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.
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.
The silver nanowire
sensors conform to a patient's skin, creating close contact.
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.
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.