Non-contact respiratory measurement in a horse in standing position using millimeter-wave array radar

This study aimed to apply radar technology to a large quadruped animal. We first developed a non-contact respiration measurement system using millimeter-wave array radar for a horse in standing position. Specifically, we measured the respiration of a stationary domestic horse in stables. Simultaneously, we measured the respiration rate using infrared thermography and developed a method for analyzing the radar information while verifying the rate of agreement. Our results suggested that the radar technology detected breathing and accurately measured the respiration of a horse, despite variation in the breathing frequency. To the best of our knowledge, this is the first study to apply a non-contact respiration measurement system using millimeter-wave array radar has been applied to large animals in an upright position, thereby demonstrating its potential application in animal husbandry and welfare.