Increasingly, devices are moving from exclusive use in specialized healthcare settings, such as hospitals, and into home-use and community care.
Unlike the clinical settings, the home is an uncontrolled environment. Although these devices are referred to as ‘home use medical devices’, they are not solely used in the home and users can carry them in their bags and use in them various environments. The context of use is not clearly defined, but the home environment is the most used. An uncontrolled home environment will increase the hazards and negative effect for people, especially for older people interacting with home use medical devices. Besides, each user's home is unique and the location of medical devices at home is unknown (by the manufacturer) and changeable. Furthermore, using more complex medical devices at the home may carry unique challenges, and the home environment itself may pose environmental or safety hazards that can affect a device’s functionality.
Home use medical devices may be exposed to environmental hazards that may adversely affect performance. These hazards include:
the presence of children or pets
sanitation issues such as vermin or dirty household items
Other environment hazards are:
Children at Play
Electromagnetic Interference (EMI)
Pets and vermin
Power outages and sources
In addition, the location of the home (e.g., elevation, urban versus rural, etc.), noise levels inside and outside of the home, air quality, temperature, and humidity may affect device performance. Furthermore, unlike trained hospital staff, home users are likely not equipped to handle medical emergencies in the event of a natural disaster or an electrical outage, particularly in the absence of the back-up power and/or water supply that a healthcare facility may have.
Case studies from FDA (2010) ‘Medical Device Home Use Initiative” can present the real damage due to lacking consideration of the home environment.
Case Study 1:
An individual with an implantable cardioverter defibrillator (ICD) was playing with a Wii video game. As he was playing with it, his ICD began to have intermittent pacing. The problem stopped when he stopped playing the game.
An individual with an implantable cardioverter defibrillator (ICD) was playing his electric guitar at home. As he was unplugging the guitar from the amplifier, feedback started to come from the amplifier, and the individual felt a painful vibration at the site of his ICD. His left arm became immobile for almost two minutes. The painful sensation stopped when his wife unplugged the amplifier.
Case Study 2: Noise Levels
A paediatric patient was receiving ventilator therapy in the home, and the ventilator tubing became disconnected. The patient’s mother was asleep and did not hear the ventilator alarm. There were other ambient noises in the home (e.g., television), and they may have interfered with the mother’s ability to hear the alarm. The patient died.
Case Study 3: Presence of Household Pets
A patient was put on peritoneal dialysis because of her failing kidneys. She lived in a one-bedroom apartment with her cat. The cat’s litter box was initially in her closet, but she moved it into her bedroom after the closet became filled with dialysis supplies. Although the patient kept the cat out of her bedroom while she was undergoing dialysis, there was cat fur and dander throughout the room. Cat fur got into the patient’s dialysis tubing and entered her peritoneum, and she contracted peritonitis. The patient was subsequently treated and has recovered.
Therefore, designers and manufacturers should ensure that the device design process appropriately considers the environment in which the device is to be used, the work patterns of users and the specific individual needs of the user. The user in this case could be any individual involved in the use of the device including health professionals, patients, and care givers. The diversity of use environments is critical to successful medical device design, which has led to the growing use of in-depth human factors research to more rigorously identify and mitigate the hazards.