essential for the well-being of these animals and for research purposes. Unfortunately, current methods are either too invasive or not very accurate. However, a recent study has looked into the possibility of using millimeter-wave radar technology to measure the heart rate of chimpanzees by detecting subtle body movements. This breakthrough could lead to improved methods for monitoring the heart rates of both captive and wild primates.
Measuring the heart rate of great apes in captivity is essential for both health management and animal studies. However, existing most methods are either invasive or inaccurate. Now, researchers have investigated the potential of using millimeter-wave radar technology to estimate heart rate from subtle body movements in chimpanzees. Their efforts will hopefully pave the way to better practices and techniques for monitoring heart rates in wild and captive primates.the potential for health monitoring, accurate and non-invasive heart rate measurement can also provide valuable insights into the physiological and emotional states of nonhuman primates.
The study, published in the Journal of Biological Rhythms, involved using millimeter-wave radar technology to measure heart rate in three captive chimpanzees. The researchers found that they were able to accurately estimate heart rate from subtle body movements, such as breathing and chest wall movements. This non-invasive method has the potential to revolutionize the way heart rate is monitored in nonhuman primates, both in the wild and in captivity.
The health benefits of monitoring heart rate are clear, and it is also valuable in studying animal cognition. For instance, research has shown that a chimpanzee’s heart rate can change in response to psychological stress, emotional stimuli, or familiar humans.
Various methods have been developed to measure heart rate in great apes. In addition to traditional contact measurements, the most common approach involves using a wireless device attached to the animal to monitor and transmit its heart rate from a distance. However, the installation of the device often requires anesthesia, which carries its own risks. Additionally, the device itself can be disruptive to the animal’s natural behavior.The act of directly measuring an animal’s heart rate could cause stress to the animal or others in its group. A less intrusive method involves using video feed to estimate heart rate, which has been tried with some species of primates. However, the accuracy of these methods is highly dependent on lighting conditions and the animals’ movements.
Given these challenges, a research team led by Asisstant Professor Takuya Matsumoto from Shinshu University, Japan, aimed to find a more effective alternative. In their recent study, published in the American Journal of Primatology on May 22, 2024, the researchers explored whether millimeter-wave radar-based techniques could provide a better solution.The technology originally created for humans has potential for measuring heart rate in chimpanzees. The co-authors of the study are Dr. Itsuki Iwata, Dr. Takuya Sakamoto, and Dr. Satoshi Hirata, all affiliated with Kyoto University.
The proposed method involves sending high-frequency electromagnetic pulses at the animal’s chest and capturing the resulting echoes. These echoes can then detect small body movements, which are used to estimate heart rate using specialized algorithms. Dr. Matsumoto emphasizes the motivation behind the study, stating, “Millimeter-wave radar technology has been extensively developed for applications in various fields, and now we can potentially expand its use to non-invasive monitoring of chimpanzee health.“The researchers initially focused on the potential applications of radar technology in automated driving and medicine. However, a conversation with a radar researcher at an academic conference inspired them to explore the possibility of using radar technology on primates other than humans. This led to the start of a joint research project.
In order to test their approach, the researchers conducted experiments during the annual health checks of two adult chimpanzees at Kumamoto Sanctuary, Wildlife Research Center, Kyoto University. The chimpanzees were anesthetized, and a radar system was placed about half a meter above their chest. Additionally, traditional electrocardiography (ECG) signals were recorded and used for comparison.
To determine the accuracy of the radar-based technique, researchers compared the heart rates recorded via ECG with those obtained using millimeter-wave radar for chimpanzees. The results showed that the two methods closely matched, validating the proposed strategy. Dr. Matsumoto emphasized that despite the muscular bodies of chimpanzees raising concerns about measuring their heart rate in a similar manner to humans, the study demonstrated the feasibility of noncontact heart rate measurements through the analysis of subtle body surface movements. He also noted that these findings could broaden the potential applications of this technology.
“Techniques in studies of animal psychology and wild primatology involve using millimeter-wave radar-based methods for heart rate monitoring,” the researcher explained. ”These methods offer significant advantages over standard practices. They are entirely noninvasive, allowing for frequent use without causing stress to the animals. Additionally, heart rate can also be remotely measured using video analysis with a digital visible light camera, which doesn’t need specialized equipment and can reuse existing videos. Two main techniques are utilized: imaging photoplethysmography, which detects blood volume changes, and periodic movement extraction, which measures heart and respiratory rates from body movement.”The researchers hope that their work will lead to more innovative ways of monitoring vital signs in captive animals, such as heart rate and respiration rate. Remote measurement of heart rate in apes could improve their health management and welfare in captivity, such as in zoos. Further studies are needed to validate the proposed method for use in regular practice, where animals have the freedom to move in their enclosure.With any good fortune, these methods might assist us in maintaining the well-being of our nearest relatives and gaining a greater insight into their world. This progress paves the way for further exploration into primate behavior and physiology, which will benefit both captive and wild primates and improve our comprehension of these animals and their habitats.
