Electrical engineers at the University of California, San Diego demonstrated a wireless communication technique that sends magnetic signals through the human body. The secure, low-power innovation could lead to a wireless sensor network for full-body health monitoring.
In the study, the electrical engineers demonstrated a technique called magnetic field human body communication, which uses the body as a vehicle to deliver magnetic energy between electronic devices. The magnetic fields are able to pass freely through biological tissues, so signals are communicated with much lower path losses and, potentially, much lower power consumption. Researchers showed that the path losses associated with magnetic field human body communication are upwards of 10 million times lower than those associated with Bluetooth radios.
Because Bluetooth radio communicates data over the air, anyone standing within 30 feet can potentially eavesdrop on that communication link. Magnetic field human body communication, however, employs the human body as a medium, making the communication link less vulnerable to eavesdropping.
The researchers' prototype consists of copper wires insulated with PVC tubes. On one end, the copper wires are hooked up to an external analyzer; the wires on the opposite end are wrapped in coils around three areas of the body: the head, arms, and legs. The coils serve as sources for magnetic fields and are able to send the signals. With the prototype, researchers were able to demonstrate and measure low path loss communication from arm to arm, from arm to head, and from arm to leg.
