6-DOF arms and plungers. The torque

limiters were attached in the arm middle part as safety

device; b) DOF configuration of one arm

2. Plunger. A plunger which applies

force to the facial tissues is located at

the end-effector of each arm. We

have designed different kinds of

plungers by changing their shape,

material, and number of passive

degrees of freedom. Such plungers

are exchanged easily depending on

the needs of the kind of massage

(Figure 19).

Figure (19) several types of plungers

3. Safety device. The WAO- 1 has been

designed to applied force to facial

tissues of patients. Therefore, we

require considering safety features

that are needed to avoid as much as possible any possible risk to the

patient. For that purpose, we have

proposed the safety system shown in

Figure 20. As it can be observed; at

first software limiters and watch dog

timer are implemented into the

control software of the robot. In

particular, rotational speed and

motion positioning are limited within

safety range of operation. The

second safety feature has been

implemented by attaching limit

sensors at each DOF as well as fuses

to limit the current supplied to each

motor. The third one is implemented

through torque limiters. The torque


15/20


limiter has been placed in the middle

part of each arm. In the case that the

plunger load Fpr exceeds the

threshold Fth; even if the robot

system presents an unexpected

failure meanwhile applying force on

the patient's face, the arm will bend

and the load will be also released to

avoid any injury to the patient

(Figure 21). Finally, the fourth and

fifth safety features enables to the

doctor and the patient to stop the

operation of the robot at any time in

case of emergency. [7]

Figure (20) Outline of safety system. WAO-1 is

equipped with different kind of safety features.

The safety devices are implemented by software,

electrical and mechanical means.

(a) (b)

Figure (21) Torque Limiter principles: a) when Fpr<

Fth is found, the applied force is transmitted rough

the torque limiter, b) when Fpr> Fth is found, the

applied force is disabled.

2.5 Head Massage

In this study they focus not on the

development of control algorithms, but on

how a massage given by simple robot is

perceived. This is even more important since

for certain types of massages that are being

perceived as more pleasurable when

performed by another actor. It is well

documented, for example, that you cannot

tickle yourself. Furukawa, Kajimoto and

Tachi developed the Kusuguri system to

overcome the problem of remote tickling byusing smart phones and vibrators. Their

study provides a first clue on robotic tickling

devices. [5]

Figure (22) The Happy Head Trip massage device

The massage device in this studyovercomes this practical problem. The

movements of a simple robot are not

necessarily well controlled and the head

massage device functions as spring between

the robot‟s hand and the scalp of the

participants. Even if the movements of the


16/20


robot might be slightly rough, it does not

cause any discomfort for the users. A scalp

massage using the head massage device is

therefore a good starting point for testing the

effects of a simple robot giving a

massage.[6]

Tactile interaction with a robot might

also have an influence on the attitude users

have towards robots. Negative attitudes

toward robots can decrease perceptions of

anthropomorphism and closeness of the

relationship between the human and robot.

We therefore investigated if receiving a

massage from a robot might change the

attitudes of users towards robots.[5]

Based on the arguments above we

define the main research questions of this

study as: [13]

1) Do humans perceive a head massage

received from a human masseur as

more pleasurable than a head

massage performed by themselves?

2)

Do humans perceive a head massagereceived from a simple robot

differently in terms of pleasure than

a head massage done by themselves?

3) Do humans change their attitude

towards robots after they had a

physical experience with them?

2.5.1 Method

We performed a within subjects

experiment in which the independent

variable masseur was either the subject

him/herself (self) or the experimenter

(human) or the Nao robot (robot). A within

participants structure of the experiment was

the preferred choice to compensate for

individual differences in the appreciation of

head massages. Some participants might

have a more sensitive scalp than others. The

assignment of the participants to one of the

six possible sequences of conditions (shr,

srh, hsr, hrs, rsh, rhs) for self (s), human (h)

and robot (r) was counterbalanced.

2.5.1.1 Measurements

To measure the pleasure of the

massage experience they used the “Massage

as Pleasant” subscale of the Attitudes

Toward Massage (ATOM) scale. We only

had to change the tense of the questions,since the original ATOM scale asked about

a general attitude, while we had to ask about

a specific prior experience. This scale

consisted of five questions on a five point

likert type scales in which 1 denoted

“strongly disagree” and 5 denoted “strongly

agree”. [5]

1) I liked to be massaged

2) Receiving massage is relaxing

3)

Receiving the massage improved mymood

4) Receiving the massage made me

nervous (reversed item)

5) I liked to be touched by the masseur

We took the average of the five items to

calculate the dependent variable pleasure. A

high value on the ATOM scale therefore

indicates a high level of pleasure. In

addition, we measured the participants‟ view

on robots with the Negative Attitude

Towards Robots Scale (NARS) [16]. The

NARS scale consists of 14 items in three sub

scales that each are being rated on a five

point likert type scales in which 1 denoted


17/20


“strongly disagree” and 5 denoted “strongly

agree”. A high value on any of the three

NARS sub scales indicates a high negative

attitude towards robots. We also asked the

participants about their prior experience

with robots. In addition we video recorded

the participants to be able to analyze their

facial expressions during the massages. The

video camera was placed slightly aside in

front of the participants so that it could

record the facial expressions of the

participants. All participants were fully

aware of the presence of the video camera

and its recording function. They were to

specifically told that their facial expressionwould be analyzed, but rather that the

overall session would be recorded.

2.5.1.2 Participants

They had 18 participants at the age

between 18 and 49 (mean 25.6) of which 7

were women and 11 were men. Most were

associated to the University of Canterbury,

New Zealand. Twelve participants neverinteracted with a robot before, five reported

they had interacted 1-10 times, and one

reported that he interacted more than 10

times with a robot. The participants received

cookies as a reward for their effort. [6]

2.5.1.3 Setup

The experiment took place in a 3x5

meter room. The participants were seated on

a chair. The robot was standing behind them

on a box that was placed on a table (see

figure 22(b)). This was the only position in

which the robot was able to reach the scalp

of the user. For security reasons we strapped

the NAO robot to the box and the box to the

table. The robot could therefore not lose

balance and fall onto the participants.

The robot held the massage device in

its left hand. The experimenter was seated

behind the participants to control the robot.

This prevented that the participants might

have been under the impression that the

experimenter is controlling the robot. The

experimenter, in fact, only started the robot

action sequence and supervised the motion.

The movements of the robot action sequence

was designed using the Choreograph

software prior to executing the experiment.

The experimenter would have aborted anyaction that might have made the participants

feel uncomfortable. Fortunately, this was

never necessary. [6]

For the human condition, the

masseur stood behind the participants as

shown in Figure 22(a). For the self

condition, the participants were given the

massage device. The massage devices were

washed with soap and water after every

participant.The questionnaires were

administered using an iPad. We used the

Qualtrics service to design, present and

collect the questionnaires. The participant

could remain in the chair throughout the

whole experiment. [6]

2.5.1.4 Process

The experimenter welcomed the

participants and asked them to sit on a chair.

Once the participants were seated, the

experimenter provided an iPad that

contained the introduction and consent form.

When the participants agreed to the consent


18/20


form, the participants handed the iPad back

to the experimenter. The experimenter then

explained to the participant the order of the

conditions they will experience, and that

after each condition, they will be asked to

fill out a short survey. Once this has been

explained, the experimenter passed the iPad

back to the participants, and asked them to

fill out a demographic survey and the NARS

survey. The NARS survey consists of three

sub scales: Negative attitude toward

situations of interaction with robots (e.g. I

would feel nervous operating a robot in front

of other people), Negative attitude toward

social influence of robots (e.g. Something bad might happen if robots developed into

living beings) and Negative attitude toward

emotions in interaction with robots (e.g. I

feel comforted being with robots that have

emotions). After the participants finished

filling out the two surveys, they handed the

iPad back to the experimenter.

The experimenter then provided to

the participants the head massage device so

that the participants may familiarizethemselves with the device. Once

familiarized, the participants handed the

head massager back to the experimenter.

The experimenter then instructed the

participants on which of the three conditions

the participants would be exposed to first.

For example, in the masseur, self,

robot ordering, the experimenter instructed

the participant that the masseur will give a

head massage to the participants for around

45 seconds. A stop watch was used to time

(a) Human

(b) Robot

(c) Self

Figure (22) The Masseurs Conditions


19/20


the session. This duration was selected to

avoid any strain on the arm. If the

participants had to hold up the arm much

longer, it might have caused some

discomfort. The masseur asked if the

participants are ready. If the participants

respond in the affirmative, the masseur then

began the massage. Once the massage was

completed, the experimenter provided the

iPad back to the participants and asked them

to fill out the first pleasure questionnaire.

After the question had been completed, the

experimenter took the iPad away from the

participants and instructed the participants

that it is now time for the self massage. [6]

2.5.2 Discussion of Head Massage

It is not surprising that the robot was

not able to give a head massage that was as

good as the one received from a human

masseur. The human‟s ability to sense and

act is largely unmatched. The superiority of

humans is not limited to this study. Would a

human control condition be included in most

HRI studies then we would most of the time

have to admit that, despite all our efforts in

developing robots, humans are still the

better butlers, companions, and conversation

partners. But we shall not despair over this

obvious disadvantage. The robotic

development is still at its beginning and we

shall not dismiss technologies in their early

stages. Even Apple‟s first iPad, the Apple Newton, was hardly usable and it failed in

the market.

The main reason for the robot‟s

limited massage skills are its lack of a visual

or tactile feedback loop. The robot was not

able to adjust its massage to the

characteristics of each participant. They

were different in height, skull size, hair

length, and hair strength. Moreover, some

participants appeared to have a much more

sensitive scalp than others. [6, 11]

3. Conclusion

The development of the body

massage robot has the advantage of opening

up a new market through the development of

the machinery and equipment related to

health and advanced robotic technology.

Products from various combined fields aremanufactured, such as health support

services that provide entertainment, health

devices, and sport raining systems. The body

massage robot is an interdisciplinary area

that includes biotechnology, nano-

technology, information technology and

robot technology. Besides, the intellectual

massage robot is expected to promote a new

business field.


20/20


References:

1. Sungil Yi, Dongju Moon, Yongju Yang, Kangeun Kim „Healthcare Robot Technology Development‟ The

International Federation of Automatic Control Seoul, Korea, July 6-11, 2008

2. Ren C. Luo and Chih C. Chang „Electromyographic Evaluation of Therapeutic Massage Effect Using

Multi-finger Robot Hand‟ 2011 IEEE International Conference on Robotics and Automation Shanghai

International Conference Center May 9-13, 2011, Shanghai, China

3.

Panya Minyong, Takanori Miyoshi and Kazuhiko Terashima „Expert Massage Motion Control by Multi-

fingered Robot Hand‟ Pmeedings of the 2003 IEEE/RSI InU. Conference on Intelligent Robots and

Systems Las Vegas. Nevada ' Oclaber 2003

4.

Panya Minyong, Keisuke Mouri, Hideo Kitagawa, Takanori Miyoshi and Kazuhiko Terashima „Hybrid

Impedance and Force Control for Massage System by Using Humanoid Multi-fingered Robot Hand‟

5. Ryan Walker and Christoph Bartneck „The Pleasure of Receiving A Head Massage From A Robot‟ The

22nd IEEE International Symposium on Robot and Human Interactive Communication Gyeongju, Korea,

August 26-29, 2013

6. Keisuke Mouri, Kazuhiko Terashima, Panya Minyong, Hideo Kitagawa and Takanori Miyoshi

Identification and Hybrid Impedance Control of Human Skin Muscle by Multi-fingered Robot Hand

IEEE/RSJ International Conference on Intelligent Robots and Systems San Diego, CA, USA, Oct 29 - Nov2, 2007

7. Jorge Solis, Yuichi Obokawa, Hiroyuki Ishii, Hiroki Koga, Atsuo Takanishi and Akitoshi Katsumata

„Development of Oral Rehabilitation Robot WAO-1R Designed to Provide Various Massage Techniques‟

2009 IEEE 11th International Conference on Rehabilitation Robotics Kyoto International Conference

Center, Japan, June 23-26, 2009

8. Ren C. Luo, Chih C. Chang, Vi-Wen Pemg „Impedance Control on a Multi-fingered Robot Hand Based on

Analyzed Electromyographic Information for Massage Applications‟ IEEE International Symposium on

Industrial Electronics (ISlE 2009) Seoul Olympic Parktel, Seoul, Korea July 5-8, 2009

9. Hiroki Koga, Yuichi Usuda, Masao Matsuno , Yu Ogura, Hiroyuki Ishii, Jorge Solis, Atsuo Takanishi,

Akitoshi Katsumata „Development of Oral Rehabilitation Robot for Massage Therapy‟ 6th International

Special Topic Conference on ITAB, 2007, Tokyo

10.

Yuichi Obokawa, Jorge Solis , Hiroyuki Ishii, Hiroki Koga, Atsuo Takanishi, and Akitoshi Katsumata

„Clinical Massage Therapy with the Oral-Rehabilitation Robot in Patients with Temporomandibular Joint

Disorders‟ 9th International Conference on Information Technology and Applications in Biomedicine,

ITAB 2009, Larnaca, Cyprus, 5-7 November 2009

11. Masao Kume, Yoshitosi Morita, Yutaka Yamauchi, Hideaki Aoki, Makoto Yamada, Kazuyoshi Tsukamoto

„Development of a Mechanotherapy Unit for Examining the Possibility of an Intelligent Massage Robot‟

12. Chul-goo Kang, Bong-ju Lee, Ik-xu Son, Ho-yeon Kim „Design of a Percussive Massage Robot Tapping

Human Backs‟ 16th IEEE International Conference on Robot & Human Interactive Communication August

26 - 29, 2007 / Jeju, Korea

13. Takeshi Ando, Maki Takeda, Tomomi Maruyama, Yuto Susuki, Toshinori Hirose, Soichiro Fujioka,

Osamu Mizuno, Kenji Yamada, Yuko Ohno and Honda Yukio „Biosignal-based Relaxation Evaluation of

Head-care Robot‟ 35th Annual International Conference of the IEEE EMBS Osaka, Japan, 3 - 7 July, 201314. Jingguo Wang and Yangmin Li „Massaging Human Feet by a Redundant Manipulator equipped with a

Tactile Sensor ‟ 2010 IEEE/ASME International Conference on Advanced Intelligent Mechatronics

Montréal, Canada, July 6-9, 2010

Body Massage Robot Technology

Documents

Transcript of Body Massage Robot Technology