Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York, United States of America.
College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America.
PLoS One. 2024 Mar 4;19(3):e0299047. doi: 10.1371/journal.pone.0299047. eCollection 2024.
Small animal studies in biomedical research often require anesthesia to reduce pain or stress experienced by research animals and to minimize motion artifact during imaging or other measurements. Anesthetized animals must be closely monitored for the safety of the animals and to prevent unintended effects of altered physiology on experimental outcomes. Many currently available monitoring devices are expensive, invasive, or interfere with experimental design. Here, we present MousePZT, a low-cost device based on a simple piezoelectric sensor, with a custom circuit and computer software that allows for measurements of both respiratory rate and heart rate in a non-invasive, minimal contact manner. We find the accuracy of the MousePZT device in measuring respiratory and heart rate matches those of commercial systems. Using the widely-used gas isoflurane and injectable ketamine/xylazine combination, we also demonstrate that changes in respiratory rate are more easily detected and can precede changes in heart rate associated with variations in anesthetic depth. Additional circuitry on the device outputs a respiration-locked trigger signal for respiratory-gating of imaging or other data acquisition and has high sensitivity and specificity for detecting respiratory cycles. We provide detailed instruction documents and all necessary microcontroller and computer software, enabling straightforward construction and utilization of this device.
小动物在生物医学研究中经常需要麻醉，以减轻研究动物的疼痛或压力，并最大限度地减少成像或其他测量过程中的运动伪影。麻醉动物必须密切监测，以确保动物的安全，并防止生理变化对实验结果产生意外影响。许多现有的监测设备价格昂贵、具有侵入性或干扰实验设计。在这里，我们提出了 MousePZT，这是一种基于简单压电传感器的低成本设备，具有定制电路和计算机软件，可实现非侵入性、最小接触方式下的呼吸率和心率测量。我们发现 MousePZT 设备在测量呼吸率和心率方面的准确性与商业系统相当。使用广泛使用的气体异氟烷和可注射的氯胺酮/二甲苯胺组合，我们还表明，呼吸率的变化更容易被检测到，并且可以先于与麻醉深度变化相关的心率变化。设备上的附加电路输出一个呼吸锁定触发信号，用于呼吸门控成像或其他数据采集，并且对检测呼吸周期具有高灵敏度和特异性。我们提供了详细的说明文档和所有必要的微控制器和计算机软件，使该设备的构建和使用变得简单直接。
