User Interface Requirements for Medical Devices

Driving Toward Safe, Effective, and Satisfying Products by Specification

Michael Wiklund, Jacqueline Edwards, Erin Davis, Alexandria Trombley

• Publisher: CRC Press
• Year: 2021
• ISBN:
  9781000471847
• Edition: 1
• Topic: Business
• Subtopic: Service Industry
• Index: Business

This book is a practical guide for individuals responsible for creating products that are safe, effective, usable, and satisfying in the hands of the intended users. The contents are intended to reduce the number of use errors involving medical devices that have led to injuries and deaths. The book presents the strong connection between user interface requirements and risk management for medical devices and instructs readers how to develop specific requirements that are sufficiently comprehensive and detailed to produce good results – a user-friendly product that is likely to be used correctly. The book's tutorial content is complemented by many real-world examples of user interface requirements, including ones pertaining to an inhaler, automated external defibrillator, medical robot, and mobile app that a patient might use to manage her diabetes. The book is intended for people representing a variety of product development disciplines who have responsibility for producing safe, effective, usable, and satisfying medical devices, including those who are studying or working in human factors engineering, psychology, mechanical engineering, biomedical engineering, systems engineering, software programming, technical writing, industrial design, graphic design, and regulatory affairs.

1

What Is a User Interface?

DOI: 10.1201/9781003029717-1

People interact (i.e., engage) with the world around them using their senses. Accordingly, when we interact with medical devices, such as a dialysis machine, syringe, infusion pump, or surgical stapler, we also use our senses. The parts of any such device that we see, hear, touch, smell, or taste comprise the user interface. Accordingly, the user interface might include hardware components, software screens, labeling (including user documentation), soundscapes, aromas (odors), material that literally has a taste, and more.

As illustrated in the following section, user interfaces may be one particular type or many (i.e., a hybrid).

HARDWARE

Here are some examples of hardware user interfaces or components therein, noting that the overall product might be a hybrid of hardware, software, and labeling.

Examples
Rotary knobs used to adjust the gas mixture (i.e., the amount of air, nitrous oxide, and oxygen)
Guardrail (bed rail) that keeps a patient from falling out of a hospital bed
Package and blister pack containing vitamin capsules
Pushbutton (“M,” for memory) used to recall and display the most recent measurement recorded by a glucose meter
Training-only electrode pads used to simulate delivering a cardioverting shock using an automated external defibrillator

SOFTWARE

Even though a computer display is technically a hardware component, the display and the information presented on it (i.e., on screens) are normally referred to as the software user interface. Generally speaking, people use their eyes and a pointing device (e.g., mouse, fingertip, trackpad, stylus) to interact with information presented on a screen. Notably, a device’s software user interface may incorporate more than one display.

Examples
Small, segmented LCD display that presents the temperature measurement taken by a forehead digital thermometer
Tablet LCD display that presents hemodynamic parameter values and waveforms on a patient monitor
Large LED display that presents images of the coronary arteries, captured by an intravascular ultrasound imaging system
Touchscreen display, which displays information and touch controls, is built into a blood hematology analyzer
Smartphone and smartwatch screens display a patient’s sinus rhythm data, which is analyzed to determine if there is atrial fibrillation

LABELING

Labeling is a term of art in the medical industry, referring to the words and symbols that might appear on hardware and software user interfaces as well as the various types of documents (virtual and printed) that accompany a medical device. Here are some examples.

Examples
Stop symbol printed on a syringe infusion pump’s button
Enteral feeding product labels that enable clinicians to document the time and date
“Getting started guide” that introduces new users to a colon cancer screening kit
User manual that thoroughly describes a tonometer’s operation
Package insert that provides step-by-step guidance for performing a COVID-19 test

SOUNDSCAPES

The sound generated by a device, which might be produced by a speaker or contact between physical components, is also a user interface element. We refer to such stimuli as a soundscape. A soundscape may include the following types of s...