USER CENTERED DESIGN PROCESS OF OSAMI-D

Developing User Interfaces for a Remote Ergometer Training Application

Florian Klompmaker, Bj

orn Senft, Karsten Nebe

C-Lab, University of Paderborn, F

urstenallee 11, 33102 Paderborn, Germany

Clemens Busch, Detlev Willemsen

Sch

uchtermann Schiller’sche Kliniken GmbH & Co KG, Ulmenallee 5-11, 49214 Bad Rothenfelde, Germany

Keywords:

Tele-medicine, Tele-monitoring, User centered design, Usability, User interfaces.

Abstract:

In this paper we present the user centered design process of the research project OSAMI-D. The project

addresses cardiac disease patients during the rehabilitation at home by offering an IT-based solution for a su-

pervised ergometer training. The user centered design process consisted of multiple user studies. We analyzed

the needs and preferences of a speciﬁc user group and developed user interfaces that are easy to operate by

them.

1 INTRODUCTION

Rehabilitation after a cardiac event is well established

and highly effective to restore health and to positively

inﬂuence possible risk factors. But some studies have

shown that these factors may deteriorate one year af-

ter an event (EUROASPIRE I and II Group, 2001),

(EUROASPIRE II Study Group, 2001). In Germany

there are so called coronary sport groups for phase III

rehabilitation following the common inhospital phase

II rehabilitation. This system is supported for one

year by the insurance companies. However only very

few patients participate on such programs. Reasons

are often a lack of availability close to home, a lack

of desire for training in a special group for cardiac

patients or scheduling conﬂicts (Bjarnason-Wehrens

et al., 2006). Secondary prevention can enhance risk

proﬁles if it is regularly conducted. An additional in-

dividual IT-based program can therefore help to close

a gap for patients willing to do exercises for their

health.

1.1 OSAMI

Many telemedical applications and devices available

these days are aimed to healthy sportsmen (e.g. the

POLAR systems

or athlosoft by T2BEAM

) or el-

http://www.polarusa.com

http://www.athlosoft.com

Figure 1: Scheme of the OSAMI-D system.

derly people during their everyday life (e.g. (Gay and

Leijdekkers, 2007), (Oppermann and Lorenz, 2008)).

There is no system available until now that addresses

cardiac patients for secondary prevention. The Ger-

man project OSAMI-D addresses remote ergometer

rehabilitation as an example of use.

OSAMI-D is a subproject of the European ITEA2

research project OSAMI (Open Source AMbient In-

telligence). It targets open source common founda-

tions for a dynamic service-oriented platform which

is able to personalize itself in large diversity of coop-

erating software intensive systems.

OSAMI-D offers rehabilitation patients an er-

gometer bicycle (see ﬁgure 2) that is controllable via

a touch screen monitor. Further on it consists of wire-

less vital data sensors (ECG, Oxygen Saturation and

Blood Pressure) that are connected via bluetooth to a

base station. This base station is connected via the

internet with a supervision centre (e.g. a heart clinic)

where the data is observed either live or by post pro-

268

Klompmaker F., Senft B., Nebe K., Busch C. and Willemsen D..

USER CENTERED DESIGN PROCESS OF OSAMI-D - Developing User Interfaces for a Remote Ergometer Training Application.

DOI: 10.5220/0003160602680273

In Proceedings of the International Conference on Health Informatics (HEALTHINF-2011), pages 268-273

ISBN: 978-989-8425-34-8

 2011 SCITEPRESS (Science and Technology Publications, Lda.)

Figure 2: Ergometer bicycle equipped with tablet PC (left),

ECG bluetooth sensor developed by the company Cor-

science (right top) and body sensors (right bottom).

cessing (see (Klompmaker et al., 2010) for further de-

tails). Through an intelligent event system based on

current vital parameters the patient can also exercise

ofﬂine on her own. A training report is in any case

sent to the hospital. Figure 1 shows a scheme of the

OSAMI-D system.

1.2 User Centered Design

User centered design (UCD) is an established

methodology in the software-industry that focuses on

the users of a future system and aims to create so-

lutions that ﬁts the users needs, their requirements

and supports their tasks and goals. The usability of

products gains in importance not only for the users

of a system but also for manufacturing organizations.

According to Jokela (Jokela, 2001), the advantages

for users are far-reaching and include increased pro-

ductivity, improved quality of work, and increased

user satisfaction. Manufacturers also proﬁt signif-

icantly through a reduction of support and training

costs (Jokela, 2001). The quality of products ranks

among the most important aspects for manufacturers

in competitive markets and the software industry is

no exception to this. One of the central quality at-

tributes for interactive systems is their usability (Be-

van, 1999) and the main standardization organizations

(IEEE 98, ISO 91) have addressed this parameter for

a long time (Granollers et al., 2002). In recent years

more and more software manufacturer consider the

usability of their products as a strategic goal due to

market pressures. Consequently, an increasing num-

ber of software manufacturer are pursuing the goal of

integrating usability practices into their software engi-

neering processes (Juristo et al., 2001), (Nebe, 2009).

Also several telemedicine applications in research and

practice apply UCD processes in order to create so-

lutions for a speciﬁc user group, e.g. (Hoogendoorn

et al., 2010).

In order to create usable solutions it is necessary

to involve users in early stages and during the pro-

cess of development. UCD adds to this by providing

different methods applicable at different stages in the

process of development. Examples include contex-

tual and behavioural analysis (in terms of interviews,

site-visits, user tests etc.) in order to gather the users

requirements, needs and habits and to know their en-

vironment.

1.3 Motivation

For OSAMI-D it is crucial that users of the system

easily understand the information that is presented.

The user interfaces informs them about current vi-

tal data, hints from the system or a remote supervi-

sor and asks them questions about their wellbeing.

A training in OSAMI-D consists of several steps like

sensor setup, trainingplan update, pre-questionnaires,

training (warm up, training phase and cool down)

and post-questionnaires. Therefore the system has to

guide the users carefully through every single step.

This takes great demands up the user interface design.

For example the use of medical and technical terms

has to be avoided and easy understandable icons have

to be designed. Text should be short and clear. The in-

formation should not scare the patients but also warn

them in the right manner. Buttons and further user in-

terface elements should make use of a clear metaphor

and produce a unique actions for the user.

Another issue that OSAMI-D addresses is to keep

up the training motivation of the heart patients. Indoor

ergometer training is often very monotonous and frus-

trating. Therefore entertainment features as well as a

regular system feedback about training success is very

important for these kind of telemedical applications.

This paper is structured as follows: In the next

chapter we will explain the prior work of the OSAMI-

D UCD process. Then we explain the user study we

performed in a clinic to evaluate the current prototype

before we describe the results. Finally we sum up and

list some future work.

2 PRIOR WORK

The project OSAMI-D follows an iterative UCD

process for designing the user interfaces. We al-

ready evaluated the user interfaces of the precur-

sor project SAPHIRE (Busch et al., 2009) which

was more technically driven and therefore had some

USER CENTERED DESIGN PROCESS OF OSAMI-D - Developing User Interfaces for a Remote Ergometer Training

Application

269

lack in user interface consistency. Using this results

we developed paper based mockups of the OSAMI-

D user interfaces and presented these to patients in

the Sch

uchtermann clinic (the clinical representative

partner in the OSAMI-D project) who attended car-

diac rehabilitation at that time and which were fa-

miliar with similar hospital based systems. This user

study is described in (Klompmaker et al., 2010). It

helped us to identify several shortcomings of our ini-

tial design ideas. Taking the results as input for devel-

opment, now the ﬁrst working software prototype of

the OSAMI-D system is ﬁnished. In this paper we de-

scribe a user study that was performed by six test per-

sons using this prototype. The results we present will

be used to create the ﬁnal version of the prototype.

Due to law restrictions it cannot be used by real pa-

tients before a complicated certiﬁcation process is ac-

complished but this is not the intention of the research

project. Figure 3 and Figure 4 show some screenshots

of the OSAMI-D user interfaces.

Figure 3: OSAMI-D Main Menu.

Figure 4: Screen during the training phase.

3 USER STUDY

As a result of previous user studies (Klompmaker

et al., 2010) it turned out that there is a motivation

barrier for patients using a system like that one devel-

oped in the project OSAMI-D. The new prototype that

has been created addressing major usability problems

resulting from previous studies but basically willing

to motivate the users during their training. Because

the whole OSAMI-D project aimed to be user centred

another ﬁnal evaluation was planned. The method and

results are described below.

3.1 Method

Usability tests are a standard method in UCD to iden-

tify potential problems of a (future) system. In this

method potential users perform representative tasks

with the system in a controlled environment. Tasks

are part of a more complex user scenario. Thereby

users are observed in terms of

• what the users do

• where they succeed

• where they have difﬁculties with the user interface

During the course of a test the participants are asked

to vocalize her thoughts, feelings, and opinions while

interacting with the system (called ”think aloud”).

Usually a usability test is performed by at least

three persons. One that moderates the session and

gives the instructions and another one that makes the

recordings and notes while the participant performs

her tasks.

3.2 Setting

The usability test took place in a room of the

Sch

uchtermann Klinik. In the room itself an er-

gometer was placed that had a 17” single-touch-PC

mounted on the handlebar and a webcam on top of

it. The functional patient interface prototype was in-

stalled on this PC. The entertainment system in this

demonstrator was limited to a news feed reader, that

could be used during the training. Even though the

prototype fulﬁlled not all the entertainment require-

ments resulting from the previous study, the authors

believed that it would be sufﬁcient to testify whether

the motivation barrier could be reached. One major

problem that could not be solved beforehand was the

collection of live-data from the patients training (pa-

tient’s blood pressure, pulse and oxygen saturation ).

In order to solve this the needed vital data for the

patient interface was simulated while the ergometer

data like speed, pedaling frequency and load was real.

HEALTHINF 2011 - International Conference on Health Informatics

270

For the simulated values the so called ”wizard of oz

method” (Kelley, 1984) was used whereas a facili-

tator had access to the patient interface. Hence he

was able to generate speciﬁc data like upcoming error

messages or warnings as well as live vital data which

can be shown during the training.

As a consequence of the missing live data acquira-

tion the test team decided not to involve real patients

as participants for the test. It might have been too dan-

gerous not being able to see their live data in the train-

ing. Further on a complicated petition in the clinic

would have been needed to allow for real patients as

test persons. However, as the main reason for this

study was to reach the motivation barrier and to eval-

uate minor usability issues, it seemed to be acceptable

to take non-patients into account.

Six employees of the Sch

uchtermann Klinik in the

age of 51 to 64 years have been chosen. None of them

has had any contact or involvement with the OSAMI-

D project before. Four participants were male and

two female. Therefore they represented the potential

user group quite well. Most of them are employed

as medical staff except one who was in the facility

management. Their afﬁnity for computer is widely

distributed, but at least everyone uses a computer at

work.

As mentioned in the method section, we asked the

participants to think out loud while using the patient

interface. This helps to understand their behaviour

and to get an idea of what they are thinking. In addi-

tion to the audio signal we recorded the patient itself

using a webcam and captured the screen of the pa-

tient interface in parallel. A speciﬁc software helped

recording simultaneously i.e. the audio and video

streams. In this setting one person moderated the ses-

sion while two others handled the recordings and took

notes.

The evaluation was structured into four parts. In

the ﬁrst part, the participants were being introduced.

After that a pre-interview was done in which demo-

graphic and personal data was collected. The partic-

ipants were also asked about their expectations and

knowledge of the ergometer training procedure. The

third part was the main part of the evaluation - the

usability test itself. As the subjects ﬁnished the us-

ability test, they were interviewed a last time. In this

post-interview they were asked about their impression

of the patient interface and also how they think about

this training procedure for real patients.

Each evaluation took about 30 to 45 minutes per

participant (6 to 10 minutes introduction and pre-

interview, 18 to 25 minutes for the usability test, and

6 to 10 minutes post-interview and farewell).

3.3 Results

As an overall result it turned out that most of the mi-

nor usability weaknesses have been solved properly

and that the new concept seems to be usable at all.

The implementation of news feeds was very high ac-

cepted by the participants. However, because of the

short duration of the major test it could not be clearly

examined if this entertainment feature really could be

an improvement of the monotonous training in the

long term. There are strong indices based on the user

feedback but further evaluation is needed.

Even if we did not found any serious usability

problems, there has to be done some rework in the

detail. Four major issues need to be improved:

• Trainingstart

• Switch between views in the training

• Vocabulary and icons

• Some interactions and metaphors with the touch

screen

The ﬁrst issue is the trainingstart. Currently, the

training is started immediately after pressing the OK

button after the sensors have been connected success-

fully. The problem is, that not a single user realized

that the training needed to be actually started. It took

up to two minutes for some users to realize being al-

ready in the training session, which already started

(most participants needed about 30 seconds). It would

be better if a countdown - similar to computer games

- would run and the training starts not until the count-

down ran off. This is an issue that is important for

all automatic applications in the medical ﬁeld that re-

quires the patient to start at a certain time.

The second issue is the switch between the views

in the training (the standard view shows the vital data

curves while the second alternative is the entertain-

ment system currently showing a news feed) . At the

moment it is realized with a button-like metaphor but

there is now visual connection between the buttons

and the view area. In this case a tab like metaphor

would make a lot more sense, even if users could fa-

miliarize with the button metaphor after a training pe-

riod.

The third issue is about the vocabulary and the

icons. In the patient interface some medical terms

were used, that are even unknown to the users, who

are employed as medical staff. An example for this

is the term ”SpO

” (meaning oxygen saturation). Ac-

cording to the statement of the chief of the medical

technical department, especially SpO

is a measure-

ment parameter that could be hard to interpret for reg-

ular patients. So it could be better to give the patient

USER CENTERED DESIGN PROCESS OF OSAMI-D - Developing User Interfaces for a Remote Ergometer Training

Application

271

less data, so that he is not overwhelmed with too dif-

ﬁcult terms. For real applications that aims to sup-

port the patient without a supervisor this leads to the

conclusion that medical terms have to be used very

carefully in such systems.

Figure 5: The icons we used during the training: (1) pulse,

(2) blood pressure, (3) rpm, (4) load, (5) speed, (6) remain-

ing time.

Beside the vocabulary there are problems with in-

terpreting the icons, especially the icons that are dis-

played during the training (see ﬁgure 5). Only a few

icons were understood correctly by all of the users but

most need some additional information like units for

sensor data values. Especially icons for rpm (revo-

lutions per minute) and load (in watts) could not be

interpreted by most of the subjects. Figure 5 shows

the icons that are visible during the training. Some of

them have to be redesigned even though we thought

we already solved this problem by designing icons

carefully at the very beginning. Another solution to

this problem is to establish a tooltip like information

provider for single touch that provides the user with

additional information. This could be realized for ex-

ample with a long touch on an icon, that results in fad-

ing in additional information next to the icon. In the

authors work on the implications of a user interface

design for such a system (Klompmaker et al., 2010)

it was decided to use easy symbols for the vital data

and ergometer data. But according to this user evalu-

ation it was veriﬁed that the symbols are not easy to

understand. According to the problems that the users

had with the icons, they have to be used carefully in

medical applications if they are intend for patient use

only. It could be necessary to provide patients with

additional data for the icons, so they can use the sys-

tem in the most appropriate manner.

One user had also problems to interpret the mean-

ing of the remaining time. The user thought this

would be training duration. This could be due to the

fact that she did not realize that the training had al-

ready started.

The last issue concerns the interactions and

metaphors that also includes the already mentioned

view switching. Because of the use of a touch screen

some standard computer metaphors were not cor-

rectly interpreted or could not be used. For example

displaying links in blue color in the heading of the

newsfeed section was hardly be identiﬁed as a link.

It is necessary that links are marked with additional

information. Another problem is the warning at the

bottom of the screen (see ﬁgure 2). Most subjects

were close to the screen being able to read the news-

feed etc., that they recognized warnings very lately.

Warnings and hints are most important for the train-

ing so they have to be highlighted in a better way

(e.g. blinking or similar highlighting can attract at-

tention). Recognising warnings lately is a general

problem of medical applications, especially if they

are designed for elderly people. They often have a

poorer vision and need glasses while most people do

not wear glasses during their exercises. This makes it

even harder to recognize smaller items on the screen.

4 CONCLUSIONS AND FUTURE

WORK

In the presented user study the authors veriﬁed the im-

plications for a patient user interface design used for

remote training supervision. It was shown, that the

design implications lead to a demonstrator that can

be well used, although there are some minor issues

that have to be reworked. The news reader as part

of the entertainment system earned positive feedback.

Therefore such an entertainment system may help to

make ergometer training at home a better alternative

to outdoor activities. An entertainment system has

the possibility to solve motivation problems caused

by the monotonous nature of the ergometer training

but this has to be veriﬁed in the long term use. With

the user evaluation we also determined that there are

some additional implications that have to be consid-

ered in medical applications. This is for example the

emphasis of a task start where the immediately han-

dling is required. Further on icons and vocabulary

have to be chosen carefully, especially if they are criti-

cal. One interesting thing we found out, is that critical

warnings can be recognised very lately because of too

much and too small information. We conclude that

only necessary information should be used in such

patient interface and this information should be large

enough to be read also by people with a bad vision.

The entertainment system and similar additional in-

formation is not realy necessary but very useful in

this context. Therefore it should be easily available

via user interface elements that are placed marginally.

The next step in the iterative UCD process is to use

the results described in this paper as input for the ﬁ-

nal project prototype. We currently design new icons,

rearrange and resize some user interface elements, re-

name several labels and develop additional informa-

tion available via tool tips and similar metaphors. Fur-

HEALTHINF 2011 - International Conference on Health Informatics

272

ther on the entertainment system will be improved.

Since video conferencing is another technical aspect

addressed in OSAMI-D it is possible to playback

movie ﬁles or music as well.

Another ongoing topic is the creation of user in-

terfaces for the supervisors in the clinic. They get

much live data visualized that has to be analyze in

real-time in order to identify critical situations. Last,

a mobile solution is planned where patients can exer-

cise outdoors using a mobile device. Smartphones are

able to serve as base station but they come along with

small displays that cannot be kept in view during the

training all the time. Here we have to ﬁnd different

possibilities for the interaction with and for the user.

ACKNOWLEDGEMENTS

The authors would like to thank Andreas Bleiker

and the Sch

uchtermann Schiller’sche Kliniken in Bad

Rothenfelde for supporting the user study presented

in this paper.

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