Haptic stiffness identification by veterinarians and novices: A comparison

Palpation is important in both veterinary and medical health professions. It is however difficult to learn, teach and assess. More must be understood about the skills involved in palpation. The present study compares the ability of practicing veterinarians and veterinary students to identify stiffness values. An absolute identification paradigm was used where a force-feedback device rendered virtual surfaces with 5 levels of stiffness within a ldquoclinically relevantrdquo range of 0.2 - 0.5 N/mm. The results from 12 veterinarians and 14 veterinary students show that the veterinarians performed significantly better than the students (p Lt 0.001). The mean information transfer was 0.97 bits (almost 2 perfectly-identifiable stiffness levels) for the veterinarians and 0.58 bits (1 correctly-identified stiffness level) for the students. However, neither group was able to reliably identify more than 2 levels of stiffness, indicating that the success of veterinarians in clinical practice probably relies on additional properties such as size, shape and texture. Our findings suggest that stiffness perception in the context of veterinary medicine is a learned clinical skill. Quantifying expert ability will help inform teaching methods and set targets for students. Similar psychophysical methods can also be used to monitor student performance throughout the learning process. Future work will examine the contributions of other object properties as well as motor strategies to palpation performance.