The device, called "Vital Dust," transmits patient data to a hospital or centralized location, allowing others to see the data and also gain a global view of all patients in the field who are being similarly monitored. It measures heart rate and the percent of oxygen saturation in the blood, an important indicator of a person's cardiopulmonary status. A radio transmits the information to a wearable or handheld computer, where it is displayed for a medical team.
"If there is a mass casualty event, having this information on all the victims will allow the emergency medical technicians to triage right then and there, giving the sickest people priority. In single-person casualties, we'll know right away if the patient has a sudden change in status and needs immediate attention," said Matt Welsh, Ph.D., assistant professor of computer science at Harvard University, one of Vital Dust's developers and lead author of the study.
"This advance may lead to a more rapid triaging system," said Steve Moulton, M.D., one of the researchers who tested the device.
Vital Dust consists of a small, low-power computer connected to a sensor that fits over the patient's fingertip. It is about six centimeters by three centimeters, or the size of a pack of chewing gum. Vital Dust runs on two AA batteries and includes an embedded microprocessor, memory, and a wireless communication interface.
Another unique feature of Vital Dust is its ability to store the pre-hospital electronic medical record together with a record of the patient's vital signs.
"This form of data management enables a copy of the pre-hospital record to travel with the patient, giving hospital-based personnel the ability to review what was done in the field and determine how those maneuvers may have influenced the resuscitation process," said Moulton.
Moulton and his study co-authors are integrating Vital Dust sensors with iRevive, a pre-hospital, mobile database, to automate the process of capturing patient information.
One of the unique features is that the radio can adjust the power for transmitting information, Welsh said.
"If a patient's heart rate slows dangerously or his oxygen saturation level drops precipitously, the system will automatically adjust the transmission power so that a stronger signal is sent out and has a greater chance of being received by the paramedic," he said. "The radio would back off transmitting other patients' data, thus giving a critical patient's signal an even greater chance of going through." This is the first wireless network designed to give priority to victims that are in critical condition, Welsh said. "Continuous real-time monitoring of vital signs in the field should greatly improve the effectiveness of emergency medical care."