Data_Sheet_1_An Automated Canine Line-Up for Detection Dog Research.CSV

Currently, there is a need to develop technology that facilitates and improves detection dog research. The aim of this research was to develop an automated computer-driven olfactory line-up task. The apparatus consisted of three olfactometers. Each olfactometer was equipped with flow meters to regulate air flow and dilution and six solenoid valves connected to odor jars. Each olfactometer generated an odor which was carried to an odor port where the dogs sample it. The olfactometer's valves were activated by a microcontroller, and a Python program was built to control each olfactometer and randomize and balance the odor presentation. Dogs (N = 12) received one or two 40-trial training sessions in a day where they progressed through a series of training phases where they learned to detect and alert to double-base smokeless powder (SP). An “alert” consisted of a 4-s nose hold. This was measured by infrared sensors in the ports. For each trial, the apparatus recorded dogs' search latency, sniff time, port entries, and response. All this information was automatically recorded in a csv file. A photoionization detector (PID) and solid-phase microextraction followed by gas chromatography-mass spectrometry (SPME-GC/MS) were used to evaluate the odor dynamics and to instrumentally verify odor presence and clearance. A control test was conducted at the end of the training to ensure dogs were alerting exclusively to the odorant. All 12 dogs readily learned to operate the apparatus within 23 days, and all exceeded 85% accuracy. Control tests indicated dogs were leveraging only olfactory cues and not unintentional cues such as auditory cues from the apparatus. Analytical data showed that odor was detected in the port immediately after the activation of a valve and that odor clearance occurred immediately after the valve was closed. The apparatus developed was easy to operate by the dogs and allowed substantial data collection using double-blind testing procedures in a very short period at an affordable cost point for research equipment (~$5,000 USD). The apparatus may prove to be a useful research tool to provide optimal odor stimuli control, ensure double-blind conditions, reduce labor, and significantly increase the amount of data collected.

当前，亟需研发可助力并优化检测犬研究的相关技术。本研究旨在开发一套计算机自动化控制的嗅觉阵列测试任务。该实验装置包含三台嗅觉仪（olfactometer），每台嗅觉仪均配备用于调节气流与稀释比例的流量计，以及六个连接气味瓶的电磁阀（solenoid valve）。每台嗅觉仪可产生气味，并将气味输送至气味端口供实验犬采样。嗅觉仪的电磁阀由微控制器驱动，同时通过自研Python程序实现各嗅觉仪的控制，以及气味呈现顺序的随机化与平衡化处理。本研究共招募12只实验犬，每日可完成1至2组、每组含40次试次的训练任务，实验犬需通过一系列训练阶段，学会检测双基无烟火药（double-base smokeless powder，SP）并作出相应示警动作。示警动作定义为犬鼻持续停留4秒，该动作通过气味端口内的红外传感器进行记录。每次试次中，装置会记录实验犬的搜索潜伏期、嗅探时长、端口到访次数及反应结果，所有数据均自动存储至CSV文件中。研究采用光离子化检测器（photoionization detector，PID）结合固相微萃取-气相色谱-质谱联用仪（solid-phase microextraction followed by gas chromatography-mass spectrometry，SPME-GC/MS），对气味动态变化进行评估，并通过仪器手段验证气味的存在与清除情况。训练结束后开展对照测试，以确保实验犬仅对目标气味剂作出示警反应。12只实验犬均在23天内熟练掌握装置操作流程，且全部达到85%以上的准确率。对照测试结果显示，实验犬仅利用嗅觉线索作出反应，未受装置发出的听觉等非预期线索干扰。分析数据表明，阀门开启后端口可立即检测到气味，而阀门关闭后气味即刻完成清除。本研究所开发的装置操作简便，适配实验犬使用，可在极短时间内通过双盲测试流程完成大规模数据采集，且作为科研设备成本低廉（约5000美元）。该装置有望成为一款实用的科研工具，可实现最优气味刺激控制、保障双盲实验条件、减少人力投入，并大幅提升数据采集量。