Wearable Biomonitoring Instruments

Body-monitoring technology could be used to detect when someone is experiencing anxiety or stress related to a specific situation that could lead to relapse.

“We know that stress is the most accurate predictor of relapse, and relapse is often preceded by stressful episodes characterized by feelings of strong negative moods,” says Timothy Baker, PhD, professor of psychology at UW–Madison. “This suggests that autonomic nervous or somatic system activity associated with stress and distress can be used to detect such stressful episodes, which is important since laboratory research shows that individuals may actually be unaware of when they are becoming stressed or experiencing negative moods.”

Indicators of stress, such as heightened skin conductance of electric current and increased heart rate, pulse, and muscle tension, usually accompany higher states of arousal, and these physiologic indicators can be measured by wearable technology available today. Such products offer different measurement capabilities and come in forms such as shirts with integrated sensors, removable patches, or sensors that attach to fingers. BodyMedia (www.bodymedia.com) is one of the leaders in creating easy-to-wear monitors that collect the physiologic information needed to measure arousal and incorporate integrated wireless data transmission and Web-based interfaces for interpreting results.

Consider the following scenario of how such wearable technologies might be used to improve addiction treatment and recovery:

A husband (in recovery from alcoholism) and his wife attend a party. The couple begins to argue, and the physiologic sensors the man is wearing record a spike in arousal. An application sends a message to his mobile phone asking if he needs any support. Likewise, the sudden increase in stress triggers text messages to be sent to the mobile phones of people in his support network, such as a peer sponsor and a therapist, who immediately call him to make sure he is managing the stress appropriately (i.e., not drinking).

Biomonitoring devices have some limitations despite their many possibilities. First, the most fully featured devices can be relatively costly. Although costs can be expected to decrease over time, the current instruments also are not specific enough to maximize their use for people in recovery; they indicate general arousal rather than specific emotional states such as anxiety or depression. An elevated heart or pulse rate or drop in the resistance of skin to the passage of electric current can be associated with emotional or physiologic arousal but does not indicate whether the arousal is positive or negative. A person may be aroused because he is craving alcohol or drugs—or because he is flirting or watching his favorite football team score a touchdown.

Despite these shortcomings, general arousal data could be used to trigger automatic “check-ins” to confirm if a person is doing okay or to cross-check physiologic data against his schedule to objectively discuss routines or situations that may relate to negative arousal and increased likelihood of relapse.

Embedded Microchip Sensors

Another type of body-monitoring device that offers the potential to prevent relapse involves microchip sensors (with wireless capabilities) implanted in the body. Embedded sensors could assess rising cortisol levels that indicate cumulative stress over a person's day rather than immediate stress that comes from a moment of high risk for relapse. Research indicates that a pattern of gradually rising distress levels is a significant predictor of relapse. This suggests that information on gradually emerging stress levels may be useful in the timing of interventions.

“If a pattern of escalating stress could be short-circuited, this might give people in recovery the resilience to resist addictive impulses as they arise,” says Dr. Baker. Rising stress levels, measured by the implanted microchips and transmitted to reporting devices such as computers and phones, could alert the person in recovery that he should implement some healthy stress-management strategies such as exercise or meditation, or inform treatment providers and peer sponsors that additional support may be needed.

Microchips could be designed to trigger the release of implanted pharmaceutical agents to reduce cravings for alcohol or other drugs when overall daily stress levels surpass a given threshold.

Zarlink (www.zarlink.com) is among the early innovators developing wireless microchips that could be integrated with a specialized, implanted medical device to monitor hormonal stress levels or other physiologic indicators to assist in preventing relapses for individuals in recovery.

One limitation of the current technology is that the monitored individual needs to be in close proximity to a data-collection station for the data to be transmitted wirelessly and subsequently acted on.

Implanting sensors might raise privacy concerns and strike some as being too intrusive. “We are very sensitive to the ethical issues involved in considering these types of technologies and believe they could only be used on an opt-in basis,” says Dr. Gustafson. “Yet when we see addiction as a chronic illness similar to other conditions that require a proactive disease management regimen such as diabetes, asthma, or hypertension, we believe many people might choose such an option if it could improve their health, prolong their lives, and reduce the suffering associated with addictive disorders.”

Brain Imaging

Current and emerging brain-imaging methods could detect specific brain activity that might indicate a high-risk relapse event. These technologies include functional magnetic resonance imaging (fMRI) or positron emission tomography (PET), which show indirect measures of blood flow. Studies using imaging technologies to measure blood flow in the brain do indeed indicate that specific emotions and addictive cravings can be tracked using these technologies. Ideally, such technologies could pinpoint the activation of addictive cravings or other emotional states that could precede relapse, triggering appropriate supports as needed.

Brain-imaging technologies’ current limitations restrict their near-term deployment to improve addiction treatment outcomes. First, pinpointing areas of the brain involved in specific emotions or impulsive cravings is still an inexact science with significant variability in brain activation patterns across different people. Brain- imaging equipment is expensive and complex. The most common models are about the size of a coffin, imposing significant restrictions on mobility, and are certainly not wearable.3

TABLE. Comparison of body-monitoring methods for relapse prevention

More mobile brain-imaging technologies such as infrared spectroscopy are under development, but cost and mobility restrictions likely will be obstacles to wide deployment of brain-monitoring technology to improve addiction treatment and recovery outcomes for at least the next one to three years.

Wearable Alcohol and Drug Detectors

Wearable body-monitoring technology to track alcohol and drug intake has been used for years, primarily by the criminal justice system to support treatment and enhance supervision of repeat offenders of substance abuse–related crimes (e.g., driving while intoxicated). Alcohol Monitoring Systems (www.alcoholmonitoring.com) offers one of the most advanced and widely adopted of these technologies with its SCRAM (Secure Continuous Remote Alcohol Monitor). A bracelet strapped to an ankle tests imperceptible emissions of sweat about once an hour. Once a day, a modem downloads the data to Alcohol Monitoring Systems’ servers, and a person's data can be viewed via a Web interface. If the person had any alcohol—even mouthwash—it shows up.

These devices are used primarily in the context of criminal justice, but they might have potential as an opt-in solution for individuals with a history of unsuccessful transitions from residential to outpatient treatment and other continually failed efforts to maintain abstinence. People in recovery might choose to wear such a device as a way to assure higher levels of accountability to therapists or loved ones when entering high-risk situations. Wearing such a visible device as an ankle bracelet, however, might have a stigmatizing effect.

The Bottom Line

The potential for using body-monitoring technology to prevent relapse is an exciting one. The table summarizes the pros and cons of the technologies profiled in this article. At the end of the day, the most significant factors affecting whether these technologies are adopted is whether they improve outcomes and if providers are reimbursed for using them with their patients. “We must demonstrate outcomes for these technologies to be adopted,” says Dr. Gustafson. “Our intent is to run pilot tests to assess their feasibility and then demonstrate measurable benefits from their use. Ultimately, decision makers will want to see that these technologies provide a tangible return on their investment.”