Design for Health

Applications of Human Factors

Arathi Sethumadhavan, Farzan Sasangohar

• Publisher: Academic Press
• Year: 2020
• ISBN:
  9780128166215
• Topic: Psychologie
• Subtopic: Psychologie appliquée

Design for Health: Applications of Human Factors delves into critical and emergent issues in healthcare and patient safety and how the field of human factors and ergonomics play a role in this domain. The book uses the Design for X (DfX) methodology to discuss a wide range of contexts, technologies, and population dependent criteria (X's) that must be considered in the design of a safe and usable healthcare ecosystem. Each chapter discusses a specific topic (e.g., mHealth, medical devices, emergency response, global health, etc.), reviews the concept, and presents a case study that demonstrates how human factors techniques and principles are utilized for the design, evaluation or improvements to specific tools, devices, and technologies (Section 1), healthcare systems and environments (Section 2), and applications to special populations (Section 3).

The book represents an essential resource for researchers in academia as well as practitioners in medical device industries, consumer IT, and hospital settings. It covers a range of topics from medication reconciliation to self-care to the artificial heart.

• Uses the Design for X (DfX) methodology
• A case study approach provides practical examples for operationalization of key human factors principles and guidelines
• Provides specific design guidelines for a wide range of topics including resilience, stress and fatigue management, and emerging technologies
• Examines special populations, such as the elderly and the underserved
• Brings a multidisciplinary, multi-industry approach to a wide range of healthcare human factors issues

Section 1

Devices, tools, and health care IT

Outline

• Chapter 1 Designing for medical device safety
• Chapter 2 Designing for medication safety
• Chapter 3 Design for digital health
• Chapter 4 Design for eHealth and telehealth
• Chapter 5 Design of mobile health technology
• Chapter 6 Design for effective care collaboration

Chapter 1

Designing for medical device safety

Russell J. Branaghan^1,2, Emily A. Hildebrand² and L. Bryant Foster², ¹Arizona State University, Tempe, AZ, United States, ²Research Collective, Tempe, AZ, United States

Abstract

This chapter provides an overview of human factors (HF) related to medical device design. It introduces the importance, process, and methods of HF design and evaluation. Furthermore, we discuss where these activities fit into a product development process. We discuss several critical principles of good HF design, which can reduce the common and tragic HF problems associated with medical devices. Finally, we provide a case study of the design of a total artificial heart (TAH), illustrating how to apply an HF process to a real-world medical device.

Keywords

Patient safety; usability; user experience; artificial heart; design; process; user interface; usability testing; wireframe; participatory design

Introduction

Medical devices diagnose, prevent, monitor, treat, alleviate, or compensate for disease or injury (World Health Organization, 2018). They range from thermometers to left ventricular assist devices and include hospital beds, infusion therapy instruments, pulse oximeters, implantable devices, such as pacemakers, and some mobile apps (Branaghan, 2018). They even include in vitro diagnostic products, such as lab equipment, reagents, and test kits (United States Food and Drug Administration [FDA], 2018).

The importance of medical devices is rising due to several factors, including advances in technology, increases in lifestyle-associated disease (Menotti, Puddu, Maiani, & Catasta, 2015; Weisburger, 2002), and an aging population. For example, the world’s population of people 65 years and older increases by approximately 850,000 every month (Kinsella & Phillips, 2005), and half of the people who have ever reached the age of 65 are alive today (Rowe & Kahn, 2015). As a result, focusing on the safety and usability of medical devices can improve human health drastically.

Medical devices developed with human factors (HF) principles and methods not only make devices easier to learn, more efficient to use, more satisfying, and better able to fit into peoples’ lives, but they also reduce the likelihood of physical or psychological injury to patients, caregivers, and health-care providers (Wiklund & Weinger, 2011). The HF and patient safety literatures are replete with cautionary tales of death at the hands of use error. These stories play out in a predictable manner, with well-meaning users accidentally operating devices incorrectly, with tragic results. Typically, although the user was blamed, the device itself made the error possible. For example, Wachter (2012) describes an incident reported in Smetzer, Baker, Byrne, and Cohen (2010), in which an obstetric nurse accidentally connected an opiate pain medication intended for an epidural to a mother’s IV line. The lines and bags for the IV and epidural lines were so similar that the nurse simply confused them, resulting in the mother’s death.

In another example, provided by Zhang, Patel, Johnson, and Shortliffe (2004), a nurse, trying to program an infusion pump to deliver 130.1 mL/h, pressed the appropriate keys “130.1” but failed to realize that the decimal point on the device only works for numbers up to 99.9. Consequently, the pump ignored the decimal point and delivered the drug at 10 times the intended rate—1301 mL/h. These problems are not limited to a few devices but are more common than most people realize, with issues identified on insulin pumps, ablation systems, automated external defibrillators, duodenoscope reprocessing, and many more (United States Food and Drug Administration [FDA], 2016a).

Recognizing the gravity of this problem, this chapter provides an overview of HF as it relates to medical device design. It introduces the reader to the importance of HF, the process and methods of HF design and evaluation, and where these activities fit into a product development process. Following this, several principles of good HF design are provided. Applied with care, these principles can reduce many of the common HF problems in medical device design. Finally, a case study involving the design of a total artificial heart (TAH) is provided. This case study illustrates the application of these methods and guidelines to a real-world medical device.

Human factors design process

The HF design process involves an early and constant focus on users and their tasks to ensure that the device fulfills, and hopefully even improves, users’ needs for safety, efficiency, effectiveness, and satisfaction. However, good designs do not emerge fully formed from solely considering users’ needs. Good design involves redesign. That is, it develops through an iterative process which not only identifies user needs but also involves end users in the development and design-validation process.

In this section, methods and a process for implementing an HF design approach are provided. Regulatory bodies and standards organizations (such as the International Standards Organization [ISO], US Food and Drug Administration [FDA], European Conformity, and Association for the Advancement of Medical Instrumentation [AAMI]) have become instrumental in providing standards and guidance (see AAMI, 2009; United States Food and Drug Administration [FDA], 2016a,b; ISO, 2015) for executing these processes. Fig. 1.1 summarizes the information commonly found in these standards by representing the three main steps required for incorporating HF into medical device design and development. Ensuring compliance with the required regulatory standards and guidance is an important consideration in any medical device design.

Figure 1.1 Process for incorporating HF into medical device design and development. HF, Human factors.

Identify device users, environments, interfaces

Device users

The first step in an HF design process is to identify and understand users, including their behaviors, needs, desires, capabilities, and limitations. This is critical for designing medical devices appropriately. For example, a user interface (UI) may need to be completely different for physicians and elderly patients. Begin to understand all the potential users by asking questions such as

• • Who purchases the device?
• • Who receives the device?
• • Who unpacks the device?
• • Who sets up the device?
• • Who uses the device? Are there different users for different tasks?
• • Who cleans, reprocesses, or provides maintenance for the device?
• • Who disposes of the device?

Once these questions have been answered and the user groups are clearly defined, a second set of questions can help identify each user group’s characteristics, abilities, and limitations, such as

• • Do the users have physical or cognitive limitations?
• • What is their level of education?
• • Do they require specialized training?
• • What is their emotional state when using the device?
• • Are they in a state of panic because the device is used only in a state of emergency?

Device environments

The next step considers where the device is used. Different environments have unique characteristics; these distinctions greatly influence how a device is used, and these influence many aspects of its design. For example, there would likely be different design considerations for a device used in an outpatient clinic versus the one used in a patient’s home. Specifically, users in health-care facilities are likely to be able-bodied, trained medical personnel. The use environment is likely to be well-lit and sanitized, with easy access to electrical power. This is not true of home environments. Patients at home may have a variety of physical and cognitive deficits. Homes are designed for comfort, intimacy, entertainment, and socialization. They are not, however, designed for medical devices.

Questions that can be helpful in identifying and characterizing intended use environments include the following:

• • Where will each end user interact with the device?
• • What is the lighting like?
• • How about ambient noise?
• • How much space do users have?
• • How hot or cold does each environment get?
• • What other equipment is also in the environment?

Device interfaces

Finally, to understand how users may interact with the device, it is important to identify all the device interface components. The term “UI” is often thought to mean a “graphical UI (GUI),” such as the screen on the device in Fig. 1.2. However, for medical devices, all elements that a user interacts with when using the device comprise the “device UI.” The device UI therefore includes the packaging of the device and related equipment or accessories, any additional labeling provided on the device, the accompanying instructions for use (IFU), any hardware features, such as physical buttons, knobs, or levers, and of course, the GUI (Food and Drug Administration, 2016b). An HF design process should be applied to each component of the device interface.

Figure 1.2 The C2 Hospital Driver provides pneumatic power to the SynCardia temporary TAH from implantation through patient recovery in the hospital. C2, Companion 2; TAH, total artificial heart.

Methods for identifying users, environments, and interfaces

HF applies knowledge and methodologies from human sciences to improve the match between people and their products by characterizing the users, their environments, and how they will interact with the device (e.g., Lee, Wickens, Liu, & Boyle, 2017). Two common methods include the following:

• • Contextual inquiry

This is the process of observing and interviewing users in their use environments to reveal insights about their interactions with the device (Beyer & Holtzblatt, 1997). Contextual inquiry is a method that was derived from ethnography, a practice adapted from the field of anthropolo...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Dedication
• List of contributors
• About the editors
• Preface
• Section 1: Devices, tools, and health care IT
• Section 2: Healthcare systems
• Section 3: Special population
• Index