Carla Benton

Millimeter wave radar for remote measurement of vital signs

We present the development of a 228 GHz heterodyne radar system for the remote measurement of respiration and heart rates. The advantages of a millimeter wave system include a higher sensitivity to small displacements, transmission through the atmosphere and clothing and the ability to maintain a collimated beam over large distances. We present a set of respiration and heart rate measurements out to a range of 50 meters.

Remote respiration and heart rate monitoring with millimeter-wave/terahertz radars

The characteristics of continuous-wave millimeter-wave/terahertz radars make them candidates to remotely sense the physiological parameters of individuals, such as respiration and heart rates. The characteristics of these radars include transmission through the atmosphere and clothing, well-collimated beams, and sensitivity to small displacements. The directional Doppler velocity can be used to measure the movement of a subjects chest wall due to respiration and the more subtle motion of the body due to the cardiopulmonary system. We will present an overview of two systems that have been developed along with representative data from each.

Nondestructive terahertz imaging for aerospace applications

The full potential of terahertz imaging systems for nondestructive aerospace imaging applications has not been realized due to the lack of data linking damage and defects to terahertz signatures coupled with the complexity of modeling the signatures. Terahertz systems (0.1 - 2.0 THz) may be ideally suited for NDI applications because of the ability of THz radiation to penetrate through substances commonly found on the surfaces of aircraft structures while maintaining the optical resolution required to detect defects. We will discuss several systems that we have used to study the signatures of a set of target samples with known defects.

Micro-Doppler radar signatures of human activity

We will present the continued development of a millimeter-wave/sub-THz radar system used to capture and assess micro-Doppler signatures of humans. This system is being developed to remotely monitor respiration and heartbeat rates at standoff distances of up to 100 meters. We will discuss the latest hardware and software developments and recent studies of the performance of the system under a variety of conditions.

Millimeter-Wave Radar for Vital Signs Sensing

In this paper, we will describe the development of a 228 GHz heterodyne radar system as a vital signs sensing monitor that can remotely measure respiration and heart rates from distances of 1 to 50 meters. We will discuss the design of the radar system along with several studies of its performance. The system includes the 228 GHz transmitter and heterodyne receiver that are optically coupled to the same 6 inch optical mirror that is used to illuminate the subject under study. Intermediate Frequency (IF) signal processing allows the system to track the phase of the reflected signal through I and Q detection and phase unwrapping. The system monitors the displacement in real time, allowing various studies of its performance to be made. We will review its successes by comparing the measured rates with a wireless health monitor and also describe the challenges of the system.

Millimeter-wave radar systems for biometric applications

Millimeter-wave and terahertz radar systems can play an important role in multimodal layered sensing systems targeted at measuring both physiological and behavioral biometric data for security and medical applications. We will describe a 228 GHz heterodyne radar system that is capable of measuring respiration rates at standoff distances of up to 50 meters and simultaneously measure respiration and heartbeat rates at a distance of 10 meters. We will discuss the latest hardware and signal processing developments and a wide range of studies aimed at optimizing the performance of the system under a variety of potential field applications.