Scientists have developed a new, wearable sensor that uses
silver nanowires to monitor electrophysiological signals, such as
electrocardiography (EKG) or electromyography (EMG).
According to the researchers from North Carolina State University, the sensor is as accurate as the 'wet electrode' sensors used in hospitals, but can be used for long-term monitoring and is more accurate than existing sensors when a patient is moving.
Long-term monitoring of electrophysiological signals can be used to track patient health or assist in medical research. The monitoring may also be used in the development of new powered prosthetics that respond to a patient's muscular signals.
Electrophysiological sensors used in hospitals use wet electrodes that rely on an electrolytic gel between the sensor and the patient's skin to improve the sensor's ability to pick up the body's electrical signals. However, this technology poses problems for long-term monitoring.
The new nanowire sensor is comparable to the wet sensors in terms of signal quality, but uses a 'dry' electrode. This change makes the device good at long-term-monitoring.
"People have developed other dry electrodes in the past few years, and some have demonstrated the potential to rival the wet electrodes, but our new electrode has better signal quality than most - if not all - of the existing dry electrodes. It is more accurate. In addition, our electrode is mechanically robust, because the nanowires are inlaid in the polymer," says Dr. Yong Zhu, an associate professor of mechanical and aerospace engineering at NC State and senior author of a paper describing the work.