Development of an Integrated Virtual Group Training

System for COPD Patients

Jonathan B. J. Dikken

, Bert-Jan F. van Beijnum

, Dennis H. W. Hofs

, Mike P. L. Botman

Miriam M. Vollenbroek-Hutten

1,2

and Hermie J. Hermens

1,2

Institute for Biomedical Technology and Technical Medicine (MIRA), University of Twente,

P.O. Box 217, 7500AE Enschede, The Netherlands

Roessingh Research and Development, Roessinghsbleekweg 33b, 7522AH Enschede, The Netherlands

Keywords: Physical Condition, Virtual Group Training, Chronic Obstructive Pulmonary Disease, Home-based Exercise

Training, Integrated Training System, Design, Evaluation, Exergaming.

Abstract: COPD patients experience a downward spiral of fear for breathlessness, inactivity and social isolation which

leads to a bad physical condition. Motivation to keep patients compliant to their training scheme is a key

factor in home-based exercise training. This paper presents the Integrated Training System for COPD

patients; a home based virtual group exercise system to facilitate improvement of the exercise capacity

safely at home using a virtual group environment. The four components of the system are the Home Trainer,

the Virtual Exercise Environment, the Web Portal and the Controller. These components are implemented

in a prototype. An in-training evaluation was performed to evaluate the subsystems used during a training

exercise. All subsystems are working correctly during the evaluation. In this paper the focus for the

Integrated Training System is on COPD patients, but the system might be used for other groups such as

Chronic Heart Failure patients or elderly people in general.

1 INTRODUCTION

Chronic Obstructive Pulmonary Disease, a common

disease characterized by persistent airflow

limitation, is one of the leading diseases in many

countries which will grow to the 4

largest cause of

death in 2030 (Global Initiative for Chronic

Obstructive Lung Disease, 2013; Mathers & Loncar,

2006). In 2007 in the Netherlands 323.600 people,

about 2% of the population, were diagnosed with

COPD. These figures are comparable to the

surrounding countries (Rijksinstituut voor

Volksgezondheid en Milieu, 2010).

The downward spiral of breathlessness fear,

inactivity and social isolation leads to a bad physical

condition (Global Initiative for Chronic Obstructive

Lung Disease, 2013). To overcome this downward

spiral patients can be enrolled in a pulmonary

rehabilitation program (PRP) which improve the

exercise capacity (Croitoru et al., 2013; Nici et al.,

2006; Shahin, Germain, Pastene, Viallet, & Annat,

2008). However, most benefits deteriorate after the

rehabilitation program is finished (Egan et al., 2012;

Gosselink, 2002; Karapolat et al., 2007; Nici et al.,

2006; Spruit, Troosters, Trappenburg, Decramer, &

Gosselink, 2004).

Maintenance strategies can retain the effects of a

pulmonary rehabilitation program. Du Moulin et al.

shows that home-based exercise training is effective

as maintenance of the exercise capacity (Du Moulin,

Taube, Wegscheider, Behnke, & Van Den Bussche,

2009). Also Beauchamp et al. showed a significant

improvement of the exercise capacity with a

community based maintenance exercise program

(Beauchamp, Francella, Romano, Goldstein, &

Brooks, 2013). Motivation to keep patients

compliant to their training scheme is a key factor in

home-based exercise training.

This paper presents a home-based virtual group

exercise system to facilitate improvement and

maintenance of the physical condition of COPD

patients. In this paper we focus on the technical

design of the system and the medical case it should

cover. The system should cover all important aspects

of home-based exercise training: means to do the

training, motivational support and professional

guidance. Therefore we call it the integrated training

101

B. J. Dikken J., F. van Beijnum B., H. W. Hofs D., P. L. Botman M., M. Vollenbroek-Hutten M. and J. Hermens H..

Development of an Integrated Virtual Group Training System for COPD Patients.

DOI: 10.5220/0004801601010108

In Proceedings of the International Conference on Health Informatics (HEALTHINF-2014), pages 101-108

ISBN: 978-989-758-010-9

 2014 SCITEPRESS (Science and Technology Publications, Lda.)

system (ITS). The goal of the system is to facilitate

improvement and maintenance of the physical

condition of COPD patients safely at home using a

(virtual) group environment. This will reduce

disabilities in activities of daily living (Garcia-

Aymerich et al., 2003; Tak, Kuiper, Chorus, &

Hopman-Rock, 2013).

In Backgrounds relevant training aspects,

motivation aspects, adherence aspects and existing

exergames will be given. After the Design

Considerations are explained, the Architecture of the

ITS will be drawn. The Implementation will be

tested in the Evaluation. With Discussion and

Conclusion this paper will be finalized.

2 BACKGROUNDS

2.1 Training

Different opinions exist about the use of either

power training or endurance training as the most

suitable method to improve the physical capacity

(Puhan, Schünemann, Scharplatz, & Bachmann,

2005). Studies have conflicting outcomes on which

training intensity and method gain the best results,

however all studies suggest an improvement of the

physical capacity by physical training (Global

Initiative for Chronic Obstructive Lung Disease,

2013; Gosselink, 2002; Korczak, Huber,

Steinhauser, & Dietl, 2010; Puente-Maestu et al.,

2000; Rijksinstituut voor Volksgezondheid en

Milieu, 2010). The type of exercise should

correspond as much as possible with the activities of

daily living. Cycling, walking and walking stairs are

the most suitable exercise forms.

To be effective, a training session should be

intense enough. The optimal heart rate is between 60

and 80 percent of the maximal heart rate (Global

Initiative for Chronic Obstructive Lung Disease,

2013; Janssen, 2001). With 60-80% of the maximal

heart rate a patient will train in the aerobic zone.

Staying in the aerobic zone for the whole training is

not mandatory, but the total amount of time in the

aerobic zone determines the efficiency of the

training.

2.2 Adherence and Motivation

The above results regarding physical training for

COPD patients have been used by the KNGF, the

Dutch physical therapist association, to develop the

therapeutic guideline for COPD patients (Gosselink

et al., 2008).

The lack of therapy adherence of COPD patients is a

known problem with physical exercises (Nici et al.,

2006). Therapy adherence can be increased by

enjoyment and social interaction (Ryan, Frederick,

Lepes, Rubio, & Sheldon, 1997). Burke et al

conducted a meta-analysis of 44 studies to qualify

the effect of the setting of the training (Burke,

Carron, Eys, Ntoumanis, & Estabrooks, 2006). Four

categories where defined: home-based training

without involvement of third parties, home based

training with consultation (e.g. by phone), center-

based training and center based training with

additional attention for group dynamics. A superior

result was found in groups with a high social

cohesion among the participants in comparison to

normal center-based training and home-based

training with consultation. The latter two had a

superior result in regard to individual training

without involvement of third parties. One can

conclude that both good group dynamics as

professional consultation result in a better therapy

outcome.

Social motivation theories can help in increasing

therapy adherence. One social motivation theory is

social support, which is associated with how

networking helps people cope with stressful events

and enhance psychological well-being and can be

categorized in appraisal, companionship, emotional,

instrumental and informational support (House,

1981; Sonderen, 1991). Another theory is the social

comparison theory which includes competition,

cooperation and normative comparison between

members of a groups (Janssen, 2001). These theories

will be used in the implementation of the Integrated

Training System.

2.3 Existing Exergaming

Several professional and consumer exergames are

used for improving the physical condition of

patients. Professional products include the Cybex

Trazer, LightSpace, and Sportwall. Consumer

products include the Sony PlayStation (with Dance

Dance Revolution), Nintendo Wii and Xavix (with

J-Mat). The energy expenditure with these 6 systems

are comparable with the energy expenditure of

walking (Bailey & McInnis, 2011). The Cybex

Trazer, LightSpace, Sony PlayStation with DDR and

Xavix are based on moving to specific positions.

These four systems require non-continuous dynamic

movements. Such movements are unsuitable for

COPD patients because injuries can occur.

Measuring and controlling the intensity of the non-

continuous dynamic movements is difficult. The

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Sony PlayStation with DDR supports multiplayer

sessions at distinct locations. The other systems

don’t support virtual groups where users play at

distinct locations and can see each other. Social

interaction is limited when players are at distinct

locations.

With Sportwall a player should hit specific

positions on a wall with the hand or a ball. This

system requires non-continuous dynamic

movements as well. Because it is a professional

product it is unsuitable to put at patients’ homes.

This system lacks the possibility to train in virtual

groups and thus the possibility for social interaction.

Wii Sports include five simulation games which

can be controlled by arm movements: baseball,

boxing, bowling, golf and tennis. A precise motor

system is important to use the described systems.

Also this system has the disadvantages of non-

continuous dynamic movements.

A system more tailored to the need of elderly

people is the Espresso Bike in combination with the

NetAthlon riding software. This system was used in

a randomized clinical trial in older adult cognition

(Anderson-Hanley et al., 2012). It has a simple user

interface and doesn’t require very fast responses

from the users. The training intensity is accurately

controllable by changing the resistance of the bike.

The intensity can be measured accurately. The

system focus on cognition aspects and the

improvement of the physical condition is a side

issue.

For COPD patients a system is needed that is

safe, has a low risk for injuries, can measure and

control the intensity accurately and support social

interaction.

None of these systems are built for – and suitable

for accessible physical exercises at home for elderly

people. None of the systems use a virtual group

environment to support social interaction for the

enhancement of therapy adherence.

3 DESIGN CONSIDERATIONS

Cycling on a home trainer was chosen, because a

home trainer is well known for COPD patient from

rehabilitation programs and can measure and set the

training intensity. Using the home trainer at home

increases the accessibility of the system. The ability

to control the power by changing the resistance

contributes to the safety of the system.

 A virtual environment will be used to be able

to have a group setting at home. In the virtual

environment patient can train and interact with

each other.

 The oxygen saturation level should be above

90% during training sessions to prevent

desaturations.

Requirements were elicitated from a literature

review, observations of PRPs and interviews with

physiotherapists and movement therapists using a

scenario and the People-Activity-Context-

Technology (PACT) framework (Huis in't Veld et

al., 2010). A detailed description of the design

process is given by Dikken et al. (Dikken, 2012;

Dikken, van Beijnum, & Hermens, 2013).

4 ARCHITECTURE

The ITS (Integrated Training System) is divided into

four components: the home trainer (HT), the virtual

exercise environment (VEE), the controller (C) and

the web portal (WP). The home trainer is an ergo

bike with some additional sensors, the virtual

exercise environment is a computer game in which a

patient can cycle together with other patients and the

controller ensure a safe and efficient training by

collecting and analyzing data from the home trainer

and giving feedback. The controller sends the

physiological and exercise data to the web portal. On

the web portal this data is shown. The overview of

the architecture is shown in figure 1.

Figure 1: High level architecture of the Integrated Training

System.

Users of the ITS are COPD patients and their

supervisors, the physiotherapist. Patients use the

whole system, while the physiotherapists only use

the web portal component.

DevelopmentofanIntegratedVirtualGroupTrainingSystemforCOPDPatients

103

4.1 Home Trainer

With the home trainer patient can perform physical

activities. On the home trainer the training intensity

can be controlled and patient data is acquired.

Patients will experience force feedback from the

home trainer.

The home trainer component contains all sensors

and actuators of the system. Quantities that need to

be measured are power, cadence, heart rate and

oxygen saturation level. This component consists of

a home trainer, a heart rate belt and a pulse

oximeter.

4.2 Virtual Exercise Environment

The virtual exercise environment (VEE), showed in

figure 2, provides motivation during a physical

training. The VEE is essentially a computer game in

which multiple players can cycle in the same virtual

environment. The avatar of a patient cycles with a

speed that reflects the performance of the patient in

the virtual environment, but the users are kept close

to each other to up keep the group spirit during the

whole training.

Several motivation theories are implemented,

which is explained in the next section. Each session

is a game in which the patient who cycles with the

best performance will win the game (social

comparison – competition). The performance is

calculated by how close a patient cycles to his

individual goal. Players are motivated when they

cycle together in the virtual environment and can see

each other (social support – companionship). When

a patient fails to cycle with a similar performance of

the other group members, he will slow down a get in

the back. To prevent a player to drop out because he

is too far behind, that player will get a boost to keep

up with the other group members. The boost will

stop when the player gets close to the other group

members to prevent disturbance of the competition.

Figure 2: Virtual Exercise Environment.

During training all interaction with the user is

provided by the VEE, except for the force feedback

by the home trainer. The interaction of the VEE

includes a user interface with an overview of the

important measured values, such as power and heart

rate and an overview with the current performance.

4.3 Web Portal

The web portal (WP) provides after-exercise

motivation: patient can retrieve their progress, set

and monitor personal and group goals and give

feedback on training results of group mates. Also the

portal is used to give the physiotherapist insight in

the training progress and configure the system.

After a training session both the patient and the

professional can see a summary of training on the

web portal. This includes a good indication of the

performance with a mark and important events such

as overperformance, underperformance and possible

desaturation events during the training. A screenshot

is shown in figure 3. Patients can review each

other’s performance (figure 4; social comparison –

competition and cooperation) and give feedback

through messages to motivate each other (social

support – companionship and emotional support).

The professional will use the training summary to

give advices.

A group of patients has the goal to reach each

individual goal (social comparison – cooperation).

The patients can compare themselves to a patient

who is performing well (social comparison –

normative comparison). Informational support

(social support) is given by sharing patient stories

with how they cope with the disease.

A detailed description of the web portal

including design rationale and the design process is

given by M. Botman (Botman, 2013).

4.4 Controller

The controller monitors and guides the safety and

performance during a training session and facilitates

data exchange between all components. For the

safety and performance three control modules are

used: the performance loop, the safety loop and the

positioning system. The controller has several

interface modules to connect to the other

components. A design overview is shown in figure

Important measured data, such as power, heart

rate, oxygen saturation level and performance, is

send to the web portal by the controller.

All modules, both interface modules as control

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Figure 3: Web Portal - Training result page.

Figure 4: Web Portal - Patient profile page.

modules, use a data bus to exchange real-time data.

With a data bus the controller is highly flexible.

Modules are not aware of each other’s existence and

can be added, removed, updated and replaced easily.

Different execution frequencies are possible,

enabling usage of sensors with different sample.

4.4.1 Performance Loop

To facilitate improvement of the physical condition

a training session needs to be effective. This is

handled by the performance module. The

performance is calculated to be able to give visual

feedback on the performance and to adapt the

resistance of the home trainer.

Based on the current power (P

) and the target

power (P

target

), which is set in the web portal, the

performance is calculated as shown in equation (1).

The result is a dimensionless value between 0 and 1,

Data

Bus

Interface

VEE

Interface

Safetyloop

Performance

loop

Positioning

system

Controllercomponent

component

VEE

component

Figure 5: Modules of the Controller component.

HT: Home Trainer, VEE: Virtual Exercise Environment,

WP: Web Portal.

where 1 indicates the best possible performance and

0 the worst possible performance.





















 















 







(1)

The speed for the VEE is calculated based on the

performance and the configured maximal speed

constant (v

max

) as shown in equation (2).









∗

(2)

4.4.2 Safety Loop

The safety is handled by the safety module. The

safety module has three different states based on the

measured oxygen saturation level (SpO

). The SpO

is compared with a desaturation threshold as shown

in equation (3). The desaturation threshold is set in

the web portal. The status is stored for the

configured interval, for example 60 seconds. Based

on the status values the saturation state is determined

and the corresponding feedback is executed, as

shown in table 1.

Status  SpO



 DesaturationThreshold

(3)

Table 1: Saturation state in safety module based on

saturation status shown in equation (3).

Status values State Feedback

All true Good Continue normally

Some true Warning

Patient is urged to

slow down and

intensity is decreased

All false Bad

Training session is

terminated

The target power is decreased in case of the

warning state. As a result the performance loop will

DevelopmentofanIntegratedVirtualGroupTrainingSystemforCOPDPatients

105

lower the training intensity by lowering the

resistance of the home trainer.

4.4.3 Positioning System

Part of the motivational support is handled by the

positioning module. As mentioned above patient are

kept together in the virtual exercise environment.

When a patient gets too far behind the player in front

he will get a boost to prevent the patient from

getting farther behind. For this equation (2) is

extended with the speed correction factor (SCF).

The new formula is shown in equation (4). The SCF

is a value between 1 and 20. The farther a patient

gets behind, the larger the SCF value.









∗∗

(4)

5 IMPLEMENTATION

The four components described architecture is

implemented in a prototype:

HT: Bremshey BE5i home trainer with a polar

T31 heart rate belt.

VEE: WebAthletics cycling game running on an

Asus ME301T Android tablet with a 22” LG

22EA53VQ monitor placed in front of the

home trainer.

C: Developed in Java and is running on the same

tablet as the VEE.

WP: Developed on top of the Liferay Portal,

running on a dedicated server.

The Bremshey BE5i has a 32-step servo motor to

control the resistance, the gear. To support patients

with cycling at the right performance a controller

module is built to set the gear based on the

performance. When P

target

< 0.6 for 5 seconds the

gear is shifted up. When P

target

> 1.25 for 5

seconds the gear is shifted down.

6 EVALUATION

The evaluation was performed with 4 healthy

subjects, cycling in separated rooms in the same

multiplayer session. Each subject was instructed to

cycle as close as possible to the given target power.

During the training session all relevant parameters

were recorded (time, power, cadence, heart rate,

speed in VEE, gear, distance, relative distance,

target power, performance and SCF). The relative

distance for each player is the distance between the

player and player in front. Performance, relative

distance and cadence are shown in figure 6. After

the training session subjects were asked to fill in a

short questionnaire.

Figure 6: Performance, Relative Distance and Cadence of

the four subjects during the exercise.

Results from the evaluation are shown in table 2.

The distance between all players is small (min: 0.0

m, mean: 13.1 m, max: 51.0 m), while the

performance for subject 4 was suboptimal. The

performance was calculated from the recorded

power and target power. This is compared with the

recorded performance. The average deviation is less

than 0.1%.

6.1 Control Modules

With a suboptimal performance of one of the

subjects the distance control module managed to

keep all subjects close to each other in the virtual

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Table 2: Evaluation results.

Subject S1 S2 S3 S4 All

Relative distance (m)

Min 0 0 0 0 0

Mean 4,3 14,2 5,4 28,3 13,1

Max 43 42 44 51 51

Performance

Mean 0,95 0,91 0,95 0,80 0,90

Performance deviation

Mean 0,003 0,000 0,002 -0,001 0,001

Standard

deviation

0,058 0,064 0,050 0,068 0,060

environment. The distance control module worked

correctly during the training. Also the performance

control module worked correctly. A small deviation

exists between real-time calculated performance and

the calculation afterwards. This might be caused by

a small delay in the power value used in the real-

time calculation.

6.2 Other Issues

The subjects reported some issues about the

automatic gear control, feedback on the performance

and feedback on the position of other users. The

automatic gear control caused the suboptimal

performance of one of the subjects. The subject was

cycling with a low power and high cadence, but the

gear didn’t shift up. Manual gear control can be

added to prevent this situation and give the users

more control. Feedback about the performance is

currently given by displaying the current power and

the target power in the virtual exercise environment.

Users have to compare these numbers themselves to

get an indication about their performance, while the

performance is an important parameter during the

training session. Suggested is to use a graphical

performance indicator.

Finally remarks were given about the position of

other users in the virtual environment. A user can

see other players in front of him with a limited

range. Players who are too far in front or behind the

user are not visible. A rear view or a third person

view, a map of the environment with indicators of

the other players, will overcome this problem.

7 DISCUSSION AND

CONCLUSIONS

The goal of the Integrated Training System is to

facilitate improvement and maintenance of the

physical condition of COPD patients safely at home

using a (virtual) group environment. The current

prototype satisfies to the goal of the system, but

leaves room for improvement. Further evaluation is

recommended.

The algorithms used in controller modules need

to be validated. For each algorithm several aspects

of the algorithm can be varied. For example with the

performance module the performance increases

linear with an increasing power, when the power is

lower than the target power. When the power is

higher than the target power the performance

decreases hyperbolic. This could be replaced by a

linear function as well. Further evaluation will

determine which alternative is the best indicator for

the performance. The gear algorithm can be

improved when the cadence is taken into account.

With a high cadence the threshold to shift up can be

decreased, while with a low cadence the threshold to

shift down can be decreased.

In this paper the technical design of the

Integrated Training System is described. Further

research into the economic and legal aspects is

needed. A sound business case should be created.

Motivation theories are implemented in the system.

The next step is to evaluate the system in a clinical

trial with the objective to evaluate the system

functionality with respect to the motivational

strength and to investigate the effectiveness of the

system with respect to improvements of adherence

to the therapy.

The focus is on COPD patients in this study.

However the Integrated Training System can be used

for other groups with no or only limited adaptations

to the system. It can be used for Chronic Heart

Failure patients or even elderly people in common to

facilitate improvement of the physical condition to

improve the quality of life.

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