First noncontact millimeter‐wave radar measurement of heart rate in great apes: Validation in chimpanzees (Pan troglodytes)

• Published in: American journal of primatology Vol. 86; no. 8; pp. e23633 - n/a
• Main Authors: Matsumoto, Takuya, Iwata, Itsuki, Sakamoto, Takuya, Hirata, Satoshi
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.08.2024
• Subjects: Anesthesia; Animal welfare; Animals; Apes; Chimpanzees; Contact stresses; Electrocardiography; Endangered; Endangered species; Frequency spectrum; Heart rate; Hominids; Human motion; Installation; Measurement; Measurement methods; Measurement techniques; millimeter‐wave ultrawide‐band array radar; Monkeys & apes; noncontact measurement of vital sign; Pan troglodytes; Peak frequency; Physical stress; Primates; Radar; Radar measurement; Research subjects; stress; Technology; Technology assessment; Weather; Welfare; stress; heart rate; animal welfare; millimeter‐wave ultrawide‐band array radar; noncontact measurement of vital sign
• ISSN: 0275-2565; 1098-2345; 1098-2345
• DOI: 10.1002/ajp.23633

Heart rate is a crucial vital sign and a valuable indicator for assessing the physical and psychological condition of a target animal. Heart rate contributes to (1) fundamental information for cognitive research, (2) an indicator of psychological and physical stress, and (3) improving the animal welfare of captive animals, especially in nonhuman primate studies. Heart rate has been measured using a contact‐type device; however, the device burdens the target animals and that there are risks associated with anesthesia during installation. This study explores the application of heartbeat measurement techniques using millimeter‐wave radar, primarily developed for humans, as a remote and noninvasive method for measuring the heart rate of nonhuman primates. Through a measurement test conducted on two chimpanzees, we observed a remarkable correspondence between the peak frequency spectrum of heart rate estimated using millimeter‐wave radar and the mean value obtained from electrocardiograph data, thereby validating the accuracy of the method. To the best of our knowledge, this is the first demonstration of the precise measurement of great apes' heart rate using millimeter‐wave radar technology. Compared to heart rate measurement using video analysis, the method using millimeter‐wave radar has the advantage that it is less susceptible to weather and lighting conditions and that measurement techniques for multiple individuals have been developed for human subjects, while its disadvantage is that validation of measurement from long distances has not been completed. Another disadvantage common to both methods is that measurement becomes difficult when the movement of the target individual is large. The possibility of noncontact measurement of heart rate in wild and captive primates will undoubtedly open up a new research area while taking animal welfare into consideration. We observed a remarkable correspondence between the peak frequency spectrum of heart rate estimated using millimeter‐wave radar and the mean value obtained from electrocardiograph data, thereby validating the accuracy of the method. Research Highlights Applied millimeter‐wave radar measured chimpanzees heart rate accurately, marking the first use of this technology in great apes. Millimeter‐wave radar heart rate measurement holds promise for managing the health of endangered great apes.