Put simply, electrodermal activity (EDA) is the measurement of the conductivity of the skin caused by sweating. The unconscious action of sweating is a strong indicator of activation of the sympathetic nervous system, which is triggered by changes in a person’s emotional state, such as stress, anger, excitement or joy.

By measuring changes in EDA, the MAP Health Watch is able to identify unusual activity in the body in real time and compare results over time, building up an accurate picture of the user’s health. When plotted against other metrics, such as heart rate and movement, MAP Health Watcher, the company behind the MAP Health Watch, is able to establish a reliable picture of both the user’s physical and mental health. So as well as indicating that your stress levels might be too high, the sophisticated algorithms and neural network developed by MAP Health Watcher are able to indicate first signs of illness that might otherwise go unnoticed.

Electrodermal activity: The stress-level indicator

Perhaps, most importantly, EDA is a valuable indicator of an individual’s psychological state. Electrodermal activity readings have long since been used in psychological experiments to measure the responses of subjects to particular stimuli. EDA is probably best known as the key component of a polygraph, also known as the ‘lie detector’, test. The technology works because most of us feel very uncomfortable when we are unable to tell the truth for whatever reason. This produces an involuntary response in the limbic system of the brain, which in turn has physical manifestations. These are what a poker player might call “tells“. Although you may be able to maintain a ‘poker face’, you will not be able to stop certain natural responses in your body, such as sweating, increased heart rate and body temperature.

Keeping an eye on mental health

Taken out of the context of a game, which we usually play for enjoyment and excitement, these are clear signs of stress. Although we all experience it from time to time, stress is something to be avoided in the long term as it can have a major detrimental effect on the health. In addition, sudden sweats during the day are also a sign of anxiety disorder, while inactivity during the day and restlessness at night are tell-tale signs of depression. All of these signs can be measured by the MAP Health Watch, which means the device also has great potential in the field of mental health.

Allowing doctors to see the bigger picture

In addition to measuring EDA, the MAP Health Watch, available on Indiegogo from this fall, contains four other sensors capable of providing clinical-grade data on the user around the clock. When it comes to measuring electrodermal activity, the device’s ability to plot chances in the skin’s galvanic activity against other vital signs in real time is particularly valuable. The data is continuously analyzed by the MAP Health Watcher servers based on sophisticated algorithms to provide the MAP Health Watcher team of qualified physicians with up-to-the-minute information on the well-being of users. Based on this information, they are not only able to track the development of the user’s overall health, but also assess the risk of  and other serious conditions. Being able to measure EDA in real time is an important part of this.

…or the sudden change of state

For example, sudden spikes in electrodermal activity may indicate the onset of a virus or bacterial infection, or even something more serious, such as heart disease or the risk of cardiac arrest. In addition, if the wearer of the MAP Health Watch is involved in an accident, the EDA data is also a valuable indicator of the severity of the incident in combination with the accelerometer, heart rate, skin temperature and estimated blood pressure readings. For instance, a sudden drop in body temperature coupled with a sudden increase in EDA may indicate a serious trauma, such as a car accident.

A powerful tool for the future

What is more, research into the significance of EDA data is ongoing, so the 24-hour data provided by the MAP Health Watch and our neural network combining readings from thousands of patients has the potential to unlock new doors in the field of medicine. Once the MAP Health Watch goes online, we will be able to collect data to an unparalleled level of detail and complexity, allowing us to explore areas that were previously inaccessible to the medical community. Watch this space.