1. Who are the Users of Medical Devices?

For any medical device it is likely that there will be different types of users. Users are not just the individuals that will operate the device but are include all the people that will come into contact with it, either as part of their professional or caring activities, or by receiving treatment or care from a device as a patient.

Identifying all potential users should be one of the first tasks when developing a new device, in other words all of the people that may come into contact with the device, even infrequently. Users of any device may fall into more than one of the following categories:

1. Patients
2. Healthcare Professionals (Doctors, Nurses, Physiotherapists, Operating Theatre Assistants, etc.)
3. Carers, parents and other family members, teachers
4. Others: e.g. those who will maintain the devices and train people to use them

2. The Importance of User Requirements

Better Quality Devices:

There are a number of reasons why developers should maintain a focus on user requirements throughout medical device development, the most notable of these being to improve patient safety by reducing the likelihood of human error when using devices. There is an increasing appreciation, within both governmental and non-governmental organisations, of the links between poor usability and human error and consequently developers are increasingly required to demonstrate the usability of their devices. However, satisfying user requirements in medical device development encompasses much more than just patient safety and should also include issues such as usability, comfort, effectiveness, ease of both use and learning, training, hygiene requirements, maintainability and servicing, storage, labelling and so on. Attention to factors such as comfort, aesthetics and portability not only improve the patient experience but may also affect the willingness to follow and complete a treatment regime and consequently improve patient outcomes.

Safer Products

Products must not only be satisfying to use but must also be safe for all those who come into contact with them. The balance between satisfaction, safety and clinical efficacy is a delicate one.

To Comply with Medical Device Regulations & Standards

Regulatory requirements for medical devices are placing an increasing emphasis on usability and other user-related issues. For example, the US FDA requires developers to apply the human factors principles that are described in this guide throughout the development to identify, understand and address use-related hazards. Increasingly, standards are being used to demonstrate compliance with medical device regulations and a number of new standards have been developed which specifically deal with usability. A standard that developers are likely to encounter is IEC 60601-1: General Requirements for Safety of Electrical Medical Equipment and the collateral standard 60601-1-6, which specifies the usability requirements for safety of medical devices. The collateral standard requires a ‘usability engineering process’ to be used during device development and this will be covered in this guide. IEC 60601-1-6 requires developers to keep comprehensive records to show that usability has been considered throughout the design process. This standard only covers electrical medical devices; however a new standard is due for publication that will supersede this. IEC 62366 Medical Devices - General Requirements for Safety – Usability will extend the requirement for manufacturers to consider usability to all medical devices rather than just electrical medical equipment.

The new requirements to demonstrate usability are an opportunity to adopt best practice. It is an opportunity to capture vital user information early on in development, information that will result in better quality devices, more satisfied users, fewer recalls and ultimately improved sales. In addition to the regulatory requirements, it is becoming more common for medical device research and development grants to require developers to demonstrate a commitment to measuring and including user requirements and to actively involve users during the design process, as a result it is in the interest of developers to develop strategies for including users in product development. Initiatives such as these may result in changing the impetus for new devices from technological push to one of customer pull.

The information in this guide will assist with planning and executing the work necessary to comply with medical device regulations.

3. Example of Involving users to improve device safety (Lin et al 1998)