Holden E, Calvo G, Collins M, Bell A, Reid J, Scott E M, Nolan A M
School of Veterinary Medicine, University of Glasgow, Glasgow, G61 1QH.
J Small Anim Pract. 2014 Dec;55(12):615-21. doi: 10.1111/jsap.12283. Epub 2014 Oct 30.
To describe the development of a facial expression tool differentiating pain-free cats from those in acute pain.
Observers shown facial images from painful and pain-free cats were asked to identify if they were in pain or not. From facial images, anatomical landmarks were identified and distances between these were mapped. Selected distances underwent statistical analysis to identify features discriminating pain-free and painful cats. Additionally, thumbnail photographs were reviewed by two experts to identify discriminating facial features between the groups.
Observers (n = 68) had difficulty in identifying pain-free from painful cats, with only 13% of observers being able to discriminate more than 80% of painful cats. Analysis of 78 facial landmarks and 80 distances identified six significant factors differentiating pain-free and painful faces including ear position and areas around the mouth/muzzle. Standardised mouth and ear distances when combined showed excellent discrimination properties, correctly differentiating pain-free and painful cats in 98% of cases. Expert review supported these findings and a cartoon-type picture scale was developed from thumbnail images.
Initial investigation into facial features of painful and pain-free cats suggests potentially good discrimination properties of facial images. Further testing is required for development of a clinical tool.
描述一种用于区分无痛猫和急性疼痛猫的面部表情工具的开发过程。
向观察者展示来自疼痛和无痛猫的面部图像，要求他们识别猫是否处于疼痛状态。从面部图像中识别出解剖学标志，并绘制这些标志之间的距离。对选定的距离进行统计分析，以确定区分无痛和疼痛猫的特征。此外，两位专家对缩略图进行了审查，以识别两组之间有区别的面部特征。
观察者（n = 68）难以区分无痛猫和疼痛猫，只有13%的观察者能够辨别出80%以上的疼痛猫。对78个面部标志和80个距离的分析确定了六个区分无痛和疼痛面部的重要因素，包括耳朵位置以及嘴/口鼻周围区域。标准化的嘴部和耳部距离相结合时显示出出色的辨别特性，在98%的情况下能正确区分无痛和疼痛猫。专家审查支持了这些发现，并根据缩略图开发了一种卡通式图片量表。
对疼痛和无痛猫面部特征的初步研究表明，面部图像可能具有良好的辨别特性。开发临床工具还需要进一步测试。
