Can RFID Monitor Patients’ Vital Signs?

It sounds like what you are referring to is telemedicine, in which patients wear vital-sign monitors and the information is constantly transmitted to a central location, where doctors monitor patients remotely.

This can be accomplished without RFID, of course. Data could be transferred to a smartphone via Bluetooth, and then be transmitted via the cell network. The problem is that most such solutions are expensive, involving bulky sensors incorporated into vests worn by a person being monitored.

RFID could potentially be both more cost-effective and less intrusive. Researchers at the Georgia Institute of Technology, for instance, have created a passive ultrahigh-frequency (UHF) tag that is so thin it can be sewn into a medical gown (see Georgia Tech Researchers Create an RFID-Sensor Medical Patch).

Researchers at Michigan State University have developed a system that employs RFID-enabled sensors to track the movements of different body parts, in an effort to monitor activity levels. The system includes three RFID tags attached to a person's upper arm, wrist and ankle. The tags contain proximity sensors and accelerometers, allowing the system's software to calculate the amount of movement and angle of a person's limbs, thereby allowing the system to monitor activity levels (see Michigan Researchers Develop RFID-based Sensors to Measure Physical Activity).

Researchers at AT&T Labs have developed a wireless device to monitor seniors within their homes. The unit is designed to detect signs of impending falls, so that preventive measures can be taken. AT&T's "Smart Slippers," developed in partnership with Texas Tech University, are based on technology used in interactive games. Each slipper's sole is fitted with pressure sensors, an accelerometer and a ZigBee communications device to monitor a patient as he or she walks. Every sensor has a unique ID, and as a person walks, pressure data is communicated via ZigBee technology to a base station within his or her home, which transmits that information to a remote host computer. The accelerometer determines the patient's speed of motion. Researchers at Texas Tech's geriatric care facility have utilized the technology to study how patients walk, in order to determine if they can detect danger signs (see RFID Slippers Could Prevent Slips).

As far as I know, there is no off-the-shelf system of sensors that can communicate a person's location, movements and vital signs via Wi-Fi.