Utilizes Adaptive Harmonics Filter to Perform Non-invasive Measurement of Vital Signs
This wireless vital sign monitor uses an adaptive harmonics filter to accurately measure heart rate from radar-collected cardiorespiratory data. A critical aspect of physiological research in small animals involves monitoring for signs of pain to ensure patient welfare and drug efficacy, which is indicated by fluctuations in respiratory rate and heart rate. The monitor market will be worth $4,375 million by 2018. Typically, contact sensors, such as the electrocardiograph, are used for vital sign monitoring. However, the use of contact sensors requires surgical insertion during the post-treatment recovery period – unfortunately, surgery on an animal after a major medical procedure can result in unwelcome side effects, which may include the death of the animal. The main obstacle for non-contact, non-invasive vital sign detection has been accurate and consistent measurement of heart rate without interference from respiration movements. University of Florida researchers have developed a non-invasive vital sign monitor that uses an adaptive harmonics filter to reliably measure heart rate without respiratory interference. This device can be used as a stand-alone monitoring device or can be embedded in computers, mobile devices, and wearable devices to allow non-invasive vital sign monitoring in a small animal; it may be adapted for clinical monitoring in human patients.
Radar-based, non-invasive, non-contact heart rate monitor
- Non-contact, non-invasive monitor, allowing consistent and accurate collection of heart rate data while reducing the risk of disruptive side effects or injuries associated with use of contact sensors
- Needs no calibration when distance changes between the monitor and the target organ, making it easier to accurately measure a small animal’s heartbeat
This wireless vital sign monitor accurately measures heart rate by filtering radar-collected cardiorespiratory data through an adaptive harmonics filter, and then identifying a heart rate from the filtered cardiorespiratory data. When measuring the vital signs of a human or animal with a non-contact monitor, available monitors detect both respiration and heartbeat. The larger respiration signal typically overshadows and obscures the smaller heartbeat. This monitor uses a computing device to determine the respiratory rate and respiration displacement from radar-collected cardiorespiratory motion data. Then, the computing device adjusts notch depths of the harmonics filter, based on respiration displacement. Finally, the computing device uses the adjusted harmonics filter to refine radar-collected cardiorespiratory data and to identify a heartbeat. Specifically, using the harmonics filter with adaptive attenuation at each harmonic frequency removes the appropriate magnitude of respiratory harmonics without weakening the heartbeat signal, and the heartbeat signal can be enhanced to provide a more accurate reading.