Concealed Simultaneous Measurements of Biopotential and Bioimpedance on Rodents

Physiological parameters in rodents are commonly monitored in animal model trials, such as those necessary to evaluate the effects of possible drug inoculations. Cardio-respiratory parameters such as pulse rate, respiration rate or heart rate can be extracted from biopotential signals as well as with bioimpedance signals. This work presents a device that makes simultaneous use of these two acquisition techniques to compute the above-mentioned parameters in rodents. For this, different animal-device interfaces have been designed that allows performing measurements in a concealed manner, without prior preparation of the animal or sedation. The electrodes used in these interfaces use were designed to be placed either in direct contact with the animal (in its burrow), or without direct contact with it (under the cage floor). The tests were performed on a Russian dwarf hamster at rest. The results show that the electrocardiogram was acquired with direct contact electrodes, whereas the respiration and cardiac changes could be identified in the bioimpedance measurements both with direct contact (frequency of 10 kHz) and without direct contact (frequency of 1 MHz).