Non-wearable pulse rate measurement system using laser Doppler flowmetry with algorithm to eliminate body motion artifacts for masked palm civet (Parguma larvata) during husbandry training

Husbandry training (HT) shapes specific actions of animals to facilitate healthcare or animal research. The challenge of HT is that learning the specific actions requires zoo-keepers to grasp the stress states of animals. Here we suggest a non-wearable pulse rate measurement system to help zoo-keepers. The pulse rate indicates the stress state. By using laser Doppler flowmetry with an algorithm to eliminate body motion artifacts, it is possible to measure pulse rates. In the algorithm, the cutoff frequency is an important parameter. This paper reports the relationship between the cutoff frequency and the blood flow signal. We applied 100 Hz, 12 kHz and 15 kHz cutoff frequencies and compared blood flow signals. The results indicated that the appropriate cutoff frequency can vary depending on the magnitude of body motion artifacts. When there are few body motion artifacts, a low cutoff frequency is suitable. Otherwise, a high cutoff frequency is preferred.