A Comparative Study of Haptic Stiffness Identification by Veterinarians and Students

Palpation is an important clinical skill in both veterinary and medical health professions. The present study compares the ability of practicing veterinarians and veterinary students to identify the stiffness of virtual surfaces through palpation. An absolute identification paradigm was used where a force-feedback haptic device rendered virtual surfaces with five levels of stiffness within a “clinically relevant” range (0.2-0.5 N/mm). The mean information transfer was 0.97 bits (almost two perfectly identifiable stiffness levels) for 12 veterinarians and 0.58 bits (one correctly identified level) for 14 veterinary students. Although the difference between the two groups was significant (p <; 0.001), neither group was able to reliably identify more than two levels of stiffness, indicating that the success of veterinarians in clinical practice probably relies on additional properties such as size, shape, and texture. Analyses of force versus time and displacement versus time recordings suggest that the superior performance of the veterinarians may be partially attributable to motor strategy. Specifically, veterinarians used a greater mean maximum force (2.0 N) compared to students (1.6 N) (p <; 0.05). However, further studies are required to investigate motor strategy in more detail. The implications of our findings for veterinary education and quantitative skill assessment are discussed.