The tail immersion assay is a widely used method for measuring acute thermal pain in a way which is quantifiable and reproducible. It is non-invasive and measures response to a stimulus that may be encountered by an animal in its natural environment. However, tail withdrawal latency data are usually collected manually, and precise temperatures of the water at the time of measurement are most often not recorded. These two factors can reduce the reproducibility of tail immersion assay data. We designed a device, TailTimer, which uses the Raspberry Pi single-board computer and a temperature sensor, to automatically record both tail withdrawal latency and water temperature. The device has a radio frequency identification (RFID) system that can record the ID of animals. Our software recognizes several specific RFID keys as user interface commands, which allows TailTimer to be operated via RFID fobs. We also programmed the device to only allow tests to be conducted when the water is within ± 0.25 °C of the target temperature. Data recorded using the TailTimer device showed a linear relationship between tail withdrawal latency and water temperature when tested between 47 - 50 °C. We also observed a profound effect of water mixing speed on tail withdrawal latency. Our data further revealed significant strain and sex differences, valorizing TailTimer in its ability to detect genetically-determined variations in thermal pain sensitivity.

中文翻译：

---

TailTimer：一种用于自动化啮齿动物尾巴浸没测定的开源设备

尾部浸没测定法是一种可量化和可再现的，用于测量急性热痛的广泛使用的方法。它是非侵入性的，可以测量对动物在自然环境中可能遇到的刺激的反应。但是，尾巴抽水潜伏期数据通常是手动收集的，并且测量时水的精确温度通常不会被记录下来。这两个因素会降低尾部浸没测定数据的可重复性。我们设计了TailTimer设备，该设备使用Raspberry Pi单板计算机和温度传感器来自动记录拖尾时间和水温。该设备具有可以记录动物ID的射频识别（RFID）系统。我们的软件将几个特定的​​RFID键识别为用户界面命令，这使得TailTimer可以通过RFID遥控钥匙进行操作。我们还对该设备进行了编程，使其仅在水在目标温度的±0.25°C以内时才可以进行测试。使用TailTimer设备记录的数据显示，当在47-50°C之间进行测试时，尾巴撤回潜伏期与水温之间呈线性关系。我们还观察到水混合速度对拖尾延迟的深远影响。我们的数据进一步揭示了明显的劳损和性别差异，使TailTimer能够检测到由遗传决定的热痛敏感性变异。使用TailTimer设备记录的数据显示，当在47-50°C之间进行测试时，尾巴撤回潜伏期与水温之间呈线性关系。我们还观察到水混合速度对拖尾延迟的深远影响。我们的数据进一步揭示了明显的劳损和性别差异，使TailTimer能够检测到由遗传决定的热痛敏感性变异。使用TailTimer设备记录的数据显示，当在47-50°C之间进行测试时，尾巴撤回潜伏期与水温之间呈线性关系。我们还观察到水混合速度对拖尾延迟的深远影响。我们的数据进一步揭示了明显的劳损和性别差异，使TailTimer能够检测到由遗传决定的热痛敏感性变异。