Articles on Law, Science, and Engineering

High Tech Devices in Low Tech Environments: The Lay Use of Medical Devices

By Edward P. Richards, Research Director, National Center for Preventive Law, and Charles Walter, 8 IEEE Engineering in Medicine and Biology Magazine #4, pg. 60 (December 1989)

In a previous article, "How is a Lawnmower Like an Anesthesia Machine?", we discussed product misuse by an expert. In this article we discuss the problem of the misuse of medical devices by patients and other untrained individuals during home use. Since extensive home use of medical devices is a new phenomenon, there are few legal precedents to go by. This article, therefore, is based on the authors' experience with companies that provide medical devices for home use and discussions with individuals involved in home health care.

Litigation, however, is sure to come. Due to escalating costs, the current trend in health care is "cost containment," which may include moving patients out of the hospital and into the home. In many cases, such as outpatient testing, this benefits the patient and saves money. In other situations it forces sick patients from the hospital into situations where they do not receive adequate care. Unfortunately for medical device manufacturers, these patients are often sent home dependent on medical devices for survival.

Biomedical engineers design life-support devices to be used by skilled technicians in a constantly monitored environment. These devices are not meant to be idiot-proof, nor are they meant to be failure proof. If properly designed, medical devices fail in predictable ways and alert support personnel to the need for intervention. The failure mode analysis for medical devices depends on assumptions about both the availability of skilled personnel to maintain the device, and about the environment in which the device operates.

When a device is put in a home, the usual assumptions about the availability of personnel and the working environment may be invalid. Accordingly, the engineering and design of medical devices should be examined before such devices are used in a home environment. It may be possible to simplify the design of home devices, thereby making them more affordable and easier to use. This may result in two versions of the same medical device: one for prescribed home use ("home-use devices") and one for use under the direct supervision of a health care provider ("capitol equipment"). An example is home-use devices for physical therapy which are simplified versions of capitol equipment used for the same therapy in a hospital or clinic.

More fundamentally, equipment manufacturers need controlled environments in which their devices are placed. While capitol equipment is usually found in a controlled environment, home-use devices are not. The classification of home environments is based on two factors: 1) the willingness of the family to care for the dependent individual; and 2) the family's resources. This results in four scenarios: 1) willing families with adequate resources; 2) willing families with inadequate resources; 3) unwilling families with adequate resources; and 4) unwilling families with inadequate resources.

Families with adequate resources may be unwilling or unable to care for a family member who is dependent on a medical device. While the rhetoric of deinstitutionalization is heavy with positive talk about independence and normal lifestyles, the reality is sometimes much less rosy. These patients are often very sick, in need of constant attention, and without hope of improvement. Caring for such patients may be emotionally difficult (or impossible) for other family members.

The most difficult problem is children. Modern advances in medical technology, combined with uncontrolled applications of the technology without regard to its long term implications, have resulted in the survival of children who are dependent on ventilators or total parenteral nutrition for their survival. These children have episodic illnesses, but are frequently healthy. In theory, such a child may be expected to have a normal lifespan, but in reality recurrent infections or other complications of instrumentation kill them before adulthood.

Caring for these children is time consuming and emotionally draining. The parents love the children but resent the restrictions they impose on family life. The guilt this generates is exacerbated when the child dies. The parents may seek someone to blame for the child's death to assuage their own guilt over being relieved that they are not longer tied down. If they think an equipment failure occurred, that someone will be the device manufacturer.

The first issue medical device manufacturers must confront is whether they want their devices used in the home. The extra costs of designing and engineering a home-use device may not be justified by the volume of home-use sales. Additional costs associated with home-use devices or capitol equipment used in the home include expanded training materials and manuals, difficulty in tracking machines for maintenance and recall, and lack of control of use supervision, all of which may lead to increased risks of liability for injuries. These costs may outweigh the benefits for devices that are used in the home only occasionally.

If the manufacturer does not want its equipment used outside medical care institutions it must take four steps: 1) every contract for sale must limit title to the equipment; 2) each device must be clearly labeled with warnings against use by patients or other untrained individuals; 3) all manuals must clearly state that the use of the equipment is strictly restricted to qualified personnel; and 4) the manufacturer must attempt to prevent any foreseeable use of the device by unauthorized individuals.

Manufacturers of home-use devices or that condone or encourage home use of capitol equipment should try to establish communications with the individuals using their devices. Since home-use devices and capitol equipment are often sold to end-users by independent distributors who may carry a line of competing products from several manufacturers, it may be necessary to establish the customer link through a distributor who is reluctant to reveal the names of its customers. This should be addressed contractually at the consummation of the manufacturer/distributor relationship through the use of a confidentiality agreement.

The difficulties associated with establishing links with device users through independent distributors encourage device manufacturers to sell their products directly to end-users.

In either situation, the device manufacturer should ensure that individuals operating its devices be trained and have simple operating instructions and warnings available at all times. This means that all warnings and instructions should be written in terms easily understood by patients and other laymen, and that they cannot be separated from the equipment. An example is the instructions and warnings permanently placed on many office copying machines. If the equipment is too complex to explain in permanently attached instructions, the decision to encourage home use should be re-examined. If alternative engineering designs cannot simplify the device, it does not belong in home use.

The manufacturer should provide comprehensive training materials, preferably including a video-tape. Facilities for viewing the video-tape should be provided at various product distribution centers. These materials should cover all aspects of machine operation and any necessary user maintenance. The training should state bluntly that improper operation of the device can cause injury and death.

The device should be labeled with a warning that operation of the device by a person who has not received the manufacturer's training constitutes misuse and will endanger the patient's health. In addition to family members, this warning is aimed at home-care nurses who lack adequate training for devices that they are expected to maintain. Home-care nurses should demand that they be properly trained on every device they are expected to work with.

The manufacturer should provide a standard consent form for any person, or that person's parent, or guardian, who may be injured if the device is misused or malfunctions. This form should state that medical devices are not perfect and that a failure or misuse of the device can kill or injure the patient. It should explain that, by choosing home care over hospital care, the family assumes the duty to care for the patient at all times and to properly maintain the device.

Most importantly, the consent form should stress that the patient and family understand and accept that home care involves personal responsibility for providing patient care and is more dangerous to the patient than being cared for in the hospital: "I hereby acknowledge that this medical device is essential to my health. I accept that this device may be misused or fail and that I may die as a result thereof if I do not immediately receive emergency medical care. I acknowledge that this emergency care is not available in my home, but I accept this increased risk of death in return for the benefits of being at home."

This consent form should also spell out all resources necessary for the home use of the device. These may include continuous observation of the patient 24 hours per day, ground fault detector outlets, an emergency power generator, and any other special equipment and personnel requirements. The patient or responsible person should initial each item to verify that it is being provided. The physician discharging the patient should also be required to sign a statement that he has found that these requirements have been met.

This consent form serves two purposes. It documents that the patient has accepted the risk of home care using the medical device. More importantly, it makes it more difficult for hospital personnel to send medical devices home under inappropriate circumstances. In some communities, medical devices are prescribed to patents who are sent to homes without proper wiring, adequate supervision, or access to emergency care if the device fails. Thus, this consent form would help patients and their families resist the pressure generated by the current wave of "cost containment" to take sick patients out of hospitals.