Interaction Design for Medical Systems (Whitepaper)

Interaction Design
for Medical Systems
Whitepaper
by Elizabeth Bacon
Principal, Devise Consulting

Document v1.2; v1.0 published Feb 24, 2011

Copyright © 2011-2013 Devise Consulting All rights reserved

Table

of

Contents

1. INTRODUCTION — 3
2. REGULATORY PERSPECTIVE ON DESIGN — 4
3. FROM ENGINEERING TO DESIGN — 5
4. POWER OF USER RESEARCH — 7
5. ITERATIVE DESIGN PROCESS — 11
5.1. Product Conception Phase — 14
5.2. Design Framework Phase — 16
5.3. Detailed Design Phase — 18

6. PRODUCT DOCUMENTATION — 20
7. ORGANIZATIONAL STRUCTURE — 23
8. CONCLUSION — 25
9. REFERENCES — 26

Case Study Example Index
USER RESEARCH — 10
DESIGN PROCESS — 19
DOCUMENTATION — 22

Whitepaper • Interaction Design for Medical Systems

2

1. Introduction
DOUBLE-EDGED SWORD OF CHANGE
When products are hard to use, they cause people
pain. That pain may be largely psychological, as in the
frustration of a nurse who has to enter a standard
value into a system over and over. But in the case of
some critical medical systems, that pain may actually
be physical: picture the despair of an elderly patient
who lives alone when she fails to tighten a small
connector with her arthritic fingers.

Have you ever sat in product development meetings where several
team members expressed strong and differing opinions about
what “the user” really wants? Have you ever experienced delays
while team members struggle to articulate and finalize product
requirements? Or have you ever managed a project where the basic
product mandate changed late in the development phase?

Perhaps you feel the pain of your customers’ bitter
complaints, or the squeeze of disappointing sales
figures. Perhaps you recognize that the medical
systems you develop aren’t easy to use. Such painful
insights are the first steps towards embracing change.

As somebody in charge of planning and managing medical system
development, you’re solving challenging problems on a daily basis.
You have to balance efficacy with safety, and build products your
customers actually want to buy. You also need to ensure regulatory
compliance while controlling development costs and getting
your product to market as fast as possible. Adding complexity to
today’s medical systems, they often involve a large measure of
user interactivity, whether your users are physicians, clinicians,
administrators or patients. The last things you need are unclear
requirements and shifting mandates.

Change isn’t always easy. It’s rare that people change
simply for the good of changing, and research has
shown that people are usually only ready for change
when they actively feel pain in their current situation.
[Nadler]

Help is at hand from the discipline known as Interaction Design.
Interaction Design practitioners work to ensure that your users will
have a satisfying experience with your medical products and services.
Interaction Design offers tools that help you determine what your
users really need and applies processes that deliver solid solutions.

Introducing Interaction Design activities to your
medical system development process likely means
bringing change to your organization. It isn’t always
going to be easy, but it’s far preferable to pursue
this effort now, before some extremely painful event
— such as failing to obtain pre-market approval or
suffering a product recall — forces it upon you.

This whitepaper first will explain that regulatory agencies regard
design activities for medical systems in a very positive light. Then
we’ll discuss the innovative nature of design thinking by comparing
Interaction Design to more well-known engineering disciplines.
Next, several key Interaction Design methods that benefit product
development will be introduced, supported by case study examples.
These methods include: user research; the iterative design process;
and requirements documentation. Finally, this whitepaper considers
some ways that Interaction Design practitioners can operate
successfully within a large organization.


3

“Simply put, the risk of having use-related errors in
medical systems is minimized when the organization
understands its users and fully incorporates design
processes into the product development lifecycle.”

2. Regulatory Perspective

on

Design

The American and European regulatory agencies FDA and TÜV both
espouse a user-centered approach to medical system development
that is strongly in keeping with the core principles and practices of
Interaction Design. The FDA writes that: “The majority of use error is
human in origin, and these mistakes can often be attributed to poor
system design.” [FDA] Refer also to the figure at left for the IEC’s
depiction of how human-centered design controls should operate to
inform an iterative development cycle. Happily, this iterative process
is a fundamental tenet of Interaction Design practice.
One of the most pertinent American regulatory documents
considered mandatory today is entitled “Medical Device Use-Safety:
Incorporating Human Factors Engineering into Risk Management:
Identifying, Understanding and Addressing Use-Related Hazards.”
[Kaye] Regulatory professionals have likely read the other most
relevant publications [CDRH, FDA, Sawyer]. The international IEC
60601-1 standard on Risk Management and collateral standard 606011-6 on Usability as well as AAMI HE-75:2009, a companion standard to
HE-74:2001, Human factors design process for medical devices. also
point to the positive results that design processes offer by focusing
on users throughout iterative development stages and thus mitigating
risk.

Regulatory model of good human-centered design process [IEC]

The regulatory agencies’ focus on the risk of use-related hazards is
noteworthy. Calculating the return on investment (ROI) for design
activities is notoriously difficult due to the challenge of isolating
the impact of design activities among other product development
activities. Many experts have concluded that ROI is the wrong
metric by which to judge design because it’s a tactical measurement
whereas design is a strategic initiative. [Dray] Instead, we can
reframe the rationale for design as one of risk management. Simply
put, the risk of having use-related errors in medical systems is
minimized when the organization understands its users and fully
incorporates design processes into the product development lifecycle.


4

3. From Engineering

to

Design

The field of Interaction Design seeks to improve the human condition
by improving people’s interactions with technology. Interaction
Design focuses on defining the behaviors of interactive products and
systems based on an understanding of how and why people need to
use them. In defining system behaviors, Interaction Design addresses
the system’s presentation to users and how that presentation makes
people feel and respond. The essential practices of Interaction Design
address the hands-on user experience.
The first use of the term “Interaction Design” in the mid1980s is credited to Bill Moggridge, founder of IDEO, along
with pioneering designer Bill Verplank. [Moggridge 14] Alan
Cooper advanced and popularized the discipline by founding
a dedicated consultancy called Cooper Interaction Design in
1992 and publishing two seminal books on the subject. [Cooper
et al.; Cooper]
In the medical industry, the disciplines of Human Factors
Engineering and Usability Engineering are much more
frequently represented in the organization compared to
Interaction Design. Human Factors Engineering originated
during the 1940s in the aeronautical industry, along with
the study of ergonomics. It aims to ensure that systems
accommodate the cognitive and perceptual limitations of
human beings. Usability Engineering evolved later within the
academically-grounded field of study called Human-Computer
Interaction. Its core methods focus on analyzing, testing and
inspecting systems for maximal usability.
The daunting complexity of World War II cockpits such as this Boeing
B-17G Flying Fortress caused fatal crashes, which showed the
importance of having machines adapt to human constraints instead of
forcing people to adapt themselves to machines.

Although both Human Factors and Usability Engineering reach
out towards the design of interactive systems, these engineeringbased disciplines emphasize analytical and evaluative skills versus
creative and generative skills. Instead of trying to measure users’
abilities and test system performance, Interaction Design seeks to
understand users’ needs and motivations in order to inform system

5

behavior. Interaction Design delivers tangible user-centered insights
and product innovation using methods that blend analytical and
creative thinking.
Just as the study of medicine and science is undergoing a shift from
a Newtonian, mechanical-world orientation to a more Darwinian,
biological-world orientation, product development today is
experiencing a shift from engineering-based practices to designbased practices. The power of design thinking is reaching critical
mass with technology business leaders today as a key differentiator
in competitive marketplaces. [Wasserman] Although some novel
medical technologies may not be faced with a crowded market,
that’s likely to be a temporary state of affairs. Today, we can observe
rapid commodification of even such sophisticated medical systems as
insulin pumps or pacemakers.

“The essential practices of Interaction Design address
the hands-on user experience. Satisfied users make for
successful companies. The medical industry is ripe for a
strong company to stake a claim to great design.”

COMPANY GAIN IN VALUE
(2000-2004)

Most people desire to have a good-quality experience with the
systems they use. Popular online services such as Get Satisfaction
and Angie’s List let people educate themselves about the quality of
products and services before making their purchase decision. The
rise of social networking services also magnifies the speed with which
bad user experiences can be broadcast to the world. Medical systems
are not going to be immune from this broader movement. On the
contrary, the medical industry appears ripe for a strong company to
stake a claim to great design, the way Apple has claimed that ground
in computing technology and consumer devices.
Satisfied users make for successful companies. Recent studies by
researchers at the University of Michigan showed that a portfolio of
companies with the happiest customers gained 75% in value from
2000 to 2004, dwarfing the 19% gain for the Standard & Poor’s 500
Index during the same period; happy-customer companies were also
less volatile and experienced less employee turnover. [MSN]

Happy customers deliver corporate value [MSN]


6

“User research involves understanding the behaviors,
characteristics, motivations and needs of the
envisioned system’s end users. It doesn’t take a long
time or cost a lot of money.”

Great medical products and services are viable,
feasible — and also satisfying to use

4. Power

of

User Research

Research is central to user-centered design thinking and practice.
While marketing departments often conduct research to assess the
viability of selling a product and engineering departments often
conduct research to assess the feasibility of building a product, it
often happens that nobody is responsible for conducting research to
understand what makes a product satisfying to use. Knowing how
to satisfy users is different than measuring a product’s usability.
Usability is a very important quality of interactive systems, but it is
typically assessed part-way through product development or even
later when a working system is available. By contrast, user research
should be conducted prior to finalizing your product’s scope and
certainly prior to defining the user experience.
User research may not yet be widely applied in medical system
development but it is a powerful strategic force for innovation.
Unlike most marketing or academic research, user research
is qualitative in nature. Such research involves obtaining an
understanding of the behaviors, characteristics, motivations and
needs of the envisioned system’s end users. Qualitative research
methods differ markedly from quantitative ones such as surveys or
clinical trials because statistical validity is neither expected nor
sought. For medical industry professionals, qualitative research may
seem disconcertingly “fuzzy,” but obtaining useful customer data
from small sample sizes has a solid history of successful application to
product design. [Beyer et al. 38; Calde]
Interaction Designers are trained to identify the behaviors of people
and characteristics of the system that matter most to product
success. Whether your current development effort involves groundbreaking trials to validate a novel algorithm or releasing iteration
seven of a well-established product, user research with your target
customers will reveal what people will find satisfying to use. It
doesn’t take a long time or cost a lot of money. Clarifying the scope
of your problem space up-front through user research methods can
be extremely helpful in order to focus the later efforts of more costly
implementation and production resources.

7

Research Method: Ethnography
Less Appropriate Research Tools:
Focus Groups & Surveys
Two research methods that can be inappropriately
applied to front-end product definition are focus
groups and surveys.
Focus groups are a qualitative research tool, involving
a moderator presenting questions and inputs to a
group of people in a controlled environment. Focus
groups don’t provide good design input because
designers need to learn about the actual, specific
behaviors of individuals, not the quick responses
of artificially-gathered groups. People are also
notoriously bad at self-reporting behaviors, and what
users say may differ significantly from what they
do. [Nielsen] Lastly, focus groups can tend to be
dominated by one or two strong-voiced individuals.
Generally, focus groups should be reserved for
addressing early-stage marketing issues such as
product viability and branding.
Surveys are a quantitative tool where a hopefullylarge set of people respond to a set of questions
posed by a researcher. They suffer from a basic
limitation in that they collect simple answers only
to the questions asked, so they will tend to garner
people’s opinions about surface issues. Again,
they don’t provide deep insights about people’s
behaviors and goals needed to properly define
interactive systems. Generally, surveys should be
reserved for addressing product management issues
such as competitive benchmarking or feature list
prioritization.

Ethnography is a powerful qualitative research method that delivers
deep, valuable information about your user population in a relatively
short period of time. As a user research tool, ethnography leverages
techniques developed in the fields of anthropological and sociological
research. Its practice involves designers & other product stakeholders
visiting users’ environments to observe and interview individuals
performing the activities in question.
Personal engagement between the designer and user helps to uncover
the motivations that drive people to perform and the specific design
qualities that will result in satisfied customers. Design ethnography
conducted before your medical system development effort begins
helps to reveal product opportunities. Such direct observation of
users is an essential component of the applied design thinking that
generates innovative solutions. [Wasserman]
One of the key factors that design ethnography uncovers relates to
people’s contexts of use. Contexts of use are those environments
where users will interact with your product or service. Understanding
the medical context of use especially helps to identify risk areas that
must be mitigated. Medical systems are frequently used in special
institutional settings such as hospitals and clinics that often involve
specific functional constraints such as 3rd-party systems being used in
conjunction with yours. Conducting first-hand research in the field is
essential to identifying such environmental issues.
The artifacts and models produced by Interaction Designers as
outputs from user research are retained during all subsequent
product development efforts. Such data-driven models establish a
user-centered foundation that helps keep teams on-target with their
feature-level decisions during later stages of product development.
Those often-frustrating opinions from various team members about
what “the user” wants can be assessed in light of real-world data
collected in the field. Documenting user research allows your entire
organization to benefit from the work of the research team.


8

Research Model: Personas

EXAMPLE PERSONA

One of the most powerful user research models that can be built
from design ethnography is called a Persona. Personas are fictional
user archetypes. Persona descriptions may read like a story but they
are properly based on research data. [Bacon et al.] Personas embody
essential behavioral patterns among target users. Using a friendly
and approachable narrative format, they describe users’ key tasks,
attitudes, motivations and workflows.
Personas help identify product opportunities and clarify use-related
risks. The activities of design ethnography involve understanding
people’s motivations and existing workflows. Personas embody those
findings. Analyzing why people do things and how people do things
can generate innovative solutions for ways that the newly-designed
system can support personas’ goals more directly. Personas reveal
when the new product can reduce or eliminate any frustrating or
redundant steps in the user’s current workflow.
Rich, data-driven personas also facilitate communication and usercentered decision-making. They allow the product team to share
a common understanding of target users. Team members can now
reference a specific individual persona and ground their decisions in
a shared understanding of who exactly is being served. There are no
more arguments over what “the user” wants, because specific users
are clearly understood by the whole team. Because realistic personas
generate empathy, they also encourage team members to remain
committed to delivering a high-quality, satisfying user experience.
Personas are also a powerful planning tool. Personas help product
managers prioritize target users and control scope. The designated
primary persona has needs that must be served entirely by the design
solution, while secondary personas have additional needs that must
be served in some area. The needs of supplemental personas, who
are fully served by the solutions devised for primary and secondary
personas, are not allowed to impact the design solutions. Personas
also work seamlessly with a scenario-based approach to Interaction
Design, which will be discussed in the following chapter.

Dr. Helena Reardon
Interventional Cardiologist
Dr. Reardon performs a variety of surgical procedures
every day starting at 7am. She sees her daily schedule
when she arrives to the hospital and scrubs down
outside the operating room. Most procedures
are relatively routine surgical ablations and device
implantations, but her case load of biventricular
implants has been increasing. Biventricular implants
can take hours to complete since placement of
the left ventricular lead involves tricky intravenous
navigation. She welcomed the introduction of RF
telemetry to remove the barrier of the sterile field
between herself and industry representatives, but
she’s frustrated whenever telemetry is lost because it
slows her down. Dr. Reardon’s goals include:
•
•
•

Have information at her fingertips
Trust her tools
Experience no surprises

This abbreviated persona description was developed for example
purposes only and is property of Devise LLC


9

Case Study Example: User Research
At St. Jude Medical’s Cardiac Rhythm Management Division, the design
team used ethnography to study the pacemaker and ICD implantation
procedure for a new Pacing System Analyzer product that tests
implanted lead functions before the medical device is secured in the
body. The design team spent several days in the field, interviewing
physicians and sales representatives and attending about a dozen
implantation procedures.
After studying the actual work performed in operating rooms, the
design team produced helpful documentation to share with the rest
of the product team. Modeling the maintenance of the sterile field in
a crowded workspace revealed challenges for the smooth transfer of

devices and information between people. Workflow variations were
identified between pacemaker and ICD implants, as well as around the
use of specialized tests and how test results were recorded.
Personas were created for the Sales Representative who usually
operates the Pacing System Analyzer; the Implanting Physician and
Physician’s Assistant who handle the surgical procedure; and also the
Nurse who supports everybody else in the O.R. Identifying the Sales
Representative as the primary persona clarified the target user’s
needs. Recognizing the variety of personnel, tools and workflows
involved in the implantation procedure let the product team identify
and mitigate risks such as switching between medical systems.

Users are best understood in context

Images this page

Sarah McDevitt

Whitepaper • Interaction Design for Medical Systems 10

5. Iterative Design Process
Most product development efforts will begin with problem
identification, which properly should be informed by market research,
technology research and also user research, as discussed in the
previous chapter. As a project proceeds toward its goal of successful
implementation and market release, application of core Interaction
Design processes can deliver more rapid and cost-effective results
than a project without such design involvement.
Design is a fundamentally iterative problem-solving activity. The tools
and methods applied throughout the Interaction Design process are
flexible and adaptable for each problem’s unique set of inputs and
constraints. Also, the basic Interaction Design process can integrate
well with your existing software development process, whether it’s a
waterfall or Agile development model.

Design Stages
The core design process involves three stages of thinking, making and
validating:
• Ideation: conceiving potential solutions
• Modeling: giving form to envisioned solutions
• Testing: ensuring solutions are appropriate and satisfying
The core Interaction Design process moves iteratively through the
stages of Ideation, Modeling and Testing

Moving repeatedly through successive Ideation, Modeling and Testing
stages, the outputs of each design stage iteration generate solutions
of increasing fidelity and correctness, always centered around the
needs of the target user.

“Because the core design process described here
integrates with up-front development efforts such as
requirements documentation, they do not add significant
additional time or cost. What they do is reduce risk and
eliminate guesswork throughout the project. ”

Project Phases
Viewed at a higher level, iterations of these three design stages
unfold across three consecutive project phases:
• Product Conception: determining the overall scope of the system,
defining requirements and envisioning the high-level nature of the
product
• Design Framework: defining the underlying structure of the user
experience and giving form to the features needed by primary and
secondary personas
• Detailed Design: addressing all aspects of user-system interactions
and finalizing the visual look and feel of the system’s presentation
Design activities can move quickly and seamlessly through multiple
iterations of the core design stages at each phase of the project. For
example, during the Design Framework phase of a project, design
stages could move through an iterative flow such as:
IdeationModeling
IdeationModelingTesting
IdeationModelingTesting
before emerging and moving on to the Detailed Design project phase.
Each design stage could last between a few days and a few weeks,
depending on the exigencies of your project scope and schedule.
Each project phase could last between a few weeks and a few
months, again depending on scope and schedule pressures. Because
the core design process described here integrates with up-front
development efforts such as requirements documentation, it does not
add significant additional time or cost. What they do is reduce risk
and eliminate guesswork throughout the project.

Successive iterations of the design process stages within each of the
project phases deliver solutions of increasing fidelity and correctness
leading towards implementation (waterfall model shown).


Architecting a House
An example from the field of architecture illustrates the importance
of iterating design work across several phases. When conceiving a
house, the architect begins with understanding its residents and
locating the house’s foundation on the property. Then the architect
defines the relationships between rooms as well as their principal
features, and ensures that load-bearing walls are placed correctly.
Finally, the architect addresses the finer features of the house,

PRODUCT CONCEPTION

including its visual and tactile characteristics. At each phase,
the architect is ideating, modeling and testing out ideas with
increasing levels of fidelity, from paper sketches to scale models and
perspective drawings. Changing the shape of the foundation late in
the project would be a costly disaster. Throughout the project, the
architect also collaborates with the client as well as people who will
be charged to build and outfit the house.

DESIGN FRAMEWORK

DETAILED DESIGN

Questions being answered include:
• For whom exactly is this house being
built?


• How many bathrooms are needed?

• Where should the house be situated on
the property?

• What’s the exact relationship between
the kitchen and the dining room?

• How big will the dwelling be?

• Does the scale model reveal any
feasibility or usability issues?

• What qualities of the house are most
important to the client?

• Are the hallways wide enough to comply
with safety codes?

• What style faucets should be installed?
• What kind of material should cover the
kitchen floor?
• What is the cost of a given material
choice?
• Would the resident like a large bay
window in the living room?


5.1. PRODUCT CONCEPTION PHASE
PRODUCT CONCEPTION PHASE

The Product Conception phase is focused on clarifying the overall
vision of the system and devising product features that serve that
scope. Testing concepts with users along the way helps to validate
the envisioned product scope.

Product Conception: Ideation
An important first kind of Ideation is brainstorming. Brainstorming
sessions are a productive time for all project team members to share
their favorite design ideas and feature solutions. Brainstorming is the
right time to collect wild concepts without judgment and feed them
into the mental hopper for further analysis and consideration; even
the most “infeasible” concept may have a germ of design value or
represent a new market opportunity. No single group can or should
exclusively own product innovation.
Also at this juncture, the Personas identified from design research
can be classified into their primary, secondary and supplemental
designations. This prioritization of target users strongly influences the
design decisions to follow. This activity must be highly collaborative
with key product stakeholders due to its strategic impact. Balancing
primary and secondary persona needs can facilitate product feature
prioritization during this phase and subsequent project phases. Also,
remembering that supplemental personas are out of scope can help
control feature creep.
Design process methods and outputs of Product Conception phase

Product Conception: Modeling
For Modeling initial product concepts, many Interaction Design
practitioners employ a scenario-based methodology. Using the
primary and secondary Personas chosen by the team, ideal usage
scenarios are written. These usage scenarios represent the target
user’s high-level interactions with the system across the product
lifecycle. User goals and motivations are considered deeply in order
to help the team generate innovative improvements over existing
workflows. Freshly-conceived solutions at this juncture can often
eliminate time-wasting tasks and frustrations that might exist in

the personas’ current world. Because Modeling focuses on solidifying
concepts and scope, design outputs take low-fidelity forms such as
written scenarios and whiteboard sketches.

Product Conception: Testing
In the first Testing stage, any low-fidelity design outputs can be
tested internally by reviewing Personas, scenarios and other models
with a cross-disciplinary team. Team members can help identify
requirement gaps or feasibility concerns with the proposed product
vision. Models of existing workflows can be compared to the new
usage scenarios to identify where new product concepts better
mitigate risk. If any new risks are identified, an iteration back
to Ideation ensues to ensure that no risk moves forward without
appropriate mitigators in place.
Testing of concepts with real users also can be conducted during
this phase. One type of testing is called Directional Testing, which
involves presenting multiple visual concepts to users and soliciting
their feedback on which direction the company should pursue. This
testing is useful in the event that multiple product concepts are being
considered or different visual brands are being evaluated. Like design
research, this activity should be conducted in one-on-one sessions to
minimize group-think.
Concept Testing is another helpful tool for this phase of a project.
This activity involves seeking validation for the product scope from
members of the target market, and can help identify the relative
importance of product features. Focus groups and surveys can
be used productively here; quantitative survey tools can validate
customers’ feature priorities and provide statistically valid data
that tends to resonate with upper management at medical systems
companies.

Testing during the Product Conception phase involves figuring out
what will make it fly

“The first project phase, Product Conception, will
usually involve brainstorming, usage scenarios,
and some form of concept testing. Usage scenarios
represent the user’s high-level interactions across
the product lifecycle, and help the team to generate
innovative features and mitigate risk.”


5.2. DESIGN FRAMEWORK PHASE
PRINCIPLES AND PATTERNS
Interaction Design practitioners will refer
to proven principles and patterns during the
Modeling stage. Noteworthy principles and
patterns include:
• Don’t make the user feel stupid. [Cooper 97]
This principle may capture the moral essence
of interaction design and is extraordinarily
pertinent for medical systems used by
physicians.
• Optimize for intermediates. [Cooper 45]
Few users remain beginners and few users
become experts — the majority of users exist
somewhere in-between, and need be served
with interaction mechanisms suited to their
level of expertise.

After the foundation is laid for the product concept, the Design
Framework phase involves defining the overall user experience.
Design Framework Modeling produces manifestations of the product
features that are deemed in-scope, while Testing at this juncture
validates design choices and identifies areas for further refinement.

Design Framework: Ideation
Interaction Design practitioners can use the scaffolding of usage
scenarios and persona goals to conceive the appropriate design
framework. The ultimate user experience must deliver the right
functionality in the right form at the right time. Ideation at this
phase tends to be approached both visually and verbally, using a
combination of analytical and creative tools to address how the
system can best serve users needs. If this description sounds abstract,
that’s because ideation here is a relatively intangible design stage —
the artifacts that you can see are delivered through Modeling, next.

Design Framework: Modeling

• Global navigation. [Tidwell 66] Devote an
appropriate portion of each interface to a set
of controls that take the user to key sections
of the application. This pattern gives control
to users and provides reassuring consistency.

Scenarios are expanded and deepened through successive conceptual
iterations. High-level usage scenarios are broken down into key path
scenarios. On the visual side, initial whiteboard or pencil sketches
become digital wireframes. Wireframes are digital representations of
rough product functionality, with a low level of visual fidelity. Usually
they will consist of black-and-white outlines of key system states.

• Progress indicators. [Tidwell 149] Show the
user how much progress is being made for any
operation lasting longer than 2 seconds, even
if the time estimate is imprecise. This pattern
relieves user anxiety and makes people more
patient.

Many designers will also proceed on to static mockups at this
juncture. Mockups are higher-fidelity representations of the
system, which integrate more visual polish into the product design.
Storyboards can also bring scenarios and personas to life when a
designer is handy with drawing figures or has access to life-size
models.
One of the more important tools commonly employed by Interaction
Design practitioners modeling the design framework include
principles and patterns. These may come from experts and
publications, while others are developed as internal design standards

for product families or exist as competitive standards within
established industries. Some medical design frameworks, such as
games that are intended to promote health or products aimed at
engendering a healthy lifestyle, may also need to consider emotional
affects such as playfulness and fun to ensure user engagement and
patient compliance.

DESIGN FRAMEWORK PHASE

Design Framework: Testing
At this phase, Testing generally involves additional user research. As
the product models gain fidelity, a qualitative user research method
called Usability Testing can be applied to refine and validate proposed
solutions. Usability testing is a way of measuring usability and user
satisfaction by presenting potential and current users with some form
of product model. These product models vary in resolution depending
on the maturity of the project; at the Design Framework phase they
will tend to comprise paper prototypes of the wireframes or static
mockups but could involve an interactive prototype.
Usability Testing involves presenting product models to users in
experimentally-controlled, one-on-one sessions. Such testing with
real people can reveal a wealth of information about the design
framework’s strengths and weaknesses. Usability Testing is a proven
rapid and cost-effective research technique. Respected studies of
usability testing show that sessions conducted with as few as five
users can reveal 85% of a product’s total usability problems. [Nielsen]
Applied in an iterative fashion, multiple rounds of usability testing
during the Design Framework phase can augment the design process.
To summarize the results for team consumption, usability test reports
will highlight users’ response patterns and identify areas of the
product that could use further design refinement.

Design process methods and outputs for Design Framework phase

“The Design Framework phase involves defining the overall
user experience. Designers use wireframes and mockups
and apply principles and patterns to model solutions.
Usability Testing is a proven rapid and cost-effective
research technique to validate the design framework.”


5.3. DETAILED DESIGN PHASE
DETAILED DESIGN PHASE

During this phase, typically the longest design phase of a medical
system project, the product design is further articulated by defining
detailed interactions between the user and system. The Interaction
Designer works ever more closely with cross-disciplinary team
members; in an Agile development environment, the Interaction
Design team is working just one or two iterations ahead of the team.

Design Framework: Ideation
Ideation for detailed design is informed by the inputs from preceding
Testing activities. Small interactions may require additional design
attention. Ideation here can also be driven by formalization of the
product’s visual language and initiation of product requirements
documentation. Additional concepts will also tend to emerge and
expand from the design patterns created by earlier solutions.

Design Framework: Modeling

Design process methods and outputs for the Detailed Design phase

“During the Detailed Design phase, designers
articulate product solutions with a realistic level of
fidelity, iterating mockups and potentially interactive
prototypes. When Testing shows an acceptable level of
user satisfaction, the design process transitions into a
supporting role for implementation.”

By this phase, design models transition from wireframes to highfidelity mockups at a minimum. Some organizations may find that
static mockups satisfy their modeling needs when communicating
with the development team. Higher resolution design models such
as interactive prototypes can be extremely helpful as well. Rapid
prototyping of primary personas’ key path scenarios can clarify any
problems, and this iteration helps generate stronger solutions.

Design Framework: Testing
Usability Testing activities can leverage interactive prototypes at this
phase, if available. Interactive prototypes add richness and depth to
the feature behaviors that can be tested with actual users. Depending
on the prototype code’s closeness to the actual development
language/environment, interactive prototypes can involve vetting
product feasibility, too. Going to this length also tends to make the
development team’s projected scope estimates more accurate.
When Testing shows an acceptable level of user satisfaction, the
design process transitions into playing a supporting role for the
implementation team.

Case Study Example: Design Process
At St. Jude Medical’s Cardiac Rhythm Management Division, one of
the principal clinical platforms was completely re-envisioned using
Interaction Design methods, including user research. The new product
launched as the Merlin™ Patient Care System (PCS) and it features a
large interactive touch-screen display.

Merlin PCS hardware platform

Product Conception
The team designated the Pacer Nurse as the primary persona for
the graphical user interface, marking a strategic shift from focusing
primarily on the Electrophysiologist. Workflow analysis of the previous
system showed that it didn’t accommodate the Pacer Nurse’s routine
protocols well. Ideal usage scenarios were written based on observed
real-world protocols, greatly reducing friction between the system
design and the user’s expectations. The hardware form factor and
visual branding were selected using Directional Testing.
Design Framework
The user experience was architected around the Pacer Nurse
conducting a routine follow-up for both pacemakers and defibrillators.
These steps were built into the overall navigational structure and the
layout of each screen. Key functions such as parameter programming
and device testing were heavily iterated through successive Ideation
and Modeling stages. Design concepts and user interfaces were
validated and improved with several rounds of Usability Testing with
mockups and an interactive prototype.
Detailed Design
During this phase, all aspects of the system were fully articulated and
refined within a waterfall development process. Solutions included:

Initial “FastPath Summary” screen for the Identity® ADx pacemaker

• defining elegant representations of large data sets
• refining the visual language and documenting clear Graphical
User Interface specifications
• serving a different primary persona (the Electrophysiologist) for
printed reports
• providing usage scenarios and high-fidelity mockups as design
input to formal product requirements documents
This case study is continued at the end of the following chapter.

6. Product Documentation
As medical industry professionals know, medical product approvals
are principally achieved through regulatory agencies’ review of
departmental procedures and product documentation. This focus
on process and documentation puts an extra strain on development
organizations, since authoring and then maintaining requirements
specifications can consume massive amounts of precious time and
energy.
When the Interaction Design team employs a scenario-based
approach to design, the scenarios generated during the
design process can be a useful and powerful tool to inform
requirements. Usage scenarios are written at a high level
starting in the Product Conception phase to envision the
functionality of the system; because they describe the entire
framework of the product or service, they transition well
to be an input for requirements documentation. Employing
user-centered scenarios in this way also helps to keep the
development team’s focus on satisfying the target Persona.

Scenarios support good
documentation

Scenario-based documentation works well with both waterfall
and Agile development methodologies. In waterfall models,
marketing departments often define the vision for medical
products and services using Product or Marketing Requirement
Documents (PRDs or MRDs). Including scenarios that are
based on user research adds depth and clarity to PRDs/MRDs,
establishing a foundational expectation of product scope that
faciliates project scheduling and resourcing. Development
groups may already utilize use case scenarios under a Rational
Unified Process environment, for example. Such use cases are
positioned and touted as a requirements generation activity,
but too often the authors do not possess the right data about
users’ needs in order to generate requirements that will truly
satisfy customers. Having scenarios based on design research
as design input for use case scenarios provides requirements
authors with the right information to document the appropriate
system and software requirements.

In Agile development methods such as SCRUM or Extreme
Programming (XP), the scenario is an even more integral part of team
communication techniques. User stories are abbreviated scenarios
similar to the key path scenarios used by Interaction Designers during
the Design Framework phase. Agile approaches emphasize putting a
user role as the actor in these stories, and personas map extremely
well to this approach. With Persona models at hand, the Agile
development process will no longer require constant access to real
end-users throughout implementation.
Another best practice in medical systems development is having
Interaction Design practitioners formally review requirements
throughout requirements documentation and implementation phases.
Doing so helps ensure that the defined features continue to reflect
the behaviors indicated by user research and design inputs, and is
another way in which Interaction Design helps reduce systemic risk.
The Interaction Design practitioner is intimately familiar with the
nuances of complex user-system interactions, and can more quickly
identify requirements gaps and inaccuracies than most project team
members.

“Usage scenarios transition well to be an input for
requirements documentation. Interaction Designers
formally review requirements to help ensure defined
features reflect the behaviors indicated by design
research. Design documentation can also inform user
manuals and marketing activities.”

Design documentation can also inform user manuals, which are
very important documents for both regulatory agencies and users.
Informed by user research and Interaction Design processes, user
manuals can not only include people’s real-world workflows as a
educational tool, but they can also better employ the actual language
and terminology of the target user population. Interaction Design thus
helps to bridge the gap between the medical industry professional in
the corporate office and the medical system user in the field.
Insights gleaned from user research and design thinking can also
aid medical systems’ marketing and sales activities. Knowing how
customers behave and what motivates them allows marketing and
sales representatives to pitch the most valuable benefits and features
to the target audience. A similarly helpful use of design processes
includes crafting a positive marketing message that resonates with
the target market.


Case Study Example: Documentation
At St. Jude Medical, the personas, scenarios and other models
delivered during the design process for the Merlin PCS were
leveraged for formal product requirement documents. Each
requirements document began with one or more formal use case
scenarios that reflected the routine workflow of the primary
persona, and then branched into alternative and exception flows
for the primary and any secondary personas. Interaction Design
team members were also key participants in every formal review of
requirements, helping keep implementation true to users’ needs.

Additionally, when the Merlin PCS was launched, the marketing team
used the campaign slogan: “Designed by clinicians for clinicians”. This
message resonated very positively with the target user population of
pacer nurses whose daily needs had too often been relegated below
those of physicians. The product’s ease of use, achieved through the
application of iterative, user-centered Interaction Design processes,
became a significant selling point for the new system. St. Jude
Medical’s market position moved from a distant third to a strong
second as a result.

Merlin PCS marketing brochure


7. Organizational Structure
Medical systems development is anything but a solo endeavor,
and products frequently take multiple years to move from being
a concept in someone’s mind to being released in the market. To
deliver the most value, the Interaction Design practitioner should be
a core team member from the first moments of problem identification
through the end game of market launch. Generally, the discipline of
Design (which may include Interaction Design; Industrial Design and/
or Visual Design) should have department-level representation in the
organization.
Establishing a solid foundation of user research about people’s needs
enables teams to make better decisions without requiring constant
direct user input, as discussed above. Throughout the development
process, the Interaction Design practitioner becomes principally
charged with representing the user’s perspective. However, users’
needs are not the only decision-driver in product development.
Interaction Design practitioners must know how to balance the
concerns of business and technology with those of users. Listening
and collaboration are key Interaction Design skills for forging a shared
team vision. Most practitioners are well-versed in cross-disciplinary
teamwork. The importance of successful collaboration is established
in academic design programs as well as being a best practice in
industry. [Corporate]
In any serious medical systems company, a centralized
Interaction Design team will collaborate with many parts of the
organization (other departments’ collaborations not depicted)

Interaction Design practitioners tend to operate at the intersection of
various departments, as shown in the diagram at left. This situation
is especially true for medical systems development because the
initial vision for products usually begins within clinical, research or
marketing departments while the end game of implementation is
usually the responsibility of engineering departments.
Interaction Design is not properly a marketing function, however,
since marketing is focused on product viability and selling, nor is
it properly an engineering function, which is focused on product
feasibility and implementation.

Due to the way that Interaction Design practitioners collaborate with
many different departments, one of the more successful models
for large organizations is to create a centralized consulting group.
Members of a central Interaction Design group can work on multiple
projects simultaneously, staffed according to the projects’ current
stages in the development process. Such a group can naturally
become a generalized Design department, housing Interaction Design
as well as Industrial Design and/or Visual Design team members.
One useful service that an internal Design group can provide is
training other team members in user research and usability testing.
Techniques such as those employed with ethnography support good
outcomes for any activity where medical industry professionals
will be interacting with potential or current users and customers.
Listening and interviewing skills that Interaction Design practitioners
employ for research to establish rapport with users can be taught to
others, and improved with practice.
Creating an Interaction Design group raises the issue of proper
staffing. This factor is influenced by size of your organization. While
highly-experienced Interaction Design generalists can seamlessly
support user research, ideation, modeling and testing, many
practitioners tend to specialize in certain areas such as user research
or modeling. Ideally, an Interaction Design team will have senior, midlevel and junior staff with different levels and areas of expertise.
Establishing a growth path for senior design staff is also important to
retain talent—the kind of people who finally understand your complex
domain and technology, and know how to apply that understanding
for successful medical system development.
To support the success of a Design department within a large
organization, high-level executive support is crucial. A designated
“design champion” can address the dynamics of how design impacts
the practices of other departments; s/he can help to evangelize
user research and design activities. This step could even involve
appointing a Vice-President of User Experience or Chief Design Officer
in order to fully legitimize the important effort of establishing usercentered approaches throughout the entire organization.

How can you get the most value from cross-disciplinary
collaboration?

“Listening and collaboration are key Interaction
Design tools for forging a shared team vision.”


8. Conclusion
Medical systems and Interaction Design both aim to improve the
human condition. Interaction Design practices can greatly benefit
medical systems development.
Your medical systems can and should exhibit more than just
viability, feasibility and even usability. Great medical products and
services can deliver true satisfaction to people by offering a welldesigned user experience.
Bringing user research and iterative design processes to bear
in your organization improves strategic product innovation and
reduces systemic risk. Your customers, your business, and your
peace of mind should benefit.

Key take-aways:
• Regulatory agencies strongly advocate the application of iterative, user-centered design processes to medical system
development. Interaction Design offers rapid and cost-effective ways to reduce the risk of use-related hazards.
• Interaction Design applies at the front-end of product development, going beyond human factors and usability. It’s about
defining innovative product solutions that satisfy customers — and satisfied customers make for successful companies.
• User research methods such as ethnography help reveal product challenges and opportunities. Research models like Personas
control project scope, and keep the team focused on real-world needs.
• Iterating the design stages of Ideation, Modeling and Testing across the project phases of
Product Conception, Design Framework and Detailed Design will deliver solid solutions. Usability
testing helps to validate decisions and reduce risk prior to costly implementation.
• Interaction Design methods and outputs offer benefits for requirements documentation and
development efforts, as well as supporting marketing activities.

Dr. Helena Reardon Persona

• Establishing an in-house Interaction Design group benefits the whole organization. Ensure the Design department has a strong
internal executive-level champion.


9. References
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Personas!”. <www.devise.com/further_reading>.
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Administration, Public Health Service, U.S. Department of Health and
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Essentials of Interaction Design 3. Wiley Publishing, Inc: Indianapolis, IN,
2007. (First version published in 1995.)
• Cooper, Alan. The Inmates Are Running the Asylum. Macmillan Computer
Publishing: Indianapolis, IN, 1999.
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curricula 2001.” Journal on Educational Resources in Computing (JERIC),
v.1 n.3es, Fall 2001.
• Dray, Susan, et al. “Is ROI an Effective Approach for Persuading DecisionMakers of the Value of User-Centered Design?” CHI 2005 Panel, April 2-7,
2004, Portland, Oregon, USA. ACM 1-59593-002-07/05/0004.
• Federal Drug Administration (FDA), Institute of Medicine. “To Err is
Human – Building a Safer Health System”. <http://www.fda.gov/cdrh/
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• IEC 60601-1-6 “Medical Electrical Equipment - Part 1-6: General
requirements for safety — Collateral Standard: Usability” Draft dated
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• Kaye, Ron and Crowley, Jay. “Medical Device Use-Safety: Incorporating
Human Factors Engineering into Risk Management: Identifying,
Understanding and Addressing Use-Related Hazards.” Division of Device
User Programs and Systems Analysis, Office of Device and Industry

Programs, Center for Devices and Radiological Health, U.S. Food & Drug
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DeviceRegulationandGuidance/GuidanceDocuments/ucm094461.pdf> July
2000.
• Moggridge, Bill. Designing Interactions. The MIT Press: Cambridge,
Massachusetts, 2007.
• MSN Money. “Happy customers, good stocks”. <http://
articles.moneycentral.msn.com/Investing/CompanyFocus/
HappyCustomersGoodStocks.aspx>.
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Perspective”. Journal of Applied Behavioral Science. April 1981 vol. 17
no. 2 191-211.
• Nielsen, Jakob. “First Rule of Usability? Don’t Listen to Users”. <http://
www.useit.com/alertbox/20010805.html>.
• Nielsen, Jakob. “Why You Only Need to Test with Five Users”. <http://
www.useit.com/alertbox/20000319.html>.
• Saffer, Dan. Designing for Interaction: Creating Smart Applications and
Clever Devices. New Riders: Berkeley CA, 2007.
• Sawyer, Dick, Officer of Health and Industry Programs, et al. “Do It
By Design: An Introduction to Human Factors in Medical Devices.”
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December 1996.
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Design. O’Reilly Media, Inc: Sebastopol, CA, 2005.
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99d2932d77d688976026b8e533e?pn=1>.


ABOUT THE AUTHOR
Elizabeth Bacon began her career in user experience design and
research at the seminal consultancy Cooper in the late ‘90s. She then
was the founding member of the Human Factors Design Engineering
team at Fortune 100 medical device company St. Jude Medical,
designing software systems such as the Merlin PCS which manage
implantable cardiac rhythm management devices. After St. Jude
Medical, she launched her own digital product design consultancy,
Devise, and has worked with a range of companies to research
customer needs and design innovative products. She moved into
Product Management at Providence Health and Services in 2012, and
founded the disruptive startup, Find Wellness, that year as well.
Liz now juggles work as President of Find Wellness and Principal
at Devise Consulting. She’s also proud to be a Director Emeritus of
the Interaction Design Association, the world’s leading professional
organization for user experience designers, as well as a graduate of
Stanford University. When she’s not carrying the torch for interaction
design to change the world, Liz might well be found indulging her
passion for high-performance driving.

ABOUT DEVISE
Devise Consulting provides digital product design consulting services,
specializing in User Research, Interaction Design and UX Training. Liz
can be reached at 503-347-4931 or email liz@deviseconsulting.com,
or please feel free to connect on LinkedIn.

“Let’s Devise!”


Interaction Design for Medical Systems (Whitepaper)

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