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8 Medical Devices in Home Health Care Molly Follette Story As the formal health care system has become increasingly stressed, patients are being released from hospitals and other health care facilities still needing care. As a consequence, both laypeople and professional care- givers are making use of a wide variety of technologies, some of them quite complex, in noninstitutional settings to manage their own health, assist others with health care, or receive assistance with health management. These technologies provide support not only for care related to acute and chronic medical conditions but also for disease prevention and lifestyle choices. The range of medical technologies used in nonclinical environments runs the gamut in complexity from simple materials used for administer- ing first aid to sophisticated devices used for delivering advanced medical treatment, and in size from tiny wireless devices to massive machines. Some medical devices have been used in the home for many years; other devices are just beginning to migrate there; and emergent technologies present new opportunities for health care management in the home. While some of these devices were explicitly designed for use outside formal health care settings by professional home health caregivers as well as the general public, many devices were not. Consequently, many human factors chal- lenges must be addressed to render these technologies, devices, and systems safe, usable, and effective for use in environments beyond the institution and for use by the much more varied population of users in these environ- ments. This chapter discusses standalone medical devices used in home health care. 1

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1 HUMAN FACTORS IN HOME HEALTH CARE BACKGROuND The Center for Devices and Radiological Health of the U.S. Food and Drug Administration (FDA) defines a medical device as “an instrument, apparatus, implement, machine, contrivance, implant, in vitro reagent, or other similar article that is . . . intended for use in the diagnosis of disease or other conditions, or in the cure, mitigation, treatment or prevention of disease” (Federal Food, Drug, and Cosmetic Act, 2005, Sec. 201 (h), 21 U.S.C. 321). The center’s Home Health Care Committee defines a home medical device as “a device intended for use in a nonclinical or transi- tory environment, [that] is managed partly or wholly by the user, requires adequate labeling for the user, and may require training for the user by a health care professional in order to be used safely and effectively” (U.S. Food and Drug Administration, 2009b). Medical devices used in home health care need to be appropriate for the people who use them and for the environments in which they are used. The people who use medical devices may be professional or lay caregivers or the care recipients themselves. As a group, these users have diverse physi- cal, sensory, cognitive, and emotional characteristics. The environment of use may be the home, but it may also be the workplace or another destina- tion in the community or across the globe. Environments vary in the quality and accessibility of utilities, the amount of space available, light and noise levels, temperature and humidity levels, and occupants, who may include children, pets, or vermin. All of these use factors must be considered in order to ensure that medical devices are safe and effective for people receiv- ing home health care. Historical use of Medical Devices in the Home The most common types of medical devices, found in nearly every home, are used for delivering medications or first aid. Common medication administration equipment includes dosing cups for measuring medications in liquid form, such as cough medicine, and splitting devices for reducing the size and dosage of pills. First aid equipment includes thermometers (including oral, rectal, in-ear, and forehead), bandages, ace bandages, heat- ing pads, and snakebite kits. Other types of medical devices commonly used in the home are assistive technologies and durable medical equipment. Assistive technologies are most often either mobility aids (e.g., wheelchairs, walkers, canes, crutches) or sensory aids (e.g., glasses, hearing aids). Other common assistive technologies are prosthetic devices (e.g., artificial arms or legs) or orthotic devices (e.g., leg braces, shoe inserts). Durable medical equipment includes environmental devices, such as specialized beds, person- lifting and transferring equipment, and toileting aids.

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1 MEDICAL DEVICES IN HOME HEALTH CARE Recently some medical devices have been produced as consumer prod- ucts that enable people to manage their own health care more conveniently and independently (and inexpensively). For example, a wide variety of blood and urine testing kits are available that detect different chemicals and conditions (e.g., illegal drugs, cholesterol, pregnancy). Various types of monitors and meters are available to measure health status indicators, such as blood pressure or blood glucose levels (for people with diabetes). Newer consumer devices include ones that measure blood coagulation (prothrombin time and international normalized ratio, PT/INR) for people taking blood thinning medications, blood oxygen levels (pulse-oximeter), and sleep apnea. Increasing Migration of Medical Devices into the Home Climbing costs of health care services and hospital stays and short- ages of health care facilities and of nurses and other skilled personnel have put pressure on the medical system to provide more care on an outpatient basis. Consequently, the range and complexity of medical devices being used outside formal health care institutions by diverse user populations are increasing. Even complex devices, such as ventilators, infusion pumps, and dialysis machines, are being used outside the hospital or clinic, often by lay users, even though many of those devices were not designed for and were not specifically labeled for this type of use. There are few regulations that limit the practice of using these devices in the home. One of the problems associated with medical devices used in the home is that they often are not the same models as the ones used in formal health care settings. The devices may be older or of lower quality, and pro- fessionals who encounter the devices, either in the home or when patients bring them to the clinic or hospital, may not be familiar with them. Speak- ing on behalf of AdvaMed, Susan Morris, vice president for government affairs for Kinetic Concepts (a wound care technology firm), said, “One of the biggest concerns [of manufacturers] . . . is that legacy devices, old prod- ucts that were used in the institution that may have been replaced by newer versions, are now migrating into the home because they’re available . . . but they aren’t products that we originally designed for use in the home” (Taft, 2007). Health care professionals sometimes send people home with medical devices, but consumers sometimes give the devices to other people or resell them, for example, through the Internet on Craigslist or eBay. Devices acquired in this manner are much less likely to be appropriate for the end-user, to be properly operated or maintained, or even to come with complete instructions. Another challenge for medical device manufacturers is that the device user often is not the person who selected or purchased it. The device provider

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18 HUMAN FACTORS IN HOME HEALTH CARE may be a health care professional, or it may be a distributor or supplier. In the latter cases, the device may not be the optimal choice for the end-users, and the users may not receive the education, training, or ongoing customer support they need. In turn, the device manufacturer may not understand its end-users well because it may not recognize these populations as users of its products, and its designers may never come into direct contact with them. users of Medical Devices in the Home The Centers for Medicare & Medicaid Services reported that approxi- mately 8.3 million Americans received Medicaid home care in 2004, which represents a dramatic increase over the 1.64 million who received services in 1995 (National Association for Home Care and Hospice, 2008) (see Figure 8-1). The growth trend is likely to continue. Users of medical devices in the home are a diverse population. Some users are professional caregivers, such as physicians, nurses, nurse prac- titioners, physical and occupational therapists, social workers, and home care aides. These professionals are typically associated with home care organizations (e.g., home health agencies, hospices, homemaker and home care aide agencies, staffing and private-duty agencies, companies special- izing in medical equipment and supplies) or they may be from registries or operate as independent providers. Other device users are lay caregivers, usually family members or friends of the person receiving care. Some care recipients operate devices themselves (while providing self-care). Lay care- givers may be of any age and may have developmental or acquired disabili- ties, a temporary or intermittent condition, a chronic disease, or a terminal illness (see Chapters 6 and 7). Nonclinical Environments for Medical Devices Medical devices are used in nonclinical environments that include homes, workplaces (which may or may not be in office buildings), schools, hotels, stores, places of worship, entertainment venues, and transportation systems (cars, buses, trains, airplanes, ships, etc.). Depending on the device and the procedure, people may use medical devices in a private space, such as a bedroom, office, or restroom, or in a public space, such as an airplane, theater, or park. The variety of use environments presents significant chal- lenges for device and user safety. TYPES OF HOME HEALTH CARE DEVICES Home health care devices span a wide range, as mentioned above. Table 8-1 presents a taxonomy that uses the following major categories:

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1 MEDICAL DEVICES IN HOME HEALTH CARE Number (millions) Year FIGuRE 8-1 Medicaid home care recipients, 1995-2004. SOURCE: Data from National Association for Home Care and Hospice (2008). • Medication Administration Equipment—devices used to administer medications in tablet, liquid, or aerosol form. • Test Kits—kits used for measuring the presence of various chemi- cals in blood or urine. • First Aid Equipment—equipment used to care for injuries or tem- porary conditions. • Assistive Technology—devices used to enhance personal capabili- ties, such as sensory abilities or mobility. • Durable Medical Equipment—includes medical devices used to support performance of basic activities of daily living, such as beds, lifts, and toileting equipment. • Meters/Monitors—includes a wide range of devices for determining health status or managing disease conditions, either one time or on an ongoing, intermittent basis. • Treatment Equipment—equipment used to administer various med- ical therapies. • Respiratory Equipment—equipment used to treat respiratory conditions. • Feeding Equipment—devices used for feeding. • Voiding Equipment—devices used for releasing urine or feces from the body. • Infant Care—includes machines used to monitor and treat infants. • Telehealth Equipment—equipment used to collect data in the home environment and transmit the data to a remote monitoring site.

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10 HUMAN FACTORS IN HOME HEALTH CARE TABLE 8-1 Types of Home Health Care Devices Category Device Medication Administration Dosing equipment (e.g., cups, eyedroppers, blunt Equipment syringes) Nasal sprays, inhalers Medication patches Syringes/sharps Test Kits Pregnancy test Male/female/stress hormone test Cholesterol test Allergy test Bladder infection test HIV test Hepatitis C test Drug, alcohol, nicotine test First Aid Equipment Bandages Ace bandage, compression stocking Snakebite kit Heating pad Traction Ostomy care Tracheotomy care Defibrillator Assistive Technology Eyeglasses Hearing aid Dentures (full or partial) Prosthetic device Orthotic device, including braces Cane or crutches Walker Wheelchair Scooter Durable Medical Equipment Hospital bed Specialized mattress Chair (e.g., geri-chair or lift chair) Lift equipment Commode, urinal, bed pan Meters/Monitors Thermometer Stethoscope Blood glucose meter Blood coagulation (PT/INR) meter Pulse oximeter Weight scale Blood pressure monitor Apnea monitor Electrocardiogram monitor Fetal monitor

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11 MEDICAL DEVICES IN HOME HEALTH CARE TABLE 8-1 Continued Category Device Treatment Equipment IV equipment Infusion pumps Dialysis machines Transcutaneous electrical nerve stimulation systems Respiratory Equipment Ventilator, continuous positive airway pressure, bi-level positive airway pressure, and demand positive airway pressure equipment Oxygen cylinder Oxygen concentrator Nebulizer Masks and canulas Respiratory supplies Cough assist machine Suction machine Manual resuscitation bags Feeding Equipment Feeding tubes (nasogastric, gastrostomy, jejunostomy) Enteral pump Voiding Equipment Catheter Colostomy bags Infant Care Incubator Radiant warmer Bilirubin lights Phototherapy Apnea monitor Telehealth Equipment Cameras Sensors Data collection and communication equipment (e.g., computer) Telephone or internet connections EMERGENT TECHNOLOGIES IN HOME HEALTH CARE Telehealth—which is health care facilitated by telecommunications technology—has begun to transform the home care landscape and promises to grow substantially in coming years. Currently, simple technologies (e.g., e-mail, the Internet, cell phones) can be used to monitor people’s health at a distance. High-resolution visual images and audio can be transmitted through telephone lines or broadband connections. In coming years, remote monitoring will increase dramatically and will involve more types of equip-

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12 HUMAN FACTORS IN HOME HEALTH CARE ment in the home; technologies such as wireless electronics and digital processing will support communication between a diverse set of devices and remote health care providers. Some wireless devices, especially meters and monitors, will be wearable, which will make constant monitoring pos- sible or intermittent testing more convenient. Telehealth technologies can be used to support adherence to treat- ment regimens, facilitate self-care, and provide patient education. Cameras and sensors can be used to track patient movements and behaviors in the home. Monitors can collect and transmit a variety of data to health care providers at a distance, eliminating the need to visit a clinic or to call in. These technologies can also provide reminders to people at home, such as to take medications, measure their blood pressure, perform physical therapy, or schedule follow-up appointments. Future technological advances will bring new devices, such as improved pacemakers, cochlear implants, and medicine delivery systems. Miniaturiza- tion of various components, including microprocessors and nanotechnology, will make possible advances to many types of medical devices used inside and outside formal health care settings. Some of the devices envisioned will be embedded in common household objects, such as a biosensing chip in a toothbrush that will check blood sugar and bacteria levels; smart bandages made of fiber that will detect bacteria or a virus in a wound and then recom- mend appropriate treatment; smart T-shirts that will monitor the wearer’s vital signs in real time; and heads-up displays for glasses that use pat- tern recognition software to help people remember human faces, inanimate objects, or other data. Novel handheld devices may provide new capabilities for home health care, such as skin surface mapping, an imaging technology that will track changes in moles to detect malignancies; biosensors that will perform as portable laboratories; and alternative input devices such as eye blinks (electromyography) or brain activity (electroencephalography) that will facilitate hands-free device control, which will be especially useful for people with limited use of their hands (e.g., people with paralysis or arthritis) (Lewis, 2001). Some people envision a future with more consumer-driven, preventive medicine in which consumers can evaluate their own bodies and communi- cate with health care professionals on an ongoing or as-needed basis. Other people are less optimistic that the nation will ever get to a preventive medi- cine model of health care, given the current business model being followed in the United States. The reality will probably fall between the two extremes, with some portion of the U.S. population making good use of new oppor- tunities to follow good health maintenance practices. If medical devices are well-designed with appropriate and effective application of human factors principles and methods that percentage can be maximized. Chapter 9 pro- vides more information on networked health technology for home care.

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1 MEDICAL DEVICES IN HOME HEALTH CARE HuMAN FACTORS ISSuES FOR HOME HEALTH CARE DEVICES user Issues The characteristics of individuals who use medical devices in the home are not well known by many medical device designers. Indeed, some designers do not understand well even the needs of “average” users, and home device users often have capabilities that are far different from aver- age. Particularly due to the conditions that require them to need home health care, individuals receiving care at home may have reduced physical strength or stamina (e.g., fatigue associated with chronic pain), diminished visual or hearing abilities, impaired cognitive abilities (including confusion caused by the effects of medication), or combinations of these conditions. Illness, medications, and stress can intensify the severity of any preexisting limitations in the user’s physical, perceptual, and cognitive functions. People’s ability to operate a medical device depends on their personal characteristics, including the following: • physical size, strength, and stamina; • physical dexterity, flexibility, and coordination; • sensory capabilities (i.e., vision, hearing, tactile sensitivity); • cognitive abilities, including memory; • comorbidities (i.e., multiple conditions or diseases); • literacy and language skills; • general health; • mental and emotional state; • level of education and training relative to the medical condition involved; • general knowledge of similar types of devices; • knowledge of and experience with the particular device; • ability to learn and adapt to a new device; and • willingness and motivation to use a new device. It is important to recognize that lay users may also be affected by their own emotional states, which may be caused or aggravated by the news that they or their loved ones are seriously ill. They may be overwhelmed by new terminology and the critical responsibilities associated with home care, including awareness of the potential for harm—to the equipment, to their loved ones, or to themselves—if they make an error. Instructions may be confusing, and users may have little preparation and insufficient personal or institutional support for the tasks they must perform. Regardless of their capabilities, individuals using medical devices in the home should be able to use the devices safely and effectively and without

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1 HUMAN FACTORS IN HOME HEALTH CARE unintentionally making errors that could compromise the health of the person receiving care (Kaye and Crowley, 2000). This requirement has implications for medical device design, user training programs, and ongoing support. If the human factors demands of the medical device exceed the capabilities of the user, the equipment burden may be too great to manage, and the person receiving home health care may be forced to move to a long- term care facility or a nursing home. In 2005, Hancock, Pepe, and Murphy proposed a “hierarchy of ergo- nomics and hedonomic needs” (see Figure 8-2). The purpose of the article was to suggest that once people’s needs for safety and functionality were fulfilled, designers should address the need for pleasure. This hierarchical structure could also represent the relationships among safety, accessibility, and usability. For individuals with any sort of physical, sensory, cognitive, or emotional disability, accessibility equates to function- ality. The primary imperative is that home-use medical devices be safe; the secondary imperative is that they be functional (accessible) for the people who need to use them. Ideally, devices would satisfy all levels of the pyra- mid: they would be safe and functional, but also usable and pleasurable, and even offer customization to individual users’ needs and preferences. There is no reason why medical devices, especially those intended for personal use, cannot be satisfying to use and aesthetically pleasing, and possibly even enable users to achieve their own health and life goals. FIGuRE 8-2 Hierarchy of ergonomic needs. SOURCE: Adapted from Hancock, Pepe, and Murphy (2005).

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1 MEDICAL DEVICES IN HOME HEALTH CARE Device Issues Some medical devices may not be safe for all users or use environ- ments, but medical device manufacturers have a responsibility to recognize and mitigate hazards to the greatest extent possible. In the FDA guidance document, Medical Deice Use-Safety: Incorporating Human Factors Engi- neering into Risk Management, Kaye and Crowley (2000, p. 7) explain that use-related hazards occur for one or more of the following reasons: • Devices are used in ways that were not anticipated. • Devices are used in ways that were anticipated, but inadequately controlled for. • Device use requires physical, perceptual, or cognitive abilities that exceed those of the user. • Device use is inconsistent with user’s expectations or intuition about device operation. • The use environment . . . [affects] device operation and this effect is not understood by the user. • The user’s physical, perceptual, or cognitive capacities are exceeded when using the device in a particular enironment. The FDA’s Center for Devices and Radiological Health collects data on adverse event incidents associated with medical devices. One of the FDA databases is the Medical Product Safety Network (MedSun), in which more than 350 health care facilities (primarily hospitals) currently participate and submit reports through the Internet. The database has several subnetworks that focus on specific clinical areas, including HomeNet, which focuses on medical devices used in the home environment (U.S. Food and Drug Administration, 2009b). Another FDA database collects reports from manufacturers and health care professionals in the Manufacturer and User Facility Device Experience (MAUDE) database. The data include all voluntary adverse event reports since June 1993, user facility reports since 1991, distributor reports since 1993, and manufacturer reports since August 1996. (User facilities are defined as hospitals, nursing homes, long-term care facilities, and ambula- tory and outpatient treatment facilities, including home care and hospice care.) In evaluating reports of adverse device events in the MAUDE data- base between June 2008 and August 2009, the FDA found 1,059 events for which the location of the event was reported as “home.” The devices involved in the greatest number of events were

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12 HUMAN FACTORS IN HOME HEALTH CARE particular. Poor labeling increases the likelihood that users will need to call either the doctor’s office or the device manufacturer’s customer service line, which is expensive and may not answer all the user’s questions. User confusion can lead to use errors or product abandonment, either of which compromises quality of care. All home caregivers, whether professional or lay, must be adequately trained to use and maintain the medical devices that they will use in the home. All household residents who are capable should learn how to interact with the medical equipment. Some residents should be taught about the limits of their involvement, such as children who may be taught to get help if an alarm sounds. Home users may have multiple problems with training. As described by Fisk and colleagues (2004, p. 131): The training may be provided under the stressful and emotional context of being newly diagnosed with an illness. Training provided by a health care professional may be presented too quickly, using jargon, with little practice by the patient, and without adequate explanation of the difficulties that may arise if the steps are not followed properly. When users are at home attempting to use a system, they may forget the details of the steps, have no idea about what to do if the system does not operate as expected, and have no immediate access to help. Lack of ongoing training and support is a particular challenge when device users are faced with purchasing a device when the reimbursement period ends. When a device, such as oxygen therapy equipment, is used under reimbursement, the distributor or supplier usually sets it up, services and maintains it, and delivers any necessary supplies. However, at the end of the reimbursement period, patients must purchase the device if they want to continue using it, but if they do, they lose the supports that the distributor or supplier used to provide. The home user typically has not been trained to service or maintain the device and may not know what supplies they will need or where to procure them, which can lead to seri- ous problems. Training should be provided in multiple formats, including visual and auditory information, because individuals have different capabilities, learn- ing styles, and preferences. Some people understand information better when it is delivered in visual format, and others understand the spoken word better. Some device users have limited education or are illiterate. Some people do not understand English well or at all. Hands-on training is generally most effective. Patricia A. Patterson, president of Agilis Consulting Group, is an expert

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1 MEDICAL DEVICES IN HOME HEALTH CARE in performance-based training and labeling systems for medical devices. She warns (Patterson, 2004, p. 145): Getting information into people’s long-term memory so that they can recall it when needed—accurately and consistently—is like walking on thin ice: it’s risky, and when we’re talking medical, it’s dangerous. And it has less to do with the media (a.k.a. video) and more to do with the instructional design. . . . If the user needs information to perform a task—where is that information going to be stored: in their head (long-term memory) or someplace else? We try to opt for someplace else whenever appropriate for obvious reasons. . . . What labeling can do is to minimize the need for memory by making it accessible to the user when and where needed—like stuck to the device, in the [user interface] itself, etc. In addition to clear device labeling and effective training, home care- givers need to have access to ongoing support, always by telephone but also through e-mail, on the Internet, or via telehealth connection. Ideally, some form of help should be available 24 hours a day, 365 days a year. Environmental Issues Residential environments vary considerably and can present a range of complexities for introduction of medical devices (see Chapter 10). Medi- cal devices may be used under variable conditions involving such environ- mental attributes as space, lighting, noise levels, and activity: • Rooms may be physically crowded or cluttered, making it diffi- cult for the person providing or receiving care to maneuver in the space. • Carpeting or stairs may hinder device portability or maneuverability. • The lighting level may be low, making it hard to see device displays and controls. • The noise levels may be high, making it difficult to hear device prompts and alarms. • The temperature may be very high (e.g., in Florida) or very low (e.g., in Alaska), which can cause equipment to overheat or stall out. • The humidity may be very high (e.g., in Louisiana), which can cause condensation, or very low (e.g., in Arizona), which can pro- duce static electricity. • The home may not be clean. • The household may be busy with other residents and activities, pro- viding distractions that may confuse people while they use medical devices.

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1 HUMAN FACTORS IN HOME HEALTH CARE • Children, unauthorized users, pets, or vermin in the home can cause damage to themselves (e.g., playing with syringes), cause damage to devices (e.g., chewing on tubing), or change device set- tings, which may not be noticed before the unit is used again. • Electromagnetic interference from other equipment in the home (e.g., computer gear, such as Gameboys and Wii sets) can affect medical device functions. These environmental influences can have a significant impact on how safe or risky a device is in the home. An example of electromagnetic inter- ference in the home involved a motorized wheelchair. One day when the patient was at home in the wheelchair, it began spontaneously spinning around, out of control. The patient tipped backward in the chair and fell out, sustaining an injury. After the incident the patient reported that some- one had been using a cell phone nearby, which may have contributed to the event (Weick-Brady and Lazerow, 2006, p. 203). Not all medical devices stay at home. People who work may take their device along with them to the workplace. This situation has implications for device portability (size and weight) and appearance, particularly with regard to discretion. People may also take their device with them when they go out in their communities or when they travel away from home. In this case, battery life, durability, and ruggedness also matter. A home dialysis patient who liked to travel offers an example of traveling with a significant medical device. After receiving dialysis in medi- cal centers in 19 countries on 5 continents for 11 years, he began home dialysis and now takes a dialysis machine with him when he travels. He dialyzes himself five nights a week, unassisted, using a relatively compact, “portable” machine that weighs 99 pounds (Taylor, 2008). The utilities available must be taken into consideration when selecting a medical device for nonclinical use. For example, for treatments that involve water (such as home dialysis), it will be important to have a clean and reli- able source of tap water. For devices powered by electricity, the room will need a sufficient electrical supply (including outlets and circuit capacity). For foreign travel, this may require outlet or power adapters. The device or room will also need a source of backup power, such as a battery or genera- tor, in case of power failure or other emergency (e.g., after a hurricane or earthquake). Some care recipients cannot survive long without the medical devices on which they depend.

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1 MEDICAL DEVICES IN HOME HEALTH CARE APPLICATION OF HuMAN FACTORS TO HOME HEALTH CARE DEVICES The history of medical devices used in the home is filled with stories, some successful and some cautionary. Among the successful stories, blood glucose meters with voice output are useful for a variety of users. Voice output is useful on many home health care devices because it • reinforces visual messages, providing redundant cuing that improves comprehension; • reduces misinterpretation of visual messages (including words and icons); • is especially helpful for infrequent users who benefit from prompt- ing and feedback as they use a device; • improves user confidence and trust in the device; and • reduces the burden on customer service to handle repeated contact from confused users. In addition, speech output is vitally important for people with vision impairments who cannot perceive all the visual information provided by the device. Among cautionary tales is the story of a patient who was receiving oxygen therapy in his home. When a pressure hose came loose from the respirator, an alarm sounded, but the alarm was not loud enough to be heard over the sounds produced by the device itself (and there was no remote monitoring system in place). The patient died (Lewis, 2001). In a study of telemonitoring and 19 elder home health care recipients, a few participants were unable to measure their own weight using a scale, most often because they needed help to accomplish the task and no one was available at the time; at least one-third of participants could not reli- ably interpret their blood pressure results as being normal or abnormal, and for a significant percentage of those, even periodic retraining didn’t help (Daryle Gardner-Bonneau, Bonneau and Associates, personal com- munication, 2009). A study of everyday use of ventricular assist devices (to provide cir- culatory support before cardiac transplantation) showed that the usability of these devices affected the success and acceptance of the treatment. Of the 16 study participants, 38 percent accidentally disconnected important components of the system at least once; 38 percent reported that parts of the system rubbed against their skin (particularly the shoulder strap against the abdomen when using a bag belt); and 56 percent reported that the noises from the pump, ventilators, and alarms were annoying; how- ever, the alarm signals were too quiet to wake 32 percent of them. Most

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1 HUMAN FACTORS IN HOME HEALTH CARE participants (63 percent) used a carrying case other than the one supplied, and many (44 percent) overstuffed the case with additional gear, mainly medical documents, cell phones, or eyeglasses (without which the older participants had difficulty reading the messages on the device) for which space was not provided (Geidl et al., 2009). Medical devices used in the home should be designed to be safe and easy to use by their end-users, including the people receiving care and any lay caregivers on whom they may rely. This may require that devices have fewer features in order to simplify use, such as no memory function, or have additional features, such as new alarms (which may be visual as well as auditory) or extra monitoring functions to track device usage and adher- ence to treatment regimens. It is important for manufacturers to design out hazards, rather than just add warning labels or rely on training to address problems. Not every- one reads labels or instructions—indeed, not everyone can read. Training depends on good instructors and methods, which may not always be avail- able. Both methods rely on users to interpret the information correctly and remember it when it is needed, which is difficult for some people to do. Users would be better served if devices were designed to be more error-resistant (easier to understand and operate as well as more fail-safe) irrespective of labels, instructions, or training. As psychologist and cog- nitive scientist Donald Norman recommended, for devices that are used infrequently, it is better to have knowledge in the world (i.e., in or on the device) so that the user need only interpret the visual cues provided by the device, rather than depend on knowledge in the head (i.e., in the user’s memory) (Norman, 1980). Medical device manufacturers should make a commitment to follow good human factors practices in the design of their products. They need to establish permanent human factors departments or identify and contract with qualified human factors consultants to perform the human factors analyses needed to ensure that medical devices will be safe and usable, reducing the likelihood of product misuse or abandonment. HuMAN FACTORS ASSESSMENT The Food and Drug Administration requires medical device manufac- turers to demonstrate that they have addressed human factors issues during the product’s development process. The FDA requires design controls for all medical devices sold in the United States. These are explained in Title 21 of the Code of Federal Regulations (CFR), Part 820 of which is the Quality System Regulation (QSR). Section 820.30, Design Controls, contains key human factors requirements in its subsections c, f, and g:

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1 MEDICAL DEVICES IN HOME HEALTH CARE (c) Design input. Each manufacturer shall establish and maintain pro- cedures to ensure that the design requirements relating to a device are appropriate and address the intended use of the device, including the needs of the user and patient. . . . (f) Design erification. Each manufacturer shall establish and maintain procedures for verifying the device design. Design verification shall confirm that the design output meets the design input requirements. . . . (g) Design alidation. . . . Design validation shall ensure that devices conform to defined user needs and intended uses and shall include testing of production units under actual or simulated use conditions. Design validation shall include software validation and risk analysis, where appropriate. The primary human factors guidance documents offered by the FDA are Do It by Design: An Introduction to Human Factors in Medical Deices (Sawyer, 1996) and Medical Deice Use-Safety: Incorporating Human Fac- tors Engineering into Risk Management (Kaye and Crowley, 2000). These documents include descriptions of human factors engineering methods, such as analytic and empirical approaches to identify and understand use- related hazards, methods of assessing and prioritizing hazards, strategies for mitigating and controlling hazards, and methods of verifying and validat- ing hazard mitigation strategies. They also discuss exploratory studies and usability testing methods. It is important that representative laypeople and caregivers be included in any user testing that is conducted in order to assess the safety of the medical device and its use by these populations. The potential user popula- tion may be very diverse, and it is vital to identify the users at highest risk. By studying their use of the device and its labeling to conduct essential tasks, the device manufacturer can ensure that any potential risks have been minimized, residual risks have been mitigated as far as possible, and the device is appropriate for home use. Medical device manufacturers need to ensure device safety before marketing, and they also need to make a commitment to postmarket sur- veillance of their products to make sure that no unforeseen problems appear with long-term use. If problems are discovered, manufacturers must notify current users and address the problems by providing information and replacement parts or recalling the product, as appropriate to the severity of the issues. FuTuRE DIRECTIONS FOR THE FIELD Critical gaps exist in the understanding of human factors issues for medical devices in the domain of noninstitutional health management and care. These include user issues, device issues, and environmental issues.

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18 HUMAN FACTORS IN HOME HEALTH CARE Maximizing adherence to treatment regimens is an ongoing challenge for home health care. Having a device at home may actually make people less diligent in maintaining their own health. “These risky behaviors can involve lifestyle changes, such as changes in diet or physical activity, or less attention to monitoring their health condition due to over-reliance on the device,” says Ron Kaye, human factors and device use-safety team leader at the FDA’s Center for Devices and Radiological Health (Lewis, 2001). Other problems with home device use, especially once the user has gotten accustomed to a device, include skipping steps rather than follow- ing proper procedures, not performing important maintenance tasks, and not communicating with health care professionals as often as they should (Lewis, 2001). The field needs to develop methods of improving people’s ability and willingness to follow their doctors’ recommendations and to adhere to treatment regimens while visiting health care facilities less frequently. Medi- cal personnel need to have good assessment tools and mechanisms to deter- mine whether a particular individual is a good candidate to use a specific medical device. The attributes of the device, the characteristics of the user, and the expected use environments all need to be considered and should be integrated into the assessment program. Some medical patients have comorbidities, that is, more than one disease or condition, for which they may be receiving ongoing medical treatment. The conditions and their treatments may be independent, or they may reinforce or aggravate one another. These effects must be understood and taken into consideration when treatment regimens are designed. However, concomitant conditions may also present the pos- sibility of care efficiencies. For example, treatments (e.g., drug infusions) could be delivered simultaneously, reducing the time involved, or multiple diagnostic processes (e.g., blood glucose level and coagulation time) could be conducted on a single blood sample, reducing the number of samples and the amount of blood that needs to be drawn. Device issues that need to be addressed include concern for accuracy of home health care devices, especially some of the more inexpensive types designed for home use. For example, the current international standard for blood glucose meters allows their measurements to be up to 20 percent inaccurate, but, in fact, the readings sometimes fall well outside even these generous limits (Harris, 2009). Standards for home devices need to be suf- ficiently stringent to safeguard the health of the user populations as well as engender trust in the technologies. For people who use telehealth technologies (devices that communicate with medical professionals at a distance), it is important for the devices to be interoperable (i.e., work together using the same technology). For example, a home health care system can include multiple devices (e.g.,

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1 MEDICAL DEVICES IN HOME HEALTH CARE weight scale, pulse oximeter, and blood glucose monitor) that communi- cate wirelessly using a common protocol (e.g., Bluetooth Medical Device Profile) to a communication device, such as a computer, a cell phone, or a dedicated standalone unit. Potentially, sets of devices designed for home use could communicate with and affect one another’s operation, such as a pain medication pump that would vary dosage based on the results of patient respiration monitoring. Having communication standards for medical devices is critical and several are being developed, but the idea of interoperability continues to be controversial among device manufacturers, who do not want to share proprietary technologies with competitors. With- out these standards, however, users will be limited in the selection of devices they can purchase (that will communicate with each other) and the costs are likely to be higher. Another concern regarding home use of medical devices is the training burden on health care professionals, particularly nurses. When a device is not well designed, it falls to the medical personnel involved to train—and often retrain—users to use it, which puts a strain on the medical system that it can ill bear. Devices that are well designed can encourage use, result in better health, and reduce burdens on the medical system, including training. The field also needs better mechanisms for home health care users to provide feedback to medical device manufacturers regarding the difficulties and hazards associated with use of devices in the home. Professional and lay caregivers and people receiving home care are rich sources of information about medical device use safety and errors, which need to be tapped. The experiences of real users in the real world need to be captured, studied, and used to inform and improve the design of the next generation of devices used in home health care. Environmental issues that need to be addressed include surveying and documenting the range of nonclinical medical device use-environment types, situations, and conditions. The wide variation in environmental conditions is neither recognized nor taken into consideration by the designers and engi- neers who develop medical devices that will be used in those locations. CONCLuSIONS Inevitably, as medical costs continue to climb and particularly as more devices are designed with lay users in mind, more people will use medical devices for health care in their own homes and other private and public environments. The explosion of information on the Internet has provided people with access to more data than ever before. Individuals with health concerns have resources at their fingertips that provide information about symptoms, con-

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10 HUMAN FACTORS IN HOME HEALTH CARE ditions, and treatment options, which make them more informed consumers of health care services. This knowledge, in turn, enables people to be more demanding of their health care providers. At the same time, people tend to be reluctant to blame medical devices when they have trouble using them. The professional culture in health care seems to make practitioners believe that they should be able to provide the needed care, regardless of the technology. Laypeople using medical devices tend to blame themselves if they have difficulty using a device properly, even though such difficulty often occurs because there is something wrong with the device (and not the operator). Users need to stop blaming themselves and be more demanding of medical devices. When devices are not operat- ing correctly or are difficult or dangerous to use, users need to report those problems—to their health care providers, to their state, and to the FDA. To encourage this kind of reporting, better reporting mechanisms are needed, ones that are visible, accessible, and easy to use. The medical industry needs to improve the health of the general public in the United States, and it also needs to reduce the cost of providing health care. Home health care promises to advance both of these goals. However, to enable good health care at home, medical devices need to be designed to be safer, more accessible and usable, and available to more people. Human factors engineering offers principles and processes that support industry to produce such devices. ABOuT THE AuTHOR Molly Follette Story was president of Human Spectrum Design at the time of the workshop; she is now a senior program officer at the National Research Council. Her expertise is in universal design of products and in accessibility and usability of medical instrumentation. REFERENCES Alliance for Home Health Quality and Innovation. (2008, May). The future of home health care: Containing costs while sering patients’ preferences. Available: http://ahhqi.org/ download/File/The_Future_of_Home_Health_Care.pdf [accessed June 2010]. American National Standards Institute and Association for the Advancement of Medi- cal Instrumentation. (2010). Human factors engineering: Design of medical deices (ANSI/AAMI HE75:2010). Arlington, VA: Association for the Advancement of Medical Instrumentation. B. Braun Medical, Inc. (2000). Press release: B. Braun focuses on consumer education regard- ing infusion pump decimal and calculation errors. Available: http://www.bbraunusa. com/index.cfm?84414D8ED0B759A1E3E55CD9354BA0C5 [accessed July 2009].

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