Background

Many medical sensors and monitors require direct contact with human skin, sometimes in specific locations on the body. Unfortunately, currently available wired devices pose significant hurdles, as the wires can be cumbersome for both medical providers and patients. This is not only an inconvenience, but such interference can also reduce the utility of such devices, and even discourage use. Thus, it would be advantageous if certain medical sensors and monitors did not require the use of such wires.

However, removing the problematic wires requires overcoming two separate problems: powering the device and transmitting data. Transmitting the data can be solved by equipping the sensor with a Bluetooth transmitter. Unfortunately, powering the device without employing wires is more challenging.

Current market solutions include adding elements such as small rechargeable batteries, various forms of mechanical-to-electric energy conversion, or solar energy collection. These are imperfect solutions, as they require expensive, pollution-creating lithium-ion batteries, the patient to be actively moving, or the patient to be in direct sunlight (impractical in most hospital situations), respectively.

Thus, wireless medical sensors remain impractical or cost-prohibitive.

Technology Overview

NC State researchers have developed a novel, self-powering wireless medical sensor system designed to perform electrocardiogram (ECG) sensing. To achieve self-powered operation, the system uses two (2) devices in tandem: 1) a continuous wave (CW) source designed to plug into a mobile device, and 2) the on-body sensor itself. In particular, the CW source produces a CW signal used for data transmission. Because the CW source is able to harness the power of the corresponding mobile device, the CW source does not require any independent power source.

Further, by using Bluetooth backscattering transmission, the sensor manipulates the CW signals to transmit its data. Such transmission allows the sensor to consume substantially less power than any other device on the market. The power requirements are so low that the sensor may be powered by various technologies, including a Sweat Activated Cell (SAC) power supply also developed by NC State researchers. Thus, there is no need for an expensive battery or other situationally dependent sources of power.

Based on the design described above, this technology is both cheaper and more user-friendly than any other wireless medical sensor available on the market.

Benefits

Wireless medical sensing.
No need for expensive batteries.
No need for patients to be actively moving or exposed to direct sunlight.
Environmentally friendly by saving lithium.
Low maintenance due to simplicity of design.

Applications

Wireless medical sensing
Emergency room, high-speed application of sensors
Mobile sensing for on-the-go medical uses
In-home constant monitoring without the need to regularly maintain the device.

Self-Powering, Wireless Medical Sensor

Patents

IP Status